Turns out it is harder than I expected to find projectiles for the 50 GI. Even though there are a fair number of 50 caliber choices, many of them are for magnums, and too heavy or long. Here are the bullets I’ve found, and measurements to help extrapolate to a different bullet. Anything in a table is a real measurement I took myself.
To compare how much a bullet design would weigh if it were exactly scaled down to be 45 ACP-diameter, multiply by 0.7295 = (0.451/0.501)^3.
Go here to see how the bullets actually shot.
Interestingly, except for the SWC shape, there is a strong (R^2 > 0.91) correlation between the overall length of a bullet and it’s weight. I did not expect so much correlation. Since the diameter of a bullet is tightly controlled to less than 0.001″, usually by pushing an oversized bullet through a sizing die, it makes some sense that most dimensional variations will be squeezed into variations in height. But weight differences can be caused by other things, like differences in alloy, bubbles, and nose geometry too. …The strong correlation still surprises me.
TODO: I suspect the rim-thickness (not OAL) of the SWC will still correlate strongly, but need to measure it.
👍 Rim Rock 255 grain SWC – basically a scaled-up H&G #68 (classic 45 ACP 200 grain bullseye bullet), but 5% to 7% lighter. Nominal specs: OAL 0.656, Meplat 0.281, No crimp groove. Excellent all-around bullet.
I measured one rim to be 0.333″ thick
.50GI 275gr Jacketed Hollow Point. Made by Ranier for Guncrafter Industries, and only sold through GI. $0.23 each (6/2018). It has a cupped base
Speer DEEPCURL® HANDGUN HUNTING 50 ACTION EXPRESS 50 caliber 300 grain (#4493). It is a bonded-jacket hollow-point. I haven’t done expansion testing, or found specifications, but I highly doubt it will expand at 50 GI velocity. G1 BC is nominally 0.155. It has a cupped base, I measured it as approximately 0.017 deep, but wasn’t able to get a consistent reading. $0.44 each as of 9/2018.
👍 Berry’s 300 Grain plated “Round Shoulder”. Squatter design than the GI 300 grain bullet. It is slightly shorter and has a bigger meplate. Should hit harder but have more drag.
50GI 300 grain Jacketed Flat Point. Made by Ranier for Guncrafter Industries, and only sold through GI. $0.22 each (6/2018). It has a streamlined profile and a cupped base.
Hunters Supply 325 Grain Lead Flat Nose (#0150132540). I would call it a truncated cone (TC) shape. Nominal specs “6% antimony, 2% tin and 92% lead with a Brinell hardness of 15 rated to 1600 fps without gas checks.” Meaplate approx 0.35″ to 0.36″. Each bullet had a fairly large sprue, so I am not confident in the OAL measurements. MSRP $22.99/50 $79.9/250, but MidwayUSA has them for $16.99/50 or 58.99/250 (as of 07/2018).
|0.7080 (slight hollow base)||322.6|
|0.7090 (including sprue)||322.0|
330 gr. RNFP Rim Rock says it can be used in 50 GI. Nominal specs OAL 0.713, Meplat 0.298, Nose to crimp groove 0.299. $34/100. 👎 because they are smokier, and spendier, than the Badman Bullets RNFP.
👍 Badman Bullets 330 gr. RNFP. Looks the the same as the Rim Rock RNFP, and is polymer coated. Price as of 5/2018 is $98/$188 per 500/1K. 👍 It’s a big ball of lead, which is just right for the 50 GI. No smoke and lower price than a modern JHP 45 ACP bullet is a big plus. Not the most consistent bullet.
Rainier LeadSafe Bullets 50 Caliber (500 Diameter) 335 Grain Plated Flat Nose (#50335FP5). Copper plating is nominally 0.004″ thick. Maximum recommended velocity of 1,500 fps.
They have a cupped base, I measured it as 0.0285″ deep, but have low confidence in my caliper technique. Street price: $21.99/50 $84.99/500 on 07/2018.
Berry’s 350 Grain Round Shoulder plated (with cannelure). “Can withstand velocities up to 2000 fps” so probably harder than optimal. Street price as of 6/2018 $0.22 (sale) to $0.29 each for the 500 count pack. They are intimidating to work up loads for because of their high weight.