Springer barrel length vs Velocity

[jmcgall1]

Last time i remember looking into this topic I got no definitive results but a lot of numbers being thrown around almost as if one long internet telephone game (he said... she said..)

I'm wondering if anyone has any data regarding barrel length vs velocity for springers (in both .177 and .22 cal) I'd assume a .22 cal needs even less length than a .177 but was hoping someone out there had some if any data.

I'll be cutting another barrel tonight but unfortunately I don't have a chronograph. 

It seems to be a general understanding that most springers need only 6-10 inches of barrel before there is no gain in velocity.

[longhunter]

The barell on my airhawk was almost 18". I cut it Dow to 12". I gained around 40 fps over the stock length. That was in .177.  You also need to take into account cocking force. It will get much harder with a short barell. Mike Melick had a good suggestion, one I used myself before cutting my barell. Mark the length you want your barell to be, with a piece of tape and try cocking it from that point. Then you'll know for certain whether or not it's doable.

[Bryan Heimann]

The more swept volume your gun has, the longer the barrel needs to be.  In lower power guns, a longer barrel will yield less velocity because the pellet is already slowing down from friction before it exits the bore.  In magnum .177 guns, a shorter barrel may yield less velocity because the pressure is still enough that the pellet is still accelerating out of the bore.  In .22 or .25, I believe you should be able to chop the barrel as short as you can stand to cock it and see either no change in velocity, or an increase- even with most magnum guns.  In .177, you may want to leave the barrel long on a magnum to see the most velocity.  On a mid-powered gun, you may still see gains - or no difference- with a reduction in barrel length in .177 caliber.  I think I read somewhere that the Hatsan 135 would require 30-some-odd inches of barrel to see it's true potential in .177.  But most magnum springers shoot so hard, they require heavy ammo just to slow them down enough to be accurate.  There are so man what if's and why's out there regarding barrel length.  I wouldn't even attempt adjusting barrel length for velocity gains.  For me, chopping a barrel would be more out how the gun handles.  Mike Melick posted a while back, that you ought to put a piece of tape on the barrel about where you want to chop it.  Then you place your hand no further out than the tape when cocking for a little while, to see if that is really what you want to do. It will be harder to cock if you chop it.

[jmcgall1]

I've already done a few chops and am still young so haven't faced a gun i've really felt was that hard to cock yet. probably just taking three or four inches off a beeman kodiak .22 to make it balance better. Did so with a .177 already and moved the CG back three inches and it made a significant difference to the feel of shouldering the gun.