Effect Of A Compensator vs Seperator On AP Barrrel Lift

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DaveS

Effect Of A Compensator vs Seperator On AP Barrrel Lift

Post by DaveS »

There are two styles of compensators currently found on the most recent PCP Air Pistols. The Seperator type that is nothing more then a barrel shroud with a radial arrangement(Morini,FWB,TAU) of holes with an exit channel for the pellet.
The compensators vary from the above design with only vertical venting to what looks like a more elaborate design that uses a conical insert for the barrel exit (Steyr).
Years ago for C02, the argument was made that the vertical port type compensators did indeed reduce barrel lift. By venting the propellent upwards it would push the muzzle down and canceling the lift. This was also supposed to possibly destabilize the pellet and only provided the cancelation after the pellet exited. By venting the gas behind the pellet while in the barrel and using a seperator style, the upward lift was to be canceled before the pellet exited. The seperator allowed the remaining gas to equalaterally vent behind the pellet keeping the pellet stable without adding any vertical motion. That all makes sense with an expanding gas.
Leaving the theory of CO2 behind and keeping the theory relevant to PCP air pistols, what is the effect if any on recoil and pellet stability between the seperator and compensators?

dfs

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Mark.

Re: Effect Of A Compensator vs Seperator On AP Barrrel Lift

Post by Mark. »

You've posed an interesting question. Unfortunately I don't think there's much of a way to find a "scientifically true" answer without doing a bunch of expensive testing.
I have a Morini 162, LP1 (C02) and LP10. There is definite muzzle lift in the LP1 compared to the LP10, even though their compensator designs are virtually the same. So the LP10's barrel drilling and recoil absorbing breach bolt have an effect on muzzle lift. Probably more effect than actual compensator/separator design would have.
The Morini comp seems to require a significant amount of air going through it to function well. I say this as I had a malfunction which caused very low velocity. The pistol seemed to bounce all over the place. Once repaired and higher velocities were obtained the pistol is much more stable and exhibits less muzzle lift. This is contrary to the behaviour I expected to see (I expected that a pellet being driven with more oomph would cause more muzzle lift).
I bought the LP10 and love it, but the more aft centre of gravity of the 162 Short allows me to shoot with more consistancy, even though I have to deal with recoil and muzzle lift when shooting the Morini. If you were asking this question with compensator function being a decision point in a new pistol purchase, I'd say it's all pretty much a wash. The usual "pick the pistol that fits you best" advice applies here.

Mark.
PS: My 162 still shoots tighter groups from a vise than does my LP10, but my LP1 outshoots both of them. Go figure!
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DaveS

Does anyone know what a seperator does in PCP?

Post by DaveS »

Thanks Mark.
I guess what I want to know is just what exactly does a radial seperator do in PCP. Does it just insure projectile stability ?
If it does somehow cancel muzzle lift...how? When?
My naive assumption is that with a radial venting of air, the net effect is zero. Therefore the upward muzzle lift motion is not canceled. Had there been an opposing motion that would be provided by a vertical venting compensator, the upward lift would be canceled...AFTER the pellet left the barel.
dfs

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