Thoughts on this here OCW

[DrewC]

I shot this test today and just want to see what others think is the area I should explore. Gun is a .308 tobr with a 16” barrel. Varget was the powder. I’m thinking 43,.2 is in the middle of the node. Oh and in case it helps the mv’s average per group were 42.8 - 2480. 43.0 - 2490. 43.2 - 2491. 43.4 - 2510 and 43.6 - 2512. That was using a Magnetospeed V3.

 

[spife7980]

I would do that and confirm it with .1 increments up .2 each way just to make sure it’s not a fluke. I would also shoot those without the magneatospeed speed on it unless it’s a rail mounted one.

 

[BearNaked]

^^^^^^^^^^^

what Spife said. you are in the right ball park.

 

[DrewC]

Well I went and shot another round and 43.2 is right in the middle. Chrono’d a final five shot string which gave me Single digit ES and SD. Velocity was 2492 which kind of seems fast for a 16” gas gun shooting 175 smk’s.

 

[nexusfire]

43gr of varget over 175 smk works in most 308's

 

[DrewC]

I’m starting an OCW test with 168 eld-m’s using Varget and LC brass. Same brass I used for the 175 smk’s. I’m using 2.800 as the oal. I started at 42.6 and went up to 44 gn’s. I started to get compressed loads or what at least felt like it when I got to 43.7 of Varget. Is this normal? I know the 168’s are a tad longer but looking around at others loads it seems like I shouldn’t be running into this. I was figuring my OCW would be between 43 and 43.6.

 

[JimmyT]

43.0 grains of Varget is lights out in my AR10 (Straight Jacket barrel System frankenrifle).

 

[Deleted member 113831]

43 grains - 43.4 grains is your low node and isn't in the optimal pressure range for that combo. However, in gas guns the low node often shoots the best. You notice the major POI shift at 43.6 grains. This is where this combo comes up to optimal pressure.

In bolt guns, there is often an accuracy node in the 43.5 grain - 44 grain range. My bolt gun load is 43.7 grains in heavy brass like LC, Federal and Lapua and 44 grains in Winchester brass.