View Full Version : Loading gas checked boolits

06-26-2016, 09:30 AM
Do I still have to flare the case mouth if the bullet is gas checked? Will gas checked bullets still lead the barrel or does the gas check take care of that? Also how important is it to get all the copper out of the barrel before shooting lead? Sorry for all the questions I have never loaded lead and trying to figure all this out?

06-26-2016, 10:33 AM
yes,yes and it depends.A fair amount of time reading the stickies will aid you considerably

06-26-2016, 10:55 AM
Yes, gas checked boolits will be sized down in size and damaged if not flaring the mouth. The boolit will be shaved and lead shavings can be shot out to lead your bore.

The purpose of the gas check is to seal the bore and engage the rifling without damage to the boolits base. Any damage allows gas cutting to the boolit, ruining accuracy. Boolits should be sized to fit the throat diameter, not the bore diameter. Normally .001" or more over the bore diameter. Gas checks allow boolits to be fired with more velocity than plain based boolits.

I like to use Lyman "M" type case mouth expanders and also use the NOE type that fits in a Lee universal case mouth expander die. Others are probably just as good.

Any copper left in the bore will damage boolits as they pass by when fired, ruining accuracy. It will also cause leading to your bore as the lead sticks to the copper when passing by.

Boolits that fit your throat , using the right lube and chamber pressures that aren't too much for the strength your lead alloy used will prevent leading bores.

06-26-2016, 11:09 AM
you flair the case mouth for jacketed bullets too.

copper in the barrel can grab at the passing lead boolit and cause some lead to stick to it in the barrel.
it's not a 100% gonna happen thing it's just something that can happen.
I have swapped back and forth between the two before and not had any trouble but it takes a few rounds to get the lube built back up in the barrel again [or cleaned out going to jacketed] and accuracy generally suffers during that time.

06-26-2016, 11:25 AM
Yep, flaring is necessary, not so much as to avoid shaving, yes that's important for plain based lead bullets, but you're trying to shove a lead slug with a copper cap that is upwards of .005" larger than the case mouth.The bullet needs an "entry way" to get started straight in the case. I have flared the case mouths with almost anything tapered, and have even used bottlenecked cases pushed into the case mouth and some pressure and turning flares the case mouth. Most of my case mouth flaring now is done with Lee Powder Through dies, and I have a couple M dies. Don't worry about "too much" case flare, as long as the case enters the seating die you're OK. The case life may be shortened, but brass is still readily available today and it's better to get good reloads now and worry about case life later.

Normally a gascheck stops most leading by protecting the bullet base from hot gasses (gascheck), but just as important is good bullet to gun fit. My revolvers get the bullets get sized to the same diameter as the cylinder throats and my semi-autos get bullets .002" groove diameter.

If you plan on shooting lead bullets get a copy of Lyman's Cast Bullet Handbook (I prefer the 3rd Edition, but they are prolly not available so get a 4th) and spend a good bit of time reading the stickies in all the sub-forums. There ain't much that's not covered here...

06-26-2016, 11:27 AM
The GC is a skid stopper, not a lead wipe. Lead too soft can over ride the GC .
Best to remove copper from the bore first. Up in the air of course, does a GC put down copper?
Darn we have interchanged both so I don't know. I think it depends on how many bullets are shot before boolits.

06-26-2016, 12:34 PM
Yes .l like to keep gas check in the neck of case and use a Lee fcd on my loads

06-26-2016, 02:15 PM
It doesn't take much flaring to do the job. I use and old knife sharpening steel with a cone on the end which I bought at a garage sale for 50 cents. I use hardly any pressure and any flaring is not visible but it works well. I can use it on any caliber from .24 to .338.

RU shooter
06-26-2016, 02:40 PM
It doesn't take much flaring to do the job. I use and old knife sharpening steel with a cone on the end which I bought at a garage sale for 50 cents. I use hardly any pressure and any flaring is not visible but it works well. I can use it on any caliber from .24 to .338.

very true and and an "M die" is not the thing than can be used to put a slight flair on a case mouth as can be see in the above quote. The Lee flair die works very well and have been using one for quite a number of years before that I loaded my first couple hundred bullets using a pair of needle nose pliers to put the flair on the case .


