Bare Bottomed 358156 HP


John Goins/akabeagle


I’m willing to bet that anyone who loads for the .38 Special or .357 Magnum has one of these moulds in their mould stash.  If not, they had a 358156 mould sometime in their casting career.  I think I have four at last count.  One solid double cavity version, and about three single cavity hollow point moulds.  I just seem to keep picking up the hollow point moulds minus the pins as I hate to see “orphans” running around like that.


This design has been the old standby for years.  It was designed by Ray Thompson and hailed by Skeeter Skelton as better than sliced bread in the .357 Magnum and in .38 Special cases in the magnum guns.


I’ll admit, it’s a pretty good design and a lot of thought went into the double crimp groove, adequate lubrication capacity and semi-wad cutter design.  The weight is almost ideal.  I normally shoot a lot of #358429 bullets in .38 Special and .357 Magnum handguns but even Elmer said his bullet was maybe a little too heavy for the caliber so the #358156 is just about right.


It came about with the birth of the .357 Magnum.  I’m not sure of the year but sometime in the early 40s I’d say.  The .357 Magnum was plagued with leading problems early on, because casters of the time knew much less about leading than we do now and the bullet lubes that were not as efficient.  The gas check was the cure all and for years was the answer to obtaining good accuracy and velocities in the .357 Magnums. As an additional plus, the 358156 was short enough to fit the cylinders in Smith and Wesson .357 Magnums in .357 cases.  The 358429 wouldn’t fit the Smith & Wesson revolvers unless it was seated deep in the case, which can lead to all kinds of problems.


We now know more about using larger diameter bullets poured from proper alloys, have equipment for measuring bullet hardness, and our lubes are much improved.  These advances mean that leading is rarely a problem, even with Magnum loads.


As I said earlier, the #358156 is a mould that most casters latch on to in the early stages of their mould grabbing career because of its reputation for good accuracy and no leading.  But, you very seldom see them being used.  Even though I have 4 358156 moulds, I doubt that I’ve cast and shot 500 of them in 10 years.  The reason….the cost of the gas check that’s required.  Yeah, I know, Skeeter shot them without gas checks.  I have too, and the accuracy suffers.  I have also swaged a plain base on some in a Swage-O-Matic and they work pretty well but the process is a hassle.


It gets right down to one thing on that mould….the gas check.  With the current price of gas checks running at close to $20 a thousand, they become a significant part of the reloading cost and eat into the old shooting budget.


I’d been running the thought of this around in my mind for some time and since we’d been “dehorning” (removing gas check shanks) from bullets for the .45 Colt such as the #452490 and #454485, I decided to sacrifice a #358156 HP in the name of science and turn it into a plain base.


This is a fairly new Lyman mould and casts right at .361”.  I asked my machinist shooting partner to remove the gas check shank and open the base band to about .361”.

This is a fairly easy process if you have the equipment.  This would be an EDM project, so I expected it to be right at .361”. When removing the gas check shank, it doesn’t hurt to be a little over size as the sizing process takes care of any problems you have as long as they’re not too big.  Removing the gas check shank also usually gives you a pretty wide base band, which I like in a bullet.


Lyman’s 358156 HP as a plain base


I received the modified mould back a week later and ran 100 bullets.  They dropped right at .361” on all bands.  Weight lubricated and sized is 140.6 grains, and I used GAR’s Half & Half lube for all tests.


I loaded two test lots with the new modified bullets.  Both lots were loaded in .38 Special cases.  One lot is for my Model 15 Smith and Wesson 4” and the other is for my Ruger Blackhawk .357 Magnum.  I’ll call the stronger loads .38/44 loads as they’re too hot for regular .38 Special guns.








Av Vel











Green Dot


Win SP





Acc all








Win SP




Acc 100


.357 Magnum










Acc all ranges

 Note – The load in red should not be used in guns designed specifically for the .38 Special cartridge and should be restricted to guns chambered for the .357 Magnum cartridge.


The two test lots shot well for me and proved this is a feasible modification to the 358156 design that will allow wider use in my .38/357 pistols.  No leading was detected after firing 50 rounds of each lot through each gun.


            I shot the Model 15 S&W at 25 yards on paper and it gave me about 2 ½” groups.  I plinked at some small rocks on the 50 yard berm and had no trouble hitting them from a sandbag rest.  Heartened by these results, I switched to the 100 yard berm and was able to obtain hits on football patches of light dirt.  Impact was a little low but I was able to hold over and detected no flyers out of about 20 rounds fired. I didn’t want to mess with the sights as this is my wife’s gun and I won’t go there.


            The .38/44 loads loaded for the .357 Blackhawk were tested on targets on the 100 yard berm and I detected no flyers.  It had power consistent with other .38/44 loads I use in the .357 using .38 Special cases and will make a nice field load.


            Initially, there was some skepticism as to whether the lubrication provided by one groove was adequate to prevent leading at .357 Magnum velocities. I cast another lot of 50 bullets and lubed them in the same manner.  I loaded a box of .357 Magnums over 13.5 grains of 2400 and fired them the past weekend.  Accuracy remained constant during the entire run and after firing, I wiped the bore with a dry patch and no leading was evident.  These were not maximum .357 Magnum loads and ran only 1322 FPS, but it seems as the large diameter bullets I’m using in the Blackhawk combined with our modern lube does all right at higher velocities as far as handling leading.


L: 358156 HP PB fired at the 923 FPS velocity

R: 358156 HP PB fired at 1168 FPS velocity


            The two bullets shown above were recovered from the 100 yards berm after testing.  The lower velocity load didn’t “cut the mustard” at 100 yards as far as expansion went.  The higher velocity load demonstrated classic mushrooming and lost about 1/3 of its total weight.  It would probably be a great load for field use on varmints.


            If a constant diet of .357 Magnum loads is in order in a handgun or say, one of Marlin’s .357 Magnum M1894 Carbines, it may be the best bet to retain the #358156 HP mould as is and use gas checks.  For use in handguns as a plinking and general purpose bullet, the modified bullet should be adequate and allow more shooting for the bucks with no loss in accuracy.


            As a result of these tests, I think it is both feasible and desirable to remove the gas check shank on the #358156 moulds for regular handgun use and get more mileage out of the mould. I know I’ll be using mine more here in the future as it’s a darn good little bullet.


John Goins/akabeagle


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