Cothran valve Aug 25, 2020 · The Cothran valve is the newer version. Jul 6, 2015 · 49 grain slugs are doing pretty good. 30 Marauder conversion kit along with the Cothran Powerhouse valve w/. Hill port is at . 375" opening in my air reservoir so the most excellent valve was basically a drop in being I had already embarked on some mods and just so happened to be pretty much on the same page with the dimensions as Don when he engineered his valves. He told me if regulated above 1600 psi and with an xl plenum the valve should be fine operationally as the valve spring is really only needed for filling and low pressures. Nov 27, 2021 · Custom Armada . I'm waiting on the adapter, but Don has taken a short break at the moment. Benjamin Marauder Synthetic stock. Feb 12, 2020 · GTA » ; All Springer/NP/PCP Air Gun Discussion General » ; PCP/CO2/HPA Air Gun Gates "The Darkside" » Let’s see your custom 22xx Simplified Balanced Valve Select Gate READ GTA FORUM RULES BEFORE POSTING GTA Forum Help Desk GTA Announcement Gate Dealer Area GRIP AirgunWeb Airgun Videos Airgun Repository of Knowledge Vendors and Vendor Videos AirGun Expo 2021 Airgun Expo 2022 Contests and Giveaways!!! Don Cothran M-Rod Power House Valve Select Gate READ GTA FORUM RULES BEFORE POSTING GTA Forum Help Desk GTA Announcement Gate Dealer Area GRIP AirgunWeb Airgun Videos Airgun Repository of Knowledge AirGun Expo 2021 Airgun Expo 2022 Contests and Giveaways!!! Jun 14, 2017 · A Cothran valve will handle the air delivery, with it's 0. I’m somewhat limited in pressure by the Marauder/Armada air tube. 281 Transfer Port. Nov 10, 2023 · 7/8 Cothran valve question Select Gate READ GTA FORUM RULES BEFORE POSTING GTA Forum Help Desk GTA Announcement Gate Dealer Area GRIP AirgunWeb Airgun Videos Airgun Repository of Knowledge Vendors and Vendor Videos AirGun Expo 2021 Airgun Expo 2022 Contests and Giveaways!!! Oct 5, 2015 · Cothran PowerHouse Valve and TP. 25 Cobra valve replaced with Cothran Powerhouse Jun 8, 2017 · I don't disagree that the Cothran valve is a great valve but its MUCH better suited for very high power riflesI am more-so learning and enjoying myself while doing some tinkering and attempting to do by hand what the pro's do with major tooling. Hawged out Disco valve, B&A valve, or a Cothran valve? Select Gate READ GTA FORUM RULES BEFORE POSTING GTA Forum Help Desk GTA Announcement Gate Dealer Area GRIP AirgunWeb Airgun Videos Airgun Repository of Knowledge Vendors and Vendor Videos AirGun Expo 2021 Airgun Expo 2022 Contests and Giveaways!!! Aug 1, 2017 · And what comes to cothran valve I like the simplicity of that valve thats all. This is a long one. Sep 22, 2023 · One of mine has a cothran valve, and only gets two shots per fill, but produces full size rifle power (50fpe). Too much power. In the tube will be a Cothran valve (because I have it) and a Huma regulator/plenum. Since I would be using a regulator the high pressure side would be keeping the bolt side at stock pressure levels unless it failed as well. Cothran Machine Shop 1891 Slocum Rd Hernando, MS 38632 SS 2260 CO2 Tube PowerHouse Valve for 7/8” Tube with . Getting the right hammer energy (spring/weight) can be challenging. Cothran valve tuning Select Gate READ GTA FORUM RULES BEFORE POSTING GTA Forum Help Desk GTA Announcement Gate Dealer Area GRIP AirgunWeb Airgun Videos Airgun Repository of Knowledge Vendors and Vendor Videos AirGun Expo 2021 Airgun Expo 2022 Contests and Giveaways!!! I have a Cothran valve equipped . Dec 29, 2019 · Nothing wrong with the Boss valve it will increase your FPE. This allows room for a 0. 25 Select Gate READ GTA FORUM RULES BEFORE POSTING GTA Forum Help Desk GTA Announcement Gate Dealer Area GRIP AirgunWeb Airgun Videos Airgun Repository of Knowledge Vendors and Vendor Videos AirGun Expo 2021 Airgun Expo 2022 Contests and Giveaways!!! Jan 1, 2020 · To start with, CMS stands for Cothran Machine Shop. the cothran valve is ported 1/4" which is . It will be a stretch for this platform. They use what Don calls a "Force Reduction System" where much of the area of the poppet seat is not exposed to the pressure inside the valve, enabling a much lower opening force. News: Enjoy your summer, and stay safe! Main Menu. 457 built with parts machined by Don Cothran. Don’s parts are precision made, holding tolerances to . 040" (a 56% increase in area, possibly double the flow because of friction affects)…. Have another reg set at 1800 psi, might be able to go with a heavier pellet at 1800 psi and keep the velocity just under 900 fps, but we'll see lol - oh yeah, have a Cothran valve as well! Aug 30, 2024 · The valves closure distance here is at 9. 