38 SPL with 170 gr Cast Bullets & 2400
Often on the forum someone asks about loading 160 – 180 gr cast bullets over 2400 powder in the 38 SPL for use in S&W 38/40 N frames along with 357 chambered handgun/rifles. The questions usually center around start and max loads. I have a bit of pressure test data on the Lyman 358156 seated out to the 2nd crimp groove loaded over 2400 in 38 SPL cases for use in 3844 or 357 handguns as that is what that bullet was designed for. The 358156 has become my favorite bullet of choice in the 357 Magnum for use with top end magnum loads. Also, if I was loading +P+ 38 SPLs for use in 357 magnums that is the bullet I would use. Some seem to want to use the heavier bullets though so I’ve pressure tested two different bullets [36-168K & 36-175H supplied by Ed Harris (Outpost75)].
Unfortunately, I no longer had a 170 gr Lyman “Keith” 358429 mould when I started pressure testing. I never developed an affinity for that bullet in the 357 or 38 SPL so long ago when I traded off an OM Ruger BH I let the mould go with it. I regret letting the Ruger go but not the 358421 mould. With the receipt of the 36-168K (169 gr) & 36-175H (184 gr) bullets I loaded them in 10 shot test strings of 8 – 12 gr in 1 gr increments. I used W-W 38 SPL cases and WSP primers. Alliant 2400 was used. All charges were thrown using a Lyman 55 powder thrower. The bullets were crimped in the crimp groove with moderate crimp.
Testing was done last Monday, May 22, at the local range here. Temperature was 90 degrees with 7% humidity. Testing was done in the shade so the ambient temperature is also the temperature of the ammunition.
The test firearm was a Contender with a 7.94” barrel. The pressure data and velocity was obtained via a strain gauge attached over the chamber connected to the Oehler M43 PBL. The M43 corrects the screen velocity to muzzle velocity and I posted muzzle velocity. Chronographing the similar loads in a 6” barreled Ruger Security Six results in 150 – 200 fps less velocity out of the revolver.
Test results are the averages of the 10 shots with each test string;
36-168K (169 gr)
Load……Vel……..PSI
8.0……..923……20,100
9.0…….1065…..22,800
10.0…..1151…..24,600
11.0…..1291…..27,000
12.0…..1392…..28,900
36-175H (184 gr)
Load……Vel……..PSI
8.0……..948……22,500
9.0…….1094…..24,400
10.0.....1185…..25,500
11.0…..1298…...28,100
12.0…..1396……29,700
LMG
Concealment is not cover.........