Load development, Part II.

[Jimmy2Times]

So I went out today and did my second round of load development. The last time I was out, I found the load I am using grouped tightest with 44.5 gr. of IMR 4064. I went out today to refine around that load, +/- .2 grains. The rifle is a Remy 700 SPS Tac in .308 with a bedded B&C stock and USO ST-10. I'm just up to about 100 rounds through this barrel. Shooting 168 SMK HPBTs with Winchester brass and CCI BR2 primers. I'm real happy with the 44.8 gr. load. I'm going to try some Varget next and see if I can tighten things up a little bit more.

Here's the 44.8 gr. groups:

 

[Queequeg]

Re: Load development, Part II.

It isn't really a good load unless you can shoot those groups with the rifle rested on your left shoulder, pointing behind you, while holding a mirror to see the target through the scope. You know, like Annie Oakley did it a hundred twenty years ago, with an iron sighted Winchester.






Actually, it's looks like a very good load. Did you hold on the same point of the target for each respective load? It's interesting that .2 grains of difference would have them landing in such different relative positions yet common to each charge increment.

 

[Jimmy2Times]

Re: Load development, Part II.

Yep, same point of aim for each group. POA is the orange dot. I zeroed the scope on the 44.8 load when I was done. A lot of the group variation is probably me cause I suck. But I am real happy with that 44.8 load. I'm shooting from a bipod and rear bag. I can't wait to try this load at distance.

As for shooting with the other method you mentioned, forget that. I got enough trouble shooting when I'm pointing in the right direction, much less backwards.

 

[TCA4570]

Re: Load development, Part II.

What was the range?
Five at fifty should be one hole.
Three leaf clover at a hundred.
Do you shoot that close?

 

[Jimmy2Times]

Re: Load development, Part II.

5 shot groups @ 100 yards.

 

[Breeze260]

Re: Load development, Part II.

I am going through the same process with 168 Amax and varget. I found a decent group with the velocity I wanted then I started playing with the OAL. That made all the difference in the world for me, I changed it .006 the group went from .654 to .359...... something for you to look at.

 

[Breeze260]

Re: Load development, Part II.

Are you using a chronograph? The .609 group looks like the flier that went high was velocity and maybe the one that went right was the shooter which tightens that group right up. I would try that load a few more times and try to hold that same (cheek weld, grip pressure).....Good luck