2. Its a intro, field test and overview/thoughts on a new air pistol that I bought Nov 12, 2016 · Disco Double Gets Cothran Valve, Air guns, Airgun Forum Jan 6, 2021 · You may be able to obtain a good used one through the classifieds. I have my BRod set up with a Cothran valve and the WAR adjustable regulated tank block, set at 1900 psi. Dec 17, 2018 · Don Cothran turned the above idea “inside out” with his aftermarket Powerhouse Valve. 25 20" barrel. May 4, 2018 · The weights in 40:1 lead/tin alloy are 35. 25 Cothran valve-Mrod’s and while speaking with Don about the valve design, we discussed trying a regulator in one build. Feb 11, 2016 · The Cothran valve is a balanced design, and will open with MUCH less hammer strike than an unbalanced design. All of which is way beyond the OPs original question. 25 armada?if so can someone please send me a link thanks for all the input guys May 29, 2016 · Don Cothran M-Rod Power House Valve Select Gate READ GTA FORUM RULES BEFORE POSTING GTA Forum Help Desk GTA Announcement Gate Dealer Area GRIP AirgunWeb Airgun Videos Airgun Repository of Knowledge Vendors and Vendor Videos AirGun Expo 2021 Airgun Expo 2022 Contests and Giveaways!!! May 26, 2020 · Almost like finding where the valve is either on or off. Part# Price $155 Jul 6, 2024 · I used Cothran valves in my 160fpe . What I’m mostly interested in is being able to tune a bell curve to a shot string . This site uses May 31, 2018 · Ok cool . Dec 14, 2023 · Check to enable permanent hiding of message bar and refuse all cookies if you do not opt in. Dec 23, 2023 · With the new balance valve, tuning is very different than a conventional valve or a Cothran style valve. Does 3 shots with JSB 81gr 680fps, 615fps, 580fps It is a . 300 Flex with a 24 inch barrel and a Cothran valve. The trigger group is a 1701/p-rod. how the heck would one retrofit an in tube valve into an external appendage that plugs into the receiver Now if we're just taking about "What the Cothran valve is" and if or not one of similar mechanics could be manufactured to fit the Kral ? Dec 23, 2018 · This valve is obviously "blowing open" like a Cothran valve does. The best I can do is 1075fps using 20 grain pellets. Nov 7, 2016 · Disco Double Gets Cothran Valve. I am also having the Cothran valve installed with the SSG at the same time. He specializes in the custom fabrication of Crosman and Marauder "custom parts". The Cothran poppet seal is relatively soft and will collapse a bit after sitting a while, thus requiring a little more hammer strike to open for the first shot after sitting. 032" to 0. 257 caliber, then the mods. I am wondering if any of you that have done this build and can provide me with the precise or approximate tuning adjustments for that configuration? . Shoots pellets or swaged bullets, shoots 25. 357 Texan SS from Talon Tunes or whoever sells at best price. 24 posts 1; 2; 3; Next; 3050 Co2 with Cothran valve 3050 Co2 with Cothran valve Sep 7, 2017 · The Cothran Powerhouse valve uses a 3/8" OD transfer port, so unless you do some fancy footwork, you will be faced with drilling out the tube and receiver to use that. 5 and 42. Orders less than $25. Not that it will do that much for a. There are only a few aftermarket valves for sale these days. it sucked the valve return spring over the poppet and into the seat. I managed 150fpe with this 1/4 inch transfer port on my 9mm, arrowgun with a Cothran valve. You can turn it down for pellets or up for slugs and have the best of both worlds. Select Gate READ GTA FORUM RULES BEFORE POSTING GTA Forum Help Desk GTA Announcement Gate Dealer Area GRIP AirgunWeb Airgun Videos Airgun Repository of Knowledge Vendors and Vendor Videos AirGun Expo 2021 Airgun Expo 2022 Contests and Giveaways!!! Dec 11, 2021 · Building a few . Dec 14, 2023 · Cothran Machine Shop prides itself on custom top-notch products. Apr 15, 2020 · My understanding is the Cothran valve is that it will open easier than a standard valve, but take same to close. with 10 shots per cart The three using the Cothran Valve have a modified cap to pierce the cartridge which fills (pressurizes) the tube Wyo Mar 19, 2016 · Anyway after a few test strings and now that all is fine I installed the Cothran Powerhouse valve and did a little testing to see what I could get for power from this little beauty. 9 gr JSB pellets and 69. 