gas checks?

bait dunker

I want to shoot some laser cast 200gr SWC out of my 45. DO i need to use gas checks when shooting these bullets. Thanks

bait dunker

I recently bought an Encore in 45-70 and am wanting to reload some heavy lead bullets. Im reading in most of my manuals that gas checks are required. Are the gas checks needed to fill the powder cavity to ensure better ignition, or is there another purpose? Do I just use one per cartridge? What about lead bullets with the copper gas check on the base, are the other paper gas checks still needed? Thanks, Todd

Hawk Carse

A gas check is a copper cup on the base of a lead bullet which was cast with a reduced diameter right at the base to let the gas check be put on. It reduces lead fouling and protects the base of the bullet from erosion by the powder flame.

Black powder loads for .45-70 usually have a card wad between the powder and the base of the bullet. Serves as a gas check and to keep bullet lube out of the powder.

A card wad is not needed for smokeless powder and might be a risk because of air space allowing it to fly free and damage chamber or barrel.

I don't think a gas check is required for .45-70 smokeless unless you are going to load it very hot. Plain base will do.

CapnMidnight

I use Oregon Trail/LazerCast bullets when loading lead in any of my 45-70s. As has been said, you only need a gas check if your really going to pump them up. Oregon Trail now have gas checked bullets for sale.
W.D.

MMOMEQ-55

I cast my own LSWC at 405gr traveling around 1350FPS and with no leading problems. I also have a 325gr FNL load at around 1900FPS and have to use a gas check or it will lead the barrel some. I cast my own like I said and they are pretty hard.





The copper disc at the base of these bullets are gas checks.

Rocky Raab

I don't load for the 45-70, but I shoot nothing but cast bullets in my 30-30.

At muzzle speeds up to 1200 fps, plain base bullets or bullets designed for a gas check but without the check installed (as Lazer-Cast bullets used to come), accuracy and leading are not problem. But somewhere between there and 1500, accuracy goes to pot without a gas check - at least in that gun with that cartridge.

My standard load launches a 170-gr cast bullet at 1600 fps, and it absolutely requires a gas check.

bpost

One advantage of a gas check for higher pressure (increasing MV requires increased pressure) is at some point the presure on the bullet base can start deforming it. This happens it as the bullet starts to move and engage the rifiling, accuracy suffers. A gas check helps protect the base from deforming. As pressures rise gas blow-by comes into play too. Gas blowing by the base causes further deformation and cutting, causing leading and accuracy issues. Using a gas check bullet design helps keep this from happening.

All of this is for naught unless the cast bullet fits the bore correctly. A properly sized cast bullet, properly lubed can be driven pretty fast with no leading. Slug your barrel to find the diameter. A cast bullet sized .001 over bore diameter is considered about right.

A great site for cast boolits is www.castboolits.gunloads.com

m113103

I you ever have the chance to recover some of your bullets a lot of your thoughts will change. When shooting indoors one of the bullseye shooters recovered his bullets out of the traps. He was shooting around 3gr of bullseye with a 230gr cast bullet and you could see the flame cutting on the base of the bullet. This is why you smell lead with a plain base bullet. We also recovered some 38 SWCGC and the cutting was not present. We also noted that the gas check had some lead streaks on them like they were scraping the barrel on the way out. Some of the indoor ranges were asking shooters not to use plain based bullets to keep the airborne lead smoke down. This is why the casting co. are offering a gas check bullet.

budman46

one theory regarding copper gas checks is they "scour" lead that might be deposited by a bullet faster than 1500fps.

budman46