Opinions Wanted: Barrel Choice for Suppressed SBR

[RicosRevenge]

Hey guys,

Looking at my first Grendel build and need some advice from those that have been there.

Building an Upper that will swap duties with my .300BLK upper on my SBR. This will be shot suppressed for hunting mainly (this will be my deer and pig set up here in TX) but may also get some "fun" time out to 1,000.

Questions:

What is optimal barrel length? Should I go with a 10.5" or a 14.5"?
What is optimal twist for a short barrel shooting 120-123 gr. pills?

I know absolutely no one that shoots a Grendel - I do have friends shooting 6.8 but I like to be different.

Thanks a ton!

~ Rico

[LRRPF52]

The short barrels are optimum with 1/7.5 twist, which is what AA discovered over years of testing, so all their 18" barrels and under use that twist.

If it was just hunting at normal ranges, I would tell you to get the 10.5" upper and throw a .30 cal can on it, but since you want to shoot out to 1000yds also, you are going to need more barrel length for that. 16" will just barely get you there at sea level. What part of Texas are you in? If you are in West Texas and can get into some higher elevations, you will get more supersonic reach due to thin air.

In the areas that are orange, a 14.5" with the 123gr Scenar factory load from AA will get you to 1025yds of supersonic reach. One thing I have noticed with the short barrels is that the tight twist keeps the bullet very stable at even distances past 1000yds for me, but I'm at much higher elevation as well.

A 14.5" with a TBAC Ultra 5 30 cal would be sick, and you could shoot that can on your 300 AAC as well.

[RicosRevenge]

Hey man, thanks for the reply.

Where I usually hunt is between 1,200-1,600' (near Fort Hood SW of Waco). The main purpose of this rifle is hunting from a box blind (read... "needs to be short") so don't worry about this being a dedicated LR rifle as I have other rifles for PRS and competition use.

The can is a Saker 762 which indeed gets use on several rifles including the .300 AAC (great can BTW).

I don't like to take shots on game more than 400-ish; so would a 10.5" be viable or stay with a 14.5?

Thank you!!

[lead chucker]

I have a 12.5" and love it! If I did it again I still go with the 12.5", it ballances very well even with a suppressor. A 11.5" would work quiet well also. I wouldn't go any longer than 12.5" though, if you did you might as well go to 16".

[am4966]

12.5 Lilja Nitrided barrel here, and don't have my can yet. But 100gr ttsx can get you some speed. Plus do some reading and there are others here taking copper pills and making them smaller too.

Good luck on your build.

[RicosRevenge]

Awesome, thanks guys. 7.5 twist for you guys?

[cory]

A button SS barrel only needs an 8" twist. The cut SS you're bordering on being good with an 8", best to go with a 7.5". A chrome barrel needs the 7.5".

[RicosRevenge]

I prefer SS barrels over chrome-lined. Thanks for the info!

[lead chucker]

Mine in a 12.5" SS 1:8 twist. It has shot everything from 90gn to 123gn bullets just fine, much better than I expected.

[RicosRevenge]

Well, after a hiatus created by dumping the "what she don't know" fund on a Desert Tech SRS; I am back on track with the Grendel build.

Decided to go with a JP 18" vs an SBR and do an adjustable gas block to be able to tune for the suppressor. Should have it up and running as soon as the barrel, gas block and rail arrive next week.

Thanks for the help.

~ Rico