6mmNormaBR/30BR ?

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BlackBrant

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I`m an avid cartridge collector, and several days ago, a fine CGN member sent me some assorted range brass.Two of the brass were 6mm Norma BR ,one was Norma and the other Lapua production, but when I tried to place a 6mm/.243 bullet into the case, it just fell in.....much too large????

I broke out my digital calipers (2 pairs in case) and all the measurements are as they should be ,except the overall case length (1.510 avg. when it should be around 1.560 avg.) and outside diam. neck (.3295 avg. should be .270 )

The case accepts .308 /.30 cal projectiles.

So what then, would this be considered a .30 Norma BR or 30BR ? Is this a common thing to do (blow out a 6mmBR to make 30 BR)

Thanks

Paul T
 
30BR is a popular benchrest round for score. I shoot one. They are formed from Lapua 6mm BR cases typically because most shooters who would shoot such a round want Lapua brass.
 
Last edited:
hend238 said:
30BR is a popular benchrest round for score. I shoot one. They are formed from 6BR brass typically because Lapua makes them and most shooters who would shoot such a round want Lapua brass.
Click to expand...

Hmmm, that`s interesting ,thanks for the info.

Is 6mm BR brass in small quantities easy to find ?

Paul T
 
Also, it's not uncommon to see 30 BR chambers with a short overall length. The case when necked from 6 to 30 and fired shortens a lot. Most 30 BR reamers out there cut a short chamber like you measured - 1.510 +/-. I had my reamer ground for an overall length of 1.550" That way I didn't have to do an excessive amount of case trimming for the initial fire forming. Just a little was needed. The reason for this is because I fire formed my cases by shooting a 6mm bullet down a 30 cal fire forming barrel that was chambered using my reamer. The case doesn't shrink using this method. Depending on some variables, it would lengthen.
 
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