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Lapua 6BR flash holes

AlNyhus

Uniformed the flash holes on 50 Lapua 6BR cases today. On a goodly number, a .059 gauge pin wouldn't begin to start in...let alone through. Now that's no biggie as I uniform to .0625 anyway....but these were especially nasty. Along with the brass shaving that were removed, there was a few bits of metallic swarf that came out of the cases (circled in blue). The primer pockets also had the most pronounced radius at the floor I've ever seen. Via a feeler gauge and with my .123 carbide uniformer, the gap due to the radius was .014.

Things that make you go "Huh????"........... :rolleyes:

LECEnKtl.jpg

ZNL5zgHl.jpg

nIkkJMdl.jpg
 
AlNyhus said:
Uniformed the flash holes on 50 Lapua 6BR cases today. On a goodly number, a .059 gauge pin wouldn't begin to start in...let alone through. Now that's no biggie as I uniform to .0625 anyway....but these were especially nasty. Along with the brass shaving that were removed, there was a few bits of metallic swarf that came out of the cases (circled in blue). The primer pockets also had the most pronounced radius at the floor I've ever seen. Via a feeler gauge and with my .123 carbide uniformer, the gap due to the radius was .014.

Things that make you go "Huh????"........... :rolleyes:

LECEnKtl.jpg

ZNL5zgHl.jpg

nIkkJMdl.jpg
Click to expand...
thanks Al-- For this thread and bringing this to lite—.
 
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AlNyhus said:
Uniformed the flash holes on 50 Lapua 6BR cases today. On a goodly number, a .059 gauge pin wouldn't begin to start in...let alone through. Now that's no biggie as I uniform to .0625 anyway....but these were especially nasty. Along with the brass shaving that were removed, there was a few bits of metallic swarf that came out of the cases (circled in blue). The primer pockets also had the most pronounced radius at the floor I've ever seen. Via a feeler gauge and with my .123 carbide uniformer, the gap due to the radius was .014.

Things that make you go "Huh????"........... :rolleyes:

LECEnKtl.jpg

ZNL5zgHl.jpg

nIkkJMdl.jpg
Click to expand...
And a standard Sinclair uniformer won't touch the bottom of the pocket until the brass moves.
 
Have not have that problem with my Peterson cases and they also seem very durable as they are now on more than 15 loads.
Clean {wet/SS pin} & AMP anneal @ time. Primer pockets holding up just fine and no burring inside the case at the flash hole. I would be reluctant to bore out the flash holes more than the most minimum that spec and decapping pin allow.
A friend had me use my KM flash hole uniformer on some of his 6PPC cases to open the flash holes to 0.082“ and the accuracy went right into the toilet… :confused:
 
Al, I appreciate the care that you take with your cases and understand that you compete.
When I first ordered my 6BR from Cooper a little over 20 years ago they tried to discourage me by saying brass availability could be problematic. So I just went out sourcing brass wherever it was available. I bought up 400 rounds of Lapua and also 400 Remington. People started to suggest opening up the flash holes. At that time, I was under the impression that all you needed for proper ignition was a spark and sufficient pressure for the powder to burn properly. I tried every primer and powder combo combined with Euber 68 gr. bullets and couldn't detect any difference on target with my rifle.
So my question is, can you see the difference real time on target with reaming flash holes?

Remington and Lapua continue to shoot the same groups although the Euber bullets are no more.
All groups are 5 shots

.392.1.JPG5_8_12.jpg6brgroup4_2_12.jpg
 
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I have 2 lots of Lapua 6BR brass ( 6bra fireformed now 5 x ) and as I was prepping it for the 6th loading I noticed the edge around the flash hole in the primer pocket side has a burr ridge running around it. I used a Redding Primer Pocket Uniform tool to clean that edge up.
I am unable to find a photo to share.
 
AlNyhus said:
Uniformed the flash holes on 50 Lapua 6BR cases today. On a goodly number, a .059 gauge pin wouldn't begin to start in...let alone through. Now that's no biggie as I uniform to .0625 anyway....but these were especially nasty. Along with the brass shaving that were removed, there was a few bits of metallic swarf that came out of the cases (circled in blue). The primer pockets also had the most pronounced radius at the floor I've ever seen. Via a feeler gauge and with my .123 carbide uniformer, the gap due to the radius was .014.

Things that make you go "Huh????"........... :rolleyes:

LECEnKtl.jpg

ZNL5zgHl.jpg

nIkkJMdl.jpg
Click to expand...
Scary. One more thing that I useta not worry about. You mind saying what tools you used? Thanks
 
Kracken McGraw said:
Recent production, I assume?
Very unusual by Lapua standards.
Click to expand...
I had a set of pin guages. I only have a .061 pin gauge and I am missing the .062, because that's my life and everything goes missing. The .061 on my new production 6br Lapua went through the 50 plus pieces I have tried no problem. Wonder what the .062 pin would do.
 
Kevin1990 said:
I had a set of pin guages. I only have a .061 pin gauge and I am missing the .062, because that's my life and everything goes missing. The .061 on my new production 6br Lapua went through the 50 plus pieces I have tried no problem. Wonder what the .062 pin would do.
Click to expand...
I bet the hole is in standards. We inspect the case plenty of times during the loading process, so we should be able to see the rare burr like AL was showing.
 
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