Pistol Barrel Length and Velocity--Results

[Old School 611]

I have a standard load I use in 9mm 115gr FMJ. Well I took out three 9mm GLOCKs of different barrel lengths and shot them over the chrono today. Make what you want out of the results but it suprised me a little. Five shots were fired and averaged.

 

G34-5.32" barrel Av. 1191.4fps S/D15.23

 

G19- 4.02" barrel Av 1106fps S/D 4.75

 

G26- 3.46" barrel Av 1136fps S/D 12.15

 

I expected what I got between the G34 and G19 but the G26 suprised me. Any thoughts?

 

 

Wrong Catagory please move to RELOADING

[Shane45 807]

The G26 has a tighter bore creating higher velocity.

[Shane45 807]

One other thought, are all the barrels stock glock polygon rifled barrels?

[Old School 611]

All the barrels are stock GLOCK. Now the 26 was clean and the others were dirty. But all shots on the 26 were consistantly higher. Weird isn't it? And look at the Standard deviations. Barrel manufacturing tolerances maybe?? Please don't make me slug the barrels... :shock:

[GRIZ 3,369]

All the barrels are stock GLOCK. Now the 26 was clean and the others were dirty. But all shots on the 26 were consistantly higher. Weird isn't it

 

Not really. I've seen variations of 150 fps on NEW consecutive serial numbered guns. Variations of 100-150 fps are not unusual as you will find as you chrono more loads.

[Shane45 807]

When I shot IPSC I used to do my reloading in sittings of roughly 500 rounds. I shot out my 1911 barrel. I replaced it. From the same batch of reloads my velocity went up a lot. So did the pressure. I had to back my load down a lot from where it was with the old barrel. I had always attributed it to old worn vs new tight.

[Old School 611]

When I shot IPSC I used to do my reloading in sittings of roughly 500 rounds. I shot out my 1911 barrel. I replaced it. From the same batch of reloads my velocity went up a lot. So did the pressure. I had to back my load down a lot from where it was with the old barrel. I had always attributed it to old worn vs new tight.

 

 

The G34 has about 5000 rds through it the G19 about 2-300 and the G26 less than 50. so that adds to the confusion.

[GRIZ 3,369]

I shot out my 1911 barrel.

 

How many rounds did you take to do that? I have a Combat Commander since 1975 and am still on the factory barrel. I've shot maybe 20,000 rds but mostly lead bullets.