0, 38. I had grandiose plans to test them and hunt with them but alas work always comes first. (He makes one for the marauder as well) As a bonus, this gun came with a custom stock, that upon research, appears to be a Michael Chavka stock, made on November 12 2012, and is either the first or one of the first thumbhole stocks that he made. Aug 21, 2021 · cothran valve unreliable, Air guns, Airgun Forum. The poppet head is hollow and runs over a solid stem carrying the O-ring that seals the chamber, simplified in this drawing. It is a copy of his Discovery Powerhouse valve that has been araound for several years. Valve is a disco/ pro-top setup. Fits Gen1 and Gen2. 22 with a shorter barrel though. Cothran stainless tube, magnum air valve, side lever Breech , power adjuster, tj barrel, marauder trigger group…. Great for hunting bigger game and/or distance shooting. Great for hunting bigger game and/or distance shooting. Buy a stock . 25 Gen I MRod w/WAR valve/SSG & MM custom t-port @ 0. A Hill valve, a JSAR gen 2 balanced valve or a Cothran valve. Select Gate READ GTA FORUM RULES BEFORE POSTING GTA Forum Help Desk GTA Announcement Gate Dealer Area GRIP AirgunWeb Airgun Videos Airgun Repository of Knowledge Vendors and Vendor Videos AirGun Expo 2021 Airgun Expo 2022 Contests and Giveaways!!! Dec 28, 2023 · To start, I just ordered the NOE 308-154-FN-BF2 5 cavity aluminum mold. 30 cal, but I know many have built . I own a Raptor HP in . 25 caliber so that is 50%. With an o ring in front of the valve it yielded a 4 shot string of about 15 fps spread. This . 0, 37. 25 multi shot bnm breech, marauder . Jun 9, 2016 · Don Cothran M-Rod Power House Valve Select Gate READ GTA FORUM RULES BEFORE POSTING GTA Forum Help Desk GTA Announcement Gate Dealer Area GRIP AirgunWeb Airgun Videos Airgun Repository of Knowledge Vendors and Vendor Videos AirGun Expo 2021 Airgun Expo 2022 Contests and Giveaways!!! The Kral Valve extends as part of the air tubes end fitting ( AKA: Hatsan'ish) . Dramatically increases power. No disrespect to them and not taking any credit away as what they do is quite amazing! Or maybe a Cothran valve? I had all but ruled out the Cothran valve until I read Bob Sterne's Disco Double testing with a regulated Cothran valve, the results were impressive. Fill adapter, IIRC from a Disco. Jan 2, 2025 · Working on a . 22 1322 upgraded to 2289 . And the valve flow path will need to be modded or replace the valve with a Tim Hill valve, JSAR valve or Cothran blow open valve. Both guns are regulated and magazine fed. May 28, 2016 · Don Cothran M-Rod Power House Valve Select Gate READ GTA FORUM RULES BEFORE POSTING GTA Forum Help Desk GTA Announcement Gate Dealer Area GRIP AirgunWeb Airgun Videos Airgun Repository of Knowledge Vendors and Vendor Videos AirGun Expo 2021 Airgun Expo 2022 Contests and Giveaways!!! Jun 18, 2016 · Cothran PowerHouse valve for the M-Rod!, Air guns, Airgun Forum GTA » ; All Springer/NP/PCP Air Gun Discussion General » ; PCP/CO2/HPA Air Gun Gates "The Darkside" (Moderators: Rocker1, only1harry, splitbeing) » Taming of the shrew (Cothran valve) Nov 18, 2016 · The valve is his balanced valve that he makes for the discovery. NEW. Visit the post for more. Lubed, sized and sorted. 357. They is no need to change hammers or springs to get more power. Don Cothran that is. Log in; Sign up; March 07, 2025, 10:04:24 PM. 40 Badger (arrived!). More geared toward high-powered non-regulated guns. 250 TP and bout 3" plenum. I guess another question to ask would be will the huma or altaros work with 4500? Would a valve fastener upgrade be all that is necessary for the cothran valve be anchored to the tube? Dec 23, 2018 · This valve is obviously "blowing open" like a Cothran valve does. 457 calibers guns I build. 257. 17 Webley Hurricane. With a 14" barrel, getting right at 17 fpe using a Disco valve combined with a P-Rod hammer spring and a 2300 power adjuster all the way in. 2 shots to zero and done. Made in USA. The short Flex has a Shogun, the long Flex has an Emperor v1. But in my little 12' fun range (pathetic, I know), I have some Bob's BT's 49gr and they are going 2. Feb 2, 2017 · I am about to embark on a . Here are the results: 54. 