The Lyman 358156

A Double-Duty Dandy!

The Lyman 358156 is a dual-crimp groove slug of gas check design designed by Ray Thompson.

The following load data is for 357 Magnum guns and large framed .38 Specials capable of handling Magnum pressures.

When the .357 was first released, Winchester loaded the new Magnum with swaged 158 grain SWC bullets. Going in excess of 1,500 FPS, the pressures were too great for the soft slugs, resulting in severely fouled/leaded barrels after shooting just two-cylinders worth. Frustrated, savvy handloaders used harder cast bullets to remedy the leading. Savvier handloaders used Ray Thompson’s design — the Lyman 358156 —which incorporated a gas check (GC).

A GC is simply a copper cup crimped onto a cast bullet designed for one. The copper cup protects the base of the bullet from hot gases and scrapes any lead fouling from the barrel as it travels down the bore. Gas checked bullets can be shot at higher velocities and usually more accurately than plain based bullets. Today, aluminum gas checks are used and appear to work as well as the more expensive copper checks. I have a few dies that make GC for even more self-sufficiency.

Tank uses Sage’s Outdoors gas checks. They’re a bargain compared to other makers.

Skeeter's Favorite

Skeeter Skelton held the Lyman 358156 dear to his heart. Whenever I see 358156 bullets, I can’t help thinking of him. He used these slugs for heavily loaded .38 Special loads and the .357 Magnum. Since the 358156 is a dual crimp-groove design, he’d take advantage of it. He used the lower groove when loading .38’s and the top groove for .357’s. This provides more case capacity in the .38 brass, lowering pressures with the bullet not being seated as deeply.

Using the top groove for .357 brass keeps overall cartridge length in “spec” for .357 Magnum cylinders. When loaded in .38 Special or .357 Magnum brass this way, the 358156 slug cycles beautifully in Marlin 1894C carbines. It’s also an extremely accurate bullet in the Marlins. I’ve found top accuracy occurs when sized .359” in the microgroove guns.

The Lyman 358156 shoots exceptionally well in the Marlin micro groove 1894c. Who says cast isn’t accurate in micro-groove barrels? Not Tank! Size the .359” for top accuracy.

Tank’s Ruger Service-Six has had a bunch of Lyman 358156 loads shot through it, as has his S&W model 28.


I’ll admit, I shoot a heck of a lot more .38 Specials than Magnums, simply because I find a lot more .38 brass at the range and it is cheaper to buy. And guess what? I don’t feel shortened or cheated doing so. My favorite heavy load using .38 Special brass consists of the 358156 loaded over 13.0 grains of 2400, with the bullet crimped in the bottom groove and a standard small pistol primer. Velocity runs over 1,300 FPS from most handguns and well over 1,600 FPS from my Marlin carbine. For Magnum brass, I use 14.5 grains of 2400, obtaining 1,450 FPS from handguns and almost 1,800 FPS from the Marlin.

Medium loads in .38 brass use 11-11.5 grains of 2400 for almost 1,100 FPS and 13 grains of 2400 in Magnum brass for 1,200 FPS. Again, these are accurate loads, usually all you can hold.

Light loads with .38 brass and the 358156 consist of 5 grains of Unique or 6 grains of AA #5, for around 950 FPS from handguns. From the carbine, over 1,300 FPS is the norm. Accuracy is excellent with this load.

Here’s the Lyman 358156 loaded in .38 Special and .357 Magnum utilizing proper crimp groove.

Gas Checks

I use a LEE APP press for both sizing and crimping my gas checks. The APP Press allows one to drop the bullet nose first into the sizing die and simply drop the Gas Check on top of the bullet shank, sending it through the die as you pull the handle. Your GC will be crimped on perfectly and as tight as a bottle cap. There is no need to snap the GC onto the shank as with other lube/sizing presses. It prevents sore fingers and makes shooting GC’s a lot more fun.

Using the LEE APP press for sizing and crimping on gas checks is a breeze.

Simply drop the gas check on top of the bullet shank and send it. Your gas check will be bottle cap top and square.

Versatile Indeed

Using these loads makes the Lyman 358156 a versatile bullet indeed. It will handle deer sized game with the hotter loads, especially when shot through a Marlin carbine. So, pick yer’ poison for proper application with these three different power levels. There’s no need to shoot full snort loads all the time. It saves wear and tear on you, the gun and loading components. So, take advantage, amigo! You’ll appreciate it, as will your gun — and your wallet.