Alpha 30BR brass

[AlNyhus]

For neck thickness, .012 would be a good number. Rounding the bullet diameter up to .3090, that would give a .333 dimension over the bullet pressure ring. Either a .335 or .336 neck reamer would be good 'no turn' fit. For the popular .330 and .331 neck diameter reamers, a .012 neck would let you do a nice light cut while still getting a full clean up (assuming the necks would be a consistent .012).

For case length, 1.500 would be the easy button to fit most 1.520-ish chamber lengths.

Personally, I'd take a longer neck length (1.540 or so) and then trim the neck length back to fit my individual chamber length for a true custom fit. Most don't actually measure chamber length, though...relying on the reamer print.

Good shootin' -Al

 

[Ccrider]

I think the neck thickness should be designed around the most popular reamer being used for the 30br——— a no turn for the Robinet reamer.

Rounding the bullet diameter up to .3090, a .010 neck would give a 328 finished round—adequate clearance for a 330 or 331 no turn.

The longer neck length would allow one to trim to desired length.

 

[RGRobinett]

I think the neck thickness should be designed around the most popular reamer being used for the 30br——— a no turn for the Robinet reamer.

Rounding the bullet diameter up to .3090, a .010 neck would give a 328 finished round—adequate clearance for a 330 or 331 no turn.

The longer neck length would allow one to trim to desired length.

Longer and thicker ARE "no brainer" attributes: brass can be [easily] removed . . . somewhat difficult to, "put back". I'd specify that the body Dia. @ .200" ahead of the bolt-face DATUM not exceed 0.469'". RG

P.S. Regarding neck-wall thickness, I'm with Al: 0.012" minimum & turn for less.

 

[jimmymac]

For neck thickness, .012 would be a good number. Rounding the bullet diameter up to .3090, that would give a .333 dimension over the bullet pressure ring. Either a .335 or .336 neck reamer would be good 'no turn' fit. For the popular .330 and .331 neck diameter reamers, a .012 neck would let you do a nice light cut while still getting a full clean up (assuming the necks would be a consistent .012).

For case length, 1.500 would be the easy button to fit most 1.520-ish chamber lengths.

Personally, I'd take a longer neck length (1.540 or so) and then trim the neck length back to fit my individual chamber length for a true custom fit. Most don't actually measure chamber length, though...relying on the reamer print.

Good shootin' -Al

1.540 would cover the bases nicely with my 1.530 chamber. Trimming is easy! Thickness as you specified would also be fine with my .330 neck. The max case OD of .469 at the .200 line that @RGRobinett suggested would also work good for my application.

 

[jackieschmidt]

Has there ever been a “Factory” case manufactured with a neck thickness of less than .013.?
Manufacturing problems may prohibit the necks being any thinner than .013 prohibitive.

 

[Evan]

Has there ever been a “Factory” case manufactured with a neck thickness of less than .013.?
Manufacturing problems may prohibit the necks being any thinner than .013 prohibitive.

My Norma 22 PPC USA came out of the box at 0.011 and seemed thin for factory.

 

[AlNyhus]

Has there ever been a “Factory” case manufactured with a neck thickness of less than .013.?
Manufacturing problems may prohibit the necks being any thinner than .013 prohibitive.

Jackie, that's a really good point. Consistent necks of .012-.013 would be better than thinner and all over the place, especially for a true 'no turn' chamber.

Good shootin' -Al

 

[Ccrider]

Has there ever been a “Factory” case manufactured with a neck thickness of less than .013.?
Manufacturing problems may prohibit the necks being any thinner than .013 prohibitive.

Neat question. Someone was manufacturing and selling 30br cases several years ago. I stumbled across them on the internet.

I actually bought the last 50 or 100 cases. I don’t remember how they were headstamped. I never used them and have them tucked away somewhere. I will dig them out and do some measurements.

 

[Ccrider]

Ok. I pulled the 30br brass out that I ordered a couple of years ago. Turns out that it is actually Peterson 7mm br brass that has been sized/necked up to 30br.

It’s 468 at the 200 line, .011 neck thickness, .332 neck and 1.497 length.

 

[AlNyhus]

Ok. I pulled the 30br brass out that I ordered a couple of years ago. Turns out that it is actually Peterson 7mm br brass that has been sized/necked up to 30br.

It’s 468 at the 200 line, .011 neck thickness, .332 neck and 1.497 length.
View attachment 1700108View attachment 1700109

The Peterson 7BR brass is the Rodney Dangerfield of 30BR cases.

Minimal neck up and turning, small enough at the back end to fit even the tightest chamber and it has the large flash hole. It's well annealed out of the box and f-forms beautifully.

It's different from the 'Lapua spec' BR cases in that it's spec'd for the OG (original) Remington 'BR' chamber....1.520 long and about .0015-.002 smaller at the back end than the 'Lapua 6BR Norma' brass.

No matter how many times this case has been mentioned re: making 30BR cases, few seem to connect the dots.

Good shootin' -Al