more results from my 22xx valve comparisons…
testing three valves:
MA (Roy) modified stock Crosman valve
Boss Valve
Discovery Valve
So far I have only tested the MA and the Boss (the Disco will be next)
In all fairness to Roy’s valve, this is not being tested in a gun built by him, so one cannot truly scruitinize it’s performance. It is merely a “part” taken from the “whole” that was his vision and intention. When I received the gun that was “possibly” built by him, the TP was old and the gun had a few leaks…The TP was of the aquarium tubing variety. From the looks of how it performed in a cart gun, and from the looks and sound of the co2 it wasted each shot…I can’t help but think Roy built this valve for a “bulk fill” gun. I am no pro, so please chime in if you have any deductions…, but for some reason the valve remained open for too long when shooting with the MA valve as opposed to the Boss valve. A poor shot count was the result.
Here are a few of the measurements (differences) between the 3 valves
the valve body port opening measurments:
0.1575 Boss
0.1535 Disco
0.198 MA
The MA is much larger than the others (I suspect too large to enable ideal back pressure to close the valve …perhaps I will try a stiffer spring in the future on this valve)
Everything else in this test was equal. The gun is a 14″ Crosman 2250 on 12 gr carts. The TP is poly tubing from Alejandro (AC custom parts–for those who don’t know him, he does great work!)
The measurments on his tubing are:
0.193 id
0.239 od
0.037 wall thickness
Again, the only difference in each test was the valve bodies (the internals were shared).
73 degrees, 14″ barrel, 14.3 gr CP’s, 15 seconds between shots
First test MA valve
558
561
559
555
557
561
569
563
565
567
565
555
559
553
549
546
536
As expected by the sound of wasted gas, and the extreme “muzzle blast” …this shot count was way too low.
The Boss valve performed much better in this “cart” gun (I will test them both again in the near future in bulk filled guns to see how they do. I also want to try Roy’s valve out again with a stiffer valve spring…)
Boss Valve
561
573
581
582
580
573
575
576
570
569
572
569
570
570
573
572
573
566
565
575
576
578
580
579
572
559
After shot 26 it dropped fast. Not too bad, and ES of 21 and a high fpe of over 10.5 and 26 usable shots!
I will test the Disco valve the next chance I get and post pics of my latest carbine called: “Drilled & Filled” . For any old school Hot Rodders out there…you may have an idea on how this one will look 😎 It’s way past my bed time…Good night!
All Replies
BTW…I’m still watching for your shooting comparison with the stock disco valve numbers…I’m not surprised that the B&A made better use of air than the MA..the one I have (MA) was like too..until I put a regulated HPA bottle on it.
I just bought the stock (Archer Airguns)…then I bought a new 2260 from Crosman, using the April code for a 20% discount 😆 😆 So, it’s a brand new PCP gun..Only rifle I have with wood on it, but I’ve wanted one of those stocks for a long time..it is really comfortable-think I’m gonna like it!
Packrat,
I always liked those stocks. Did you have a complete gun, or did you just score the stock? Keep us posted on this build and how she shoots. I just finished my carbine. I will do some small tweeks to it in the future, but for now it is ready. I will try to post some pics in the morning under a new topic…be on the lookout. Goodnight.
Got it together enough to shoot about 70 pellets…gotta tear it bacd down and do some finish on wood work ..like the hole underneath where the gauge is..need to stain where I got down to bare wood while fittin the Crosman action into the stock..I REALLLLYlike the looks of that type stock
That’s cool packrat 😎 I appreciate your honesty. Most people do not possess such humility. In a hunting situation your shooting is good enough, and in a “zombified” post apocolyptic situation…”center mass” will get you home 😉
Until I finish my current project, the only other rifle I have is my TalonSS, in .22 caliber…when I’m “on” I can shoot 5 shot groups that I can cover with a nickel…PLENTY good enough for hunting I mean hell it’s only a 12″ barrel and shoots THAT good..I’m happy with it.. I think some of the guys that claim the one-hole accuracy can honestly shoot that good. I know I’m not that steady…Both my rifles may be capable, but I’m not, so I don’t spend a lot of time considering it.
Hey Walter–when you get a chance, I’d sure like to know about the springs in BOSS valves.
Do you have any other rifles that you can shoot “one holers” with??? I have three in my stable…unfortunately when you have such accurate rifles you tend to demand that kind of performance from other rifles…within reason of course. That is why I’d like to know if those guys who claim “one hole” accuracy out of a 25.00 Crosman barrel are delusional or not???? 😯
Well the 2260/Disco I’m building now will have the full 24 ” barrel, so I’ll get a chance to see first hand how tight of groups are possible I misunderstood when I read your post about the “one-holers” ..I’ve read that too,all I can say is that those guys are a better shot than I am!! the gun may be capaable of doing it, but apparently I’m not 😯
Hey Walter–when you get a chance, I’d sure like to know about the springs in BOSS valves.