6 gr. 2 ID for TP. Many people are making power valves for the 22xx guns these days the best is the Cothran valve. Increase depth of valve body to tube oring seat as tube is slightly smaller ID than what valve is intended for. 17 late '60's Crosman Powermaster 760 in the original box A 9mm handgun/rifle uses 1-16" and shoots 115 gr. The builder Oct 20, 2016 · The barrel is a TJ's 1:10 twist has anyone used this barrel in their project and what pellet & weight worked best. 177 multi shot bnm breech has a LW 18" barrel Boyd disco stock, 1600 psi reg bottle, shoots JSB 10. I am basing that off of Travis's own words prior to the release of the Flex. 257"ports perfect for the job. 040" (a 56% increase in area, possibly double the flow because of friction affects). My 160fpe gun with Cothran valve is very efficient (36 inch barrel and 72gr projectiles). Apr 27, 2018 · Unless you already just prefer the . I used the above method to resurface the seat. 17 Daisy 853 GTA » ; All Springer/NP/PCP Air Gun Discussion General » ; PCP/CO2/HPA Air Gun Gates "The Darkside" (Moderators: Rocker1, only1harry, splitbeing) » 3050 with a Cothran valve on co2 I am not getting the cothran valve to go to a big bore gun but would prefer to stay at 25 caliber to still use cheap ammo but be capable of tuning to shoot at 80 to 100FPE with a still decent shot count and JSB 34 grianers. Click to expand That is VERY nice shooting!!! Feb 9, 2017 · Now here's the question: How does the porting, in this case Cothran valve with . Cothran Valve with longer stem for use in QB78 Consider the below parts as free to the buyer of those parts listed above. 308 molds, you can get a . And the barrel port needs to be drilled and reamed to . 161 to . I bored the stem hole to . 17 (Cothran valve on deck). After being commissioned to make a left-handed version of the Crosman steel breech, he has gone on to make many different parts for the Crosman 22XX line. once here, you want to dial in just enough hammer strike to get the valve to open and achieve your desired FPE. Used in Slayer and RAW airguns. I drilled out the barrel to . Apr 13, 2021 · Before I learned that peek poppets were not worth the trouble in Cothran valves I damaged a brass seat pretty badly while experimenting with vent sizes in a 300fpe QB . Share. only in the SS valve and the Cobra/Python valves. Nov 24, 2023 · I could be way off base, but if it walks like a duck, and quacks like a duck, or in this instance, behaves like a Don Cothran valve, then the culprit very well may be the vent/balance chamber volume in the worse case, and best case the valve is over-sprung. The Flex is based off the Marauder. Glad we did. Sep 22, 2022 · Shoehorning a Cothran Powerhouse valve into a pp800 . Mar 31, 2016 · Cothran PowerHouse valve for the M-Rod! Select Gate READ GTA FORUM RULES BEFORE POSTING GTA Forum Help Desk GTA Announcement Gate Dealer Area GRIP AirgunWeb Airgun Videos Airgun Repository of Knowledge Vendors and Vendor Videos AirGun Expo 2021 Airgun Expo 2022 Contests and Giveaways!!! Feb 22, 2016 · Cothran PowerHouse valve for the M-Rod! Select Gate READ GTA FORUM RULES BEFORE POSTING GTA Forum Help Desk GTA Announcement Gate Dealer Area GRIP AirgunWeb Airgun Videos Airgun Repository of Knowledge Vendors and Vendor Videos AirGun Expo 2021 Airgun Expo 2022 Contests and Giveaways!!! Jun 11, 2023 · the Notos looks to be a Snowpeak product, the safety button is the same as the Chaser and with that i wonder if there is another grub screw hiding under the grip area and if the trigger assembly isn't like a Chaser setup Cothran Machine, Air guns, Airgun Forum Thank you to our advertisers! he makes the Powerhouse valve, SS high pressure PCP tubes, breeches, bolts, Rolller Triggers Cothran valve leak? Select Gate READ GTA FORUM RULES BEFORE POSTING GTA Forum Help Desk GTA Announcement Gate Dealer Area GRIP AirgunWeb Airgun Videos Airgun Repository of Knowledge Vendors and Vendor Videos AirGun Expo 2021 Airgun Expo 2022 Contests and Giveaways!!! Jan 28, 2022 · I still have some chromoly tube from past projects and waiting for the ebay sidelever breech, . 25 is about 70% of . The barrel is the lothar barrel from a 2300kt. Jun 1, 2016 · Don Cothran M-Rod Power House Valve Select Gate READ GTA FORUM RULES BEFORE POSTING GTA Forum Help Desk GTA Announcement Gate Dealer Area GRIP AirgunWeb Airgun Videos Airgun Repository of Knowledge Vendors and Vendor Videos AirGun Expo 2021 Airgun Expo 2022 Contests and Giveaways!!! Sep 13, 2016 · That's from cothran machine shop. similar to their Disco PowerHouse Valve. 8 FPE with Hunter Supply 49 gr bullets and all groups were under . Jun 18, 2020 · Have a Magnum Airpower valve in her now, and she's topped out velocity wise, reg is at 1600 psi. 17 Daisy 853. Bob Stern started his twin Brod builds and as we know he also is quite the builder and tuner but also fantastic in detailing his work with graphs and elaborate Feb 11, 2016 · . 