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Reloading Notes

Observations and loads that I found worked well with my firearms.

.38 Special

Ruger GP-100 vs. Charter Arms Undercover

The GP-100 with the 4" barrel consistently shoots the same ammunition about 100 fps faster than the Undercover with the 2" barrel.

Marlin 1894 vs. Ruger GP-100

The 125gr JSP with 6.0gr Unique shoots about 225fps faster in the 1894 with the 18.5" barrel than in the GP-100.  This isn't as big of a gain as we get with the .357 (around 500fps) because the .357 rounds use a slower burning powder and can take advantage of the longer barrel. This load is a little hot for the regular (non +P) .38's, and may even be at the upper end of .38 +P, depending on which manual you reference. However, they're very accurate in the GP-100.

Lead vs. Jacketed

I recently started loading 158gr Speer LSWCHP's over 4.6gr and 4.9gr Unique.  The 4.6gr is in the upper .38 Special range, and the 4.9 is mid +P range.  Both were accurate in the GP-100, although I didn't do much accuracy testing in the Undercover. In the Blackhawk (with a 9.5" barrel) the two loads clock between 1000-1100fps, which is allegedly as fast as you can push a soft lead bullet without leading.

Cost-wise, the LSWCHP beats the JSP hands-down at $0.13 per round versus $0.20 (a $7 savings on a box of 100!) Having never done it before, I was initially a little hesitant to load lead bullets. However, I blew through a 500-round box in a month and a half loading a bunch of empties I had laying around.

Due to the aforementioned leading, and the microgroove barrel in the 1894, I can only shoot jacketed bullets in it. So, I'll still be loading the 125gr JSP's for plinking

Also, fixed sight .38 snubnose revolvers are apparently calibrated to put 158gr lead bullets at the point of aim.  Any of my jacketed bullets were about 6-7" low, and the LSWCHP's were dead on!

.357 Magnum

125 grain bullets

After doing some research online, it appears that slow burning powders with light (125gr) bullets tear up the forcing cone.  Fast burning powders like Unique and even 2400 appear to be less of an issue. I'm probably going to be loading less 125's in .357, but I loaded batch of 125's over 16.8gr 2400 that I still need to chronograph.

The 8.8gr Unique (1338 fps) is a mid-range velocity for that bullet weight, which I'm not too unhappy with. However, the 9.2gr load was barely faster, but clearly much higher pressure since I had problems extracting the shells from all the guns I tested.

140 grain bullets

Due to the reported problems with 125gr bullets, these are going to be my new "light" .357 standard. The conventional wisdom is that they can be driven almost as fast as the 125gr, and are almost as heavy as the 158gr.

I was very happy with 10.8gr Blue Dot, which is below the 11.5gr max listed by Speer. We did some testing with some at 11.5gr, and they were going much faster than reported in the manual, even out of the shorter GP-100. They were going 1600fps out of the 9.5" Blackhawk barrel! After doing some research, I believe this to be caused by Blue Dot being inversely temperature sensitive.  In other words, the colder it gets, the more pressure it generates.  Normally, powders will generate less pressure in cold weather.

158 grain bullets

My hunting load for the Marlin 1894 is 17.6gr 300-MP under a 158gr JSP. I had purchased the relatively new 300-MP powder on seeing the numbers on Alliant's site, but it appears these velocities may be more overstated than the norm. It chronographed at 1717fps, with a muzzle energy of 1035ft-lbs. It worked very well on a little Bambi (oops!) going in behind the shoulder, and exiting with about a 3/4" hole through the ribs. The deer collapsed on the spot. I went with a JSP over an XTP hollowpoint because, in this case, I'd rather trade some expansion for some penetration. The behind the shoulder shot over-penetrated, but on a larger deer with a through the shoulder shot may not.

Upon reading that the Federal American Eagle 158's chrono at 1850fps out of 18.5" barrel, I want to:

  • Chronograph the handful of those I have left to verify
  • Attempt to work up some H-110/W296 loads, which will meet or exceed that velocity
  • Stock up on the American Eagle's if I can't come up with something comparable


The 12.5 grains 2400/53 grain Sierra JHP is designed to simulate a .22 Hornet/.218 Bee load.  It uses a 53 grain Sierra Matchking hollowpoint, which is not designed to expand.  2400 is a medium burning pistol powder, but faster than most rifle powders. The intent is to have something to use on rabbits that won't cause massive damage like a standard varmint load. In accuracy testing, this load put 4/5 bullets in one hole at 22 yards, and the fifth hole was 1/4" below that.