AR10 barrel- 1/10 or 1/11.25 and why?

[HRider]

I am building another Large frame rifle. It will be primarily used for HeMan Iron, but will be a flat top, so I can mount a scope on it and shoot other matches. I am looking at a Critierion 20" stainless rifle gas barrel. They call it a hybrid profile, it has a .750 gas journal an is 1/11.25 I believe. I have looked at other barrels also. I have an old Armalite AR10 that has a 1/11.25 barrel and is very accurate. Besides having more torque, what should I expect out of a 1/10? What am I giving up now if anything?

Thanks,

Hurley

editbto add: It will be 7.62x51

Edited May 8, 2018 by HRider

[wgj3]

Slightly slower twist will let you run the lighter bullets (110-125gr) a tiny bit faster and you won't give up anything to the extremely heavy stuff (over 175/178gr) since they are far from ideal in the gas guns.

[tact]

175s are super sweet in an 1/11.25, but I imagine in comps you are not sending 175s.

[Matt in TN]

I have a 1:10 that shoots 125gr very well.  It also shoots 175gr very well.  And 155gr.

 

So I don't think you're giving anything up by going 1:10.