Roy built my 2250…has 18 inch barrel….I have since converted it to 13 cu.in.bottle HPA…..anyway…with 14.3 Crosman Ultra magnums, or 25.4 JSB exact Match Monsters, the gun , at 25 yards will shoot 8 shot groups that can be completely covered with a US quarter ( $0.25 ) and I’ve done it more than just once or twice, so I know it wasn’t just a “fluke ” or luck.. I do not know if Roy did anything to barrel other than cut to 18 inches and re-crown, but it is as accurate as I could ever hope for…just so you know that what you’ve heard is true……
I’ve read too that 1 inch of barrel length is worth 10 fps, and 8fps and 3fps and all sorts of numbers .Looks like, from your numbers, one inch is 3fps.
Packrat,
That is the kind of accuracy that I achieved with my, 14″ and 18″ barrel. I did even better with my 24″ (1/2″ groups or better). Yes, these are great groups that will translate into usable “hunting” shots…I was referring to the claims of “One hole” accuracy (you know, 1/8 to 1/4″ five shot groups) that I have heard a few times mentioned on forums. I have achieved such accuracy out of my LW and BSA barrels…, but I wasn’t sure if it would even be possible with these 22xx guns.
I think in the real world, 1/2 to 1″ groups at 25 yards is more realistic. If anyone knows any different, please let us know.
Later!
Some great data there. You are earning your airgun education through experience!
After you are done with the Crosman guns, the next logical step is the QB 7x series… Cheap guns that can be made into great little shooters.
Keep up the good work.
Rob,
yeah, I’ve been all over Archer Airgun’s website a million times. I see it happening someday for certain.
I don’t know when I will be done with these “fun” crosman guns…My work bench looks like a chaotic pile of pieces (at least I finally know what piece goes where…) I have enough stuff to make five guns. I will be doing three carbines and two pistols. Two stainless, three black. I will post pics as they develop. Thanks Rob!
80Grit—I’m with ya!!! MAX length for me on the 2250 is 18″ just seems to be best of both worlds..long enough to get full use of propellant, and short enough so as to look perfect, imo.
Roy built my 2250…has 18 inch barrel….I have since converted it to 13 cu.in.bottle HPA…..anyway…with 14.3 Crosman Ultra magnums, or 25.4 JSB exact Match Monsters, the gun , at 25 yards will shoot 8 shot groups that can be completely covered with a US quarter ( $0.25 ) and I’ve done it more than just once or twice, so I know it wasn’t just a “fluke ” or luck.. I do not know if Roy did anything to barrel other than cut to 18 inches and re-crown, but it is as accurate as I could ever hope for…just so you know that what you’ve heard is true……
I’ve read too that 1 inch of barrel length is worth 10 fps, and 8fps and 3fps and all sorts of numbers .Looks like, from your numbers, one inch is 3fps.
80…
Some great data there. You are earning your airgun education through experience!
After you are done with the Crosman guns, the next logical step is the QB 7x series… Cheap guns that can be made into great little shooters.
Keep up the good work.
Packrat,
I forgot to ask Walt that same thing. Perhaps he will let us know.
UPDATE:
I took off the 14″ barrel (to test another, but also because it was not up to par in accuracy…five 5 shot groups @ 20 yards with 14.3 cp (brown box)
14″ barrel
.807″ ctc, .864,.890,.455, .998 (one flyer)
The 24″ barrel is from Roy at mountain air. The only mod I did to it was a countersunk tranferport (as per Walter’s advice) polished the port and inleade as well. I thought it would do much better in the fps arena…someone please chime in as I understand every inch of barrel adds 10 fps on a PCP gun. Is there a similar rule of thumb on Co2 guns???? I added 10″ to the barrel, and I gained an avg of 30 fps more than the 14″ barrel. I had a high fps of 613.
I put in a fresh co2 cart and shot five 5 shot groups @ 20 yards with the brown box cp’s (cleaned, lubed, and dried—they were very dirty and WOK recommened such treatment)
Groups were better with the 24″ barrel.
.496″ ctc, .495, .467, .584, .398
I am going to send my 18 and 14″ barrels to someone for accurizing as I have no intention of owning a 2250 in 24″ barrel. Max lenght for me on theses guns is 18″…, but I prefer 14″ barrels in carbine form.
I don’t know if I am expecting too much from these Crosman barrels…I have heard stories of guys shooting one hole groups at 25 yards with them…so far that has not been my experience with them.
Knowledge is power, it is all good.
Thanks for sharing all of this with us
Roachcreek
Roachcreek,
you are correct. I love that guys like Walt take the time to educate newbies like me…That’s what I love about this forum…great bunch of guys and a vast store of knowledge.
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Well, it’s looking like I will have to hold off for a while before testing the Disco valve…until after I finish building my .25! I finally have all the parts for it. It is sitting on my work bench “screaming” to be put together. It is going to be nasty! 😎