Benjamin Jefferson State Air Valve

Hi all,

I have a gen 2 marauder. Lots of good mods. Lots of tuning. Several Jefferson state parts that I am happy with.

My factory air valve broke. Decided to take a chance on the JS air valve. Installed it and I am having issues with my fps ranging from 550-950. It’s all over the place. I text the owner, which I think is a stand-up guy. He hasn’t responded yet, (no biggie) it is the weekend after all. In the meantime, I wanted to see if anyone has any experience with one. Any issues? Any feedback?
 
I have one that works very well for me, but I do recall it taking a little while to stabilize. I'd have to look, but I think I set it up with a buffer on the hammer too (o-rings in the tube), and I also run a TSS on it as well. But once it stabilized it became very consistent.
This is good info. I have the TSS too. I have played with multiple spring combinations. It is truly all over the place. I’ve put about 100 shots through it. Wasn’t sure if I was wasting my time.
 
What hammer are you using. That is a huge deviation. Also what is your reg set at? Those numbers look like the effects of hammer drag.
I use the JS delrin hammer. I couldn’t tell you what my reg is set at. I’m concerned the valve is not working properly so before I just assume that’s the case, thought I’d see if anyone else has experienced the same issue.
 
If hammer is too light .. OR, hammer spring spring tension is too low ... the valve will not cycle correctly.
As well if using in a UNREGULATED rifle, the speed will change with pressure which is VERY MUCH SO a trait of this type balanced valve.

This i see as suspect ???
Without writing a huge paragraph, I see what you’re saying. I suppose my response is “according to their YT video, they recommend only using 1 of the 2 springs with this valve (of the TSS). I still have the spring backed off enough to give it no ‘hammer bounce’. The video says that “because it takes minimal hammer pressure to open the valve, you don’t want to slam it with both springs “.
 
Balance valves are notorious for giving headaches when tuning. Cold shots will commonly be very low in FPS compared to 2-3 shots in due to o-ring break out friction, never mind running friction and once that o-ring goes dry. Hard pass.

Save yourself the headache and return to a conventional valve.

-Matt
 
Balance valves are notorious for giving headaches when tuning. Cold shots will commonly be very low in FPS compared to 2-3 shots in due to o-ring break out friction, never mind running friction and once that o-ring goes dry. Hard pass.

Save yourself the headache and return to a conventional valve.

-Matt
i agree ! Tim Hill valve is smooth and holds up well
 
Here's an update for anyone following or looking to learn:

I removed my regular and the valve was not correctly firing. I would describe it as "seizing". Once the tank pressure dropped below 2100, it would shoot completely normal. So, I put the regular back in with it set to approx 2000 psi. Gun is shooting really good now. I will attach 2 images of my shot strings. The first one is from the stock(OEM) valve with my huma regulator. The second is the JSAR balanced valve with the huma regular. I calculated the standard deviation of the 1st 40 shots. The stock SD was 9.64. The JSAR SD is 3.11.

IMG_1182.jpg


IMG_2386.jpg
 
Hi all,

I have a gen 2 marauder. Lots of good mods. Lots of tuning. Several Jefferson state parts that I am happy with.

My factory air valve broke. Decided to take a chance on the JS air valve. Installed it and I am having issues with my fps ranging from 550-950. It’s all over the place. I text the owner, which I think is a stand-up guy. He hasn’t responded yet, (no biggie) it is the weekend after all. In the meantime, I wanted to see if anyone has any experience with one. Any issues? Any feedback?
I had an issue with my JSAR valve and sent an email but never got an email response. Eventually Matt called and left a voice mail explaining he was way behind on getting to his email and the best way to get ahold of him was to call him. I did call and he took care of my concerns. Give him a call.
 
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I had an issue with my JSAR valve and sent an email but never got an email response. Eventually Matt called and left a voice mail explaining he was way behind on getting to his email and the best way to get ahold of him was to call him. I did call and he took care of my concerns. Give him a call.

Yea I sent an e-mail a week ago asking about any black friday deals and never heard back, but no hard feelings as I know he is currently a one man show and probably a bit overwhelmed!

-Matt
 
Hmm, I first installed my new edition JSAR SS valve unregulated and was getting about 940 fps average with the JSB 34 grain pellets (67 fpe). I have the JSAR MDS hammer, striker is set so that face of striker is flush to the face of the hammer, it does not protrude. Stock spring. I could get 16 shots. My rifle is a .25 caliber.

I regulated with the Houma and XXL plenum and Tim Hill gage manifold. I now have the TSS installed. I drilled the barrel to .196 and am using a poly type TP. I set the regulator for 2,000 psi. I get now 16 shots at 890 with the JSB 34 grain pellets (60 fpe) but instead of a fairly peaked bell curve unregulated the velocity is flat. If the rifle sits for several days the first shot will be slightly low but consistent thereafter.

JSAR side lever receiver, JSAR aluminum tube, JSAR MDS buffer hammer set flush, JSAR TSS, Houma reg with XXL plenum, Tim Hill gage manifold, Tim Hill short shroud, DFL adapter, DFL mod, poly tube TP and barrel drilled to .196 port, reg set at 2,000 psi, 5.9 pounds bare:



I can push it up to 70 fpe but accuracy begins to go (still decent) and one magazine+1 is all it has.
 
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