Re: Fav powder for a 6-284 29" barrel
Totally suprised you had the 107 gr SMK come apart. I built myself a 30" Lilja barreled rifle with a 1-8, 3 groove barrel. About the hardest barrel there is on match bullets. I cut my throat very long as this is a single shot rifle. Base of bullet shank seated flush with base of neck.
My standard load for three seasons was 57.0 gr RL-22 which was good for 3580 fps. Yes, thats correct, 3580 fps average and velocity spreads were in the mid teens. Accuracy with this rifle was outstanding. The harder I drove them, the better it got. It would EASILY beat 1/2 moa and generally ran in the 1/4 moa range out to 500 yards. Past that, in good conditions, it was not hard to hold 1/2 moa.
Never once did I ever have a bullet failure. After three seasons the bore was starting to get some serious heat cracking for the first 7-8" of bore. Fearing I was about to loose a very good shooting barrel I decided to drop the charge to 55.0 gr which still produced 3450 fps. In comparision a very comfortable load. Accuracy may not have been quite as good but I believe this was due more to the worn throat more then the reduced load at this point.
As far as case life, even at the top pressure loads I was getting 5-6 firings per case with the modified Winchester 284 cases.
I have always liked the old Win 284 cases. They support alot of pressure and are much better quality then most would have you believe. Not as easy to form but not that bad at all with a neck bushing die to step them down a bit.
Since then, I have built a couple dozen 6-284 rifles with 28 to 30" Lilja barrels. I have since switched to the 1-9 barrels as they are plenty for the 107 gr class bullets and are easier on the thinner jacketed 105s from Hornady and Berger.
In my testing, my velocity results of this first rifle were not uncommon, nore was the accuracy.
Again, I am suprised your seeing pressure signs with 53.0 gr RL-22. You must have a very short throat length. Another thing that could be the problem, check to make sure you have proper neck clearance. You should be able to push a bullet through a fired case neck without much resistance at all. If you can not or there is noticable resistance, your neck diameter in the chamber is to tight and you will need to turn your neck thickness down.
All this said, your rifle is shooting extremely well, sometimes its best not to look to hard for greener grass and realize what you have in front of you. Yes your velocities are a bit off average for that barrel length but accuracy is far more important then shear velocity.
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