Hello, I have been loading .223 rem with loads from the nosler 5th ed. manual and I overlooked the primer they suggest. They list a rem 7 1/2 primer and not being familiar with remington primers thought it was their version of a small rifle primer when actually the rem 7 1/2 primer is a small rifle magnum primer.

I have been using the winchester small rifle primer and now wonder what would the rem 7 1/2 primer do to my loads?

The loads I have been testing are doing good but seems like primer has a little cratering around where the firing pin hits the primer.

I'm using .223rem, winch case, WSR primer, benchmark powder @ 28gr max. load, nosler 40gr b.tips.

To change now to a Rem 7 1/2 primer given that you're currently using a "max" load means to me starting low again and working back up....as it would if any component is changed.

My own experience when changing to a mag primer was that I worked back to the same load I formerly had.....but still drop back and work up.

You're dealing with 50,000 PSI about a few inches from your face.....something to never forget.

In all sincerity however most any modern action will tolerate the change with no to little effort.

I definitely agree with vapodog on this subject. The components you load with are very cheap compared to the cost of a emergency room visit.

From where did you get the message that Rem / 1/2 is a "magnum" primer ?
After reading your post, I inspected the case which says "Bench Rest Primers".

This is the starting point to my complaints about this damned "m" thing: sometimes "m" stands for "magnum", sometimes for "match grade". - Total confusion.

As I did some comparisons with different primers exploding into a PU web, I'm quite sure the Rem 7 1/2 is NOT "magnum".

This finding is supported examining targets shot with different primers/same charge at 100m with 6 PPC in a Stolle Panda - not much of a difference.

The difference in "standard" "magnum" and "benchrest" primers is mostly in the label and the price. It is unusual to find a primer of significantly different briscience to make a significant difference in pressure or velocity in cases as large as most bottleneck rifle cases. Of course, the smaller the case, the more significant the difference in primer energy. However, it is only with small cases and small powder charges that differences in primers start to show up in velocity/pressure.

just as waitaminit has said, the way I understand it is that the 7-1/2 is a bench rest primer. Not sure if it has a hotter charge than a 6-1/2 but if it did I would think they would designate it as a "magnum" primer. But it still could be hotter.

quote:

Originally posted by Stonecreek:
The difference in "standard" "magnum" and "benchrest" primers is mostly in the label and the price. It is unusual to find a primer of significantly different briscience to make a significant difference in pressure or velocity in cases as large as most bottleneck rifle cases. Of course, the smaller the case, the more significant the difference in primer energy. However, it is only with small cases and small powder charges that differences in primers start to show up in velocity/pressure.

primers

Thanks for replies, I understand and I would rework the load up but I'm curious if anyone has used both to compare and see any added benifit from going to the rem 7 1/2.

I apoligize on calling rem 7 1/2 a magnum primer, I looked it up and it did say benchrest primer, I guess the small magnum pistol primer blended in with but I can only see it being a hotter primer than the WSR or the rem 6 1/2 or why would they come out with it.

Neverflinch, I went to the post you put up on primers, interesting results.