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Run in load.
Posted: Tue Dec 27, 2016 9:31 am
by scott/r
Just wondering what I should load for running in a new barrel. I've never run in a new barrel before, so I did all the searches here for cleaning procedures and that's all cool. But I couldn't find anything as to what sort of loads to make up. Do I make soft loads or heavey ones or what? It's a 32" medium palma in 308 and I'll be sizing new cases at the same time, so my thoughts were for a soft load because of the cases. But am I doing the right thing for the barrel?
Re: Run in load.
Posted: Tue Dec 27, 2016 10:26 am
by DenisA
I'm about to start running in a new .308 barrel and fire forming some brass at the same time Scott.
I believe it's important to make sure the case base is square against the bolt face so that the brass flows forward evenly meaning a jammed seating. I won't be using a hot load on fresh brass as the base and head need to be work hardened for better case life, but I won't be using a mild load either because I want the fire forming to be consistent. I'll be fire forming with moly coated Hybrids. Hybrids don't leave much bullet in the case and have a shorter bearing surface, so I'm expecting that jammed moly coated hybrids will give a kinder pressure curve.
My fire forming/barrel break in load will be moly coated 155 Hybrids jammed .010". 45gn ar2208. The first couple will be a slightly lighter charge just to check for pressure signs, unlikely though I think.
I'm hoping the moly will also make the copper removal between shots quicker and easier to remove. I did this recently with a new 300wsm barrel and 210 VLD's moly coated and it seemed to work well.
I will be running coated bullet for the life of this barrel.
Re: Run in load.
Posted: Tue Dec 27, 2016 10:42 am
by scott/r
I was thinking of using 44.5 grn of my 2206h with the 155.5 fullbore bergers. Which would be about the same sort of pressure as you've got with 2208 and moly. I was only going to sit them on the the lands, but that's a good point about having the case up hard on the bolt face. Thanks Denis.