308. First testing with the Hill Valve. The plan is to shoot that slug at 1080fps. Oct 4, 2015 · Cothran PowerHouse Valve and TP. Cothran and WAR Join forces!!!, Air guns, Airgun Forum Original plan is to run the Cothran valve with . I'll share the results once I open the ports up further. 25 Mrod platform. Don Cothran M-Rod Power House Valve Select Gate READ GTA FORUM RULES BEFORE POSTING GTA Forum Help Desk GTA Announcement Gate Dealer Area GRIP AirgunWeb Airgun Videos Airgun Repository of Knowledge AirGun Expo 2021 Airgun Expo 2022 Contests and Giveaways!!! Sep 30, 2017 · My personal valve technology is 100% free to the community (reduced poppet od + valve stem + seat OD for reduced cocking force and better air flow) when coupled with either delrin or peek material makes for much less required hammer energy to open the valve while retaining great long shot counts unregulated with tight es's the same as stock (2 . A comprehensive look if you will. 2550 - Cothran Valve, LW barrel, SSS with recessed striker - 15 fpe avg. I tried increasing the vent diameter from 0. Ordering a Crosman challenger trigger guard and last, I need to have some barrel bands made by someone. Mine is a cothran valve disco build with 1-16" twist 28" barrel. 250 transfer port. 5" barrels with nominal pellet weights) Get out your popcorn. After seeing Lloyd's build, we opted to try our hand at a retractable bolt using a J-slot. The tube was already set up to pin the valve, and I am using a 1500 psi output reg. 257 rifle and to be honest I don’t shoot it often at all . 357 barrel. I put a Cothran valve in the Mini and although I have another for the HP, have not needed to change it out. Nov 7, 2016 · Disco Double Gets Cothran Valve - Page 2. 22 LW barrel with a TKO which I've already put together. 25 exhaust port, play into this equation? . Need to chrony. Jun 30, 2021 · average wait time on cothran valve ? Select Gate READ GTA FORUM RULES BEFORE POSTING GTA Forum Help Desk GTA Announcement Gate Dealer Area GRIP AirgunWeb Airgun Videos Airgun Repository of Knowledge Vendors and Vendor Videos AirGun Expo 2021 Airgun Expo 2022 Contests and Giveaways!!! Nov 10, 2016 · The Cothran valve is supplied with a 1/4" exhaust port, but Lloyd has shown that can be increased to 9/32". Going larger would require enlarging the throat to increase flow, which would alter the internal balancing of the valve, something I would not personally be willing to experiment with. Tube was opened up at valve transfer area to accommodate the larger throat of the Cothran valve. 30 cals and I have never seen that mentioned, so presumably nobody has had an accident. I have outlined are about as far as you can take a stock QB78 valve, aside from enlarging ports more so. "If you are going to mod it, flat top is the way to go and with lighter valve spring (you have to cock it to get air in) and drill the valve oil next hole size will reduce pumping strain. This is a in drop in valve. 2 and using PTFE . However, I haven't tested out the Cothran valve yet. Bob in your drawing you’re using 50% of the poppet area to reduce it to 50% of cracking force . GTA » ; All Springer/NP/PCP Air Gun Discussion General » ; PCP/CO2/HPA Air Gun Gates "The Darkside" » qb78 Carbon Bottle . 030 and put a 9 lb return spring in the valve. 2000psi reg bottle. When the Cothran valve came out, I was tickled that it already fit the . Don mounts the piston such that it has a slight bit of in/out play----I honestly think this is to counter any potential stiction---it allows the poppet to lift slightly without requiring the piston to move in the balance chamber, then perhaps the Mar 21, 2024 · Negating their large bore advantage. 22 cal do they make it for . Apr 5, 2023 · Even a Cothran style valves, an over vented valve with too large of a balance chamber should not SLAM shut, because it will have lost so much pressure in the system to remain open, that there won't be enough force TO slam it shut Nov 7, 2022 · I've done a 2240 hpa mod on a Cothran 2240 pcp set up. 5%~ of the barrel length, why 47. 