My .357 Hog Hammer (Condor)

[MJP]

It's just that, you add springs when they are not needed, it's the valve that doesn't flow right. Take all the springs out, and the spring retainer nut, shim the top hat and limit valve travel to a point where it doesn't dump anymore. And see where your fpe goes.
The springs collapse inside the valve body and limit flow, and the valve closes faster, without the springs the valve flows faster and closes fast when opened proper amount.
I'm using a big valve that needs a heavy hammer but it works.
Just a side note, only thing made by af in my gun was a condor tank, but that is replaced by luxfer tank now.

I think it's 1:16 twist if I remember correctly.

Marko

[Qdoggus]

It's just that, you add springs when they are not needed, it's the valve that doesn't flow right. Take all the springs out, and the spring retainer nut, shim the top hat and limit valve travel to a point where it doesn't dump anymore. And see where your fpe goes.
The springs collapse inside the valve body and limit flow, and the valve closes faster, without the springs the valve flows faster and closes fast when opened proper amount.
I'm using a big valve that needs a heavy hammer but it works.
Just a side note, only thing made by af in my gun was a condor tank, but that is replaced by luxfer tank now.

I think it's 1:16 twist if I remember correctly.

Marko

I guess the same would apply if the valve doesn't have a retainer nut? The spring retention is made into this valve via a lip, it has a weird flared spring too, like you'd see on a battery. As for the shim, what did you use? My valve body is 9mm OD so I don't think I'll find a proper shim at talon tunes. Again, thank you for the advice. It would need to be a fat shim because there is at least 1/2"  or more between the rear of the tophat collar and the brass insert.

[YEMX]

Any chance of getting some more pics of the bolt handle?

[Qdoggus]

Any chance of getting some more pics of the bolt handle?

Sure, after I get a knurled handle.

[MJP]

Yeah it works in that valve too, I have a machineshop and four lathes and couple of machining centers that I can use in my spare time... Steel washers turned in a lathe or just use a stack of normal washers. Btw, my valve has 12mm od and 9mm id.

[Monkeydad1969]

Any chance of getting some more pics of the bolt handle?

There you go again.  Don't you enough irons in that fire?

LOL!!!!!

Joe

[Onebaddj]

Not sure how i missed this till now. Very nice build! Love threads like this with tons of info and ideas.

[YEMX]

Any chance of getting some more pics of the bolt handle?

There you go again.  Don't you enough irons in that fire?

LOL!!!!!

Joe

Never!!  I'm building a .257, remember?  LOL

[Qdoggus]

Yeah it works in that valve too, I have a machineshop and four lathes and couple of machining centers that I can use in my spare time... Steel washers turned in a lathe or just use a stack of normal washers. Btw, my valve has 12mm od and 9mm id.

That's a mighty big valve you have....lol. I'm going to try this. I'll test springless, and then a spring in front of the brass insert, where the shims would go, just want to learn something.

[Qdoggus]

Not sure how i missed this till now. Very nice build! Love threads like this with tons of info and ideas.

Thank you! I always love learning and contributing.

[MJP]

You cant put the spring between the brass and the tophat, spring needs a cavity where there is space to compress, or else it gets hammered useless, and the brass part too.

Marko

Edit, forgot to mention, the line where the valve works is very narrow, I use 2mm tophat gap, but 2.1mm will dump on heavier bullets over 200gr.

[Monkeydad1969]

Any chance of getting some more pics of the bolt handle?

There you go again.  Don't you enough irons in that fire?

LOL!!!!!

Joe

Never!!  I'm building a .257, remember?  LOL

Now, but what build later?  I'm just watching out for you.  LOL!

[Qdoggus]

You cant put the spring between the brass and the tophat, spring needs a cavity where there is space to compress, or else it gets hammered useless, and the brass part too.

Marko

Edit, forgot to mention, the line where the valve works is very narrow, I use 2mm tophat gap, but 2.1mm will dump on heavier bullets over 200gr.

Challenge accepted...

