Gas Checks and 950fps revolver loads

Just getting back into casting and have a bunch of misc lead, wheel weights, plumbing scrap and misc lead with no history. Melted down some of the lead yesterday and poured about -60- 1lb ingots. Just wanted to see if my turkey oil cooker burner could handle it (it did).

Don't have a hardness tester and looking for some feedback related to loading for example 130 gr cast GC bullets for 950 fps (120K plus power factor) in a .38 revolver. At that light bullet weight and velocity and using a gas check...would bullet hardness be less of a concern?

Also with that combination would aluminum gas checks be a good combination...I like the idea of aluminum vs copper.

Thanks

Sounds like your alloy may be a bit soft.
No worry however, At that velocity you'll be fine.
Just be certain the bullet is large enough.
A lot of inaccuracy issues and leading are caused by a cast bullet that is too small.

I shoot thousands of aluminum gas checks, no problems for me at all.

Ben

What kind of mold do you have that casts 130gr GC bullet? It seems a bit high velocity for this weight unless its +P or longer barrel for 38 spl. At this velocity I wouldn't worry about GC, I shoot 9mm faster without GC. I am looking myself for no lube groove GC .359 bullet mold so I can push it 1400-1500 fps from my GP100 .357

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... a bullet loaded in a round with a FPS less than 1600 does not need a gas check

I echo Ben's advice as I shoot a lot of 130's in my .38/.357 guns. 10's of 000's so far.

At the worst, add some Linotype or hardball alloy (96-2-6) if you want/need a harder bullet. Much easier than adding GC's and cheaper.

I did purchase a PB (plain base) GC maker in case I decided to drive that bullet over 1500 fps in the rifles but never got around to it. I bought aluminum for it as well.

I shoot 38 spl loads with wheel weight cast 125 grain hollow points out of mp mold lube sized to .358, 1000fps with 5.3 grains be86, shoot them all day long out of 38 spl S&W, 357 ruger and Rossi rifle all day long with no problems. no gas checks
I put together a soup can full of them yesterday and will go out and pop them off this afternoon

Thanks guys...got a little off track...I understand that GC's ain't required under certain FPS...I was curious as to if a GC would reduce the concern for bullet hardness, if so, worrying about specific alloy properties would be less of a concern.

Secondly, I contacted a GC manufacturer and they stated that aluminum GC's are less expensive but actually harder than copper. So sticking with a plain base lead bullet (vs bevel) complements the obturation process which is less likely with GC bullets.

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Originally Posted by 8shot

Thanks guys...got a little off track...I understand that GC's ain't required under certain FPS...I was curious as to if a GC would reduce the concern for bullet hardness, if so, worrying about specific alloy properties would be less of a concern.

Secondly, I contacted a GC manufacturer and they stated that aluminum GC's are less expensive but actually harder than copper. So sticking with a plain base lead bullet (vs bevel) complements the obturation process which is less likely with GC bullets.

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GC's will not only add about $25/1000 your your bullets, but slow down processing. Alloy improvement is easy to do and cheaper. You can buy Linotype for about $3/lb. 1000 130 gr bullets will weigh about 18 lbs If you add in 33% linotype it will cost you $18 and you will cast a better bullet. Even if you had to go to 50/50, your cost would be only $2/1000 more than using gas checks.

GC's are a last resort IMO. Properly sized and with any decent alloy, you will not lead a .38 Spl load. If you get leading, size up in increments of .001" until leading goes away.

The only 38/357 I ever needed to use gas checks on was a Lee C358-158 SWC HP, purchased back when they still made HP molds, and it had a gas check shank. I have used plain base gas checks on some hotter loads, back before I started powder coating. I shot a ton of very soft boolits cast from reclaimed swaged hollow base wad cutters, no leading. The OP should have nothing to worry about.

The ONLY time I leaded a bore was when I shot some hot 41 Magnum loads but had switched lube, they were out of Javalina. I never had a problem with Javalina but the 'lube on the shelf' was a big epic failure. About 10 rounds of light loads with gas checks cleaned the bore.

My current allow has been 50/50 COWW/pure lead and am launching at 2250 fps powder coated plain base 223 boolits. Like Don said above, fit is king, a properly sized and lubed boolit will not be a problem. PC gives me slightly better performance accuracy wise, lubed with PBGC slightly better still, the best being PC and PBGC, at least in 38/357/9mm/357 SIG. They all hit soda cans at 100 yards off hand, just some are more consistent at center punching the can vs just a hit. YMMV

I plan on using aluminum checks on plain based .44 cal boolits. Pure plus 2% tin. If I can get them to be accurate enough I will hunt with them. That is much less expensive than pure linotype for full power magnum loads.

I shoot thousands of GC bullets out of my 38 SPL revolvers. They always give the best accuracy and you can use very soft alloys for excellent expansion with HPs. I also use PB'd bullets for my most used generic "blastin" loads. The GC'd (mostly 358156s) are used for my most accurate high performance loads.

So, yes the GC does reduce the concern for hardness.

Not a matter of whether I "need to" but a matter of choice. My 358156 cast very soft (usually a 40-1 alloy), GC'd and HP'd and loaded over 5.5 gr Unique (a +P load) in 38 SPL cases expand very well when shot out of my 2 1/2" M19 and 4 and 5" S&W M10 and M15s. Velocity runs 950 - 1030 fps with the PSI for that load being less than the SAAMI MAP for 38 SPL +P.

I also make my own GCs and use .012 aluminum. They work fine. I also have a couple thousand old Lyman slip on GCs which also work fine in the 38/357 cartridges. I use the crimp on Hornady 35 GCs on 200 gr cast for my 35 Rem.

If you load a case with a .38 boolit made with a GC rebate, do you have to load it with a GC or can you just seat it as if it was a PB?

Got a Lyman 358480 HP PB that casts about 133 grains. I use Pat Marlin's .35PB pop can checks on them. Sent a bunch to a friend in Texas with armadillo problems. They work really good. He calls them "diller thrillers". That's a good weight in a .38 Special and no leading with the GCs./beagle