10mm Velocity difference between a 10" Contender and 6" Glock?

[REDLINE]

I've got a good idea what to expect for 10mm velocity differences between the G29, G20, and G20 6".

What I'm curious about is how much additional velocity is gained going from a G20 6" to a T/C Contender 10" chambered for 10mm Auto?

Obviously it would depend on plenty of variables like the specific powder being used, but in general does anyone know what can be expected?

I had a hard time deciding which subforum to put this one in.

[sqlbullet]

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

Depends a lot on the load.  135's go up about 100-150 fps between 6" and 10".  200's head up about 50 fps.

[REDLINE]

Wow.  That's a good bit less than I was hoping.  I thought a 10" Contender might be cool.  Though I suppose having the ultimate chamber support possible one could handload some pretty serious ammo just for it.  Interesting. 

[Yondering]

BBTI's 10mm numbers are dissapointing, but look at the loads they tested; most are not really "full power". If you're loading your own, you may see much higher velocities than they predict, in your 10" barrel.

[REDLINE]

True.  I did consider that.  Though they did test the one 180gr load by Buffalo Bore which I wouldn't generally consider an all out slouch.  Then again the powder they use may make it a moot point anyway in terms of a 10" tube.

[Yondering]

Yep, that Buffalo Bore load looks like a hot one, but most of the others are just mid-range. Like you said, some powders will show more gain in a longer barrel; the faster powders (which would be adequate for most of those loads they tested) won't show as much gain as barrel length increases.

I don't have any information about 10" barrels, especially in a fixed breech like a T/C, but I can tell you that even 40 S&W, with the right powder, can gain 300-400 fps with a 180gr bullet between 5" and 16" barrels. I would expect gains in the 10mm to be as good or better, but subtract some of that for your mid-length barrel. Maybe as much as 200-ish fps gain is possible, as a guess?

[REDLINE]

Makes sense.

[sqlbullet]

The Buffalo Bore load on the BBTI site supports a 200 fps gain.  It jumps 179 fps between 6" and 10"

[GoldBead]

Here is some rifle data with some Contender data as well. Most loads are designed to burn in a 5 inch tube to reduce flash. Some max loads in AA#7 or AA#9 might be the ticket. I might give Underwood a look as well as they have some fast loads. You are looking for max fill of case as well as max pressure. Hmmmm Try 800x !

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[REDLINE]

Good stuff GoldBead.  It would be super cool to know what psi all the loads are hitting.