Thread: Flat primers

at the range today with a new to me husky 6.5. Pretty mild starting load and Bullet neither cramping cartridge space nor jamming the lands. Easy bolt lift and extraction.
Figure the headspace is a little excessive. No sign of case head expansion/separation.

Something to watch out for. Rifle is off to gunsmith sometime for bedding and trigger job as well.

Originally Posted by stevodog

Attachment 144115

at the range today with a new to me husky 6.5. Pretty mild starting load and Bullet neither cramping cartridge space nor jamming the lands. Easy bolt lift and extraction.
Figure the headspace is a little excessive. No sign of case head expansion/separation.

Something to watch out for. Rifle is off to gunsmith sometime for bedding and trigger job as well.

Greetings Stevodog,
Primers that look like that are common with 6.5 x 55 cases that are full length sized. A lot of the US dies set the shoulder back too far, even for commercial rifles, and the the flat edge is due to head space and nothing else. Primer appearance is practically useless in determining pressure. Velocity is a much more accurate measure.
Regards Grandpamac.

What brand of primers the federal ones are quite soft in my experience

Originally Posted by grandpamac

Greetings Stevodog,
Primers that look like that are common with 6.5 x 55 cases that are full length sized. A lot of the US dies set the shoulder back too far, even for commercial rifles, and the the flat edge is due to head space and nothing else. Primer appearance is practically useless in determining pressure. Velocity is a much more accurate measure.
Regards Grandpamac.

yes, good to know. I was not concerned about pressure but rather headspacing. I can see how variations in chamber size can occur over 100years of cartridge history.
I have never seen a primer flat like that in any of my rifles and am satisfied its not dangerous. (No case head expansion).
Ill still get the gunny to check with gauges all the same

Originally Posted by northdude

What brand of primers the federal ones are quite soft in my experience

yep, I only use federal primers and they all look like the rem mag cartridge

Originally Posted by mimms2

Nope.

such a helpful guy aye

Ill bump size the next lot to a snug fit

those arent flat......well only a little...
so what I do when setting up dies..as per OLD Nosler manual is to set up the full length die as per normal BUT instead of screwing it DOWN the extra turn screw it BACK OUT a turn....load up a case and try it in rifle for fit.... theory is the shoulder isnt pushed back down so case can grow a little bit untill it is the right size for your chamber..

I think the primer is pretty flat and thought I'd post it as a point of interest.
I have a remedy in mind thanks to the feedback. This Could potentially caused an issue if I carry on without changing anything and continue up the load development ladder.
Maybe ill take more care to custom bump my cartridges to the chamber in all rifles

When you/manuals say a turn you mean a complete 360 rotation right? or 180?

Probably MDs question but I will wind back 1 full turn(360) and bump my way back in till a snug fit

you supposed to have ram in upmost position and screw FL die in untill it makes firm contact with die then turn it 1/4 turn down more (assumably to take up any slack)

back to manual..
to set the FL sizing die for partial resizing,follow the same procedure,except that a space of approx 1/16" should be left between the die and the shell holder.......
so thats my screw it till it touches then back it off a turn......
found on page 31 of #2 Nosler manual.

Originally Posted by Micky Duck

you supposed to have ram in upmost position and screw FL die in untill it makes firm contact with die then turn it 1/4 turn down more (assumably to take up any slack)

back to manual..
to set the FL sizing die for partial resizing,follow the same procedure,except that a space of approx 1/16" should be left between the die and the shell holder.......
so thats my screw it till it touches then back it off a turn......
found on page 31 of #2 Nosler manual.

Greetings All,
In my experience partial sizing works best in more tapered cases, like the 6.5 x 55, .30-06 etc when loaded to lower pressure. Cases like the .308 often do better with either minimal full length sizing or neck sizing. Partial sizing is as Micky has explained above and does not touch the shoulder. Minimal full length resizing goes further into the die until the shoulder is just pushed back enough to just chamber with the slightest amount of resistance. With partial sizing the die will be 1.5 mm or so of the shell holder and with minimal full length resizing 0.1 mm or so. My T3 6.5 x 55 needs the die set 0.2 mm of the shell holder. This is my experience and your results may differ. You just need to work out what works for you.
Regards Grandpamac.