Effect of Air Pistol Barrel Length on Intrinsic Accuracy?

[nglitz]

Well, OTD got it in one!

That, and we need to look up the definitions of accuracy vs. precision.

[Jon AP]

The question of barrel length on "intrinsic accuracy" (what I would call "mechanical accuracy") is, as has been suggested, infinitesimal. Pistols capable of shooting groups that amount to a single slightly fuzzy hole regardless of barrel length aren't fertile grounds for improvement in the pistol or the pellet.

The same cannot be said of the impact of barrel length upon the shooters ability to deliver practical accuracy. Bore time and sight radius do make a difference, and it has been my experience that shorter barrels (within reason) lead to slightly higher scores. Our forum sponsor apparently has found this to be true based on much broader experience than my own limited sample, hence their limitation on sales of the non-compact pistols. I regret not having chosen a compact pistol instead of my Steyr LP1P. I'm very fond of my Steyr but if I had it to do over again I would have gone with a shorter barrel.

Nobody should take the apparent consensus that barrel length has no impact upon mechanical accuracy to indicate that barrel length doesn't make any difference or isn't important.

[DFWdude]

Nobody should take the apparent consensus that barrel length has no impact upon mechanical accuracy to indicate that barrel length doesn't make any difference or isn't important.

Recently, I did some velocity experiments with my LP10. Having chronographed it in standard configuration to 565fps, I then removed the barrel shroud and taped over the barrel vents with duct tape. The idea was that retaining the air pressure -- rather than venting it -- MIGHT cause the velocity to increase, although I had doubts. Sure enough... The velocity was exactly the same, 565fps. No change at all.

This tells me that the barrel in the LP10 need only be as long as the first vent nearest the breech (4.75" or 120 mm). In terms of useful velocity, the rest of the barrel beyond is not important.

In the past, I have shortened CO2 powered LP1 barrels, and found velocity differences, due to the continuing vaporization of CO2 in the barrel of that design. That made sense.

However, any PCP design -- with all the potential compression available at the start of the shot -- needs a barrel only long enough to reach the required velocity. Choke the shorter barrel as per normal Steyr practice, and the accuracy should be no different, either. Just restore the 350mm sight radius with a blooper tube, and what do you have... a one-handed Olympic 10m RIFLE. Is that so bad? Just my opinion.

Just thinking outside the box, the puppy below was reputed to shoot just as accurately as a stock FWB, too. Imagine...

[gwsb]

WOW! I am glad I lived long enough to see this.

A subject Rover would not weight in on.

[Rover]

I don't sniff "opinions."

[JamesH]

needs a barrel only long enough to reach the required velocity.

And ideally some extra length to reduce a bit of excess pressure.

Unless your barrel crown and pellet base are always perfect.