The .357 Magnum revolver cartridge is a favorite with many people for hunting and self-defense. It is a proven performer with a great balance of power and controllability. It is available in handy mid-size revolvers. It is a great trail gun cartridge and easy to reload. I use it as a sidearm to keep on my person when rifle hunting or walking around my property.
It is hard to go wrong choosing a .357 Magnum revolver from any of the major manufacturers. Both single-action and double-action revolvers are readily available. The Ruger Blackhawk series of single actions are extremely reliable. I personally use a four-inch barrel Ruger Security Six stainless revolver, which I find to be light, handy, and rust-resistant.
Introduced in 1935 by Smith & Wesson, the initial .357 Magnum velocity was rated at 1,515 fps with 158-grain Lead bullets. It had a well-deserved reputation of barrel leading due to the soft lead bullets that were then used. This reputation led to the use of modern jacketed bullets or the use of gas checks on cast bullets. The gas check was so named because it literally stopped or “checked” the burning gases that caused the barrel leading often experienced with lead bullets.
If you are faced with a badly-leaded revolver barrel you can often clean out the leading by using the pure copper Chore Boy pot scrubbers. Make sure you get the all-copper ones, there are some out there that are copper-coated steel and those will damage your bore. Wrap some of the Chore Boy scrubber material around a standard bronze brush and use this to clean the bore. The results are excellent and tremendously faster than using the bronze brush alone.
The .357 Magnum does very well with commercial jacketed bullets. If these ever become unavailable or extremely expensive you can get the same performance from a good-quality cast bullet with a gas check. Please note that jacketed bullets are generally .357-inch in diameter while cast bullets are commonly sized to .358 inches. You should use the .358 inch diameter for gas-checked cast bullet loads.
This article presumes you already have knowledge and the basic equipment to reload revolver ammunition and basic bullet casting. For those who want more details there are some resources listed below — mostly from SurvivalBlog. Understand that these online information sources will not be available if there are problems with accessing the Internet. So you might want to review these and capture information offline that you would like to reference later.
There is a wealth of information about reloading and bullet casting available on the web and a lot of good information on this site. If you are not already doing so you can use the Search function on the Survival Blog website for these and many other topics. Here is some related information in Survival Blog for instance:
Bullet Casting: A (Relatively) Simple Introduction, by AVL
Finding and preparing lead for bullets: Melting Lead for the Meltdown, by Charles J.
Smelting Scrap Lead for Bullet Casting
Some other good websites on bullet casting and related information:
https://www.artfulbullet.com/index.php?threads/articles-from-the-pages-of-lasc-us.10104/
A very good resource for cast bullet alloys:
https://www.artfulbullet.com/documents/Kelter_Cast_Bullet_Alloys2.pdf
If you prefer you can order a variety of very good lead bullet alloys from:
https://www.rotometals.com/bullet-casting-alloys/
Here is some information on making your own gas checks:
https://www.castpics.net/subsite2/HowTo/MakingGC.pdf
This article is intended to be limited in scope. I will try to explain the benefits of gas checks in this application and how to use them. The .357 Magnum cartridge is featured to add some specifics to the mix and because I have reloaded it and used gas-checked cast bullets in it for many years. I will aslo touch on few topics that are directly related.
If you reload your own .357 Magnum cartridges you already know that primers, powder, and bullets are required consumables. If you cast your own bullets, you reduce your dependence on manufactured components to primers and powder and, of course, a suitable alloy of lead. If you use gas checks on your cast bullets you will have to add gas checks to your list of required items or learn how to make them. Commercial gas checks are a fraction of the cost of the equivalent factory-jacketed bullet. Since many powders can be used successfully in the .357 the critical item needed to reload is then primers. You might want to also stock up on good quality new primers.
You can use gas checks to make cast bullets suitable for full power or close to full power .357 Magnum reloads and yet have very little or no barrel leading. This level of bullet weight and velocity will take up to deer size game cleanly and consistently with proper shot placement.
The information presented here applies generally to many other handgun cartridges and some rifle cartridges. It is common to use gas-checked cast bullets for .30 caliber rifles, although the reloading process is slightly more complex. These bullets can be driven to useful velocities, although typically not as fast as jacketed rifle bullets.
Yes, there is a cost associated with the equipment needed to cast your own bullets. This is a one-time expense. You can cast bullets with little more than a cast iron pot for the melted lead alloy, a lead bullet-casting dipper, and a bullet mold. There is a definite learning curve but it is actually pretty intuitive. I would however highly recommend getting a good sizer-lubricator. This is not required but will make gas check attachment and bullet sizing and lubricating much faster and easier.
You probably know that most lower velocity lead bullets such as the .38 Special, .44 Special, .45 Colt, and .45 ACP generally do not lead the barrel if the lead alloy, bullet diameter, bullet lubricant, cylinder throat size, barrel grove size, and barrel condition are all correct. Even these calibers will lead if one of these parameters is incorrect, for instance using a very soft lead bullet or a cast bullet with an undersize diameter. The velocity at which gas checks are required to prevent barrel leading is also dependent on the aforementioned parameters.
When Will Leading Occur?
Due to all these factors, there is no hard and fast rule telling us at what velocity barrel leading will occur. A commonly-accepted rough rule of thumb is that leading can start at around 900 feet per second depending on the factors already enumerated but some leading will almost certainly occur at velocities of around 1300 fps and above.