25" into 2 2x8's put together---thru the first and about halfway into the 2nd. 224 build based on a disco platform. Jun 10, 2015 · However, if you are considering using the stock QB valve for . Apr 15, 2020 · I don't have personnel experience with them, but have heard the same thing about the Cothran valve. Sep 17, 2020 · Belated Cothran Powerhouse Valve Select Gate READ GTA FORUM RULES BEFORE POSTING GTA Forum Help Desk GTA Announcement Gate Dealer Area GRIP AirgunWeb Airgun Videos Airgun Repository of Knowledge Vendors and Vendor Videos AirGun Expo 2021 Airgun Expo 2022 Contests and Giveaways!!! Dec 15, 2018 · That would be me. Select Gate READ GTA FORUM RULES BEFORE POSTING GTA Forum Help Desk GTA Announcement Gate Dealer Area GRIP AirgunWeb Airgun Videos Airgun Repository of Knowledge Vendors and Vendor Videos AirGun Expo 2021 Airgun Expo 2022 Contests and Giveaways!!! Jul 23, 2016 · Travis has been working with the Cothran valve and I assume it will be used to make enough power in . 00 shipped free. . 4 gr JSB pellets, 75 FPE with 39. Price $120. 357, and plan on running a regulator around 2200 psi or sobut thats just my opinion. 5 grain slugs at 980fps. 3 860fps. 219" exhaust port on a 20* angle, just like on the Disco valves. It's pretty easy to get things misaligned a little and it doesn't take much to loose power. -Matt Dec 1, 2016 · Don Cothran M-Rod Power House Valve Select Gate READ GTA FORUM RULES BEFORE POSTING GTA Forum Help Desk GTA Announcement Gate Dealer Area GRIP AirgunWeb Airgun Videos Airgun Repository of Knowledge Vendors and Vendor Videos AirGun Expo 2021 Airgun Expo 2022 Contests and Giveaways!!! Oct 24, 2021 · So, I'm curious, I have a Gen 1 Marauder, Cothran valve, Hill guage block and a bit thicker main spring. You may or may not find these suitable for your use. 357, but a . Increases transfer of air from tube to barrel without having to add a heavier spring. The HPS valve is designed to be adjusted with primarily regulator pressure and dwell adjustment. We need 2 cookies to store this setting. The Balanced Valve used in the Slayer, which is similar in concept to those made by Lloyd Sikes (and my last diagram) can produce a bell-curve, but they have to sacrifice the easiest possible Aug 14, 2019 · Selling these two set ups as they have been collecting dust since I bought them. Log in; Sign up; April 07, 2025, 05:54:40 AM. Any larger will require tube and breech to be opened up as well as machining larger flats. Feb 12, 2016 · Yup the new Cothran Marauder Powerhouse valve is just coming out. 281 valve is used in all my . Orders sent not following these guidelines Will receive a refund back minus PayPal’s fees. I would not recommend a Cothran for your application but the shot count would be the same with massive power increases provided you port correctly. My latest build is an all custom 500fpe (maximum) . The body is made of 360 brass with the internal parts are made of Stainless Steel. Oct 16, 2021 · They also need to be aligned just right to get the best from your gun. So they do work. 5% and not 45% or 50%, well, because I said so! LOL (for demonstration and based on my tests of 19. The Cothran valve ports are 1/4” and could be opened up slightly, but I’ll stick with 1/4” for now. 25, cothran valve, TJ barrel, Spring Tension adjuster, (2) Rich Dudek "slug Magazines" Dec 6, 2019 · Just today, i took the whole rifle apart and replaced all the o-rings and serviced the Cothran valve. Feb 15, 2016 · Don this thread is about the Cothran Powerhouse valve for the Marauder which just came out a week or two ago so you must be talking about the Cothran Powerhouse Disco valve that has been out for a few years. 25, cothran valve, TJ barrel, Spring Tension adjuster, (2) Rich Dudek "slug Magazines" May 22, 2020 · My Cothran valves don't suffer from either. What kinds of performance do others get? Ever tried more than 3Kpsi? I bumped up to 3500psi for one test (Cothran valve will not lock up) I own 2 cothran 2240 bottle guns both have powerhouse valves . 300 Flex with a 17 inch barrel and Cobra valve, then I have a . 4 JSB 870fps. More money than what it's worth but it is fun and shoots pretty well. 25,can the cothran valve be bored too or is there no need to open it? How big a port size does it come with? Also bob mentioned the ss jsar valve but I can only find it for . Otherwise you will be prompted again when opening a new browser window or new a tab. Sep 7, 2017 · The Cothran Powerhouse valve uses a 3/8" OD transfer port, so unless you do some fancy footwork, you will be faced with drilling out the tube and receiver to use that. Trigger group will be a 2240 match (?) with included striker. and it made NO difference to the way the valve operated. 