[msredneck]

OK I'm a newbie here....Have just completed my 2nd USPSA match. I'm shooting a G17 Production class.

I am about to embark on 9mm reloading pretty heavy. I have done a search on this forum...I really have... and can't seem to get a definitive answer to the following:

small pistol primers are still very hard to find....small magnum are very easy to find.

I have Rem 5 1/2's (small mag)...can I use these with with a relatively slow burning powder like Hod. Universal Clays?

I've seen references to substituting small rifle primers for small pistol and reducing the starting charge wt by 10%.

Can I substitute the Rem 5 1/2's (small mag pistol) for the 1 1/2's (small pistol) safely?

Many Thanks for your help

[The_Vigilante]

You shouldn't have any problem substituting small pistol magnum for small pistol primers. Will add approx. 5-10 fps to your cartridges. Standard advice is to start at the bottom range of the load and work your way up. Good luck.

[msredneck]

Many Thanks...I always start on the low end of the powder charge....

a second question...so what's the real difference between the two primer types....just the thickness (not hardness) of the primer cup?

I sure wish Remington would put small Magnum pistol on the box...

Both the 5 1/2's and the 1 1/2's say small pistol....easy to mix up

Thanks again...

[fred fague]

I shoot 9mm major open and have seen about 15ft per sec with Win and Rem magnums. Shooting minor with magnum primers should not be a problem. Also temp does not seem to change the chrono results. There are other factors, which can change your chrono results; bullet type, crimp, and OAL. Always case gage all your loads.

[mrg]

Been using Federal SPM for a while, before SPP became available around here. I think the only difference is how much. or how hot the priming material is. I can't tell the SPMs are any harder.

Mark

[rfwobbly]

msredneck, on Sep 7 2009, 03:06 PM, said:

a second question...so what's the real difference between the two primer types....just the thickness (not hardness) of the primer cup?

From what I understand...
• Magnum primers are simply hotter than standard primers
• Rifle primers and pistol primers differ in that rifle version uses a thicker material to withstand the higher chamber pressures

So....
• To use magnum pistol primers in place of standard pistol primers start over at the lowest load.
• To use standard rifle primers in place of standard pistol primers test them to see if your hammer spring is strong enough.

[LarryP]

msredneck, on Sep 7 2009, 12:06 PM, said:

Many Thanks...I always start on the low end of the powder charge....

a second question...so what's the real difference between the two primer types....just the thickness (not hardness) of the primer cup?

I sure wish Remington would put small Magnum pistol on the box...

Both the 5 1/2's and the 1 1/2's say small pistol....easy to mix up

Thanks again...

FWIW: If you look on the Rem 1 1/2 box it will warn you not to use in .40 cal. Their reloading advice says to use 5 1/2 for .40 cal.

LP

[Graham Smith]

LarryP, on Oct 6 2009, 09:07 AM, said:

FWIW: If you look on the Rem 1 1/2 box it will warn you not to use in .40 cal. Their reloading advice says to use 5 1/2 for .40 cal.

How strange. I ran through some I had left over from loading 9mm and never even considered that as an issue. I wonder why?

[G-ManBart]

I don't have much experience with Remington primers, but I know that both Federal and Winchester SPM have a harder/thicker cup than standard SP. In both of my Open guns standard SP primers will flatten a fair amount with SP, but either not at all or just barely with SPM. Federal shows more difference than Winchester in that regard. Fed SP behind a 175PF load will flatten them pretty well, but Win SP only flatten a little bit....with SPM or SR from either company it's either zero or a very small amout of flattening. So, the SPM's have to use a harder cup material, thicker cup or maybe both.

One caution about using SPM or SR primers in light 9mm (Minor) loads. At the reduced pressures it's possible that there isn't enough pressure to seal the primer in the primer cup when the round goes off. If that happens hot gasses blow past the primer and will cause wear on the breachface of the slide. In some cases it might take a long time to cause visible wear (a circle shape around the firing pin hole where the metal has been burned away) and in others it can happen in a couple of hundred rounds.

Best bet is to check the breachface after 50-100 rounds and simply feel that area to see if there's an indention. If there's none, go another 100 and check again. If you manage several hundred without a problem it's just something to keep your eye out for in case it slowly starts to develop....you'll be able to catch it early enough you don't have to replace the slide because it obviously isn't acting fast if it took that long to develop. Again, this is only with really light loads. R,