Lapua .223 brass

[peterdobson]

A customer says he is having difficulty resizing Lapua .223 Rem brass for an AR15 and has had a slamfire and thinks the rim hardness is too soft.

We have never seen this but if an issue would like at address it.

Anyone seen or been made aware of Lapua .223 Rem brass issues with AR15s?

Regards,

Peter

 

[stubblejumper]

I had no issues with my ACR.

 

[bigedp51]

American Lake City 5.56 military brass is the hardest in the base followed closely by Lapua and the softest is Federal .223. All commercial contract 5.56 cases are also made to military standards and must meet hardness standards. And as I stated before Lapua has the hardest brass in the base of any of the commercial .223 cases. The brass hardness was brought up at AccurateShooter.com and one of the members had a company that makes ammunition and tested the cases with a Rockwell hardness tester.

If your customer had a slamfire he was using the wrong primer or a improperly seated high primer.

Below any primer with a cup thickness of .025 should be used with the AR15.

The M14 and M16 rifle had slamfires problems during the early testing phase of these rifles and the firing pins were lightened. These slamfires only occurred when a single round was loaded into the chamber without the magazine in position. When the rifles were fed from the magazine it slows bolt velocity and lowers the inertia on the firing pin.

My guess to the problem is the wrong thickness primers, improperly seated primers or a dirty bolt and nothing to do with Lapua brass.

 

[alberta tactical rifle]

A customer says he is having difficulty resizing Lapua .223 Rem brass for an AR15 and has had a slamfire and thinks the rim hardness is too soft.

We have never seen this but if an issue would like at address it.

Anyone seen or been made aware of Lapua .223 Rem brass issues with AR15s?

Regards,

Peter

My questions would be whose barrel and what chamber? Or more appropriately what chamber dimensions are in that rifle. Something is odd here.

 

[SND]

I'm not sure how a slamfire could be related to rim/head hardness. If the head is growing and causing resizing problems after firing the issue is elsewhere, likely too hot a load for that rifle, or maybe something else changed with the chamber/barrel and it's now causing pressure issues even if "same load I always used" type deal...
If you know what lot# he has and you still have some of it in stock, shouldn't be too hard to get it hardness tested and compare with other lots.

 

[peterdobson]

Thanks for input and from the customer:
Well, the problem appears to have been sorted.
When I put the die in the rockchucker press single stage, there is
no problem at all. The brass drops right in to the gauge and the
brass moves smoothly through the die with no heavy pressure on
the handle. So it would seem that the Lapua brass is a bit much
for my progressives and from now on I will size the cases single
stage, which I actually don't mind. It's much easier on the case rims
too.
I have a small base die coming tomorrow morning, but I don't think
it will be necessary unless maybe after several reloadings.
So I consider this problem solved and will live and learn.