75 Jul 2, 2016 · The key to the Stage 2 valve is drilling the valve out to 1/2" and permanently installing a piece of 1/2" aluminum rod about 3/8" long (shown in red) to move the valve seat forward. Cothran PowerHouse valve for the M-Rod! Select Gate READ GTA FORUM RULES BEFORE POSTING GTA Forum Help Desk GTA Announcement Gate Dealer Area GRIP AirgunWeb Airgun Videos Airgun Repository of Knowledge AirGun Expo 2021 Airgun Expo 2022 Contests and Giveaways!!! Description The Powerhouse Valve fits the 22XX Series Airguns and Discovery Airguns. 25 cal LW Polygonal barrel, but that is not surprising as I cut the chamber to allow for bullets as well as pellets. Select Gate READ GTA FORUM RULES BEFORE POSTING GTA Forum Help Desk GTA Announcement Gate Dealer Area GRIP AirgunWeb Airgun Videos Airgun Repository of Knowledge Vendors and Vendor Videos AirGun Expo 2021 Airgun Expo 2022 Contests and Giveaways!!! Feb 4, 2017 · Lloyd started off with his friendly 30 cal Mrod build with the Cothran valve and I set back and watched him in AWE of his skills meanwhile learning as he goes and soaking it in. Then mad dog or self made rigid heavy stock, & either Doug's or Cothran valve; but I hear Cothran ' is tearing the gun up inside. Comes With mounting Screws. 17 Daisy 853 Feb 11, 2016 · . Hope to have the valve in my hands early next week and that my 25 cal heavy pellets & Hunter Supply bullets arrive soon after. 357 = 70 % bore portingyou should send your valve + bolt probe to JSAR and request 85%-90% bore porting equal to the . Jul 28, 2017 · That is what happens with a Cothran valve, it's very easy to open, but the velocity is 100% dependant on pressure, you cannot tune it for a bell-curve. 25/. 257 cal. Currently running the Hill Valve. 30 Marauder build, utilizing Mountain Airguns . so if the hill valve can be bored to . . Its hard to really invent something original and completely new, they are mostly variations of existing tech refined to new use on airguns. Regarding the Cothran valve I actually have a couple of different generations to work with, one of which has a larger diameter balance chamber. Trim rear of valve stem to allow more hammer and spring travel but still allow for full valve lift. 4. I would allow the rod to move radially to allow for self-alignment with the poppet, like Cothran does. 198 to match depending on ultimate goal. My . I got over 150fpe out of it with my arrowgun and it will do much more. 25 Gen I MRod w/WAR valve & SSG (Cothran valve on deck). 357 caliber has roughly twice the bore of a . , both 28" long. 180 TP. Aug 11, 2010 · Don Cothran has been machining parts for years. They all chamber perfectly in my . Mar 5, 2018 · There is something else going on, however, just like in the Cothran valve, so that once the valve cracks it tends to "blow open" because the force holding the poppet against the seat disappears, but it takes slightly longer for the balancing force to disappear as the pressure in the middle of the poppet rises from atmospheric to full pressure GTA » ; All Springer/NP/PCP Air Gun Discussion General » ; PCP/CO2/HPA Air Gun Gates "The Darkside" (Moderators: Rocker1, only1harry, splitbeing) » Hawged out Disco valve, B&A valve, or a Cothran valve? The Cothran valve does this but uses a metal sleeve for the front hollow section of the poppet. Scroll to top. Description Powerhouse Valve fits Marauder air tube. Also, not sure you want to use a setpoint much higher than 1500-1700 psi on the QB's, maybe the Cothran tube allows for higher pressures? Dec 14, 2017 · Buy a . Feb 1, 2023 · Cothran valve, 9" TJ's 1:26 . 30 Flex set up with a Cothran valve. Welcome to The AirGun Guild. -Matt Jan 8, 2017 · Also in using the cothran valve I will be using a 26 gram MDS with aluminum insert form Motorhead in place of the stock hammer to help lessen the hammer strike on the cothran valve. USA orders over $25. Knowing my tube ID was VERY close to that of a 22xx. He is also meticulous and is focused on quality and consistency. 25 Condor & have Tony redo it. It uses a . I have a . Ultimately, your choices may depend on how many mods you are willing to accept, and if you can do them yourself, or have to pay to get them done for you. The unimpeded air flow allows power with ease. Share with: Link: Copy link. 357 upper will suffocate without proper valve work. Keep the projectile in the barrel for a long enough time for the valve to close and allow the gas to expand some. 001” to Crosman specifications. Feb 26, 2022 · Efficiency with the Cothran valve is best with a light weight hammer, a very long barrel, and/or a very heavy projectile. Dec 1, 2016 · Don Cothran M-Rod Power House Valve Select Gate READ GTA FORUM RULES BEFORE POSTING GTA Forum Help Desk GTA Announcement Gate Dealer Area GRIP AirgunWeb Airgun Videos Airgun Repository of Knowledge Vendors and Vendor Videos AirGun Expo 2021 Airgun Expo 2022 Contests and Giveaways!!! Oct 24, 2021 · So, I'm curious, I have a Gen 1 Marauder, Cothran valve, Hill guage block and a bit thicker main spring. Put everything back together and POI was almost exactly unchanged, shooting at exactly the same power settings. 