6.5 CM Proof CF barrel load development

[SmokyJoe]

Did some load development today in a new 6.5 CM 22’ Proof CF barrel. LRI cut a Berger chamber for it, with the shorter throat, optimized for the Berger 140gr Hybrid. While waiting for some new 140’s to arrive, I loaded Berger’s 130gr Hybrids in three lengths: 0.010”, 0.040” and 0.090” off the lands. I had already done a ladder indicating a node at 43.0gr of H4350 with an average velocity of 2767fps. Results at 0.010” off the lands were much better than the other two lengths.

The first 60 rounds through this barrel did not group very well, averaging about 1.2moa. I previously have used Bartlein barrels, (medium palma) which would settle in to excellent groups after about 20 or 30 rounds. I decided to try the Proof to shave some weight. Running another 45 rounds through the Proof barrel today showed approx 0.5moa groups, as shown in the attached photos. Still need to work on my technique, but this looks promising for the 130gr Berger Hybrids. Next up will be the Berger 140gr Hybrid and the Barnes 127gr LRX

RIFLE:
Defiance Hunter action
Proof 22” CF barrel
LRI 6.5CM Berger chamber
Manners EH1 with chassis
Kahles k312
Weight: 10.5lbs loaded

LOAD:
Berger 6.5 130gr Hybrid
43.0gr H4350
Prime brass, neck turned to .0145” thickness
210M primer
COAL: 2.774"
0.010” off lands
Avg. Velocity: 2767fps
Groups avg ~0.52moa

Berger 140gr Hybrid
41.4gr H4350
0.010" off lands