338 lapua reloading help

[cb4128]

Am at a cross roads in my 338 lapua reloading process - I worked up to max in .5gr increments at 100 yards and had 2 good loads - 1 was at 89.5gr (about 3/4" in a triangle) and 1 at 90.5gr (.4 - 2 in 1 hole and 1 just lower).

So, I revisited the 90.5gr and adjusted my seating depth; but with my magnetospeed attached to get velocity spreads. My groups were terrible, but I had 1 really good velocity spread at .090" off the lands - SD-3, ES-7 (2,749 fps avg)

*First thought is to load up that same 90.5gr load at .015" off and .090" off and see which one groups better (without the magneto attached, as it definitely affected my groups on this rifle)

**Does anyone have any suggestions that I should try?

Current load recipe:

Lapua brass
Federal 215m primer
300gr Berger Hybrid
90.5gr of H1000

I also have Retumbo to try, but wanted to continue down this path for now as it shows promise and I know several guys have had good luck with the H1000 powder with these components.

 

[dougduey]

The MagnetoSpeed can definitely mess with POI and grouping. Shoot without it on and see if the issue goes away. I always shoot with it on when starting out the load process to find max and see what kind of velocities I'm getting, then I take it off and don't use it until I'm pretty much done with the load or need velocity verification or checking how stable the velocity is for a certain load. I look for a velocity node where the velocity flattens out. Then I'll load up 10 rounds in the middle of that flat spot and see how it groups with 5 shots and then put on the Magneto for the next 5 shots and see what my ES and SD are for velocity. If I have good ES and SD but the groups aren't as tight as I'd like, I'll adjust seating depth.
H1000 and Retumbo are the best powders for the 300 gr bullets in the Lapua, so stay with H1000

 

[cb4128]

ok great, thanks!

 

[QuietTexan]

Start a new thread for your questions please.

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