Heavy bolt lift with mild 6cm load
- Thread starter megafans
- Start date
It is a brand new mcg
I reduced 100 gr load from 35 gr to 34.2 then increased .2 gr to get a Lazer round from 4166
at 34.4 ,no Chrono speed yet !
I had a very similar situation when I switched bullets in my old barrel. I went from 100 grain bullets to 55 grain in a factory 243. Flattened primers and super hard bolt lift. backed off the charge a few times and still had high pressures at below minimum charge. cleaned the chamber and throat area real good and pressure signs were gone.
I have a factory Colt AR 15 H-Bar...I never cleaned, thousands of rounds...never lubed the bolt, just run it dry. Thought it would stop running...it did not. Does a Chrome lined barrel, help? Mil Spec chamber?
I cut it to 16.5" fluted it & put the barrel in a different flat top upper. Mag dumps very hot, always works, fired 1000 rds in one outing, very fast, practicing trigger finger speed with a timer. I clean it maybe once a year now, and it still shoots pretty good when I slow down from the prone, even 5 into 1" with ammo it likes. Never checked it with my bore scope, cause I don't care, as long as it works, clean or dirty, seems to make little difference. The perfect high volume varmint rifle, cleaning seems to be a waste of time...for civilian use.
I've seen old magazine articles on running them 10,000 rds no barrel cleaning or malfunctions. Not necessarily recommending Colt barrels, just my experience with the one I have. No pressure signs, no malfunctions, poor cleaning, or no cleaning, very dirty, even gritty and dry...still works...again a mil spec steel & chamber with a chrome lined barrel may be a problem solver...but accuracy may not be up to expectations...or maybe it is.
I cut it to 16.5" fluted it & put the barrel in a different flat top upper. Mag dumps very hot, always works, fired 1000 rds in one outing, very fast, practicing trigger finger speed with a timer. I clean it maybe once a year now, and it still shoots pretty good when I slow down from the prone, even 5 into 1" with ammo it likes. Never checked it with my bore scope, cause I don't care, as long as it works, clean or dirty, seems to make little difference. The perfect high volume varmint rifle, cleaning seems to be a waste of time...for civilian use.
I've seen old magazine articles on running them 10,000 rds no barrel cleaning or malfunctions. Not necessarily recommending Colt barrels, just my experience with the one I have. No pressure signs, no malfunctions, poor cleaning, or no cleaning, very dirty, even gritty and dry...still works...again a mil spec steel & chamber with a chrome lined barrel may be a problem solver...but accuracy may not be up to expectations...or maybe it is.
