Re: VERY disappointing results .223 w/TAC & 77 SMK
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Downzero</div><div class="ubbcode-body">CCI 400 primers do not belong in any AR-15. They are too soft.
Spherical powders typically require magnum primers, per the reloading manual.
I do not use anything besides magnum primers in my AR-15s, and I highly suggest that you do the same OR use the primers designed for military rifles with floating firing pins.
Although I don't think that any spherical powder will produce 600 yard accuracy, if you want to try it, using the proper primer is essential.</div></div>
Well after reading your post I went back through the Sierra manual and did not see anywhere where it recommends this. So I then broke out the Hornady and Nosler and look at their service rifle data...they call for Winchester small rifle primers. No where do I see them saying it is dangerous or even them recommending magnum primers.
In fact here is some info below from 6mmBR.com on the subject as well as Sierra's AR-15 load guide. Not trying to argue with you but your statement is pretty "aggressive" and would like some more facts on the use of magnum vs standard primers for use in AR-15's.
Take care,Stan
http://accurateshooter.net/Downloads/sierra223ar.pdf For use in semi-automatics and AR15s, we advise that you stick to CCI and Remington primers. These brands have harder cups and are much less likely to pierce primers. Also, the AR15 has a free-floating firing pin that dents the primer on loading. This creates a risk of slam fires. So you want hard primer cups. The latest generation of Winchester primers, with brass-colored cups, should be avoided for AR15 use. The old silver Winchester primers worked fine, but the current WSRs are soft and can be pierced more easily than CCI or Rem primers. A poll of Highpower competitors (mostly shooting ARs) showed that Rem 7 1/2 primers are the most popular (33.23%), followed by CCIs (25.78%). The majority of CCI users favored the CCI BR4s, but both CCI 400s (small rifle standard) and CCI 450s (small rifle magnum) were also popular. Only 10.25% of Highpower shooters polled used Federal primers (either 205M or 205). At the time of the poll, many shooters reported using WSRs, but this was the older version with silver cups. See NationalMatch.us website for complete poll results.
For maximum protection against primer piercing and slam-fires, CCI also markets the #41 military primer. Possessing a very hard cup, with decreased sensitivity, #41 primers are designed to resist slam fires in rifles lacking firing pin retraction springs. In a bolt-gun or semi-auto AR-15, it is not necessary to use #41 military primers. But this is an appropriate option for some military applications.
