When should you consider gas checks?

[Changeling]

I only have one revolver that I use cast in (only) it is set up for LBTWFN 260 gr with gas checks. This is how I was told to set it up and it works great.

Question: When you guys are considering a new bullet revolver relationship how do you decide to use or not use gas checks? Do you base it on velocity expected with the gun/caliber/load combination or what. How do you know?
This is something I just don't understand.

[jack19512]

Higher velocity generally calls for one for me, as far as when it depends on what velocity for the gun in question starts to lead. If the leading does not occur at say 1300 fps. but starts leading at 1400 fps. then around 1300 fps. is where I might start using one.

[lathesmith]

Change, velocity isn't the only factor, but it's about 80-90% of the equation. And, there isn't a hard and fast rule as to exact velocity when a check is required for optimum results. But, in general and on average, any revolver load that is below 1100 fps, gas checks are a waste of time and money. above about 12-1400fps, they become almost a necessity. And once again, these aren't set in stone, but it's a good place for a beginner to start. Keep reading about gas checks and their usage, and how and when other guys do and don't use them, and you'll start to get the hang of it.
lathesmith

[Changeling]

Change, velocity isn't the only factor, but it's about 80-90% of the equation. And, there isn't a hard and fast rule as to exact velocity when a check is required for optimum results. But, in general and on average, any revolver load that is below 1100 fps, gas checks are a waste of time and money. above about 12-1400fps, they become almost a necessity. And once again, these aren't set in stone, but it's a good place for a beginner to start. Keep reading about gas checks and their usage, and how and when other guys do and don't use them, and you'll start to get the hang of it.
lathesmith

I see what you are saying as for the higher velocities, it makes sense. Is there any problem/advantage to using them at the lower velocities like 800 fps and up irregardless of cost, witch amazes me by the way?

[9.3X62AL]

I fully agree with all that is written above. Trying to elaborate on it further would be like taking spray paint to the Sistine Chapel.

I would add that a similar pressure/velocity threshold also applies to rifles shooting cast boolits and their need for gas check usage.

The cost of the things is the principal downside if an application doesn't require them, assuming they are seated squarely and consistently on the shanks. Sorta like using Nosler Partitions for varmint hunting--they work fine, but the tariff is steep. There was a time not long ago when concerns about cost of gas checks was largely a non-factor for most casters--at nearly 4 cents per boolit for the larger calibers, that is no longer the case.

[S.R.Custom]

...in general and on average, any revolver load that is below 1100 fps, gas checks are a waste of time and money. above about 12-1400fps, they become almost a necessity...

In an handgun, maybe. My rifles will all shoot plain based bullets cleanly @ 1400 fps. To get 1400 fps out of a handgun, you need lots of pressure, and that's where you need the gas check. For me, the deciding factor in whether or not to use a gas check is if the word "magnum" or "Casull" appears in the cartridge's name, and I'm loading to that potential...


..Is there any problem/advantage to using them at the lower velocities like 800 fps and up...?

There's no problem... but no advantage, either.

[shooting on a shoestring]

Changeling, I have at least one GC mould for each caliber I cast. I use them extensively in my rifle calibers, and seldom in my revolvers (.45 Colt and .357 Magnum hot loads,.38 Spl has no call for them at all).

SuperMag hit it. If you have a magnum or casull, then get a GC mould, work up some stomper loads, then after a short while, you'll be shooting mostly non-GC loads, and loving the flexibility to stomp or not.

[azrednek]

I've seen some improvement in the shot to shot accuracy using gas checks in questionable bores.

[44man]

I find gas checks are only needed for softer boolits. If I shoot a 50-50 WW and pure mix with PB boolits, they scatter all over but the same boolit design with a check will group. Now as I harden boolits more I do not need a check in any of my revolvers.
Even my 45-70 BFR shoots a PB into 1" at 100 but the hard boolits are not good for deer at 1632 fps so I need softer boolits. Then I NEED a gas check.
The .44, .45 and .475 will kill like crazy with hard boolits so none of these need a check.
Velocity is not where to look, alloy hardness will dictate the gas check or not.

[Bullshop Junior]

What caliber?

[Changeling]

I see what everyone means, since this in for a 45 Colt I won't be getting/needing gas checks.

[Changeling]

I find gas checks are only needed for softer boolits. If I shoot a 50-50 WW and pure mix with PB boolits, they scatter all over but the same boolit design with a check will group. Now as I harden boolits more I do not need a check in any of my revolvers.
Even my 45-70 BFR shoots a PB into 1" at 100 but the hard boolits are not good for deer at 1632 fps so I need softer boolits. Then I NEED a gas check.
The .44, .45 and .475 will kill like crazy with hard boolits so none of these need a check.
Velocity is not where to look, alloy hardness will dictate the gas check or not.

I wrote the post wondering whether I would need them for the new 45 LC but because of the great replies I don't think I will, the guys made a lot of good sense.
However I got to thinking about your reply and thought I better answer it so we are on the same wavelength so to speak seeing as you might be working on it if the police ever get through investigating me.
At this time I intend to use water dropped WW like in the 44Mag (no problems). I don't actually know the hardness (no tester) they were but according to Veral Smith they were probably around 20 bhn. If there is a need to go harder I can always oven harden them up higher. I had worked up to and was using the 260 gr LBTWFN with 22 gr of 2400. No idea of the velocity but I didn't have a leading problem.
I will be using the water dropped WW in the 45 because it did work so well in the 44Mag but after reading and talking to the guys I would like to not use them (gas checks) if I don't have to and I see no reason now that I will. I do Not expect to run the 45LC at velocities over 1300fps and more than likely in the 11 to 1200 fps range and also another load in the 8 to 900fps range or there abouts because the final decision will be up to the revolver.
Personally I don't intend to use any bullets past 260gr (that could change), as I have seen what that weight did in the 44Mag in the LBTWFN and was totally amazed but I haven't made any decision as to who's or what bullet yet for the 45 other than weight. Heck even that could change.

[targetshootr]

You don't need em for plinking or targetshooting and then if you get used to shooting a certain fps load, cranking it up by a factor of two may not be practical either. There are lotsa threads saying most anything in the lower 48 can be taken with an a/c ww 250 gr boolit at 1000 fps so for me, gc aren't practical at all.

[9.3X62AL]

An old formula that has been used to determine suitability of a certain alloy for a given pressure rating is to multiply the Brinnell Hardness rating (BHn) x 1,422.

There is some "cheat" to this estimation, though--best exploited through use of boolits that fit the throat and grooves closely. 9mm Luger and 40 S&W are my most frequent and egregious "violators" of this rule. I use 92/6/2 alloy in both calibers (BHn 14-15) well past 20K PSI.