This is the 2nd step in the load development process. The 1st step was to blow out the brass with Bullseye and play dough using an old barrel. Next time I’ll use wax instead of the play dough. This time I loaded a mild charge and then started working with the bullet seating depth. These were the best results of the day. I’ll finish shooting the rest of the brass with this load to complete the brass forming. The next go-around I’ll work up to the max charge and should find a sweet spot somewhere just north of 3000 FPS. We’ll see…
I went to the range this morning, to get chrono readings and to see if the case lengths made a difference. Lot 1 & Lot 2 case lengths are 1.500” & 1.490” respectively. Temperature was 60°F and very humid.
numbers look too close to call for me, targets are all very good. I don't know how one would pick one or the other...or how anyone can trim that accurately to get them all to 0.001" I know I can't! LOL
Looks like she's a shooter though, and again, a good driver makes all the difference! Well done!
Hi Shane, re: the charge, 51.00 on the Harrells averaged out to 28.0 grains, but then that will vary with humidity. So, on my next outing I’ll repeat the exercise with weighed charges. We’ll see…
Re: case length, the researching I did seemed to indicate folks were trimming to the 1.490”. Well that’s a lot of metal removal with a manual Redding case trimmer as the Lapua brass I’m using is measuring about 1.503”. Removing.003” is a lot easier than removing .013” In fact, it was taking two passes to achieve!
BTW, the barrel is coated with a product from Cerakote called, “Transfer Grey”. It is designed to dissipate heat and it seems to work pretty well. It is used in the automotive racing industry on things like radiators. A disadvantage, I noticed is there is more mirage from the heat coming off the barrel, so a heat shield is necessary.
LMOA… Good observation George. Cerakote also makes a high temperature coating that can go straight to room temp water from 1800°F - without cracking. It was originally produced for piston heads and exhaust components, but it works well for suppressors too which get very hot. So that’s why I have it, but occasionally I get a Motorhead in the shop who wants me to coat their heeders.
Good morning all! It appears the gun will shoot when driven well…
GreyFox and I went down to AL to shoot a UBR match Saturday and I got lucky. Rick took home 1st place in the Unlimited class, shooting a 220 Beggs. We had a great time and a nice sunny day, albeit a bit windy. My next build, which is underway, is a PD rifle in 20 VarTarg on a 788 Rem action.
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