6mm Creedmoor help

[Laceygm]

Need some help with a load.

I worked up a load for my 6mm CM that was shooting pretty good last week. Took the load out today and was all over the place, showing pressure signs and SD was in the 30s. Temperature was similar but was 1000’ higher in elevation.

Load is 105 gr Hornady HPBT Match, 41.8 gr H4350, CCI 41 primers and Lapua small primer. 2.727” OAL.

I can’t find much info using Lapua brass.
According to Quickload I’m on the high end of the pressure curve, but under SAAMI max.

Anyone using these components that is willing to share info would be appreciated.

 

[BuildingConceptsllc]

Not that bullet but a Berger 108 and I've run 4350 with it and been right there. I run a little bit more than that now with staball. Like you said, you are on the higher side but I wouldn't think you're over max but , each gun is different. How many rounds are on the barrel? Does the barrel need to be cleaned?

 

[Laceygm]

Not that bullet but a Berger 108 and I've run 4350 with it and been right there. I run a little bit more than that now with staball. Like you said, you are on the higher side but I wouldn't think you're over max but , each gun is different. How many rounds are on the barrel? Does the barrel need to be cleaned?

200 rounds through the barrel.

 

[BuildingConceptsllc]

200 rounds through the barrel.

I'd clean it then first and see if that fixes your issue. They tend to pick up more carbon and copper in that first however many rounds then settle out. The other thing is neck tension on your brass. If you didn't run it through a mandrel initially, that could also be a contributor, just having some different neck (interference fit) tensions.

You are at the upper end of pressure though so keep that in mind.

 

[Laceygm]

I'd clean it then first and see if that fixes your issue. They tend to pick up more carbon and copper in that first however many rounds then settle out. The other thing is neck tension on your brass. If you didn't run it through a mandrel initially, that could also be a contributor, just having some different neck (interference fit) tensions.

You are at the upper end of pressure though so keep that in mind.

Just a heavy brush and jag cleaning or copper removal?

 

[BuildingConceptsllc]

Just a heavy brush and jag cleaning or copper removal?

I use a nylon brush and a jag combo with bore scrubber and it gets very clean. I don't use any metal brushes.