Hmmm.. Odd that Walther would design a pistol specifically for concealed carry but state that +p isn't recommended despite most defensive ammo being loaded to higher pressures. I'll heed the warning, thanks.
I will however have to test the functionality of my intended carry ammunition which *is* +p rated. (Corbon DPX 9mm+p) Do you think 20 rounds in a row will hurt it?
The P99 is 100% A-okay with +P rounds. It is rated for all SAAMI ammunition (regular pressure, and +P), and C.I.P. ammunition, which is actually hotter than SAAMI +P.
More specifically, my P99 came with a little blue card that says:
Your firearm has been designed for ammunition of a specific type and caliber. Use only ammunition in conformance to the provisions of C.I.P of SAMMI and corresponding to the caliber of the pistol. The correct caliber is specified on the pistol. Particularly when using reloaded ammunition the permitted gas pressure according to C.I.P or SAMMI must not be exceeded. Excessive pressure can damage or even blow up any firearm. Ammunition with velocities and perssures higher than those for which the firearms was designed will subject the firearm to additional stress, may cayse excessive wear, and may cause serious damage to your gun. Before loading, always wipe off any excess grease and oil and check that the bore of the barrel is clear and that there is no obstruction in the bore. Always wear ear and safety glasses when shooting. Alert bystanders to the importance of wearing ear protection and safety glasses.
Any damage or harm to neglection of the above instructions releases the producer from any product liability and / or warrenty.
A copy of the owners manual is available free upon request from:
Carl Walther GmbH, P.O. Box 43 25, 89033 Ulm, Germany
Also, I run Winchester Ranger +P+ through mine, without incident.
I'm almost 100% certain that I've read a post on here before where somebody called Walther and asked, they then responded that the gun was rated for standard pressures, not +p pressures, and use of these cartridges would void one's warranty...
To answer the question about P99 handling 20 rounds of +P...Yes it can.
I fired a box of Corbon powerball, one of regular corbon, one of speer gold dots (all are +P) and a few other boxes of different defense ammo and the gun is doing fine.
Kacerdias, definitely use more than one box to test your gun...I general hear people reccommend 100-200 defense rounds but I say that with a disclaimer as I haven't seen an actual study on the issue of defense ammo reliability from duty guns.
on page 6 of the P99's INSTRUCTION AND SAFETY MANUAL one can read : ... If you prepare your own handloads be very careful, and do not exceed recommended pressure in line with those generated by standard factory loads (not +P) ...
Indeed after firing quite some +P ammo I found that the barrel (breech side) of my P99 showed excessive play caused by a battered locking block. Conclusion : I had to replace the locking block and now I stay away from +P loads because it causes premature wear.
If the standard 9 mm round is not hot enough for you, get another gun / caliber.