257 (stock Cothran valve) and 260fpe 7mm (slightly modified Cothran valve). 6 FPE with 25. Nov 8, 2016 · Disco Double Gets Cothran Valve, Air guns, Airgun Forum Aug 15, 2022 · Trim rear of valve body to seat onto the stamped tube notches for original valve at correct(ish) location. Sep 17, 2022 · But I have no means to properly make a valve, so I sent the gun to Don Cothran to see if he'd put something in it. Jun 27, 2016 · We started with a stock . 257, Cothran valve, 36" TJ barrel. If I can arrange it, I will get two 10" twist barrels, one in 6mm and the other in . GTA » ; All Springer/NP/PCP Air Gun Discussion General » ; PCP/CO2/HPA Air Gun Gates "The Darkside" (Moderators: Rocker1, only1harry, splitbeing) » Dec 25, 2018 · . 30 and a Mini in . 9cphp, 10 pumps is 708fps and for bigger varmint I can go 20 pumps for 830fps. Feb 13, 2023 · Matt spent and spends a lot of time fixing issues from the last ownership; this is beyond the call of duty. Perhaps this is due to the blow-open nature of them. Cothran PowerHouse Valve and TP. It won’t be as efficent in the 70-80fpe range as a WAR valve with the Cobra but the fpe range you’ll be capable of will be huge. The Cothran valves and my valve are not tunable via hammer strike. They each have amazingly effective DonnyFLs on them. At some point I'll do a white paper on the operation of different types of balance valve pros and cons along with their operational behaviors. Looking to see 80 to 100 FPE when it is all set up and tuned hopefully 16 good shots 3050 Co2 with Cothran valve. Nov 24, 2023 · If changes in hammer spring preload do not effect the muzzle velocity of a gun with a balanced valve, the balance chamber volume is too great, or the vent/jet feeding that chamber is too small, essentially creating a Cothran valve effect. Arsenal 257420 BT, 71. 1:26 is a proven twist rate. with 20 shots per cart 3050 - Cothran Valve, Bob S / TJ's barrel, SSS with recessed striker - 25 fpe avg. 22, both outstanding guns. I have other pistols as well, so it doesn't bother me to have such a low shot count in one, and for the hunting I do, it's rare I even take more than 2 shots. I believe there is a little more to be had in my current valve, but the gun is still very easy to cock and I don't want that to change too much. Nov 30, 2016 · The velocity of the Cothran valve appears to be set by the pressure it has available for that shot. I personally would increase the cocking/lockup pin to 10-32 in a . At some point Don made a change, I'm not sure of when it was made and if the larger balance chamber was an early/late design, but I do indeed have 2 different valves. The interchangeable bleed jets on the front of the valve are not used in this design. Same tube diameter same valve as the WAR valves in a standard Flex. Well, for a number of reasons, he did not want to mess with it, and I got it sent back along with a 22xx powerhouse valve. 3" or 47. 234 tp and barrel port, but I don't have the right adapter yet for the valve side. 00 call to get shipping cost. Jul 20, 2017 · Cothran valve stem question Select Gate READ GTA FORUM RULES BEFORE POSTING GTA Forum Help Desk GTA Announcement Gate Dealer Area GRIP AirgunWeb Airgun Videos Airgun Repository of Knowledge Vendors and Vendor Videos AirGun Expo 2021 Airgun Expo 2022 Contests and Giveaways!!! Sep 18, 2020 · I have a Cothran 308 on the disco platform with his valve. My understanding is the Cothran valve is that it will open easier than a standard valve, but take same to close. The JSAR Gen2 can be used in both regulated and unregulated. Aug 20, 2023 · 36" long SS tube made by Don Cothran safe for 3k fills, Don even said up to 3500psi but I stayed at 3k. They are the first and most power balanced production valve. I appreciate your very detailed input. I believe its going to turn out very nice now and better and easier than I first anticipated. The tube, breech, barrel bands and power adjuster are from there. My first 5 pumps is no sweat and gives me 556fps with 7. knubyeew mgfxmx gtwje biu kyla bjtlq lkgfzyrr swkgtt xtj kpznv