Bullet weight for AR10

[Benny]

Share the loads you are unhappy with, it may shed some light.

The load(s) I finally arrived at to use for hunting purposes in my Remington 750 in 308 with an 18" barrel may surprise you.
Everything, including factory ammo would give me a 2 1/2" group.
Of all things, I arrived at a load that gave me 3/4" groups at 100 yards using 150gr Remington PSPCL with 48.0gr of BL-C(2).
One of the most notorious short barrel semi/auto firearms reputed for jamming and poor groups using a so-so bullet with iffy powder is giving acceptable groups and function.
I tried the same powder/volume with 150gr Remington SP round nose and got the same groups but 1 1/4" higher and 1 3/4" left.

The short barrel "may" be a problem with certain powders. Not so much as to velocity loss but to even powder burn. BUT not necessarily needing a "fast burning" powder. Simply backing off of the volume may help dramatically.
My load is well below the max, I even dropped down near the minimum suggested (45.0gr) and still maintained the good groups.

By the way, the Remington 150gr PSPCL is published to have a muzzle velocity of 2820fps (probably in a 24" barrel). In my 18" barrel it averages 2630fps.
The same bullet with 48.0gr of BL-C(2) is averaging 2625fps, 45.0gr is averaging 2465fps.

[JeffreyDeGraff]

Share the loads you are unhappy with, it may shed some light.

The load(s) I finally arrived at to use for hunting purposes in my Remington 750 in 308 with an 18" barrel may surprise you.
Everything, including factory ammo would give me a 2 1/2" group.
Of all things, I arrived at a load that gave me 3/4" groups at 100 yards using 150gr Remington PSPCL with 48.0gr of BL-C(2).
One of the most notorious short barrel semi/auto firearms reputed for jamming and poor groups using a so-so bullet with iffy powder is giving acceptable groups and function.
I tried the same powder/volume with 150gr Remington SP round nose and got the same groups but 1 1/4" higher and 1 3/4" left.

The short barrel "may" be a problem with certain powders. Not so much as to velocity loss but to even powder burn. BUT not necessarily needing a "fast burning" powder. Simply backing off of the volume may help dramatically.
My load is well below the max, I even dropped down near the minimum suggested (45.0gr) and still maintained the good groups.

By the way, the Remington 150gr PSPCL is published to have a muzzle velocity of 2820fps (probably in a 24" barrel). In my 18" barrel it averages 2630fps.
The same bullet with 48.0gr of BL-C(2) is averaging 2625fps, 45.0gr is averaging 2465fps.

So far, all my loads have been with 165gr SST. I’m using LC brass and CCI primers. Powders have been W760, IMR4895, H4895, IMR4064, Varget, and RL15. I can’t remember exact charge weights at the moment (at work), but what seems funny, is that, let’s say, 40.5gr of varget will be a 3” group, 41.0gr varget will be a 1” group, 41.5gr will be 2.5”. With RL15 41.0gr 2.75”, 41.5gr 2.25”, and 42.0gr .75”.


JTD

[Benny]

but what seems funny, is that, let’s say, 40.5gr of varget will be a 3” group, 41.0gr varget will be a 1” group, 41.5gr will be 2.5”. With RL15 41.0gr 2.75”, 41.5gr 2.25”, and 42.0gr .75”.

Well, that shoots a lot of my theories in the ass!
This appears to be working on the realm of rpms per bullet length. Which I'm not up on.

[JeffreyDeGraff]

Well, that shoots a lot of my theories in the ass!
This appears to be working on the realm of rpms per bullet length. Which I'm not up on.

I think this is just turning out to be a finicky rifle.


JTD