Going from aluminum to copper

I have been working on a load for my .223. When I got all the stuff to cast I bought some aluminum gas checks. I have tried multiple ways, and even have tried ones from different companies now, but they all seem to get deformed bases when seating/sizing. A member sent me some copper checks to try and I also had another company send me a few gator copper checks to try. Those go on fine and I do not get the base deformation with them. I am guessing the aluminum is just softer.

So my curiosity question is if anyone has found a big difference going from one type of gas check to another as far as loads go. I have not shot any of the copper checks yet. I am hoping that I do not have to go chasing another load down again. My groups with the aluminum were not horrible, but I would get the occasional flier here and there and wondered if it was because of the bases being deformed. It was very hard to cull/separate them by how much the bases got deformed so I just loaded and shot them if they did not look too horrible. But I know that they were not all the same, and who knows if they were all oriented in the case the same way when shooting.

Wanted to see if anyone has tried to squeeze the last bit of accuracy out of their loads and tried switching between aluminum and copper, with all other things being equal. Its probably one of those "just shoot them and see how they do" kind of things, but my curiosity is if the aluminum - being softer - will conform to the bore better than the copper ones. The copper boolits weigh right at 1 grain more than aluminum ones, so I do not think weight will be an issue other than it will have that full 1 grain at the rear of the boolit, not spread out evenly.

Newton,

Are you using a Lee Push Through Sizing Die?

I have found that aluminum checks are significantly more susceptable to tearing vs. copper checks. One thing I have found is if you are using a Lee Push Through Sizing Die try putting it through base first. This seems to correct a lot of those issues.

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Originally Posted by elwood4884

Newton,

Are you using a Lee Push Through Sizing Die?

I have found that aluminum checks are significantly more susceptable to tearing vs. copper checks. One thing I have found is if you are using a Lee Push Through Sizing Die try putting it through base first. This seems to correct a lot of those issues.

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Yes, Lee die, smoothed out to a mirror shine. Before smoothing it out the checks would completely tear, now they just leave a ridge of sorts where the base is not supported by the sizing stem. In the future I am going to try a larger sizing stem, but realize that it might come at some cost of clearance issues inside the die. Preliminary tests, with a small brass rod on top of the lee sizing stem, does show some promise.

I have tried base first, but while it does not tear the bases, it is a lot harder to get the check on straight. Copper seems to be the way to go at this point really. I put some on boolits last night and will load them tonight. I do not have enough to try a whole lot of load testing, but I will try the same load that shoots well with the aluminum. I am hoping to luck out in this situation, but I have a gut feeling I will not.....

I get better accuracy from the copper checks with about 1/2 grain MORE powder. Theory I have is the check is harder so it needs a little more gas behind it. YMMV

I use Vulcancheck gas checks (.0145 " .310 diam.) for my 30-06 rifle. I put the gas check on the bullet by hand and then use my plastic hammer to lightly seat it. A visual check at this point to verify that they look seated. Then I run them thru my .309 LEE sizer base first. Poly coat them and again run them thru the sizer. So far I have not had a problem with this method.
I use copper gas checks from NOE for my 243. to me copper is softer that Aluminum. After I cast and size, I let them lay on a towel for a day or two. Then I put on the gas check. Then I powder coat them and re-size. Then store them or load them.

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Originally Posted by aspangler

I get better accuracy from the copper checks with about 1/2 grain MORE powder. Theory I have is the check is harder so it needs a little more gas behind it. YMMV

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This is what I was thinking I would have to do. But was not sure, if they didn't group like I want, if I should go down and up. I think I will start with going higher. Good to hear I might get better results though. I figured I would seeing how the bases would be more uniform.

Hopefully by the end of the week I'll have some results. If I can pull my sub MOA down to consistent 1/2" groups I'll be smiling from ear to ear. I only have enough copper checks right now to do a very small amount of testing, but hopefully blammer will be able to get me some coming in the mail shortly.

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Originally Posted by vrh

I use Vulcancheck gas checks (.0145 " .310 diam.) for my 30-06 rifle. I put the gas check on the bullet by hand and then use my plastic hammer to lightly seat it. A visual check at this point to verify that they look seated. Then I run them thru my .309 LEE sizer base first. Poly coat them and again run them thru the sizer. So far I have not had a problem with this method.

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My gas checks slip on with no pressure needed. But once crimped they stay on tight. If the boolit wasn't so small, and had such a pointed nose I could see pushing them through base first. But until they are crimped on they just fall off. The metaplate being so small does not allow you to put the boolit on the sizing stem squarely, which results in a slight tipping one direction or the other. The closest I came was using a nose punch for a lubersizer that came with the .243 RCBS boolit mold I have. Even still, it was difficult at best. Base first, aside from a custom stem, is not going to work for me.

