Inside neck reaming??

T

tenring

Guest
I have been reloading for a very long time, and still shoot some BR. Having problem with a Savage factory .223 that I shoot in GH matches. New Lapua brass, unaltered, not neck turned, sized with Redding 246 bushing. After firing 20, 4 had necks so tight that a bullet would not slide in (could not start base of bullet into neck). Necks on the remaining 16 would allow a bullet to slide in, but with an extremely close fit. Checked inside, no donuts. The 4 tight necks explain my fliers. I have Forster inside neck reamer and K&M neck turner.

Which is the best method to uniform the neck interiors? Thanks.
 
Did you check the difference in the wall thickness of the good necks and the bad necks. That is the important dimension.

If you do not have a good set of ball micrometers to check the neck wall thickness, seat a bullet in a good case, and one in a bad case. Then mic over where the base of the bullet is in the neck. They should all be within a half thousandths or so, even with non turned brass.

If the wall thickness is the same, then the spring back on the brass is perhaps little inconsistent.
 
jackie schmidt said:
Did you check the difference in the wall thickness of the good necks and the bad necks. That is the important dimension.

If you do not have a good set of ball micrometers to check the neck wall thickness, seat a bullet in a good case, and one in a bad case. Then mic over where the base of the bullet is in the neck. They should all be within a half thousandths or so, even with non turned brass.

If the wall thickness is the same, then the spring back on the brass is perhaps little inconsistent.
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Yes, what Jackie said, but before you do anything to new Lapua cases that have been fired only once, load and fire them at least one more time. Lapua cases are tough and one firing is not usually enough to fully blow out the necks.

Gene Beggs
 
Set those four cases aside and get on with your program, or you could anneal your cases. I believe that what you are seeing is due to differences in annealing from the factory. A friend uses unturned Lapua brass for his .223 varmint rifle. He had been experiencing excessive and irregular seating force so he decided to try annealing with the kit that Hornady used to offer. That solved his problem, and improved his groups.
 
Inside neck reaming

That's a good thought Jackie. I have both Starrett and Mitutoyo tube mics. My fired cases measured 2.535 and loaded rounds were 2.486, giving me just .049 total clearance. Not enuf to fully open the necks. I got the K&M out and turned them down two thou, to keep me legal by the rules for factory, and give me sufficient clearance. I always anneal after first firing.
 
tenring said:
That's a good thought Jackie. I have both Starrett and Mitutoyo tube mics. My fired cases measured 2.535 and loaded rounds were 2.486, giving me just .049 total clearance. Not enuf to fully open the necks. I got the K&M out and turned them down two thou, to keep me legal by the rules for factory, and give me sufficient clearance. I always anneal after first firing.
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I think you have a decimal point in the wrong place as your numbers don't make sense. If you are using a ball mike, you'd be getting measurements like .0125, .0130, that kind of thing. If using a 1" micrometer, you'd get measurements like .2535 and .2486. In that case, you would have .0049" difference between the two. Its hard to mike a fired case with a 1" micrometer. You need to know the neck diameter of your chamber, which you can get using a cerosafe cast of your chamber or using one of the small hole gages along with a 1" micrometer to measure what you get off of the tool. Once you know the neck diameter of the chamber, then you can see how much clearance you have on your necks. .002" total clearance is sufficient on .22's and 6mm's. Less clearance can get you in trouble, more clearance just causes cases not to last as long and case issues from excessive sizing.
 
tenring said:
That's a good thought Jackie. I have both Starrett and Mitutoyo tube mics. My fired cases measured 2.535 and loaded rounds were 2.486, giving me just .049 total clearance. Not enuf to fully open the necks. I got the K&M out and turned them down two thou, to keep me legal by the rules for factory, and give me sufficient clearance. I always anneal after first firing.
Click to expand...

I'm sure you mean .2535 and .2486, giving a loaded round clearance of at least .0049. That sounds about right.

Keep in mind, the necks always spring back just a tad after firing.
 
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