I've already put a spring there for testing. Just kidding about the challenge accepted, but the reason I want to test it with and without a spring is because with the spring on the outside, I have the benefits of controlling tophat travel without the con of spring compression limiting flow inside the tank. A shim to my understanding doesn't compress at all so at least my theory is sound for testing. I don't have the benefit of a 12mm OD/ 9MM ID huge bore valve, nor would that work with my breech, barrel OD combination.

Update
I got a strong spring that allows 2.5mm of tophat travel fully compressed. My air expenditure went way down. Next will be to try your method.

A quick question, with proper shimming and no spring what is the lowest pressure you are shooting with. From my reading, once the pressure drops below a certain point, its not enough to close the valve, which I assume is where the shim might help out.

[MJP]

How was the fpe, where did it go?
And what do you mean by huge valve
My valve next to a condor stock valve.


The valve goes to a brass housing that has direct feed from the bottle.

Marko

Edit, I can shoot it all the way down to 1000psi if I want to. No problems in closing the valve.

[Qdoggus]

How was the fpe, where did it go?
And what do you mean by huge valve
My valve next to a condor stock valve.


The valve goes to a brass housing that has direct feed from the bottle.

Marko

Edit, I can shoot it all the way down to 1000psi if I want to. No problems in closing the valve.

Hahaha, that's exactly what I mean, mine is bigger than the factory valve but would be in the middle compared to yours.

I haven't measured fpe yet but with the thick spring in front I have no doubt it went way down. I was able to get in 6 shots without the gauge moving, and even then it only moved a smidge.

I got the idea to try your method. First I drilled the retention lip in the valve until it was flush with the ID, next I put it back together with the return spring out and a neoprene washer, two steel washers and a fiber washer at the brass insert, took a few shots (haven't chrony'd yet)... and no tank dump but it certainly got louder. So I removed a single washer, no dump, then I removed the rubber washer, no dump. Lastly, I removed all but a single steel washer, took a shot with a 127gr, and.....wait for it........ No dump. It sure as heck got a lot louder though. I'll have to chrony when I go to the range later this week.

[MJP]

Good that it works, I know why it didn't shoot too good with the spring between tophat and brass, the stock valve is not locked to the stem and it pulls the stem out of the delrin seal, and all the hammer force is wasted hitting it back in to the seal and not opening the valve.
Looking forward for chrony numbers.

Marko

[Qdoggus]

Good that it works, I know why it didn't shoot too good with the spring between tophat and brass, the stock valve is not locked to the stem and it pulls the stem out of the delrin seal, and all the hammer force is wasted hitting it back in to the seal and not opening the valve.
Looking forward for chrony numbers.

Marko

An interesting theory and one with merit. I bought a thick spring and cut out 3 coils for testing, but I guess in this process, I learned how to turn it down for quieter shots at lower power with just a spring. The power wheel has never worked like it should have, popping out the tophat to install a spring works fine though.

UPDATE...

So I went and took some chrony measurements. Surprisingly, this simple mod gained me 38fpe or from 826fps with 128gr to 904fps with 128gr. Wow! I don't even have the heavy barrel riding hammer or aluminum breech yet.

Truthfully I was a bit skeptical, and I can see that you were right, what an increase at 2900psi! I have to order some more heavy rounds so I ordered some 185gr rounds this time. Hopefully I get the heavy hammer and breech first so I can get everything set up.

Thank you for the outstanding advice!

[MJP]

You are welcome, glad to help a fellow airgunner. Opening up and bellmouthing the air passage to the bottle should add some more, then bigger port and valve seal. You should get past the 300fpe mark.

Marko

[Conner holifield]

I have a 2023 airforce condor .257 with stock valve with a talon tunes heavy hammer spring and I modified my stock valve ported out the stock top hat and removed the valve return spring are you running a stock or aftermarket valve and is it running a return spring because when I took out my returns spring in my valve I got way more fpe as air flows easier and valve opens way easier and less clutter.