.30 cal plain base gas checks?

[Spindrift]

I must admit, when I first became aware of the existence of gas checks for plain base bullets, I couldn't see any use for them. But then it dawned on me; if these small caps give the bullet the same capacities as a conventional check, it actually renders the shanked bullet designs obsolete. Think about it - you would really only need to cast Pb bullets, and check those intended for higher intensity loads- or load them like regular Pb bullets.
But the question is, how does plain base checked bullets compare to their conventional gas checked, shanked brethren?
I am tempted to order a check forming die from Pat Marlin to explore the concept.
Have anyone tested checked plainbase rifle bullets?

 

[Ole_270]

I've got a few gas checks for plain based bullets from Sage. Tried them on the 30 cal 165RD bullet and it took way too much power on the press handle to run it through the sizer. Maybe I just don't know that I'm doing with them, but on a Rock Chucker Supreme going through a .311 sizer bushing it shouldn't take that much effort.

 

[Ian]

I shot some a friend gave me years ago in my .35 Remington, had my doubts but they made a ragged hole. I think it's probably worth your money to try if you already have several PB moulds.

 

[Eutectic]

Sounds like a good fix alright ........ But here's what I found. Even soda cans at .004" (0.1mm) have to displace metal to size to our use. I've got them to work OK in revolvers (sort of). But in rifle loads accuracy suffers. I tried both aluminum and copper. The gascheck part for sealing gas seems to work OK and they may stop leading. It is quite easy for me to cut a gascheck shank on a bullet on my 3" jewelers lathe. I have tested the same exact bullet with plain base gaschecks and then with a shank cut with Hornady gaschecks installed and accuracy was much improved with the shank! Squashing the check into bullet metal even .004" appeared to me to unbalance the bullet? I also don't believe .004" thick is enough for faster rifle loads.

I might add that I have several sizes I made of push through sizers that size over a 2" length. This was for sizing lube groove bullets down .008" to .010" for paper patching and staying concentric. I had thought to try the long gradual size with plain base checks but haven't.

Pete

 

[Eutectic]

I shot some a friend gave me years ago in my .35 Remington, had my doubts but they made a ragged hole.

Can you find out the details of methods and materials he used Ian? It would be a useful bit of knowledge for us all if it would work for our own applications!!!

Pete

 

[Ian]

John Goins (Beagle) sent me some he made to try out, he was as curious as I was. I don't know the exact mould number but it was an out of production ~200-grain Lyman RN with at least two lube grooves and was a secant-ogive RFN. I don't even remember the load I used, wanna say it was RX-7. I posted about it on CB years ago, and some other places lost to history. The checks looked like beer can aluminum, still had some of the print visible, and had been applied base-first in a Lyman 450 and lubed with NRA 50/50. I sent a couple of those bullets to Bob Kell on his request and should still have a few left over in the bullet cache...if I can find them. Bob knew the mould number but I don't remember exactly what it was.

 

[Spindrift]

Thank you all for your input. I think I will add a small batch of PB checks next time I make an order at Sages, to test the concept, before investing in another check maker die. I guess using a soft alloy, and swaging the checks on freshly cast bullets base- first would be a good start. I have a couple of moulds with both GC and PB designs, which should provide a decent testing platform for the concept; PB vs PBGC vs GC.

 

[Ian]

358075/35875, 160 or 200-grain. Pretty sure that's the one.

 

[fiver]

I can see the 075 working it has a lube groove right above the bottom drive band.
I was thinking before seeing the pic of the bullet that I'd bet that a design with a smaller base band and a lube groove right above it would work better than a cut out gas check shank that left a real long base band.

 

[JWFilips]

I never really understood the concept: Putting a GC on a normal size PB bullet.....just use a G/C bullet instead!

 

[KeithB]

Back in the old days it wasn't nearly as easy to get a GC version of a PB bullet. Now we have a number of custom mold makers but that hasn't always been the case.

 

[freebullet]

I've used soda can checks quite a bit in 357. They worked pretty good in that application. They didn't want to stay on great so I was putting a tiny dash of powder coat in then placing before heat treating. Glued'em on pretty good.

 

[462]

Traces of leading in a .357 Blackhawk's cylinders were eliminated by test usage of plain base gas checks. Don't know if it's something that I'll continue to pursue, but a lifetime supply of those checks can be bought for less than the price of a gas check designed mould.

 

[Spindrift]

My curiosity got the better of me, in the end. It usually does. A Pat Marlin checkmaker for .30 PB arrived today. I have just barely set it up, made a few checks (beercan). Put them on some PB bullets with .3125 base band, sized directly to .310 base first/push-through, using the NOE top punch holder for the ram. Bullets were BHN 18. Worked like a charm!

Checks are completely embedded in the base, totally fixed. The checks made with the checkmaker often get a «bottle cap» appearance before crimp/sizing. I believe this helps with grip.

It will be fun to see how this works. For now, I see no reason why it shouldn’t.

 

[Ian]

Ha! My curiosity usually gets the better of my wallet, too. Those look good and I predict excellent results. Now you will always have the option of essentially free gas checks for making inexpensive loads.

 

[Hawk]

Yep, I use Checkmaker for plain base gas checks, also.
I've had great results on higher end loads. I've found I get better results if I use thicker aluminum cans.
Luckily, my daughter is a constant contributor of Miller Lite, screw on lid, beer cans. These are thicker than soda cans and have given me better results.

 

[Spindrift]

@Hawk , thanks for the advice- I’ll keep it in mind. I have scrounged a few different sources of check material. I’ll try the soda cans first, since I have a lot. But I also have a slightly thicker aluminum from disposable serving trays, that form beautiful checks. I’ll check it out!

 

[Spindrift]

My first groups with PBGC bullets, will be the #315- clone from NOE; the «Matchking» of .30-cal cast bullets. I will try them in my Howa .308, using Vihta N110 powder. This is my «show-me-whatcha-got»- powder for gas checked bullets in .308 or .30-06.
Cast a few more PB bullets today. The MP311-410 is a new bullet to me, I have a 2-cav HP mould. The Lee 311-100-2R is a bullet I’ve never had much success with. I’ll give it another try.

 

[Spindrift]

The PBGC gives me very sharp, nice bases when sized base-first. On the left a regular #315 GC bullet with homemade alu check. On the right a #315 PB bullet with PBGC. Hopefully, I'll get to shoot them in a week or so. Quite exciting!

 

[Glaciers]

Really like the looks of that hollow point bullet