Sorry for the lengthy post- I am starting to have pressure issues and it's only getting worse with each range visit.
My Zeus action has 22" Bartlein .218 7.5 twist M24 barrel is chambered with a .169 Alpha 22GT reamer. I use a Silencerco Harvestor 30 cal can. I am running 95SMK over H4350 in Alpha brass and CCI450. Every 150 to 200 rounds I thoroughly clean the barrel and then I bore scope to make sure to remove all the carbon ring. The barrel has 950 rounds on it.
Initially my 10 round per charge weight ladder test the barrel loved 36.7gr. I loaded 75 rounds (with a clean barrel) come to an end on round #9 with real heavy bolt lift and crazy ejector swipes. I then dropped down to the 35.8 load because it had the next best 10 shot groups, 3030fps and SD's in the 5 range. I thought that I have the recipe and proceeded to load 100 rounds and had a care free practice session.
My last match, I ran on a freshly cleaned barrel at 35.8gr, I had a dozen or so heavy bolt lifts and blew 2 primers out.
My next scheme to avoid further trouble was to find something in the 34 to 35gr region. Then my barrel loved 35.1gr H4350 at 20thou off the lands at 2940fps avg.
Loaded 50 rounds at 35.1 for Chrono and group test. On a fresh clean barrel I fired 5 at 35.8 to foul the bore with no pressure signs. But in the first 5 rounds of 35.1gr I then had blown 2 primers...so then my brain exploded and I packed up and went home for Bourbon therapy.
After an exhausting amount of 22 GT load development bumps and bruises I am out of ideas. What is happening? Are the 6GT shooters having these severe issues with carbon rings?
