Primers- How Interchangeable are they?

[Tipsymutt]

Hi guys. I’m sorry if this is a dumb question, but here goes: How interchangeable are primers? Does it matter as long as they are the right size? I have been reloading for a while now, but have always stuck to published data. Unfortunately, in the current world in which we live, reloading components are often hard to find (not to mention expensive). I have the “ 6.5 Grendel Reloading Handbook” volumes one and two, as well as data from AA, but many of the loads spec different primers. I currently have on hand CCI 450’s, but some of the bullets and powder combinations that are listed are for Remington 7.5, Wolf, or other primers. To further confuse things (or me) some reloading data doesn’t even specify a primer.
So, I guess what I’m asking is; can I use my CCI 450 primers in a recipe that calls for a Rem 7.5 of Wolf, or any other, or could this cause bad pressure issues?

Thanks!

[lazyengineer]

To be perfectly honest, in my experience - a lot more interchangeable than people act. It's on the mild end of a load, is where I personally see the difference. where a difficult to light ball powder in a mild charge is being lit by a mild primer vs a hot primer, where differences can get profound. With normal and hot loads, I tend not to notice primer really having any effect at all - personally. With the main item there being some primers are more prone to mechanical failures like piercing, on the hot end, than others; but otherwise not really affecting velocity, performance, pressure sign etc. Look forward to what some others say - some folks here have done quite a bit of work on the topic, and even wrote reloading manuals - so that's pretty impressive.

[LR1955]

Hi guys. I’m sorry if this is a dumb question, but here goes: How interchangeable are primers? Does it matter as long as they are the right size? I have been reloading for a while now, but have always stuck to published data. Unfortunately, in the current world in which we live, reloading components are often hard to find (not to mention expensive). I have the “ 6.5 Grendel Reloading Handbook” volumes one and two, as well as data from AA, but many of the loads spec different primers. I currently have on hand CCI 450’s, but some of the bullets and powder combinations that are listed are for Remington 7.5, Wolf, or other primers. To further confuse things (or me) some reloading data doesn’t even specify a primer.
So, I guess what I’m asking is; can I use my CCI 450 primers in a recipe that calls for a Rem 7.5 of Wolf, or any other, or could this cause bad pressure issues?

Thanks!

TM:

The answer is 'yes'.

Have used 450's for decades with the Grendel. All powders and loads.

Have also used standard primers with loads that give 450's as the primer without a problem.

That said -- best bet is the 450. Particularly with ball powders.

LR-55

[VASCAR2]

In AR-15’s I like to use thicker primer cups like used in the CCI 450, CCI 41, Federal Match AR and Bench rest primers like Remington 7 1/2. I have loaded some 223 ammo with standard primers that were starting to pierce even though not loaded hot. The AR-15 uses a floating firing pin and there is .008” tolerance in firing pin protrusion. The thicker primer cups add a margin of safety against slam fires or bolt depth and firing pins that might be on the long side of spec.


I always try to keep my AR-15 firing pins with the bolt and carrier where I know they are in spec.