Aluminum gas checks on pistol boolits

[barnetmill]

I doubt you will ever get a bullet out of the 40 S&W fast enough to need a check.

Pressure of a hot loaded 40 S&W can safely reach 32k PSI. Is that enough to melt some lead on the base?

Hot load hodgdon reloading center

longshot powder Bullet: 180 GR. BER FP
Diameter: 0.400"
Case: Hornady
Primer: Winchester SP, Small Pistol 7.5 1,150 33,400 PSI

[Wayne Smith]

Lead reduces copper deposits...
Copper is not scraped off bullets or gas checks from friction and left in the bore. It vaporizes and deposits as it cools.
Lead will actually help prevent copper fouling. As will tin and zinc.

CONCEPTS & TECHNOLOGY DIVISION RESEARCH, DEVELOPMENT AND ENGINEERING DIRECTORATE US ARMY ARMAMENT COMMAND ROCK ISLAND, ILLINOIS 61201

chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://apps.dtic.mil/sti/pdfs/ADA014993.pdf

Can't reach that page??

[K43]

Can't reach that page??

Try this:

https://apps.dtic.mil/sti/tr/pdf/ADA014993.pdf

[centershot]

I've used aluminum gas checks in my 30-30 and '06 rifles for a number of years now and have had no problems at all. I only use them at speeds of 1500 fps or faster, up to 1900 at the fastest, and they have been accurate and economical, what's not to like???

[Tripplebeards]

Wouldn’t get too excited about ordering from them. Just got my first and last order.



The ad is how they have it listed above and this is what they sent me



Super rough cut and uneven edges like a smashed bottle cap versus the ones that they have listed on their website that looked just like a hornady gas check with even edges. I would Assume most people buy once from them once and find out the lack of quality.

Here’s a few I squeezed on. They actually went on pretty easy and I was kind of impressed. They still have uneven voids around the boolit base. Probably not enough to worry about though.

[gloob]

Long ago I posed the question if copper fouling can make leading worse with mechanical bonding then why do copper checks riding the barrel not ?

The answer was something about the cumulative effect mostly disallowed adhesion of the copper

Copper fouling can build up in a bore so high you can see it. That can damage lead bullets fired after. The only time I've had this happen was from shooting thinly copper washed/plated bullets; the cheap Remington green/white boxed pistol ammo sold at Walmart. It doesn't come out with normal brushing.

[Land Owner]

Super rough cut and uneven edges like a smashed bottle cap versus the ones that they have listed on their website that looked just like a hornady gas check with even edges. I would Assume most people buy once from them once and find out the lack of quality.

Here’s a few I squeezed on. They actually went on pretty easy and I was kind of impressed. They still have uneven voids around the boolit base. Probably not enough to worry about though.

You satisfied your own worry. The bottle cap gas check has tremendous GRIP and STAYS ON. The check won't sail into the sky screen of your chronograph. The bottle cap grips after sizing with significant positive force.

EVERYTHING shot down a bore does some minute amount of damage. Aluminum gas checks are neither corrosive nor more or less harmful in any other way than Heat, copper, and lead. Before you ever see or experience a worry with an aluminum gas check, your barrel will be shot out from heat and projectile damage and I doubt most of us will ever get to that stage of shooting a single gun.

[braddock]

As long as you follow sage's suggestion viz. squeeze them on base first you'll be fine.
I'm in the UK and I LOVE sages system, ordered on 10/25 and they came through the door ths am, 11/1.
1/3 the price of copper in the UK. My order was 1000 .22 copper and 1000 357 aluminum. $57 for the product and $29 for air mail. In the uk a 1000 costs about $70, if you can get them.
I've loaded 308 and 30/30 with them up to 2200fps in the 308 and 2000 fps in the 30/30.
To ensure that they stay on I put a small drop of superglue in the check just before I pop the boolit in, I've pulled a few with an inertia puller and the checks stay on.
They are accurate enough, 2" at 100 with the 308 and about 3 with the win 94. I'm no great shakes as a marksman but they pull the stunt for me.

[braddock]

Here's a handful of 309" diameter hard cast with aluminum gas checks on plus liberally mule snotted.
Also shown is the invoice from sages to negate any bs factor.

[Tripplebeards]

I haven’t messed with them since I did my test. Hunting season is here you know…lol. It’s on my list of winter projects to see the rest of them and order a few more. I probably won’t put another coat of PC over the top and just run them after seating from now on, but I’ll have to test a few first. The ones I tested I put a clearcoat of PC over the gas check after I see them and I’m guessing I probably don’t need to do that.

[braddock]

Just noticed OP was al gaschecks on pistol rounds, sorry for my error, I've just loaded 100 357 158grain TC boolits and fitted gas checks as I indicated above destined for my carbine but haven't used them yet. I fully expect them to work fine.
Just put an old wives tale to bed, aluminum IS NOT aluminum oxide in any shape or form. it is soft, it does melt at a lower temperature than copper but a higher one than lead.
I'm using big loads of N110 and that's the only reason they are fitted, just to be sure.

[deces]

Some of the softest aluminum you can find for gas checks can be found with every pulled lid of a smoked oyster can.

[Land Owner]

Cat food can walls are 0.015" thick, easy to cut with a pair of sharp scissors, can be collected by ASKING your cat loving neighbors and women friends, happy to help, and "perfect" for swaging into gas checks with a Maker.

[bedwards]

I've bought left over aluminum flashing at yard and estate sales that works well.

