Shot string-modded valve?
This was done yesterday after mod. valve
TalonSS-12″ bbl.- .070 tophat-pw10 ,2,900 start – 2,300 finish 20 shot. .22 cal Kodiaks
1) 819.4
2) 809.5
3) 811.0
4) 805.0
5) 800.4
6) 801.7
7) 790.7
8) 797.9
9) 794.4
10) 790.2
11) 789.6
12) 788.6
13) er
14) 776.7
15) 775.9
16) 771.1
17) 776.3
18) 762.2
19) 765.1
20) 767.3
If this was you gun and ,these were your results ,what would you be thinking,,happy, need more tuning of tophat,more ajustments. Thanks
I don,t see a bell curve!,just power loss with each shot.
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Viewing 11 replies - 1 through 11 (of 11 total)
I believe it to be a matter of cause and affect. I have to set the tophat in an extra .010 because it opens easier, thus i have a closer spread, along with the tophat setting. If i could i would have tightened it down further, ran out of threads and patience on that one. Here is a before on my rig set at .067 16g JSB’s, tight spread and hard to beat.
The lighter spring allows for a closer tophat setting and a easier opening hammer weight, stock hammer for example. I Want to try a lighter hammer and see what i can find out. Would like a light hammer and find a small bell curve somewhere in the setup. Its entirely possible but a balanceing act. Between return spring, hammer weight, tophat setting. Power wheel is usually set in the middle and used to fine tune the best tophat setting i can achieve, given the amount of threads to work with, did i grind some of the bottom of stem, or bore out the valve seat? Things like that.
1. 796
2. 799
3. 795.6
4. 797.3
5. 798.1
6. 791.8
7. 795.4
8. 790.4
9. 791.7
1. 790.2
RiffRaff if your loosing less then 1fps per shot don’t touch it. Your where you need to be. I try to get 1fps per shot loss in terms of a spread. I gotta get my 18″ in and see how that affects consistency. I know i can loose alot of air on the 12″ if i don’t dial the tophat down after the valve mod. Might have to bite the pellet and try the shims sometime. Seems to be some great numbers coming from the simple mod. I always have to do things the hardway. But it comes down to what do you want from the rig. For me its as much power as i can get, while keeping things as consistent in terms of air conservation. I guess i don’t want to loose 10-20 fps because of shims.
I would really like to see a shot string before and after the mod.
Heyt BD! Is the lighter spring responsibe for the tighter fps?
Thanks; Mike
I’ve given you a solution in your other thread and am starting a thread on the topic now. I really give AF a call and get me a new stem/tophat, why not?
I must be lucky. With my new bottle and valve the fps spread for 30 shots is less than 20fps almost every time; this using the factory setting.
But I didnt start getting those numbers till I started using the rubber shim.
Like said before, every rig is different and result may vary.
Might have to bite the pellet and give TH adjustment a shot. But I dont wanna, heh.
i think those numbers look damn good….
i want all out on my valve and it does 32 fpe with crowmags, i would imagine a bit more with kodiacs…..
only thing i would maybe do is turn the powerwheel down a bit further….
you want to start a tad low….build ower over maybe 5-10 shots, and then let it tsrat to come down again….also you should be able to get more than 20 good shots….30-40 shots for a fill is more like it….
allso seeing you allready get high velocities from the beginning…upping your fill pressure to 3000 will give a few more shots…
Here is my best 20 shot string with modded valve, llighter return spring. Will back off the retainer and gain some adjustablility of my tophat. I know i can get this group tighter, ran out of addjustment. If i could get what i did with the unmodded valve in terms of the shot spraed this would be a sweet setup. The numbers below aren’t bad either, a little tighter would be excellant. Still killer for a 12″ barrel.
21g Kodiaks used, tophat set at .058
1. 829.9
2. 817.7
3. 820.3
4. 821.9
5. 815.6
6. 811.4
7. 813.9
8. 812.9
9. 810.5
0. 810.9 816 fps, 10 shot avg= 31fpe with a 19.4fps spread
1. 806.5
2. 802.9
3. 797.5
4. 800.4
5. 800.2
6. 798.9
7. 793.8
8. 796.1
9. 787.5
2. 793.1 807fps, 20 shot avg= 30.3fpe with a 42.4fps extreme spread.
A curve is possible with a lighter hammer and balanced return spring. Its on the to do list but viable.
Jim have been thinking about your shim project. Now we shim because we don’t have the threads left on the stem. How about unscrewing the spring retianer a turn or two Blue threadlocker to keep the retainer in place. My thought was screw the tophat in all the way, back it off 2.5-3 turns. Then setting the retainer till the tophat was set at .070. This would solve some issues at hand. Such as the lack of thread on the newer talon valves. I can get mine doewn to .060 or so and my retainer is screwed in all the way..a revolution or two out of the retainer would give a guy a much more adjustable tophat.Let me know whatyou think if you come across this.
Tophat settings i posted on deceased forum. I’ll spare you the irrelevant numbers. Tophat set at .071 and .067 both gave me the save 10 shot fps avg, and fpe avg, obviously 22.43 with JSBs. Only difference was i got a 8.6 fps spread at .067 and a 17.7 fps spread at .071 turn them tophats in boys. 8.6fps loss in 10 shots is a dream with that barrel size. I did this a while ago and since modded my valve. I’m seting my tophat at .060, .058 am going to try the above mentioned method of turning the retainer out to gain some tophat adjustment. I could tighten up my string and maintain a 30+fpe maybe 30/35 shot string. Also used a slightly lighter return spring hence the tighter tophat setting. Will work with a lighter hammer sometime this winter as time allows. Be nice to see a tight 50fps bell curve, would definately extend the useable amount of shots. Somewhere on here a guy posted a killer shot string with a delrin hammer, 15gs i want to say, tight numbers. Was early on in the forum. It would be on some of the very first pages.
That doesn’t seem bad at all to me as your slamming 21 grain pellets out there! 29fpe is great in the 12″ barrel for 20 shots….that is going to thump a critter HARD out of your SS!
Have you tried around .050 tophat? I found my gun made really no more power and was wasting air above .050 BUT you have a different valve and might not be wasting much air?
Oh yea really the only way your going to get a curve is reducing the power wheel setting…you might find this works great for you? my shot consistancy went to crap when I got too low on the power wheel though every setup is different so you need to test it out for yourself.
Let us know what you try and how it works??? Jim.
J.W, Thanks,Its a .22cal, and i don,t mine the loss after each shot, i only shoot 20 shots then handpump it back up.But,will try your suggestion, tomorrow at work. Thanks,Paul Kodiak pellets
.177 or .22? Pellet weight?
I would try the PW at 8… Do a string…
Then if that doesn’t do anything try to make the tophat gap smaller until your not losing power to gain a little more shots per 500psi increment…
Somehow I don’t see getting a bell curve, but I would be content with a consistent loss of fps per shot without erratic numbers.
Really what you have already looks pretty good to me (except for the PW is set too high) but I am by no means super savvy like some of the amigos here…
JW
Viewing 11 replies - 1 through 11 (of 11 total)
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Thanks so much BD! Yea, I was thinking -what if I lightly beveled and polished the valve seat. But I keep seeing shot strings with the new condor valve. Seems that they can post some good numbers at a low fill. I keep hearing both good and bad about their consistency? I would like to keep the fps in the 950’s at a lower fill pressure. I am not getting very many fills with the scuba tank. This would really allow me to get many more fills from the tank if I could fill at say 2000 to 2500psi. and get the same velocity. My only other option is going to a carbon tank. But first i need to find someone here that will fill it!!! That and the cost!
Thanks Mike