Barrel leading in higher velocity revolver cartridges such as the .357 Magnum can occur even if these parameters are all in place. Jacketed bullets do not leave lead in the barrel because there is a bullet jacket of a copper alloy that separates the lead from the bore. Please note that experimenters can tune a handload to a revolver or a rifle to get much higher velocities and little or no leading with plain base bullets. In many cases, these results will only apply to that one rifle and lead bullet combination.
What happens when pushing lead bullets at higher velocity is that at some point the higher gas pressures and temperatures start to erode the rear of the lead bullets and often escape around the sides of the bullet as it travels down the bore. This can distort the bullet which can reduce accuracy and increase the leading of the bore. A good quality hard-cast bullet that works well for the .38 Special may lead badly when driven to .357 Magnum velocities. Jacketed bullets do not have these problems.
How To Use Gas Checks
So what is a gas check and how and when do you use them? A gas check is a small copper or aluminum cup that fits on the base of a cast bullet from a bullet mold that has a rebated area at the bullet’s base, referred to as the gas check shank. The gas check shank leaves a place to crimp the gas check to the base of the bullet.
The gas check is many times harder and tougher than any lead alloy. Simply put the gas check adds a jacketed bullet base to the cast bullet. This almost completely stops the powder gases from eroding the rear and sides of the cast lead bullet. This barrier allows attaining higher bullet velocities without experiencing the leading issues of plain base lead bullets. There is no lead bullet alloy that can withstand the pressures of higher velocity loads in a firearm as well as a gas check design.
When using a dedicated sizer/lubricator the gas check is first placed in the sizer with the cup upwards. The rebated cast bullet shank is then placed into the cup. The handle is operated and the bullet is pressed into the gas check and then pushed into the sizer, where it is sized to diameter and lubricated under pressure. Certain designs of gas checks actually crimp onto the bullet’s shank during this operation. The gas check can be pressed onto the base of the bullet manually as a separate step if desired.
You do not normally add gas checks to a plain base cast bullet that does not already have a cast in shank in place for the gas check. I personally have used Hornady gas checks for many years with excellent results. Hornady gas checks do crimp to the bullet. Bullets such as these might be great trading material if the supply of reloading supplies is disrupted.
Many good bullet molds are available. I use several different brands with good success. The bullet mold I use for the .357 Magnum is an RCBS two-cavity gas check Semi-Wadcutter design that throws a nominal weight bullet of 162 grains. The semi-wadcutter bullet design helps bullet performance In terms of accuracy and effectiveness on wild game. All else being equal, the flat nose of this bullet design creates more energy transfer and a larger wound channel than a traditional round-nose bullet of the same caliber. Additionally, this design tends to penetrate straight, in wild game.
There are many good handload recipes for reloading the .357 Magnum. Unique, 2400, and 296 are a few commonly-used powders for full power loads. Check a good loading manual before you choose a powder and charge weight combination. You cannot be too safe in your approach to handloading.
You can use any of a number of excellent brands of bullet molds, bullet sizer/lubricators, and gas checks. After much research and experimenting I standardized on my full power .357 Magnum handload and have since fired many thousands of them. The load uses .357 Magnum brass, a 162-grain bullet cast from the RCBS 82033 38/357 SWC Gas Check bullet mold, and uses the Hornady 35 caliber gas check. The lead alloy is Lyman #2. The bullet lube is usually RCBS. The powder charge is 14.5 grs. of 2400. Standard small pistol primers are used.
This is a well-known .357 Magnum handload from the loading manuals and should be safe with careful reloading practices. You can theoretically get 482 loads per pound of 2400 Powder using 14.5 grains of powder per cartridge. Velocities from 4″ to 6″ barrels run about 1,150 to 1,350 fps, but your mileage may vary.
I make my own Lyman number 2 bullet-casting alloy. The nominal formula is typically listed as 90% lead, 5% antimony, and 5% tin. This is done by using 9 lbs automotive clip-on style wheel weights and 1 lb. 50/50 bar solder melted together. Please note that this requires the clip-on wheelweights due to their antimony content and the solder has to be 50-50 lead/tin to get the correct amount of tin. I pour the molten alloy into ingot molds and then mark the ingots with steel stamps. A “2” means it is Lyman # 2 alloy, a “50-50” means it is 50/50 solder, and a “WW” means it is wheelweight alloy from steel clip automotive balancing weights.
There are many ways to formulate Lyman # 2 alloy. Older formulas require Linotype metal which was used by printers and is now hard to find. It is hard to add in Antimony because of its high standalone melting temperature. You could melt some magnum lead shot (made for loading shotshells) at 6% antimony, 94% lead to help add some antimony. Then use any form of tin you want to raise the tin level. While 50-50 bar solder from the plumbing supply is expensive it goes a long way.
You can also make your own gas checks using one of the many gas check-making devices that are commercially available. You can search for these and information about them on the web. There are plans available that a machinist can use to make one of these devices. I am only personally familiar with the Freechecks III model which seems to work well if you use the right thickness of raw gas check material.
Of course, you will have to obtain the brass, copper, or aluminum material that the gas check is made from. The FreeChecks III uses .014″ thick material. I understand that one source for this is the Standard Grade aluminum flashing made by Amerimax and usually available locally. There is time and labor involved but a tool of this type gives you more options when using gas checks.
Be safe!