280 AI weird groups??

[Montana'eer]

I have a fairly new .280AI. 700 trued action mated to a Brux barrel, heavy contour and in a McMillan Rem hunter stock. I had the same problem. I had found a couple powders that worked using Peterson brass and Federal TA 155 bullets. However same as you- 2 touching one flyer. At about the sane round count as you- I cleaned the barrel down to zero (completely) and took it to my gunsmith. He scoped it and about 3/4 towards the muzzle end there was a mar down the rifling about 3"-4" in length. We sent it back to Brux and apparently they failed to do the final lapping. Got it back and it's better- but not bug hole better. Sub moa at 100yds.

Check your barrel would be my advice.

 

[Jeremy Henderson]

I had the same problem with my 6BR. What I found was measuring each case I had a few that were.002 longer trimmed to the others and the flyer stopped. Hope you get it figured out.

 

[Rem81]

My 25-06ai has similar problem. First shot be the odd one. Tried all kinds of bullets and switched to hammers and problem fixed!!! Rifle only likes hammers, that's ok cause they shoot little bug holes.