Shooting w/o gas checks using a gas check mould?

[the_ursus]

Would there be anything wrong with shooting bullets from a mould designed for gas checks and leaving the gas checks off? Of course, this is assuming the loads were light and leading wasn't an issue.

[randyrat]

From experience you would have a hard time fitting even a 1/2 grain of Bullseye in there.:-D
I'm trying the same thing. Others that have tried it say; Sometimes it works sometimes it dosen't.
For about 130 years others have been Paper Patching their bullets with out gas checks with great success
I'm still learning that process.

[44man]

There is no problem shooting PB boolits very fast when they are hard. When you need a gas check is when boolits are soft and shot fast. The check prevents the base from skidding the rifling. The front of the boolit will skid but the check helps grab the lands.
By leaving the check off, you have in effect a bevel base and I have not found any that are accurate.
Another problem is if the boolit is borderline for the twist rate, leaving off a drive band shortens the boolit in relation to the rifling. Some will still shoot but others can become so unstable they can tumble.
If you take a GC mold and cut the check area out so you cast a PB boolit, it will shoot as good as the checked boolit if cast with the right alloy.
If set up with a bad fit, wrong alloy or the wrong load, even a gas check boolit will lead a bore badly.

[Bret4207]

In some guns with some boolits with xome loads it works. In other cases you get shotgun like patterns. We just had a big thread on this. Do a search and you should find plenty of info.

[missionary5155]

Good morning I used to think ya had to ALWAYS use them on a gas check design... I have shot at least 500+ (Last time up there) out my Chicom sks with about 17.5 grains Acc1680 . This is with the 155 lee .313. I do not have the exact load here. Functions and accuracy it tin can at 50 yds.

[Shiloh]

=
By leaving the check off, you have in effect a bevel base and I have not found any that are accurate.
Another problem is if the boolit is borderline for the twist rate, leaving off a drive band shortens the boolit in relation to the rifling. Some will still shoot but others can become so unstable they can tumble.


I'm in the same camp.

From the Info I've gleaned from this forum, I've never tried shooting gas check indented molds without them. With the big gap on the base, and no gas check to guide and center the boolit as it is being seated in the case, small variances will give a big area for the hot gasses to vaporize the boolit.

My .30 cal 1:10 twist military relics perform best below 2000 fps. I'm getting superb accuracy, as good as my 52 year old eyes will allow, from velocities of 1650 or less.

Shiloh:castmine:

[S.R.Custom]

Seems to me it would come to:

(1) Is the checkless base sufficiently formed to leave the muzzle correctly? (No flashing on the base or gas-check nubbin and a rear driving band square to the bullet around its perimeter.)

(2) A sufficient enough rear driving band to contain propellant gasses by itself.

(3) Sufficient enough of a remaining bearing surface to prevent skidding in the rifling, particularly when shot through revolvers.

That said, give it a shot and let us know how it works! :-D

[StrawHat]

Would there be anything wrong with shooting bullets from a mould designed for gas checks and leaving the gas checks off? Of course, this is assuming the loads were light and leading wasn't an issue.


Got any specifics for us? I have used the Thompson bullet (Lyman 358156) satisfactorally. Never tried it with a rifle though.

[the_ursus]

Thanks for the info guys. I asked the question on behalf of a friend so I'll relay this info to him. Sounds like it could work but would take a bit of tinkering and could be more hassle than it's worth.

[kir_kenix]

Give it a try. I shoot several boolits regularly without gas checks with satisfactory results. Most of them are cruising at below 1500 fps or so. 44man makes a good point about bearing length without the check. Some lightweight for twist boolits may not be stabalized if you take off GC.

I have never had a problem with excessive run out while loading these boolits.

I think you are just going to have to give it a try and see how it flys.

[dromia]

Seems to be rifle dependant.

A few of us shoot .303"s indoors on a 25 meter range.

5 gns of any fast pistol powder under the Lee 113 gn GC soup can just gives one hole groups all day long.

My No 4T won't shoot this boolit worth a damn without a gas check, my mates No 4 will shoot them with or without, no difference on the target.

So you just need to try it and see.

I'm going to have the GC step opened out on a 2 holemould to see it a plain base will make a difference in my rifle. Seems a waste to use gas checks on such a small load.

[leadman]

Here in Arizona the only problem I have encountered is in the summer. If you leave lube where the gascheck is normally fitted the lube can melt and get in the powder. Just an extra step to remove the lube with the ol' thumbnail.

Some guns and bullets work good with no check, some don't. Just need to experiment.

[the_ursus]

Ok, so "leadman" raised another question for me. I live in Alaska so lube sticks to bullets well and don't have to worry about it melting but how much attention should I give to the lube that sticks to the base of my bullets coming out of the sizer. Should I be making sure they are nice and clean before seating? I've been leaving a little lube, cuz I've been lazy, on mine. What side effects might occur from this? Go easy, I'm new :)

[Morgan Astorbilt]

More of a problem with lube getting under the bullet in the sizer(Not Star), than shooting. Not much different than a bevel base bullet on both counts, the sizer depth stop has to be adjusted.
Morgan