05-03-2022, 04:55 AM
First time Grendel owner being guided through starting hand reloading by someone else with no Grendel experience. Working with a home built AR with a new barrel from a reputable manufacturer. I know and understand I have started with a "potbellied" bullet thanks to the ogive of this heavy projectile. This may be the root of my problem. I have loaded some loads and want to poll those that know:
(1) Is the load below safe to fire with such a short COAL?
(2) Is the developed COAL short enough I should be concerned for the reamed dimensions of the chamber, being an unfired barrel? I have no gages. Should I speak to the supplier about it?
Unfired, virgin Starline brass fits in chamber and extracts fine.
I see on the forum how an AR Grendel load for Hornady Interlock is expected COAL=2.245" but I can't come close to that and lock bolt lugs. Then extraction leaves the bullet in the barrel, dumping powder. I seated deeper and deeper until the round fit in with a firm fingertip press of the bolt carrier rear to close and lock lugs. Hand extraction by charging handle is now easy and smooth.
Concern: COAL is 2.131" - way off from what I expected. Nearly bottomed out the dye bullet seat adjustment.
Powder can be heard shaking just a little inside the round, so powder is not compressed. No crimp yet but doesn't seem to be the problem. Load data below.
Starline brass (virgin)
Hornady 129gr Interlock SP
25.0 gr AR Comp
CCI 450
Case trim length: 1.510"
COAL: 2.131"
I had to go this short to close the bolt and not pull the bullet on extraction. Again, no neck crimp yet.
Thanks for your help!
Neph
(1) Is the load below safe to fire with such a short COAL?
(2) Is the developed COAL short enough I should be concerned for the reamed dimensions of the chamber, being an unfired barrel? I have no gages. Should I speak to the supplier about it?
Unfired, virgin Starline brass fits in chamber and extracts fine.
I see on the forum how an AR Grendel load for Hornady Interlock is expected COAL=2.245" but I can't come close to that and lock bolt lugs. Then extraction leaves the bullet in the barrel, dumping powder. I seated deeper and deeper until the round fit in with a firm fingertip press of the bolt carrier rear to close and lock lugs. Hand extraction by charging handle is now easy and smooth.
Concern: COAL is 2.131" - way off from what I expected. Nearly bottomed out the dye bullet seat adjustment.
Powder can be heard shaking just a little inside the round, so powder is not compressed. No crimp yet but doesn't seem to be the problem. Load data below.
Starline brass (virgin)
Hornady 129gr Interlock SP
25.0 gr AR Comp
CCI 450
Case trim length: 1.510"
COAL: 2.131"
I had to go this short to close the bolt and not pull the bullet on extraction. Again, no neck crimp yet.
Thanks for your help!
Neph