Gas checks, Yes or No?

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tbhupe

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If a cast bullet is designed for a gas check, do you have to use one?

I have several moulds for pistol and rifle and they are all designed for gas checks. The rifle bullets are no problem, but if I can get away with out using them for pistol I would just rather not go to the expense and time to install them. I have 9mm, 38/357 and 44, all are used in the low to mid power loadings. These are just for high volume plinking/paper punching.

Any thoughts are welcomed.

tbhupe
 
Depends, If you put them thru a lubrisizer it will be messy, as the base will try to fill with lube. If you use lee tumble lube it will be OK but will be limited in velocity due to having no gas check and not having a firm driving band.

Rifle bullets will be very limited in velocity for the same reason.
 
I shoot a lot of cast. For rifle unless you are planning to load gallery loads GC's are a must.

For 9MM you don't need them and I am surprised you have a 9MM mold that would take them. .38spl loads I use don't need GC but for .357 loads you should unless you are loading them down. If the molds you have are made for gas checks then I would use them. Accuracy may or may not be as good if the cast bullet you are using is made gor GC and you try them without. Wouldn't hurt to experiment with your loads. If you have a Chrony keep your .38/.357mag loads running under 1100 fps and you should be good to go without GC's.

Just my 2 cents worth based upon what I have experienced. Size your 9MM bullets at laest .356 - I size mine .357. 9MM barrels are all over the map, especially Euro guns. Accuracy is excellent in all my guns without leading when using .357 sized bullets. I should add soft lubes are better than hard in handguns from my experience.

Take Care

Bob
 
Just because the mould is cut for it doesn't mean you have to use it.
A gas check is so you can push that cast bullet harder than 1400 fps and not have gas leaking past the bullet in the barrel.
If you use them at a slower velocity the only thing you are doing is costing your self the price of the gas checks.
Have fun Ken.
 
Canuck, I got a really good deal on a new RCBS 9mm mould. I actually prefer the Frontier copper-plated bullets, at least that's what my BHP tells me.

My concern is mostly with 44 and 38 that are under 900fps. Does the hot gas cause more leading than it would with a plain based bullet?

The rifle rounds are 8mm for milsurps and are around the 1500fps range. Because the volume is a lot less, those will be gas checked anyway.
 
There is only one way to find out if it will lead more than a plain base, and that is to try it. There are a lot of variables. The hardness of your alloy, the condition of your barrel, the chosen load, and velocity, and the size and fit of your bullet in your barrel. You won't find out until you try it.
Certainly, according to theory, the plain base should lead less, as the charge can seal the bore by upsetting the bullet base. This limits gas cutting at the low to mid velocity range.
 
Hello B_ _ _ _.
I shoot light 160 gr. SWC loads out of the .38 all the time without GC's and there is no difference in leading or accuracy from when they are wearing "protection". Unfortunately my Argentinian high power doesn't like the cast that I have tried in it so far, 133, 148, 158 and even 160 gr. The barrel slugs out at .357" and I have tried 356", .357" & .358" and got some spectacular bullet profiles, not round holes. Maybe the twist is too slow so good luck with yours. I will have to buy a 115 or 125 gr. mould for mine.

270 totheend
(Lyall)
 
As mentioned, if you are using a lube/resizer they will be messy especially when using soft lube. Harder lubes aren't as bad even if they fill the GC band.

Both my used RCBS 9mm and .357 bullets have a GC band but I don't bother using them for 9mm. It's funny that RCBS still sells the same part number and there is no GC band on the current 9mm mold now.

For .357 I tried them both with and without and not much difference so I'm going to start using them without. They shoot good even at Big Bubba loads so doesn't justify the cost and time of putting GC's.

Rifle bullets, the loads and velocities are just too high to go without.
 
270 totheend

You have struck on the biggest problem with the 9MM and that is the barrels are all over the map for size. If you r barrel slugs out at .357 the minimum size you should try is .358 and I would stongly suggest .359. I use the Saeco truncated cone style bullet 125gr sized to .357 with great results. I would look for a mold that casts out a minimum of .360 or replace the barrel. The latter is probably cheaper.

Sizing the bullets any less than .359 will rresult in a) Leading and b) Unstable bullets going through your targets sideways as you probably have already found out. I can only imagine what jacketed bullets do. I sized some bullets a couple of years ago .355 by mistake and had them going sideways through the target at less than 10 yards.

medicstimpy: The primary reason why you see commercial casters using hard lubes un handgun caliber bullets is it stays in place most of the time when shipping the bullets and it is less messy when shipped in bulk. Soft lubes work much better in pistol calibers. If you go to the Cast Bullet Forum their is a formula for making Felix Lube. It is a "soft" lube that you can harden to your liking with carnuba wax. Great lube and you won't get leading in any of your handgun applications.

Your .357 IF you drive your bullets hard will lead the barrel if you don't use GC. At .38 spl velocities no problem. YOu can get a machinest to take out the GC ring on your molds if you don't like using GC. You will find you will get a better seal on your bullets and you will be able to drive them faster, if that is a desire, without gas cutting.

Take Care

Bob
 
tbhupe

On the surface using a GC design without a GC would suggest you are open to more gas cutting given the bullet is not likely to obuterate enough to seal the chamber like it might with a plain based bullet. That said, what sometimes is logical in casting lead bullets becomes illogical. Try them, if they are sized properly, one or two thousandths over bore I would not expect leading at those velocities. As menitoned earlier your alloy will play a part. Straight wheelweights is all I use. I water quench them for most applications straight from the mold.

If you do experience leading use 100% Copper Chor Boy pad strands wrapped around a wire brush. A ouple of strokes and you will have the lead out of your barrels.

Take Care

Bob
 
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