Anyone with a gas ram and chrono, help please to solve a mystery!!

[Loki_79]

If you have any gas ram powered rifle and also access to a chronograph, could you please help me out by recording the fps (or power) of two consecutive shots.

1) Where the rifle is cocked as fast as you can - probably your 'normal' cocking action
2) Where the rifle is cocked as slowly as you can - try to go as slow as possible, this may be difficult with shorter barrels

The order does not matter. Please post the results on this thread.

I have good reason to believe that there should be a marked difference between the two, but hopefully all will become clear (one way or another) when a few results come in. Thanks in advance!!

[angrybear]

I don't have a gas ram, but I don't believe it should make any difference to it, being a sealed unit.

it would if you made multiple shots as fast as possible as the gas would heat up but that's a different matter.

[Loki_79]

Yes, you would certainly think so - but a certain forum member has been testing one where the difference is significant and I would like to find out if this is the exception or the rule!

I don't have a gas ram, but I don't believe it should make any difference to it, being a sealed unit.

it would if you made multiple shots as fast as possible as the gas would heat up but that's a different matter.

[thisisdonald]

I have noticed that with SSP pistols, you can cock hard, or soft and it definintely feels like the stroke is harder if you cock fast and hard.




that sounds all kinds of wrong

[lensman57]

I have noticed that with SSP pistols, you can cock hard, or soft and it definintely feels like the stroke is harder if you cock fast and hard.




that sounds all kinds of wrong

I have this with my HW 40. The difference is not a lot but is there. Now HW 40 only makes 2.6 ft.lbs at the muzzle at best so 0.3 ft.lbs differential is significant. I'd be interested to see what the result of the rifles would be.

A.G

[rhyslightnin]

Huge difference with the short barrel, low power .177 though, Mike.

Endorsement of that old saying going along the lines of, "If you've only got a little one, best do it fast!"

You've always got to have a say if there's a good slow & fast cocking going on a tone!!!!

Ooooooh Matron! Yes, I've pumped it back up to the "proper" power level now. I'll be having another go at the bucket with it next month!

I managed it a few times with mine now, tis very satisfying with the rammer..., I look forward to joining you in a bit of bucket bashing!

(I just read that back to myself & spat tea all over the screen..! Lol)

[TonyL]

Yes, you would certainly think so - but a certain forum member has been testing one where the difference is significant and I would like to find out if this is the exception or the rule!

I'd guess that if the rifle was shot very quickly, immediately after the faster / harder cocking action, then the higher temperature generated would increase the pressure inside the ram? If, however, the rifle was allowed a little "standing time" and that higher temperature dissipates, then it would be the same?

Also, higher ram pressure may not ALWAYS lead to higher muzzle velocities, a little like if a springer is oversprung?

[flyingfish]

I'd guess that if the rifle was shot very quickly, immediately after the faster / harder cocking action, then the higher temperature generated would increase the pressure inside the ram? If, however, the rifle was allowed a little "standing time" and that higher temperature dissipates, then it would be the same?

Also, higher ram pressure may not ALWAYS lead to higher muzzle velocities, a little like if a springer is oversprung?

I thought the use of inert gas was supposed to stop that happening yony

Pete

[severnsider]

I've mentioned this phenomenon several times on here in recent years. Slow cock gives lesser m.v. Than fast cock. It's a mystery to me. As BTDT pointed out, the air we breathe is 78% nitrogen so there's not much of an argument for filling with inert gas. Another member (Blackbeard) gave the matter some thought too. Loki, what has prompted you to raise the matter again?