Extended barrels effect on slide velocity?

[10mm4ever]

I'm about to order a 6 inch barrel from Storm Lake for a G-20.My question is,shouldnt an extended barrel cause an increase in slide velocity? By increasing the barrels length,it should allow more time for expanding backpressure to build and enact its force against the breechface,to my way of thinking.I'd estimate an increase in slide velocity of 20-25% over the stock 4.6 inch barrel.I'm just curious to know what everyone elses experiences have been.Thanks

[ShootCraps]

I don't think so. The breech is kept locked until the bullet leaves the barrel and it's at a safe pressure to open. Barrel length isn't going to change that.

[fun2none]

A Glock is recoil operated so barrel mass affects slide velocity. For a short duration, the slide and barrel are locked together as a single moving mass. If you increase this mass, either with a longer (heavier) barrel or attach a compensator at the end of the barrel, the slide velocity will be reduced.

I recall a 16" barrel that was part of carbine conversion. The carbine barrel dropped into a standard G17 slide assembly. Because it used the stock G17 recoil spring, the barrel had a "booster" where it met the front surface of the slide. The booster was essentially a gas piston that provided extra momemtum to accelerate the slide. A similar device was used on the German MG34 & MG42 machine guns (recoil operated).