Which Magnum LP primers are considered the hardest?

[R1ch]

The title says it all, which magnum large pistol primers are considered the hardest?

Is there any data anywhere for this?

Thanks!

 

[DukeInFlorida]

Well, my opinion is that the "soft primer" issue came up a few years ago, when one of the primer manufacturers used copper instead of brass for making cups for primer assemblies. Bad idea for AR-15's. Just the bolt closing on the primer face was enough to cause run away firing. (Slam Fires) Good thing there's only 30 rounds in the magazine. (or less if you can't have that many)

When they did that, it created this mystique about some primers being soft, and some being hard.

These days, hoewver, most of the primer manufacturers have probably incorporated a hardness test on the strip stock, and will only use it (brass) if it meets a tightly controlled hardness range.

So, "hardest primers" is going to be a relative thing, and likely to change from lot to lot. The brass they use is typically 70/30 cartridge brass. It can be work hardened, which happens during the rolling operation to make the brass strip, and during the forming operation. I'm not sure that they would want to anneal the brass after forming, since that would require a cleaning operation, and might distort the shape and sizing. So, I'm guessing that you get what you get from a particular batch of 70-30 brass.

Spec Sheet for 7030 cartridge brass: http://www.ejbmetals.com/pdf/datasheets-metal_strip/Ca260.pdf

Notice that they have four levels of hardness. 3/4 hard is as-formed. 1/2 hard, 1/4 hard, and annealed (dead soft) are operations done where annealing (heat) is applied, depending on the design of the part, and the need for softness. Again, I would doubt that the primer manufacturers would anneal, especially in light of the old "too soft" primer issue from years ago.

Since you are asking about Large PISTOL primers, I have to ask..... why are you wanting to know????

 

[R1ch]

Duke,

I knew you would have a answer that would be educational. I was almost going to ask to call you to discuss this on the phone where it is easier to communicate in real time.

I'm working with the 460 Rowland loads, and I'm getting some primer brass bits hanging in the firing pin hole. Not enough to cause issues, but enough to raise an eyebrow.

At first I thought I may be experiencing a primer flow issue, so I started investigating before I continued. For the record, this also occurs even with starting loads, following the exact published/verified load data recipe, and these loads were verified via chrony data. It occurs with lighter rounds (185 gr) as well as heavier rounds (230 gr) and throughout the powder recipe load range.

In speaking with the manufacturer (Clark Custom), they state that this phenomenon can happen with certain 1911s that use a large firing pin hole in the breach face (Kimber) vs a small one (Springfield). Those that use a small firing pin (they say that Springfield uses a smaller '38 super and 9 mm' size firing pin), don't have this issue at all.

Clark Custom's also stated that if I'm not getting enough brass left behind in the firing pin hole to cause a malfunction, then I can safely ignore it as it's mostly cosmetic in nature, or try the magnum primers as they stated because they are harder and less prone to this issue in the 460 Rowland.

FYI, I started with the exact published recipe, using the specified WLP primers, powder, bullet, OAL, etc. verifying via chrony data. When these had the issue throughout the min to max load, I then tried CCI 300 LP primers instead of the WLP primers) which showed the same issue (someone told me that CCI primers may be a bit harder than Winchester LP primers).

Clark recommend that I try magnum LP primers as they are harder than standard LP primers, or have my 1911 slide modified by installing a bushing and a 38 super/9 mm smaller firing pin.

I've read that others went to rifle primers to solve this issue, but that information came from internet postings , so I'd rather be a bit more conservative and take the advice of the developer.

So I want to try the magnum LP primers first (of course lowering the starting charge a bit from maximum when I do so) before modifying my otherwise perfectly working slide.

Not knowing if one brand of magnum primers may be known to be harder than another, I thought I would ask here first before buying some to try so I don't end up buying a brand that was 'known' to be softer than another. If there is no real difference between different brands, I won't worry about the particular brand and get what I can find to try.

If you would like to discuss this a bit more, PM me a phone number, I'll drop the dime for the call.

 

[EddieCoyle]

CCI's are harder than Winchester or Federal. I get more light strikes w/CCI than the others.

You can also try cutting the primer pocket a little deeper and going with a large rifle (not magnum) primer.