Couple AR questions.

While harder military cup primers are preferred to prevent slam fires, many use SR primers while ensuring the primers are seated .004"+ below flush.

Since all of my rifles are semi-auto, I prefer to hand prime all rifle brass to ensure primer seated depth.

I guess during current shortage, you may have to use whatever primers you can get.

Axis II said:

I have RCBS full length die set for 223rem do I really need Small base dies?

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If all of your resized brass fit your chamber, I would not.

Yes, but magnum primers often generate higher pressure with the same amount of powder. If the recipe you are using specifies a non-magnum primer, you may want to reduce the maximum load slightly.

Probably not, though the sizing die may need to be adjusted differently between the two rifles for optimum chambering and results.

Load up a couple of dummies (no powder or primer) to make sure your desired overall cartridge length fits into the magazine, and feeds and chambers before loading the rounds.

I use rcbs full length die for both my ARs, no issues. I have always used CCI #41 primers , don't know if necessary. Gives me peace of mind

I’ve always used CCI 400, and have had zero issues. I keep in mind that that pin is just floating, so of course, it’s pointed in a safe manner when chambering. Not a bad habit to have.
I’ve never needed a small base die either, but some people have!
Buy a standard set and see if it works

Axis II said:

I have RCBS full length die set for 223rem do I really need Small base dies?

Click to expand...

Occasionally, cases fired in one AR-15, then resized in a full length resizing die and then chambered into a different AR-15, the cartridges will not chamber. It is a matter of the adding and subtracting of tolerances between the two chambers and the sizing die.

If you are not having problems with your rifles with your cases, do not worry about it and use your full length sizing die. Just be aware of the issue if you obtain and use fired cases not fired in your rifles.

I normally use CCI #41 or Rem 7 1/2. I tested some Federal GM205M primers in my AR's, They are a NO GO. Had slam fires soon as the bolt closed. I was expecting this and only loaded 1 round into the mag. Then repeated it, fired every time. So I had to ride the bolt down to keep them from slam firing.