Alexander arms 6.5 grendel barrel

[crossNcrew1718]

Thinking about building a new 6.5 grendel upper for my colt lower. This barrel from Alexander arms is a 20" advantage barrel with a 1/9 twist. Says it’s good for lighter ammo, I’m assuming it’s talking about 123gr? I’m also assuming it’s CMV, there was no info I could see about it being SS or CMV. Anyone have any experience with this barrel? Should I be looking for a stainless? I plan on doing long range bench rest and taking this into the woods for hunting. Thanks for your replies in advance!

 

[ichigo]

I don't have experience with the barrel that you mentioned but with my build I use the BA 20" 6.5 Grendel DMR fluted (type 2). The fluted barrel was able to reduce the weight and still maintain the accuracy.

just a side note that your bolt type should match your barrel.

 

[crossNcrew1718]

I don't have experience with the barrel that you mentioned but with my build I use the BA 20" 6.5 Grendel DMR fluted (type 2). The fluted barrel was able to reduce the weight and still maintain the accuracy.

just a side note that your bolt type should match your barrel.

I’m do know about the bolt face needing to match. Actually AA sent me an email explaining everything about it that was pretty informative. I was more concerned with wanting a stainless barrel over cmv. The kit comes with the BCG so that’ll take some of the work out of getting it built. Thank you for your reply brother!

 

[bigjake83]

Thinking about building a new 6.5 grendel upper for my colt lower. This barrel from Alexander arms is a 20" advantage barrel with a 1/9 twist. Says it’s good for lighter ammo, I’m assuming it’s talking about 123gr? I’m also assuming it’s CMV, there was no info I could see about it being SS or CMV. Anyone have any experience with this barrel? Should I be looking for a stainless? I plan on doing long range bench rest and taking this into the woods for hunting. Thanks for your replies in advance!

No, 123's are actually on the highest end of what the Grendel will shoot you going to be geared for the 107 SMK

 

[bobke]

Unless you’re wanting to stay primarily in the lower weight range, 1:8 will handle that, as well as up through 129/130’s. Lots of good stainless button barrels from Wilson Combat, Lilja, JP and others, but if you step up to a cut rifled barrel, Bartlein, Krieger, Satern are worth the additional cost in accuracy and longevity. Not certain if there are cut rifled CMV barrels in stock out there, and you could surely have one spun up, but most of the better barrels are run in SS. Seven Grendel’s worth of experience tell me so.

 

[Greg Langelius *]

Recent (very) experience with a 24" Grendel barrel (AR Stoner/Liberty?), tends to make me suspicious of barrels that long for the 6.5G.

IMHO, the issue is the bolt face mods made to adapt the AR-15 base diameter and accept the 6.5G/x39 base. The net effect is a weaker Extractor. I had been wondering why published charge weights are so limited. Well; last Thursday I tried a load with .3gr over published max and found out why. My Extractor snapped at the junction between the claw and the shaft.

Shame on me, I violated a basic load development rule; staying within published load data limits.

I think the extended barrel length becomes significant to this issue because it extends dwell time significantly, turning a rule violation into a perfect storm.

I also have a 20" version of the same barrel model (and a spare). I will not be exceeding published charge weights as I continue developing a load; but somewhere along the way, I expect the shorter barrel length/dwell will be beneficial.

The 24" gun is waiting delivery of a JP Improved 6.5 Grendel Extractor. For the 24" rifle, I will be doing development with the 90gr TNT instead of the 120gr Gold Dot. I think the 90gr TNT might work better with the reduced pressures, and that the 24" will be more appropriate to the varmint style bullets.

So...; I think the 20"bore length is shaping up to be a more ideal upper length limit for the 6.5 Grendel in an AR platform and heavier bullets.

I can't truly specify a good idea about 1:8" vs 1:9" twist rate. My main experience with the 6.5 has been with the 260 and longer 1:8" barrels. Lately; 150gr 6.5 bullets are becoming popular. There is some doubt about whether 1:8" is enough twist; at any rate it appears to be getting to a critical point and dependent on the bullet lengths, barrel lengths, and velocities involved. Some popular wisdom suggest that stability is influenced by bore length and muzzle velocity; and I'm sympathetic to that popular wisdom. I think that the length, bullet, and velocity of that barrel could make for interesting times.

Greg

 

[steelheadr99]

I have 24" AA barrel and I have shot to 800yds with 123gn Hornady Black and it has performed with no problems. It is the 1/9 twist.

 

[Greg Langelius *]

This AM, I relented; and I bought two pounds of TAC.

My buddy keeps reminding me he told me not to use W748, and try 8208BRX. Well that schtuff is O/O stock everywhere.

The TAC is available, cheaper, and seems to have a lot more of a following than W748. Can't really justify the substitution of TAC for the 8208, but there it is; I have a 'better than W748' powder inbound.

Further research seems to indicate that neck sooting may not be the result of insufficient powder charge to achieve a neck seal, but rather, early unlocking while residual powder is still burning, and could also explain crappy accuracy.

I've used TAC before for lightweight bullets in 308 and 260; and I really like the way it meters. Price under $25/pound helps, too. I suspect it will fill/settle better, and reduce compression of loads. Speer lists TAC at min/max 25.1/27.9 2267/2468fps for the 120 Gold Dot. The only reason I dropped Ramshot (mostly, I used Big game and Hunter) was becuase it kept going out of stock at my local suppliers.

Oh, well; once more back into the fray...

Greg