45 ACP Carbine Barrel Twist

[arrowshooter]

One of my ponderings as we get muddled through the whole AR Pistol "Brace" thing is picking up a 16" 45 ACP barrel to convert a pistol to a carbine. I have come across some differential in twist rates and I am looking for some possible experiences with this animal. I see that the 1:16 twist seems to be the standard, but there is one company making a 1:10 twist (got no idea why). Since I will be running predominantly 230 gr plated round nose bullets the 1:16 seems like the best choice to keep the bullets intact, but availability may push me to the 1:10. Odds of getting a 1:16 are good right now, but in a couple of months I could be stuck with the 1:10. Is anyone running a 16" 45?

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[Member 34319]

What comes standard on things like the Tommy Gun or Kriss Vector? I'd go with that. I'm thinking the 1/10 was made for sub 16" barrels.

 

[TTSX]

Even my 8" barrel uses 1:16, so I'd just stick with that. HOWEVER, my M&P 45 with a 4" barrel uses a 1:10 and handles 185gr bullets just fine. My Glock 21s and 41 all have 1:16 barrels so my opinion is that 1:16 is the standard to follow but the 1:10 won't cause you problems

 

[kopcicle]

If ever you want to experiment with heavier than 230gr get the 1:10.
If you ever want to experiment with lighter than 185gr get the 1:16.

Also, a good place to experiment (carefully) with slower powders like IMR or H-4227 as the 16" gives you time and volume to burn slower powders.

As something of a safety measure the near rifle powders like 4227 and the somewhat touchy 296 if overloaded simply expend the over charge as a YUUUUGE fireball rather than pressure issues. Underloaded 296 has long, loud, and significant cautions, YMMV or simply explode. Also, firing dedicated carbine ammunition in a pistol can be an issue.

If you want to play, reload in modified rifle brass. I preferred 6.5 x 55 Swede. I don't think I have to mention that once you start messing with chamber pressures over 17,000 psi you need some way to positively segregate ammunition.

 

[arrowshooter]

Good points kopcicle. I do not see myself going over the 230 gr pills. My current loads are the Xtreme Plated and XTP's over 5.5 gr and 5.7 gr of HP-38 respectively. These loads work very well in my pistol pistols along with the 10.5 " barrel. Plan is to start there with the hopes of staying with one load fits all.

I'ma gunna git the 16 twist and if I decide to push a little more speed with 185's I'll be good.

Thanks for the input guys.

 

[kopcicle]

And now for something completely different...

Mauser 45 ACP Conversion Kits-Military – Rhineland Arms

www.troupsystems.com

 

[kmk1012]

And now for something completely different...

Mauser 45 ACP Conversion Kits-Military – Rhineland Arms

www.troupsystems.com

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Neat! I have a Lee Enfield that's been converted to 45ACP and uses 1911 mags. I love that thing.