Shooters have been sold a bunch of hype about the structural advantage of a small rifle primer without being informed of the metallurgical constraints of brass alloys. Brass yields at 65K psi. Unless you own a Creedmoor. They're special
The reason a small primer pocket lasts longer than a large primer pocket in theory, is the expansion percentage applied to a smaller radius is of course less. So the same amount of crush in either shows less effect in the smaller radius as expansion flow should be uniformally outward in the area of unsupported brass, namely the case head rim, groove and web.
In my 308 comparison the head expansion was similar for LRPs and SRPs, but the SRPs were noticeably firmer to seat.
So the big question now that I have used Kickinback’s full length die to neck down my 308 brass, should neck turn them (assuming there is enough clearance for safety) before or after fireforming?
trevort wrote: ↑Fri Jan 04, 2019 9:30 am
So the big question now that I have used Kickinback’s full length die to neck down my 308 brass, should neck turn them (assuming there is enough clearance for safety) before or after fireforming?
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Good question Trev, if you are sure you have enough clearance I would fireform first.
Then clean up the necks. I made 6mm SLRs out of 308 and the necks were a bit fat so I turned them before fireing only a skin though just didnt want to make to much pressure.
You could always take a skin before sizing them to 260.
Gary
trevort wrote: ↑Fri Jan 04, 2019 9:30 am
So the big question now that I have used Kickinback’s full length die to neck down my 308 brass, should neck turn them (assuming there is enough clearance for safety) before or after fireforming?
When I made 7mm-08 brass from 308 Lapua cases, I neck turned before firing to provide clearance on the minimum SAAMI spec chamber. With the 6x47 Lapua, I fire-formed then turned. Both worked, though fire-formed cases are probably a bit easier to turn if you have sufficient clearance to fire them safely.