Reply To: PA now has Ataman guns listed.

Forums PCP Airguns PA now has Ataman guns listed. Reply To: PA now has Ataman guns listed.

Link

zebra
Participant
Member

“FukoChan”

“AirgunBill”FukoChan why do you love the higher fill pressure which only gives a minimal increase of fpe in the .22 and 25 cal. and about the same or less shots per fill than other pcp rifles. Bill


Wouldn’t higher fill pressure but similar air capacity mean either higher fpe shots or more shots per fill? 


It would deliver more shots per fill but not higher fpe. Two reasons: It’s a regulated gun so it will put out consistent energy from a full cylinder all the way down until it drops off the reg. That is what the reg is specifically used for. The second reason is that higher pressure in the cylinder makes it harder to depress the valve piston when the hammer strikes so the valve stays open for less time than it does when struck at lower fill pressures.

In practice, a non-regulated gun is more powerful at higher fill pressures for the first few shots and then it gets progressively less powerful with each additional shot. Some more than other but the difference in power is not proportionate to the increase in pressure though.  You would get to a point where the hammer strike would not be powerful enough to open the valve at all if you keep increasing the pressure. You would also get far fewer useful shots as you use most of your air in the first 5-15. The noise is worse too.

More power in pcp rifles comes from a greater volume of air moving through the barrel. The same volume of air released from a higher psi cylinder would not produce a noticeable power difference. 

If you look at what the regulators are set to release, you’ll see that 1500 psi is plenty to launch a 25 cal projectile. The older big bores were apparently battle capable at only 800psi .

Storing 4000 psi instead of 2000psi just means there is twice the volume of air. You could use that to double the shot count or you could widen the valve and / or use a stronger hammer spring to achieve more power from the same number of shots. In the Ataman, Cricket, wildcat etc, the higher psi storage allows them to carry more air without the extra weight of a larger cylinder. That’s all.

In any of these guns you could remove the reg and your first few shots would be more powerful. You don’t want this though as the poi shifts with the change in power so your scope zero would be no good. High quality non-regulated guns are designed to minimize this effect as a higher extreme spread is considered a problem.

The most effective way to increase the power on a pcp rifle is to use helium instead of air. Helium is considerably lighter so a greater volume can be stored in the same sized cylinder. More importantly, when the hammer strikes the valve a greater volume is released for the same psi. Check out the Extreme Big Bore site where they show the performance of their guns with air and helium. Guns that put out 450fpe with air can reach 1350fpe with helium. It’s an amazing difference. 

You  can use helium in any pcp rifle if you have a 3000 psi or 4500 psi source (tanks can be rented). A member on a another forum claimed to be running helium with a BSA rifle and getting 180fpe instead of the 30-40fpe with air.

I am curious to try helium in the Cricket but I just don’t need the extra power (or noise). The squirrels I enjoy killing go down like a granny on ice at 48fpe so…..