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Originally Posted by newton

Yes, Lee die, smoothed out to a mirror shine. Before smoothing it out the checks would completely tear, now they just leave a ridge of sorts where the base is not supported by the sizing stem. In the future I am going to try a larger sizing stem, but realize that it might come at some cost of clearance issues inside the die. Preliminary tests, with a small brass rod on top of the lee sizing stem, does show some promise.

I have tried base first, but while it does not tear the bases, it is a lot harder to get the check on straight. Copper seems to be the way to go at this point really. I put some on boolits last night and will load them tonight. I do not have enough to try a whole lot of load testing, but I will try the same load that shoots well with the aluminum. I am hoping to luck out in this situation, but I have a gut feeling I will not.....

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Newton, the larger sizing stem will help. I had to go up in size with copper checks. If stem is too small you get skirts of copper around the bullet if anything is out of perfect alignment and sometimes the skirt or smire will bind between die and stem. Not a good day when this happens.

I make my own 30 cal checks out of aluminum. I have had no issue with any of the gas checked moulds I have. Mind you I don't have a .22 gc

Even with a slick sizer you need some lube. Try lubing a few, veggie oil works. I use BLL now - stops that ring on the base and the checks seat great. I use Cu GC as Al. galls quite easily.

I had problems and emailed Lee. They sent me a closed end die to get the checks on firmly, then could run them through the sizer. I tried both nose first and base first. The flat nose bullets did better base first, the round nose did better nose first.

On my 311 die, i beveled the entrance of the die to except 32 cal GCs.

Best thing i ever did. The checks go over any 30 cal gc base and they really form to the bases.

Any of you guys in here mentioning problems with Al checks used ones you have made yourselves out of soda cans? I just got some check makers and am wondering how much it's going to affect my loads.

What I am wondering is how aluminum gas checks affect the barrel wear. Aluminum forms an oxide on the surface almost immediately on being exposed to oxygen in the atmosphere. Aluminum oxide is one of the hardest materials known to man and is used as abrasives in industry and sharpening stones are made from it. So if my aluminum gas checks have that oxide coating on them, are they going to cause excessive barrel wear? I have some aluminum gas checks, but have not used them yet. Does anyone here know of examples of unusual barrel wear using aluminum checks? I have not of heard any, but I want to only use materials that are not going to damage my rifle barrels or pistol barrels. The price inexpensive aluminum gas checks won't be such a good deal if I have to replace my barrels more frequently. I can buy a lot of Hornady crimp on copper gas checks for the price of a new barrel.

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Originally Posted by elwood4884

Newton,

Are you using a Lee Push Through Sizing Die?

I have found that aluminum checks are significantly more susceptable to tearing vs. copper checks. One thing I have found is if you are using a Lee Push Through Sizing Die try putting it through base first. This seems to correct a lot of those issues.

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I tried base up. It makes the bottom rounded. I tried them anyway. Then I used something to flatten the bottom of the checks. Same poor results. These were on the Lee 55gr .225

I've also had poor results with aluminum checks on my 7.5x54MAS ammo. These are 160gr Lee 2R TL. But unlike the .225s I have Hornady copper gas checks for these and they shoot great.

I have seen other threads on here where guys were getting much better results using copper checks on the Lee 55gr .225 vs aluminum but I've also seen photos of nice groups shot with aluminum checks on the Lee 55gr and even decent groups with that boolit using no check at all.

So far my best groups with aluminum checks on the Lee 55gr is about 3" at 50 yards with shakey consistency kind of acting like a gas check coming off in flight or something.

Without the gas check I can't even keep them all on the berm.

Motor

newton; I make my own 30 and 35cal. aluminum checks. I keep small bins of checks that vary in thickness from about .009 to .015 although the mandrel is the same the different thickness allows for a just right fit. Also, the NOE check seating die is one of my favorite tools, it's a rare check that doesn't go on perfectly. They still need to be run through a sizing after but no more ripped or smeared aluminum. Gp

You might investigate a process called chem film used to prevent corrosion on aluminum. The military spec is MIL-C 5541.
The aluminum has the oxide stripped off by chromic acid.

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Originally Posted by Black Prince

What I am wondering is how aluminum gas checks affect the barrel wear. Aluminum forms an oxide on the surface almost immediately on being exposed to oxygen in the atmosphere. Aluminum oxide is one of the hardest materials known to man and is used as abrasives in industry and sharpening stones are made from it. So if my aluminum gas checks have that oxide coating on them, are they going to cause excessive barrel wear? I have some aluminum gas checks, but have not used them yet. Does anyone here know of examples of unusual barrel wear using aluminum checks? I have not of heard any, but I want to only use materials that are not going to damage my rifle barrels or pistol barrels. The price inexpensive aluminum gas checks won't be such a good deal if I have to replace my barrels more frequently. I can buy a lot of Hornady crimp on copper gas checks for the price of a new barrel.

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