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Posted: 4/22/2014 6:13:31 AM EDT
| Hay everybody. I have a friend that just started loading .300 blk, I've been loading it for a while. Now the problem he pressed 10 rounds Friday to check his load and his ar won't go into battery. So I thought this to be a chamber issue tried in mine and it still won't go into battery. So I mic my known good rounds and the rounds in question his mic .015 bigger than mine do just past the neck. What could cause this. One run thrue my FL sizing die and his brass chambers in both ar's. He is using a 2 die rbcs set mine is a hornady 2 die set. The only thing I can think of is that his sizing die is out of spec but it's brand new. |
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I'm not, exactly, sure what your question is. But, I'll go out on a limb.
I *think* you are saying that the outside diameter of a finished round -- at the neck -- is 15 thousandths bigger than anticipated. That's a lot. My first guess would be that in forming the brass, the thickness of the material at the neck is too great. This may vary from one brand of brass to another. If the brass is too thick, you have no choice but to turn it (Sinclair makes several tools for this). My second guess is that the expander ball on one of your sizing dies is too big (in diameter). Of course (third guess) the bullet may be seated too far out and might be hitting the lands, preventing chambering. Start out with empty brass and see if it will chamber in the gun. Then, size the brass using your dies and see if it will chamber in the gun. If the cases chamber in both these conditions, then your problem is either thick brass or bullet seated out too far. Wish I could see the cases and the gun. When ever I first develop a loading process, I always check dummy rounds at every stage of the loading process in the actual gun they'll be used in. That saves lots of frustration and expense. |
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Have him set up his die according to RCBS.
Screw the FL die into the press until it touches the shell holder. Screw the die INTO the press 1/4 turn MORE and lock it down. Lube and size a piece of fired brass. See if it chambers. Also make sure he does not have the Seating die set to deep causing an unwanted crimp buckling the case. |
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