Accurate load falls apart after 100

[Grizz1148]

not a novice. ran into something I haven't seen before. Long story short..fired 3 diff bullets today out of the same cases, same primer, same powder just testing and playing. 26 Nosler 140 smks, 135 atips, 143 eldxs, smks and atips under 1/2 moa at 100 eldxs just over 1/2 moa. Took the smks and eldxs out to 250 and they both opened up to 4". As a control for wind we shot groups at 250 with a 243 and 6.5x47 that shot well. Anybody seen this before? Couldn't test the atips as I didn't load enough but the smks have consistently shot 1/2 or better at 100. I'm going to try them again but I'm curious if anyone else has come across this. Thanks

 

[RockyMtnMT]

What is the barrel twist? You might want to check it manually.

 

[Grizz1148]

Christensen traverse 1/8

 

[ATH]

Loads accurate at close range can fall apart farther out if your velocity is not consistent enough, but this is an awfully big change for only 250 yards. Seems more like a stability or shooter issue.

 

[Grizz1148]

Loads accurate at close range can fall apart farther out if your velocity is not consistent enough, but this is an awfully big change for only 250 yards. Seems more like a stability or shooter issue.

I would agree with the shooter issue but I'm not a novice, I'm not a competitor but I shoot more in one week than most in a year. Thousands of rds a year through many guns and I've never seen this. I also know everyone can have a bad day but I just shot the 100 groups an hour earlier. Stability I guess is a possibility but how would unstable bullets shoot consistent 1/2 or less at 100?

 

[aushunter1]

Have you actually crony'd these loads to check the ES/SD?

 

[Grizz1148]

Have you actually crony'd these loads to check the ES/SD?

Yes and no. I did the atips with good numbers, did not with these 2 but 250 yds is very close range and I wouldn't think es and sd would make this extreme diff especially with a 26 Nosler. Also, the groups weren't just vertical or just horizontal, were both.

 

[L.Sherm]

I had the similar situation happen last weekend with a 6.5x06AI literally 1 hole at a 100 and 6" at 500. A .020 seating depth change brought it to .5 m.o.a at 500

 

[Grizz1148]

I had the similar situation happen last weekend with a 6.5x06AI literally 1 hole at a 100 and 6" at 500. A .020 seating depth change brought it to .5 m.o.a at 500

Good to know. I'll test that.

 

[L.Sherm]

Hows your vertical? Switching to a different primer could help also.

 

[RockyMtnMT]

Be sure and post your results. My jury is way out on the CA rifles. My sample is small but not good. Seems everyone on the net shoots bench rest groups with theirs.

 

[B-LOT Banga]

This happened to me this morning!! I shot my 28 Nosler and got a sub MOA group at a 100 yds.... stepped it out to 400 and got stupid groups. Everything the same, thinking something went wrong I went back in and but made a duplicate sub MOA grouping.

Thinking it was shooter error I shot my other rifles and made sub MOA groups at 100 and at 400 yds. But they were shooting Berger's, Cutting Edge and Matrix bullets only the Hornady 162 ELDX gave me problems. I will load more tonight and double check all measurements and weights to eliminate things.

Here below are my groups... the 1st group is the 100 yd group and the other pic is 4 shots at 400 yds (circled) and the 3rd Group has only 3 shots (not circled) before I stopped frustrated. The other rifles and bullet combinations worked as expected. This got me messed up in my head... what could be my problem?!?! I wouldn't rule out shooter error but why not with the other rifles?

 

[Grizz1148]

Hows your vertical? Switching to a different primer could help also.

That's the odd thing, vertical and horizontal were poor. Basically a 4 inch box pattern. I could understand if it was one or the other but not both. It's killing me that I can't go back and test it again right now lol.

 

[Grizz1148]

Be sure and post your results. My jury is way out on the CA rifles. My sample is small but not good. Seems everyone on the net shoots bench rest groups with theirs.

I have 2 and both shoot well but with work to get the results I'm happy with. This one I had to slow down to get it to start cooperating.