Atypical 7.62x39 casing

cunanse · March 29, 2009, 03:26 PM

I once bought some PCM 7.62x39mm SP. They're inexpensive and boxer primed. I've started reloading in that caliber and noticed that the PCM brass and only the PCM brass takes a small pistol primer. Of course, there is only one type of small pistol primer available at Sportsman's Warehouse right now: Small pistol for magnum loads. I'm loading the brass with Hornady 123-gr. PSP with 23.6 grains of IMR 4198. I'm holding off on loading the PCM brass for a bit longer. Does anyone foresee unpleasant results using small pistol primers for magnum loads? If anyone can explain the difference between normal and magnum primers, I would be much obliged.

res45 · March 29, 2009, 03:44 PM

Actually Remington uses a small rifle primer in there X39mm cases,there are a few others also,aside for that the difference between standard and Magnum primer can very. In Wolf primer the only difference is the Mag primer have a thicker cup. With American primers the Mag primers produce a hotter flame to ignite certain types of powder that are normally harder to ignite with a standard primer and in larger capacity cases like the big Mag cal. rifles.

I wouldn't recommend using pistol primers in rifle cartridges,the cups are usually thinner and can be easily pierced,there not designed to hold rifle rd. pressures. Also if your loading the X39 rds. for a rifle such as an SKS or AK you should consider using either the CCI Mil-Spec primer or Wolf SRM primer to help eliminate the possibility of a slam fire from the free floating firing pin when it strikes the primer. The Mil-Spec primer are less sensitive to primer strikes than the standard primer. If your loading for a bolt gun then you can use any standard SR primer.

Stick to pistol primes for pistols and rifle primers for rifles,short cuts aren't worth the risk.

cunanse · March 29, 2009, 03:58 PM

Gotcha. I was simply under the impression that the differences between rifle and pistol primers were diameter. Good to know,

res45 · March 29, 2009, 04:11 PM

Lots of good general info here.
http://www.exteriorballistics.com/re...ics/primer.cfm

BobMcG · March 29, 2009, 04:12 PM

SPMPs not recommended.

A magnum primer is a "hotter" loaded primer than a standard and is capable of creating higher chamber pressures than a standard primer.

I have 7.62X39 Rem brass that uses SR primers but it's available in a LRP version too. I'm using CCI-400 SRPs in them.

I also have Lapua brass that uses LR primers but is also available in a SRP version. I'm using CCI-200 LRPs in them.

A LRP would = a hotter primer than a SRP. Unless someone else has experience to the contrary I don't think it would be unreasonable to use SRMPs in 7.62X39 cases using starter loads (not max) and working up.

My load info shows:
Hornady, using Win. brass & Win. LRPs.
Sierra, using Win. brass & Rem. LRPs.
Speer, using IMI brass & CCI LRPs.
Lyman, Win. bras & Win. LRPs.
Hodgdon, Midway brass & CCI LRPs.
Accurate, IMI brass & Rem. LRPs.
Vihta., Lapua brass & ??? LRPs.
Alliant, Fed. brass & CCI LRPs.
IMR, IMI brass & CCI LRPs.

March 29, 2009, 03:26 PM	#1
cunanse Member Join Date: February 15, 2006 Posts: 37	Atypical 7.62x39 casing I once bought some PCM 7.62x39mm SP. They're inexpensive and boxer primed. I've started reloading in that caliber and noticed that the PCM brass and only the PCM brass takes a small pistol primer. Of course, there is only one type of small pistol primer available at Sportsman's Warehouse right now: Small pistol for magnum loads. I'm loading the brass with Hornady 123-gr. PSP with 23.6 grains of IMR 4198. I'm holding off on loading the PCM brass for a bit longer. Does anyone foresee unpleasant results using small pistol primers for magnum loads? If anyone can explain the difference between normal and magnum primers, I would be much obliged.

March 29, 2009, 03:44 PM	#2
res45 Senior Member Join Date: September 15, 2007 Location: NC Posts: 753	Actually Remington uses a small rifle primer in there X39mm cases,there are a few others also,aside for that the difference between standard and Magnum primer can very. In Wolf primer the only difference is the Mag primer have a thicker cup. With American primers the Mag primers produce a hotter flame to ignite certain types of powder that are normally harder to ignite with a standard primer and in larger capacity cases like the big Mag cal. rifles. I wouldn't recommend using pistol primers in rifle cartridges,the cups are usually thinner and can be easily pierced,there not designed to hold rifle rd. pressures. Also if your loading the X39 rds. for a rifle such as an SKS or AK you should consider using either the CCI Mil-Spec primer or Wolf SRM primer to help eliminate the possibility of a slam fire from the free floating firing pin when it strikes the primer. The Mil-Spec primer are less sensitive to primer strikes than the standard primer. If your loading for a bolt gun then you can use any standard SR primer. Stick to pistol primes for pistols and rifle primers for rifles,short cuts aren't worth the risk. __________________ The Reloaders Network discord Channel https://discord.gg/Nafuzht Last edited by res45; March 31, 2009 at 11:59 AM.

March 29, 2009, 04:11 PM	#4
res45 Senior Member Join Date: September 15, 2007 Location: NC Posts: 753	Lots of good general info here. http://www.exteriorballistics.com/re...ics/primer.cfm __________________ The Reloaders Network discord Channel https://discord.gg/Nafuzht

March 29, 2009, 03:58 PM	#3
cunanse Member Join Date: February 15, 2006 Posts: 37	Gotcha. I was simply under the impression that the differences between rifle and pistol primers were diameter. Good to know,

March 29, 2009, 04:12 PM	#5
BobMcG Member Join Date: February 27, 2006 Posts: 81	SPMPs not recommended. A magnum primer is a "hotter" loaded primer than a standard and is capable of creating higher chamber pressures than a standard primer. I have 7.62X39 Rem brass that uses SR primers but it's available in a LRP version too. I'm using CCI-400 SRPs in them. I also have Lapua brass that uses LR primers but is also available in a SRP version. I'm using CCI-200 LRPs in them. A LRP would = a hotter primer than a SRP. Unless someone else has experience to the contrary I don't think it would be unreasonable to use SRMPs in 7.62X39 cases using starter loads (not max) and working up. My load info shows: Hornady, using Win. brass & Win. LRPs. Sierra, using Win. brass & Rem. LRPs. Speer, using IMI brass & CCI LRPs. Lyman, Win. bras & Win. LRPs. Hodgdon, Midway brass & CCI LRPs. Accurate, IMI brass & Rem. LRPs. Vihta., Lapua brass & ??? LRPs. Alliant, Fed. brass & CCI LRPs. IMR, IMI brass & CCI LRPs.