Need help with groups...please!

[Goobie270]

I've been doing some load development for a rem 308 milspec. I'm using lapua Palma cases, gold math primers, imr 4064, and hornady 178 hpbt at an overall lenght of 2.830. A couple weeks ago I did a ladder test from 39.7 to 43.7.gr at 380 yards. The 42.2 to 43.7 all was grouped in and 1.5 inch cluster. So today I went and shot a 4 shot group of 42.2, then up in .3 gr increments to 43.7

42.2

42.5

42.8

43.1

43.4

43.7



There was absolutely no wind, and I was very confident with my shooting so I'm kinda lost on the direction to go. So should I load more around the 42.8 gr and try different seating depths or what. Thanks.

 

[Rich Coyle]

Generally I go for seating depth first with a moderate load.

 

[codyadams]

I've been doing some load development for a rem 308 milspec. I'm using lapua Palma cases, gold math primers, imr 4064, and hornady 178 hpbt at an overall lenght of 2.830. A couple weeks ago I did a ladder test from 39.7 to 43.7.gr at 380 yards. The 42.2 to 43.7 all was grouped in and 1.5 inch cluster. So today I went and shot a 4 shot group of 42.2, then up in .3 gr increments to 43.7

42.2
View attachment 99845
42.5
View attachment 99846
42.8
View attachment 99847
43.1
View attachment 99848
43.4
View attachment 99849
43.7
View attachment 99850


There was absolutely no wind, and I was very confident with my shooting so I'm kinda lost on the direction to go. So should I load more around the 42.8 gr and try different seating depths or what. Thanks.

42.8 seemed decent, about 2"? that is near half MOA. From my personal experience however, I have not had good experience with IMR 4064 in a .308.....I prefer Varget, and have heard good things about CFE .223, but have not tried it myself. I also got excellent results with Reloder 17 with heavier bullets, though of these Varget is the only one deemed temp stable.

To look into other aspects, did you do anything different? Bullet or powder lot, was temperature different when shooting, different rest, was the lighting possibly different and not helping, or was your scope parallax possibly off?

 

[Canhunter35]

Are those groups at 400 also?
I would do some seating depth tests, backing your bullet into the case because at 2.83 would be max magazine length. Go down to 2.8. I would use your 42.8 load and do the seating depth tests.
My milspec likes 168s at 2.805"
I also use varget and have used 41gr for 178amaxs and 200gr eldx with great success

 

[Goobie270]

Thanks guys. Yes those groups are shot at 380 or so. Everything I did and used were the same when I did my ladder test. Does that seem likely that I just need to play with seating depth and it could shrink my 42.8 group with such horrible groups below an above the 42.8.

 

[MudRunner2005]

Try using Varget powder.

 

[Goobie270]

I'm very excited because I never understood or took into account parallax. I'm betting I didn't have it set right. I just turned the knob until it was focused on my eyes.

If I didn't have my parallax set right could this have made my groups that spread out?

 

[codyadams]

I'm very excited because I never understood or took into account parallax. I'm betting I didn't have it set right. I just turned the knob until it was focused on my eyes.

If I didn't have my parallax set right could this have made my groups that spread out?

If you didn't have a very consistent cheek weld....absolutely. the focus should be set with the eye piece, the paralax with the side knob.

 

[Goobie270]

I thought I had a good cheek weld, but maybe had horrible parallax still and didn't notice it

 

[Goobie270]

Ok everyone I shot my same loads just seated deeper to 2.805 and all groups shot the same.. All erratic except 43.7, it was a group of 2 inches, 5 shots at 385 yards. I'm very happy with that, but should one try more seating depths to get better or is that about it?

 

[dsculley]

I would run the Berger Seating Depth Test. You can find it on this site or on the Berger site. This test is in coarse steps. After locating the best area with the Berger test, then test around that seating depth in small increments.

 

[Rick Richard]

Very worth while running the Berger Seating Depth Test.

 

[MudRunner2005]

Ok everyone I shot my same loads just seated deeper to 2.805 and all groups shot the same.. All erratic except 43.7, it was a group of 2 inches, 5 shots at 385 yards. I'm very happy with that, but should one try more seating depths to get better or is that about it?

View attachment 100468

You don't want to push the bullets in deeper... If anything you want to pull the bullets out of the case and closer to the lands for better accuracy/consistency. The closer to the lands, the less wobble and jacket distortion you will get as the bullets pushes into the leade.

 

[Canhunter35]

Ok everyone I shot my same loads just seated deeper to 2.805 and all groups shot the same.. All erratic except 43.7, it was a group of 2 inches, 5 shots at 385 yards. I'm very happy with that, but should one try more seating depths to get better or is that about it?

View attachment 100468

IMO, the top 3 shots represent the group and bottom two are shooter error. It is four hundred yards, 2" group is .5moa. My 700 milspec best load/group is 1.35" at 400 with 5 shots. It's pretty easy for me to let one slide out to 2" many times.