Staked primers - why?

[memilanuk]

Been processing some 1x fired LC 5.56 brass... mostly '10, with a fair bit of '08 and '11 in there, plus a smattering of '07, '09 and '13 as well.

A fair amount of the LC '11 stuff has what appears to be staked primer pockets:

...though they seem to swage out just fine using ye ol' Dillon Super Swager 600

Still just a teensy bit tighter than the normally crimped stuff, even after swaging, but nothing that is concerning at this point.

I am a bit curious as to *why* the manufacturer would stake primer pockets like that in the first place - and I don't think all of the '11 head stamped cases are staked, just some of them.

Any ideas?

 

[Colorado S14]

To ensure they never fall out. Common with military ammo.

 

[Huskydriver]

Yep gotta keep the primers in there under battle conditions esp for the belt feds.

Take a comparator head space measurement and see if the staked brass is longer than the other stuff..if it is, it went through a saw

 

[memilanuk]

To ensure they never fall out. Common with military ammo.

Yeah, I get that... but why stake some and crimp others? Same head stamp, same year.

 

[memilanuk]

Take a comparator head space measurement and see if the staked brass is longer than the other stuff..if it is, it went through a saw

I'll check some more of the same batch tomorrow (these are already sized, trimmed, etc.).

I've had some stuff in the past that had definitely been thru a SAW... sizing that stuff *felt* like I was squeezing a 308 case thru a 223 die.

This stuff... didn't feel appreciably different going thru the Redding F/L SB die than the rest.

 

[357Max]

Well I've got 2 different lot #'s of the same Hornady Match .224 Valkyrie 88 ELDM's

One lot is staked primer & these primers look like crap. Other lot not staked with normal shinny primers.
Why the hell is Hornady randomly staking primers??

 

[bigdaddydmd]

Supposedly the newer m855a1 round has the 4 point staked primer. The older m855 is just crimped. Next time we hit the range I'll look. We have started qualifying with the m8855a1. You can definetly feel the difference in report and recoil. It is a hotter round.

 

[clcustom1911]

Supposedly the newer m855a1 round has the 4 point staked primer. The older m855 is just crimped. Next time we hit the range I'll look. We have started qualifying with the m8855a1. You can definetly feel the difference in report and recoil. It is a hotter round.

Hows accuracy?

 

[bigdaddydmd]

Hows accuracy?

Seems slightly better. I was seeing a lot more tighter three shot groups on the zero range as a range safety. I had more soldiers qualify first time goes with it. ( not in the Infantry anymore. Medcom now so to say they aren't shooters is an understatement). I spend a lot of time teaching BRM and PMI since I'm the only swinging dick with a CIB in the unit. Its definetly hotter and higher velocity. I am ignorant on if G1 is different than M855 but the speed makes wind less of an issue on the 50 to 300 MRFF. It is as good for sure and appears to be more accurate than m855.

Edit. Also it shot fine out of M16a2s. Believe it or not a lot of the medcom still have M16s. That m855a1 really gets too moving with a 20" 1/7. I'm sure it's going to cause shorter barrel life in them