What Barrel?

[alwaysshootin]

...why, most of us, look to purchase an aftermarket barrel.

For me it is about going to a 6.02" version to add velocity in 10mm.

  Curious what kind of velocity increase you've experienced in the 6" over the factory barrel? Only asking, because when I had access to a chronograph, I never compared the two length barrels myself. To be honest, the main reason I first purchased the 6", was because Ohio has mandate of not less than 5 inches on barrel length. When I got the 6", Lone Wolf did not make the tactical length, which is what I have now. Bought it to make the length needed, and mostly, to shoot lead, without concern of leading.

[sqlbullet]

Factory ammo will see an average of 33fps increase.  But this is heavily load dependent.  Increases can be almost 100 fps for certain loads, maybe more for handloads.

http://www.ballisticsbytheinch.com/10mm.html

[Yondering]

  Curious what kind of velocity increase you've experienced in the 6" over the factory barrel?

75-150 fps difference compared to a stock G20 length, depending on the load.

[REDLINE]

...why, most of us, look to purchase an aftermarket barrel.

For me it is about going to a 6.02" version to add velocity in 10mm.

  Curious what kind of velocity increase you've experienced in the 6" over the factory barrel? Only asking, because when I had access to a chronograph, I never compared the two length barrels myself. To be honest, the main reason I first purchased the 6", was because Ohio has mandate of not less than 5 inches on barrel length. When I got the 6", Lone Wolf did not make the tactical length, which is what I have now. Bought it to make the length needed, and mostly, to shoot lead, without concern of leading.

Glad some others chimed in with a good answer.  I don't currently have a 6" barrel.  I do have a Storm Lake 6.02" G20 barrel on the way, but the estimated ship date isn't until 8-13-12.  When I get it though I definitely will do some velocity comparison work over my CED M2 chronograph and get back to posting the results in 10mm-firearms.com, and only on 10mm-firearms.com.

Included in the comparison will be some Underwood and Winchester Silvertip.  Not sure what else yet.  Maybe Hornady factory XTP or something.  I'ld like to also see if there's a velocity difference between the G20 stock recoil spring and my Wolff 24 pound spring for the G20.  Don't know, we'll see.

[alwaysshootin]

Quite a spread there with 33- 150 fps! Wish I had compared the two different barrel lengths when I had the chance. If there is a 150 fps gain, then the longer barrel, for that reason, is a sound investment, yet, at a 33 fps velocity increase, not so much. Like I said, with Ohio, mandating 5" minimum length, and wanting to shoot lead almost exclusively, is why I spent my money for the aftermarket barrel.  Only going from 1220 fps, to 1250, or, any added accuracy, not that I noticed any whatsoever, is not why I would make an additional 25% investment to the G20. That's just me though!

Have a great weekend everyone!  

[Yondering]

I'm not sure where the 33 fps figure came from? Even on the BTI website, they show 75-100 fps difference for most of the loads tested between 4" and 6" barrels.

I have never fired a load through mine that only gained 33 fps. Even factory 40 S&W gains more than that.

[alwaysshootin]

Factory ammo will see an average of 33fps increase.  But this is heavily load dependent.  Increases can be almost 100 fps for certain loads, maybe more for handloads.

http://www.ballisticsbytheinch.com/10mm.html

From here!

[sqlbullet]

I'm not sure where the 33 fps figure came from? Even on the BTI website, they show 75-100 fps difference for most of the loads tested between 4" and 6" barrels.

I have never fired a load through mine that only gained 33 fps. Even factory 40 S&W gains more than that.

Yondering, I took the data on the Ballistics by the Inch page for 5" and 6" barrels, derived a difference for each load and took an average.

Calculation	Value
average	33.89
min	3
max	93
Std Dev	27.07

You are correct.  When comparing 4" to 6" barrels, the velocity increases average to 102 fps

Calculation	Value
average	102.89
min	71
max	182
Std Dev	33.7

And, just for fun, going from 4" to 5"

Calculation	Value
average	69
min	51
max	90
Std Dev	15.1

This data indicates that factory 10mm ammo is optimized for a 5" barrel.  Gains are seen out to 14-16" barrels in most factory ammo, but they are quite incremental past 5" in most cases.  I suspect handloads will really benefit those with barrels longer than 5"

[REDLINE]

I suspect handloads will really benefit those with barrels longer than 5"

I'ld also expect to see a difference between 40S&W-level 10mm factory ammo and Underwood-level 10mm ammo.  I can't see that they would be the same across the board, possibly not even close (relatively speaking).

[sqlbullet]

I had the same thought.  They do list the buffalo bore 180 at 1399 from 5" and 1428 from 6".  This load tops out at 13" with 1586 fps.

But, handloads can be better tailored to a longer barrel.