Some ammunition companies list 9mm +P+ loads, which are not regulated by SAAMI and are loaded to proprietary pressure levels and velocities, so are only recommended for select guns. 9mm pressure vs 38 p, 9mm vs 38 chamber pressure, luger maximum pressure, max load pressure for 124 grine 9mm, max pressure for 9mm, maximum pressure for 9mm loads, minimum pressure for 9mm loads. On Speer's website they list the 124gr+p at 1220fps and the 124gr standard pressure at 1150fps. All this means it is a recognized "standard" for loading ammunition for 9 MM. That’s nearly a 30% increase from the standard. Let's use 9mm as an example. The service pressure P max of the 9mm NATO is rated at 252 MPa (36,500 psi) where CIP rates the 9mm Luger P max somewhat lower at 235 MPa (34,100 psi). Again +P+ does not exceed the proof round. The 9mm easily jolts 115 to 124-grain bullets to well over 1100 fps. I remember my FAMILY loading very hot 9mm Handloads for the surplus P-38 & P-08 pistols in the 1950's-'60's. 9mm +P is 38,500 psi, which is close. This brings us to 9mm Luger +P loads that operate at a maximum average pressure of 38,500 psi, and again are not recommended for all pistols. Thread Tools: Search this Thread: Show Printable Version. An overpressurized (+P) 9mm may have 38,500 psi — an increase of 10%. SAAMI does not publish +P+ loads and therefore they are developed by each ammunition manufacturer. +P or higher-pressure loadings may reach 1300 fps. It is a 9mm-OAL round designed to make major power factor for IPSC/USPSA right out of the box. The 9mm +P will produce slightly better performance than a standard 9mm, at a noticeably higher cost. A +P+ load is X percent higher than a +P load. Complete 9mm ammunition ballistics Chart. It is also incompatible with some guns (look at the owners manual for specifics on your gun). Most +P rated 9mm pistols are rated to withstand greater than 70,000 psi before catastrophically failing. They do well against barriers, but when the cavity fills with fluid, the hydraulic pressure builds until the side walls of the projectile explode. +P Is maximum 38,500 PSI. American made 9mm Luger didn't always function these guns. Some semi-auto pistols will handle the high pressure with no problems. As noted, 357 Sig runs 40,000 psi. Both out of 4 inch barrels. Standard pressure SAAMI loads are 35,000 PSI while +P pressure is 38,500. A higher pressure round (+P+) may be rated to something like 45,500 psi. If I we're looking for something with a little less recoil (not that 9mm has much anyway, especially in a full size gun) and with less muzzle blast, would the 124 grain standard pressure do just as well as the +p version? With that explosion comes starburst pattern fragmentation, reduced over-penetration, and 100% energy transfer. 9mm NATO can be considered an overpressure variant of 9×19mm Parabellum that is defined by NATO standards. The 9mm is a powerful number well-suited to personal defense. This does not mean your gun will "blow up" if you exceed these specifications by 1 PSI. It did, and still does. Of course you can shoot just about any 9mm Load in a RUGER BLACKHAWK .357 Convertible's 9mm cylinder. Click on a term to search for related topics. No problems with the Canadian made Hi-Powers. The 9mm is not quite as good as some of its fans think, but it is a better cartridge than most of its detractors would have you believe. 9MM Standard Pressure, as layed out by SAAMI Specifications is 35,000 PSI. But other rounds have even higher pressure. Compare all 9mm ammunition manufacturers on one easy to read chart. 356 TSW has a maximum limit of 50,000 psi.