6br high pressure

[fdshuster]

Frank: I've had them form after as few as 5 loadings in my Lapua 220 Russian and Lapua 6BR brass. Others may be fortunate and not have them form 'til a higher reloading count.

One of the reasons I keep an accurate count on the number of times brass has been loaded. After 4 or 5 loadings I do the simple test of attempting to drop a bullet into the case before sizing. Unless it's critical to bullet seating depth I then make certain the seated bullets are in front of their location. If it is critical, then they are removed.

 

[jaybray]

Why are you worrying about donuts that you don't have. If you use two hundred cases you might never get donuts before you wear the barrel out. I have 185 Lapua cases I cycle through my 6BRX. I am up to eleven reloads with no donuts. I use a FL Redding bushing die. The bushing does not quite make it to the neck/shoulder junction. Good luck with what ever you decide to do. Later! Frank

I talked to the smith who built it today and he said the exact same thing about not worrying about the donuts. I explained to him about the high pressure signs and he said it may have a tight bore and said to start at 28 grains of varget and work up. At 28.4 grains of varget, 15 thou off the lands with the sierra matchkings, at 100 yards I shot four 4 shot groups that measured 0.327,0.346 0.389 0.378, that's before subtracting the bullet diameter!! ;D 29.5 grains was to high for my gun!!. I don't have a chronograph so no clue as to velocity but to me that's very good accuracy. Tomorrow ill take it out to 300 yards and try. I never knew about measuring case web diameter until he told me, and my fired cases were 3 thousandths bigger than a new case

 

[Old Navy]

Frank: I've had them form after as few as 5 loadings in my Lapua 220 Russian and Lapua 6BR brass. Others may be fortunate and not have them form 'til a higher reloading count.

One of the reasons I keep an accurate count on the number of times brass has been loaded. After 4 or 5 loadings I do the simple test of attempting to drop a bullet into the case before sizing. Unless it's critical to bullet seating depth I then make certain the seated bullets are in front of their location. If it is critical, then they are removed.

I just did the same test using a 107 before I posted. Later! Frank

 

[4xforfun]

Yes I meant .02 grain increments, sorry typo I better try trimming to 1.550,might be the problem. I have tried the 107 matchkings, and at 29 grain start load very good accuracy right of the bat ,problem is the throat is so short that touching the lands the shank is below the neck shoulder junction. From what Ive read the donut thing will cause problems. I have some 75 grain v max ill try. since I don't have any ejector marks, flat primers, or heavey bolt lift , when I increase powder charge, do I keep going up till I blow another primer? The matchkings being a heavier bullet should show pressure sooner ? How do I tell?

Are you SURE you ment .02 incruments...and not 0.2 ? Most scales can't even measure to the hundreth of a grain.

Sorry...just had to!! ;D

 

[KUZU]

was having same problem . was bumping shoulder back to far . good luck