Cryhavoc
Silver $$ Contributor
What SAFE size to drill out lapua small primer brass
- Thread starter DLT
- Start date
Likewise, I've found that as good as the Lapua brass's quality is, I still deburr their flash holes when I first get them. Most of them don't have a burr, but a few of them do and my 21st Century deburring tool easily takes care of them.If you're not checking, you should be.
Lately, I've noticed quite a bit of variation of flash hole diameters on later Lapua 6BR cases. In the past, I've just opened them all to .0625 for a consistent size. But on some new 30BR cases I'm finishing, the diameters were all over the place.....from a few at .057 all the way to .062 as verified by a pin gauge. With a 20X loupe, all the holes were nice and round with no slivers of material to skew the measurements. This was from 50 cases this morning...you can see by the material that some holes were just touched up and some had quite a bit more removed.
Good shootin'-Al...
Steve Donlon
Gold $$ Contributor
I think it depends on the powder also. Why would they make .080" small rifle primer flash holes? If you just blow out the small primer flash hole with a large rifle deprimer, it will grow to .0695". The case size also matters and how much powder you can burn. I experimented with different size holes to see which one works best with my load. I read that the 6.5 Creedmoor was on the edge of wheather it matters that much to the average shooter as far as accuracy goes. But the small rifle primer should take more pressure. The 6 Creedmoor can burn a little more powder than the 6.5 from my reloading books. So I would not give up, I would try different sizes to see for yourself what works best for you and your loads with magnum small rifle primers.
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Those of us who have shot cast bullets are familiar with drilling out flash holes.
I did a test with my .308 comparing large and small primers with drilled out or std flash holes with jacketed bullets. It was interesting. The LRP brass did a little better with drilled holes (large as in 0.090"). The SRP brass did better with the small flash holes (Peterson brass).
I also had some 6BR that I drilled out for cast loads. Using jacketed bullets they were pretty bad. Cast bullets for it were a disaster due to the 1:8 twist.
I did a test with my .308 comparing large and small primers with drilled out or std flash holes with jacketed bullets. It was interesting. The LRP brass did a little better with drilled holes (large as in 0.090"). The SRP brass did better with the small flash holes (Peterson brass).
I also had some 6BR that I drilled out for cast loads. Using jacketed bullets they were pretty bad. Cast bullets for it were a disaster due to the 1:8 twist.
Basically, I don't think the powder really matters. But, I should point out that larger flash hole, like I found in my .308 Alpha brass, does present an issue related to pressure on the primer during ignition. I found using thin cup primers, like the CCI 400's, would easily get pierced. Going to primers with thicker cups solved this issue.
I use the mighty armory decapper. Order with the proper small Lapua pin. I decap everything with it and never an issue, even on miltary crimps. Toughest decapper ive ever seen
www.mightyarmory.com
Mighty Armory PUA Decapping Die w/ Spring Loaded Primer Flicker
The Mighty Armory PUA Decapping Die is a universal decapping die for depriming small flash hole cases with small flash holes. Recommended for use on all single stage and turret presses. Toughest in the industry!
www.mightyarmory.com
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