06-26-2016, 05:17 PM
Tip for those gas checking: anneal your gas checks in some kind of sealable tin with 1-2 stamp sized paper scraps. You gas checks will bite your bullets harder (less copper spring back), sizing bullets down is far easier, and your accuracy will improve.

Firing across a small lake I used to watch water splash where my gas checks would fly off. That has since ceased and I no longer see weird fliers that weren't my doing.

06-26-2016, 06:01 PM
Zubrato can you go into a little more detail about annealing gas checks ?

06-26-2016, 07:05 PM
Sure thing. Several ways to do it, but the key is reducing the oxidation of the copper. When you heat it up to the annealing point where it becomes dead soft, it oxidizes as well and turns dark/black. This copper oxide is pretty hard stuff and in theory you wouldn't want to shoot a whole lot of them that way for the sake of your barrel and lubrisizer.

To eliminate oxygen, I use an empty steel air pellet tin that screws together, I put a scrap of paper on the bottom, fill up with gas checks until it's almost full and put a scrap of paper on top, and screw it all together finger tight.
You don't want to do it too tight, as it becomes pretty difficult to remove later on.
I like to fill it up with checks until it barely rattles or won't rattle.

From here you can toss the tin in a campfire for a few hours, or if it's winter and I need gas checks I put my tin on a hot plate on high 30-45 minutes each side, sometimes longer.

Once you let your tin or tins cool down, and get her open you should see your paper scraps are black and crunchy, and your gas checks are a crazy kaleidoscope of color and dead soft. A little blackish haze is nothing to worry about either if a little air got in, so long as they aren't super black and crusty.

Others use capped pipe nipples, but what usually works best is what you have laying around.

I've found its surprisingly easy to do, and it really makes a big difference in the ease of sizing, seating, and even applying gas checks to shanks.

If you are gas checking bullets, I truly don't believe it matters whether they come from gator or Hornady, any and all copper checks will benefit from the process.

Edit: another benefit is peace of mind, if you need to seat your bullets with the gas check shank below the case neck. I've never had a gas check loose in the barrel, but before I started annealing I used to seat the gas check at the base of the neck, and more than a few times upon extracting the round found the bullet lodged in the rifling, and the gas check sitting at the bottom of the extracted case neck.

Now I confidently seat bullets with gas check below the neck of the case where necessary like for 223 in my AR.

06-27-2016, 03:59 AM
Zubrato I appreciate you taking the time to share the information will give it a try . Zombie 1978 what caliber and mold are you interested in using gas checks on .

06-27-2016, 04:09 AM
I'm asking because I'm not shore if you want to flair the case mouth , or possibly you are interested in expanding the case neck to seat the cast boolits with out reducing the size of the boollits .

07-02-2016, 04:19 AM
I have gotten all the things together to start the new project now , so I set up the sizing die last night ( as always I made quite a mess ) but I got it . I put lube in the one grove with a softened gas check seated on the base , but now looking at them it seems like their is space above the check ( sort of like a lube grove ) should I have set the die up to lube the space directly above the gas check as well ? The mold is a rcbs 22-55 sp c red lube and gator copper checks . Well gentlemen it's off to work for me have a good morning .

07-02-2016, 10:11 AM
If your lube is good enough with only one lube groove filled, there is no need to fill the space above the gas check. With that said, I usually fill everything except the crimp groove (if present), maybe I'm just not patient enough to adjust the depth of insertion into the sizing die.


07-02-2016, 10:24 AM
I'm sorry zombie 1978 I posted in the wrong thread , I didn't mean to lead your thread astray . Have you worked out the case flair for bullet seating issues . I thank you Robert .

07-02-2016, 10:46 AM
I'm using the Lee 170 grain mold and just looking for guidance in the process.

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