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View Full Version : Ruger P90 .45 Super


Stumper
August 22, 2010, 10:17 PM
The Ruger P90 is rated for all SAAMI, MilSpec and CIP compliant .45 ACP ammunition. The stock recoil spring is rated at 11lbs. Mine has a chamber that supports the cartridge very well forward of the web. Wolff offers heavier springs up to 16 lbs. Could you? Would you? Should I? ........(buy some .45 Super brass, install a heavier recoil spring and hot it up.)
Actually the old .45 ACP is a great round and suitable for 95% of what I want from the Pistol......but a couple hundred fps more moves it into a different class.

Stumper
August 24, 2010, 01:32 PM
Apparently there is not a lot of experience with doing this since I've have 35 views and no response.
Ace Custom 45s says that the stock P90 is suitable for 45 Super "Tactical" loads(Speced at 185gr bullet 1200fps, 1125 fps 200 grain bullet 1025fps 230 gr bullet from 5" barrel) Those figures are just a bit higher than normal .45acp +p figures. Presumably pressures could fall somewhere between the 23k CUP ceiling of .45 ACP+p and the 29,000CUP ceiling of .45 Super but based upon Ace Custom's willingness to recommend the ".45 Super Tactical" loads for several guns with advice to contact the manufacturer about full .45 super loads I suspect that the "Tactical" rounds are right at the ceiling for .45ACP+p (Small ammo companies such as Buffalo Bore and Texas Ammunition seem to be able and willing to load closer to maximum pressures whereas large companies tend to set their velocity norms a bit lower and load whatever bulk lot of powder to the nominal velocity specs (+/-)while keeping pressures under the ceiling----Some current "+p" .38 special ammo from the big makers doesn't even match standard specs in performance nor , as far as I an determine based upon case measurements, does it produce higher than standard pressures) In no case should firing .45 Super catastrophically destroy a .45 ACP-current .45 Super pressures are UNDER .45 ACP proof pressures- but such rounds could beat a gun to an early death.
I don't need to push the envelope hard but I will come back to this thread and report on my +p load testing with .45 Super brass and a heavier recoil spring when I get a chance to pursue this.

spacecoast
August 24, 2010, 01:58 PM
You've probably seen these pages, but there are apparently some risks in doing this. If it were me, I would proceed very cautiously, I'm not sure if the gun will show "signs" of overpressure without catastrophic failure as brass might.

http://en.wikipedia.org/wiki/.45_Super

http://www.notpurfect.com/main/45cart.htm

From Starline Brass:

45 Super* is the same externally as the 45 Auto, but has a thicker web, denser grain structure in the metal, and special heat treat process that enhances the durability of the case. Similar internal capacity as the 45 Auto. Some 45 Super load data was published by Triton Cartridge before they went out of business. *Loads to be shot ONLY in guns modified professionally to handle extreme pressures of this cartridge. DO NOT SHOOT IN STANDARD 45 AUTO!

Stumper
August 24, 2010, 08:26 PM
Thanks spacecoast. I do intend to proceed cautiously and will not drive the P90 to the top of .45 Super data. Instead I intend to work up some warm .45 ACP +Ps (which the gun IS rated for) but with a higher rate spring to reduce battering and keep brass recovery simple.