450Bushmaster.net

45r wrote:I decided to get an 18 inch 6.5 Grendel barrel and bolt.Got to decide which upper receiver and rail now.
The accuracy and ability to shoot better at long range and several here like the 6.5G helped with the decision.
Thanks for the replies.

I used a DPMS Lo-Pro for the added stability, but I suspect just about any one will serve you as well.


FWIW, I got the 24" ER Shaw 6.5G barrel w/AA bolt. Slower powders like AR-Comp, benefit from the extra length. Though it's not a punishing caliber, I have a Ross brake on the end. Allows me to hold the sight picture in the scope up to about 16x after each shot, without having a death grip on it.

Throws 5-shot, 100yd groups like this off of a BR setup:



Hoot

That's an awesome group.

Hoot wrote:

45r wrote:I decided to get an 18 inch 6.5 Grendel barrel and bolt.Got to decide which upper receiver and rail now.
The accuracy and ability to shoot better at long range and several here like the 6.5G helped with the decision.
Thanks for the replies.

I used a DPMS Lo-Pro for the added stability, but I suspect just about any one will serve you as well.


FWIW, I got the 24" ER Shaw 6.5G barrel w/AA bolt. Slower powders like AR-Comp, benefit from the extra length. Though it's not a punishing caliber, I have a Ross brake on the end. Allows me to hold the sight picture in the scope up to about 16x after each shot, without having a death grip on it.

Throws 5-shot, 100yd groups like this off of a BR setup:



Hoot

I just ordered the same DPMS low pro and mid-length gas tube and Hornady dies.
Still waiting for barrel/bolt.
Getting bolts seem to be slowing that down.
That is a very good group.
Hope my 6.5 barrel shoots that good.
My last 5 shot group from my 450 BM went 3/4 inch.
It's the first ragged hole group I've shot with something in an AR that kicks.

Yes, more often than not, the bolts are what hold up the combo kits. It'll be worth the wait though.

Hoot

I use that same upper on my 6.8. It is definitely beefier and a little wider than the standard M4 style upper.

Wonder if the receiver needs to be squared.
Was your barrel a tight fit.
Some accuracy guys say they bed the barrel to the receiver with blue locktite.
Still got to pick out a rail.
Since the dpms low pro is thicker it needs a rail that doesn't use anti rotation tabs that index off the receiver.
I like Samson rails but I'd have to dremel the receiver where the tabs index.
The new MI keymod looks good.
It uses the barrel nut to index tabs.
I think the extra gas block that I took off my 20 inch 450BM barrel will work.
It's small enough.
Any suggestions on what might work better.

Blue locktite won't help, and may hinder accuracy. A tightly fit extension to receiver is the best, but finding receivers with undersized bores is tough. Then you can Thermofit the extension to receiver. If you have a loose fit, Rockset can be used. Don't be shy about going into the 70 to 95 ft-lbs range for barrel torque if accuracy is your goal.

If you use a .750 gasblock, this one is pretty good. http://www.carbonarms.us/Carbon-Arms-Gas-Block.html

MarkCO wrote:Blue locktite won't help, and may hinder accuracy. A tightly fit extension to receiver is the best, but finding receivers with undersized bores is tough. Then you can Thermofit the extension to receiver. If you have a loose fit, Rockset can be used. Don't be shy about going into the 70 to 95 ft-lbs range for barrel torque if accuracy is your goal.

If you use a .750 gasblock, this one is pretty good. http://www.carbonarms.us/Carbon-Arms-Gas-Block.html

Pretty Good (?), My Took-Us, this is my go to gas block, when an out of spec barrel is being used (one that would be normally be scraped) and when I am trying to achieve phenomenal accuracy results!!

..t

Well, you learn something new every day! I've never seen a side screw gas block. Makes good sense on several planes.

Hoot

My brother has a 6.8 and reloads all types of rounds. As far as reloading, I see a little more variety in 6.8 options, but I would be happy to shoot or reload either one. From a hunting point of view, he's killed a few deer and hogs with his 6.8 and a friend has killed a doe with his grendel, but I don't think it's worth the tracking effort for either. Both the 6.8 and 6.5g to me is much like a .243.. great for foxes and such, but when the grown buck is in the crosshairs, I'd pick up a 30cal + any day.. The 6.5 is the more long range accurate weapon of the two.