MFS "+P" Factory Reply re: Pressure

nbender · Post by **nbender** » January 3rd, 2007, 6:46 pm

The following techno-babble was inspired by Normsutton, who prodded me into writing the MFS factory to ask about the pressures of their "+P" 9x18, in regards to whether it is safe to fire in the P-64. I received the following reply:

We are sending you in attachment the details of the ballistical testings of our 9x18 Makarov+P.

The ammunitions meet with C.I.P. standards, therefore they may safely be used in any weapon.

Kind regards,

György Károly

The attachment provided by MFS is in Hungarian, but it's easy to read the column on pressure testing. Of 30 shots fired, the highest pressure recorded was 1,333 bars, which is equal to 19,334 psi.

There is not a lot written about the design aspects of the 9x18 cartridge in regards to pressure parameters. The Ultimate Makarov Guide, by Walton Cude, states that the Makarov was built to withstand pressures " ... somewhere between 17,000 and 24,000 psi". I spent some time looking at ammunition manufacturers and most don't publish pressure data - just muzzle velocity. Barnaul lists 17,071 psi for the 9x18. The International Defense Equipment Exhibition, 2006, held in Bulgaria, listed a 17,068 psi 9x18 cartridge.

If anybody can add to 9x18 cartridge pressure data, or pistol pressure design parameters, please chime in.

saands · Post by **saands** » January 3rd, 2007, 9:35 pm

FWIW ... my QuickLoad software shows the 9x18 as having a max pressure of 1,600 bar (or 23,206 psi) ... and they list it as a CIP limit, not a SAAMI limit. I guess that doesn't contradict anything that you have there ...

Saands

nbender · Post by **nbender** » January 3rd, 2007, 9:47 pm

Thanks saands. A reply on Gunboards stated that the Speer reloading manual lists SAMMI max @ 24,100 psi. So, according to the MFS data, the cartridge is well within pressure limits.

Post by **normsutton** » January 3rd, 2007, 10:01 pm

nbender

A BIG THANK YOU FOR ALL YOUR IMFO

nbender · Post by **nbender** » January 5th, 2007, 10:48 am

Widener's has the best price on this ammunition at $8.35 a box:

http://www.wideners.com/itemdetail.cfm? ... =6869&dir=

saands · Post by **saands** » January 5th, 2007, 3:04 pm

I should have mentioned that I don't think that cases from max loads shot in a P64 with standard springs can be reloaded as there will be a healthy (or maybe unhealthy

) "smilie" after it is fired ... and this is on loads that work just fine in the PM. I also wouldn't load max loads on once fired brass as it looks like they do get fully stressed by the experience! This may be a moot point, however, as I rarely ever see the cases from max loads after they eject as they seem to reach a low Earth orbit fairly easily.

Saands

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