[braddock]

Here's 3 images of one of 100 or so cast plain shank boolits i selected at random showing how they end up after the gas check is squeezed on.
None of the superglue I put in the gc has leaked out.
FWIW, I loaded these the same as I did for the ungas checked loads, please bear in mind I'm using a rossi r92 carbine which is a really strong gun, 14.5 grns of N110, coal is 1.575", mv is around 1750 fps and accuracy with iron sights under 2" at 50 yards 5 shots. I have to say the recoil is noticeable,not heavy just noticeable.
Forgot to mention I use S&B small rifle primers only.

[Tripplebeards]

I sure hate to get a boolit super glued up in my sizer from the excess leaking out!…lol. I haven’t messed with any since archery season is here. I’m sure I’ll load some after the first of the year again. I don’t think I’m going put an extra coat of clear powder coating over them anymore. I think they’ll probably stay on just fine running them through my sizer after I powder coat them.


Here’s a couple I shot. This is actually the first one I shot and it ripped through the dirt/clay media in the ground, and I found it laying in the grass about a few inches away from the box I shot through. I tumbled it with clear powder coating after seating the plain base gas check that’s why it looks kind of bubbly on the bottom from the residual clear powder coating that was underneath stuck to the gas check. It definitely stayed on regardless, but I don’t know if it needed it.



Here’s another one I shot at the range and it was a gravel backstop so my hollow point expanded to the point where it deformed the base and still knocked off the gas check after it was powder coated.




The gas check was found a few inches away from the boolit. Still fits on it nicely…




So even when they’re powder coated on, they’re still not going to stay on through really heavy media, which I don’t care. I’m guessing if I didn’t clear coat over the top of them, they still would probably blow right through a deer and stay on the projectile. I’m sure I’ll do more testing in the future. It’s just hunting season started so I quit playing around with them. Was just tickled pink that I didn’t get lighting in my factory Glock 20 barrel anymore thanks to using the plain base gas checks. I even ran them through my lee bulge buster and undersized the bases to .3995” and by barrel slugs at .400….and I still didn’t get leading and great close range accuracy.



Well, the one bullet that looks real nice above, went through some soft clay ground, and the other bullet hit gravel almost like hitting a brick wall so I would assume I will call the top one a rib shot for a deer and the other one was a solid backbone hit…lol. Will call that a good test media “work out” for those plain bass gas checks….lol. I was using green Dot at around 1100/1150 ft./s if I had to guess. It’s an 8 pound jug. I had laying around that I ended up with from an estate sale that I basically got for you might as well say free for what I paid for it. Figured it’d be a good test powder for my pistols. I loaded some up in my 35 Whelen last year to try, but that gun had a loose barrel. I’ll have to retest it someday with that powder.


I also tried the above 16/1 alloy load on a trap line raccoon and a possum. The raccoon I shot with this alloy and this load. Just put a bullet diameter hole in and out of the head and out the neck. But the skull felt like a loose pocket of change. The pass on my shot with a 12.5 BH bullet half wheel alloy. I had two exits. I would assume that alloy is obviously brittle and part of the HP lip broke off, separated, and exited separately. The additional hole was pretty small next to the boolit hole that exited.

[braddock]

Your boolits look to be much softer than mine, which I think are very hard cast and obviously not HP, very interesting images, informative too. Thanks for posting them.
BTW compared to mine that looks like a microgroove barrel, mine looks like the rifling marks are cut out with a chisel they're so deep.
Can't provide images, they've all gone back in the melting pot.

[Tripplebeards]

They were shot out of a factory Glock barrel with polygon rifling…or whatever they call it. That Glock is the only thing I’ve ever gotten leading in. The PB GCs fixed my leading issue.











This is an 8/1 pewter lead mix which is equivalent to the “famous” 16/1 alloy that everybody always raved about it. It tested 11BH with lee tester. Peels back and holds together pretty darn good imo. Never weighed it yet, but I’ll have to. It’s a pretty tough and malleable alloy.


The clay backstop expanded to the size of a nickel. The gravel backstop to the size of a quarter. Both shot into back stops around 15 yards. The from our group buy. I thought it was gonna be 180 grains with a hollow point but I believe it’s 180 grain solid. It’s closer to 162 or 163 grains with the big HP pin. This time I see them I’ll have to do it with a flat base insert instead of the tapered seating insert so it doesn’t indent a little ring around the tip of the hollow point. Who knows… maybe that thinner tip indention helps it with a more rapid expansion? Maybe I’ll take it out during our annterless only holiday hunt and see if I can shoot a deer out of my tree stand at close range and see how it does.

[BJung]

I'm glad I found this discussion. I recently purchased Sage 9mm/38, 40, and 45 sample gas checks to experiment with my handgun loads. I'm still shooting testloads of pellet, .22lr, and jacketed range lead cast hollow points that have been cast pure, 40:1, 30:1, 20:1 with tin. My load is based on the most accurate load using a FMJ/JHP core lead. Expansion was best with the pellet lead. This load is not always the highest listed on the reloading chart. My thoughts is that the highest charge deforms the bullet; and it won't stabilize. And so, the gas check might help. Has anyone noticed that the gas check increased the "accuracy" of a cast bullet at a charge that previously would not group well?

[gloob]

Yeah, that's the point.

Lead has poor thermal conductivity and a low melting temp. Where a boolit sprouts a leak, that jet of hot gas will quickly erode that side/spot on the boolit, then it will foul the barrel and destabilize in flight.

A check might help maintain gas seal, but even if it sprouts a leak, the copper/aluminum will spread out the heat from that jet of gas, so the boolit can be pushed to higher velocity and still make it out of the barrel before it start to melt in that spot. And if the boolit is still pushed too hard to where this fails and accuracy plummets, the check will hopefully at least take most of the melted lead with it and not leave fouling.

That's my take, anyway.

Seems like you have been experimenting with gas checks for years, now!