10 January 2021
Info on Colt DA 45 (ACP) on hand Since 1957 -58 as follows: Bore 0.444-0.445, Groove 0.451-0.452, chambers 0.455-0.456, Cylinder pass 0.007, hold 0.008. Bore and chambers are frosted from early use with corrosive ammo, otherwise in excellent condition with a tight action and reasonably heavy trigger pull.
On hand is a partial box of Remington 45 Auto Rim cartridges with 230 grain lead bullets, probably from 1962 -63. Also recorded below is data from Federal ball Lot FC 1950 FC 61 headstamp.
Some velocities recorded at 10 feet are as follows:
Colt DA Army Colt 1911A1 from 1943 US
RP 45 AR 230 gr Lot E185 709 FPS
FC 61 ball 748 FPS 767 FPS
Speer 250 SWC/5.5 Unique 669 FPS
0.454 dia LLA LD #11
H&G 22 250 gr RNFP 0.454 sized 812 FPS
/lubed/5.5 grs HP 38 LD #8
25 yard accuracy results were miserable due to my own handicaps and are not included - will try again another day. My best accuracy was with a Ruger convertible 45 acp with a scope on it, so I have hope for better results.
XXX - Please note, That after researching loads in multiple sources, that the 250 H&G mold load with 5.5 grs of HP 38 exceeds most recent loading recommendations - it was the only reference I could find for a 250 gr bullet in what I had on hand under max recommendations, the 1998 Midway 45 ACP Loadmap pamphlet. The load did fine in all the revolvers I tried S&W 1917, 25-2, Colt 1917 and Ruger NMBH 45 convertible which did record 878 fps from a 7 1/2 inch barrel. Also note that all the above have chamber throats of 0.455" or above. Am currently revisiting this load and will probably reserve the remaining rounds for the NMBH. The 250 grain bullets were the only ones on hand that came close to fitting the 0.455 chambers and loaded rounds chambered satisfactorily.