Anyone else shooting 6.5 CM in the AR platform? I've seen a lot of info on the net regarding reloading 6.5 CM, but not a lot of hard data for gas guns. Most of the posts regarding gas guns are opinions or anecdotal.
Tried a few different factory loads and settled on Winchester Match 140 grain. Though by far Lapua is my favorite brass, I do like Winchester better than most. Here's a 3-shot bug hole and a relatively tight 5-shot group at 100 yards:
Once I have enough brass, I'll wean myself away from the factory ammo. This morning I finally tested some hand loads. Not a bad day for first time reloading 6.5 CM:
Stupid Iphone has the photo turned, but best group in what should be upper right . Worst group center with Magnetospeed attached.
Self-built AR-6.5 CM with a 20" tapered target barrel, 100 yards. Using the JP High Pressure BCG.
Tried Nosler RDF 140's with IMR 4350 and Hornady 123 ELD's with Varget. Best group upper right was the Hornady ELD's loaded .005" jump off the lands. Varget, close but under max load per Hodgdon specs. No signs of overpressure on cases or primers. Once fired Winchester brass, still in spec so no need to trim yet. Need to download the chrony data, but as I recall the ES was very low.
The RDF's were not that great with groups slightly above 1 MOA. I think the IMR 4350 was part of the problem- too much variation in velocity. It's supposed to be near identical to H4350 but a little less temperature stable.
I have read that 6.5 CM in gas guns favored bullets lighter than the 140's and that the Hornady 123's were particularly good for the AR-308 platform. If you search 'Varget for 6.5 Creedmoor', you'll see one or two favorable posts followed by a few dozen posts about how H4350 is supposed to be the best. My theory was that in a 20" barrel, especially a barrel with gas port; the faster burning Varget would be better matched to the system as well as the lighter projectile. Today's results are at least one data set in favor of that.
Tried a few different factory loads and settled on Winchester Match 140 grain. Though by far Lapua is my favorite brass, I do like Winchester better than most. Here's a 3-shot bug hole and a relatively tight 5-shot group at 100 yards:
Once I have enough brass, I'll wean myself away from the factory ammo. This morning I finally tested some hand loads. Not a bad day for first time reloading 6.5 CM:
Stupid Iphone has the photo turned, but best group in what should be upper right . Worst group center with Magnetospeed attached.
Self-built AR-6.5 CM with a 20" tapered target barrel, 100 yards. Using the JP High Pressure BCG.
Tried Nosler RDF 140's with IMR 4350 and Hornady 123 ELD's with Varget. Best group upper right was the Hornady ELD's loaded .005" jump off the lands. Varget, close but under max load per Hodgdon specs. No signs of overpressure on cases or primers. Once fired Winchester brass, still in spec so no need to trim yet. Need to download the chrony data, but as I recall the ES was very low.
The RDF's were not that great with groups slightly above 1 MOA. I think the IMR 4350 was part of the problem- too much variation in velocity. It's supposed to be near identical to H4350 but a little less temperature stable.
I have read that 6.5 CM in gas guns favored bullets lighter than the 140's and that the Hornady 123's were particularly good for the AR-308 platform. If you search 'Varget for 6.5 Creedmoor', you'll see one or two favorable posts followed by a few dozen posts about how H4350 is supposed to be the best. My theory was that in a 20" barrel, especially a barrel with gas port; the faster burning Varget would be better matched to the system as well as the lighter projectile. Today's results are at least one data set in favor of that.
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