Reduced Loads in Large Cases

[Grapeshot]

This is way out there. Some years ago, 33 or more years ago, back in the 1970's I read an article about an individual who inserted one cartridge into another to give him a smaller combustion chamber in the cartridge he was developing small charges for.

The gist of it was that he opened/expanded the neck of the cartridge he was going to modify, decapped the cartridge and cut off its neck, removed the rim and extraction groove, and drilled out the primer pocket, and inserted into the modified cartridge. He then ran the original cartridge up thru the sizing die, bringing it back to the original speck.

He then re primed that case dumped his reduced powder charge into the case, making sure it went into the case he had earlier inserted, seated his bullet, and fired it down range.

According to the author, the inner case expanded and was now locked against the inner wall of the rifle's cartridge.

Does anyone else here remember that article or it's author?

[AnthonyB]

I believe that was in one of the three bullet casting annuals put out by the folks at Handloader magazine.

[frnkeore]

You'll find it in "The Art of Bullet Casting" compiled from Handloader and Rifle magazines, published by Wolfe. It's a reprint from a '70 something Handloader. I also have the magazine but, can't find it at the moment.

Basicly, you cut the neck off a 223, drill the primer pocket to about 3/16 and open it to 33/35 cal, chamfer the rim off it, too. Open a 308 neck to .375 in steps and push the 223 into the 308 case untill it bottoms out. Then resize it back to 308.

Frank

[frnkeore]

Also, it doesn't deal directly with anything but the 308. But, I think you could stuff 308 or '06 in side a belted mag case and maybe a M1 carbine inside a 223 case.

Frank

[Rio Grande]

Why go to all the trouble?
While 'detonation' is a possibility with small loads of slow-burning powder in larrge cases, people have been shooting light and ultralight loads in similar sized cases w/ fast burning powder for a long time w/o problems.

[HARRYMPOPE]

i tried it and it never shot any better than my standard 308 cast loads. it was Jim Carmichael's article.it was alot of work to make 20 cases.I thought about doing something similar for plain-base 30-06 loads with 6-9g of powder,but havens done it yet.

[nanuk]

I wonder if the technique of using Lino and drilling a flash tube and powder chamber would work better.

you could do more for less, and you could create any sized chamber. I have heard some as small as the neck, boolit seated on top of powder (1gr Bullseye??) and getting near supersonic velocity.

my memory fades, but it did sound interesting.

[Doc Highwall]

I just use AA5744 powder with no fillers.

[GH1]

I just use AA5744 powder with no fillers.
Or Trail Boss.
Gh1

[Artful]

Actually paid for some cases to be CNC lath turned with smaller internal volume
(between 300 whisper and 7.62x39) to use in 308 subsonic loading - you will find with 5744 or Trailboss that powder position in the standard case will cause velocity variations.

IE if you have the barrel down with powder by bullet then raise it level to shoot it will give different velocity than if you have the barrel up with powder by primer and bring it level to shoot. Got very fustrating so spent the money for custom cases to solve the problem by having 100% loading density with trail boss powder.

Granted with was very specific wanting bullets to only be between 950 and 1050 fps for suppressed rifle use.

[leadman]

There was a company many years ago that made reduced volume cases, but I think they are long gone.

[Artful]

Several companies had made them - currently I know of no US company that makes them. Trail boss is a reasonable solution for most situations. Part of the reason the 300 BLK is gaining in popularity is it's a factory round attempting to give a subsonic solution. The other alternatives are heavy 9mm subsonic loads and subsonic loadings in 38spl and 44 spl for suppressed weapons and of course the subsonic 22LR which is quietest of all.

[wiljen]

Paul Matthews did that using 30-06 cases cut back and drilled out inside the 45-70 case. He wrote for handloader and it is also covered in his book "40 years with the 45-70".

[frnkeore]

I found it...........

The original write up was in Handloader #36 March - April 1972 page 42 By Jim Carmichel.

Frank

[badbob454]

this is way out there. Some years ago, 33 or more years ago, back in the 1970's i read an article about an individual who inserted one cartridge into another to give him a smaller combustion chamber in the cartridge he was developing small charges for.

The gist of it was that he opened/expanded the neck of the cartridge he was going to modify, decapped the cartridge and cut off its neck, removed the rim and extraction groove, and drilled out the primer pocket, and inserted into the modified cartridge. He then ran the original cartridge up thru the sizing die, bringing it back to the original speck.

He then re primed that case dumped his reduced powder charge into the case, making sure it went into the case he had earlier inserted, seated his bullet, and fired it down range.

According to the author, the inner case expanded and was now locked against the inner wall of the rifle's cartridge.

Does anyone else here remember that article or it's author?

use your zinc wheelweights to fill the case... Size, deprime necksize and fill the case with zinc by heating up the case and dripping in zinc fill to the base of the neck ... Put clay or mud in the primer hole and drill out the center to the DIAMETER SIZE /volume you want CLEAN OUT PRIMER POCKET install primer and powder seat bullet =reduced volume case

[Alferd Packer]

Yes, I remember that article by Jim
Carmichael.
Actually it makes great sense nowadays.
He made the precursor to the 300 blackout .
He put a .223 case inside a .308 case, thereby reducing the internal diameter although still a bit bigger, It was a. attempt to use a .223 case to shoot .308 size and weight bullets.
That's all a .300 blackout is.
A .223 case necked up to shoot a .308 size bullet.
Jim was ahead of his time in this endeavor.
Anyone else see this?
The .300 BO is one of the hottest AR conversions going today.
You can approximate the same using your own .30 caliber rifle.

[MUSTANG]

Back in the 1970's and early 1980's there was some level of popularity for caliber conversion sleeves or adapter sleeves that allowed a smaller length round to be fired in a Rifle Chamber. I have 5 or 6 of these in .223 that allow .22 Long Rifle to be fired in a .223 rifle. There were a variety of these made for rifles to allow firing pistol caliber ammunition. An on line article on this:

https://en.wikipedia.org/wiki/Caliber_conversion_sleeve

[country gent]

That was done with the 45-70 carbine load by the US army years ago. A cardboard sleeve was inserted in the case lowering powder charge to 55 grns of powder and maintaining compression with the 405 grn bullet.
With the case inside a case I would be concerned with cases sealing the chamber. Epoxy or lead in the case head then a hole drilled thru would work but pouring molten lead or lino t type into the head would anneal the case head, shortening primer pockets life and possibly destroying the case, a long skinny depriming rod would be needed.

Some over the years have played with flash tubes in the cases to ignite the front of the powder charge even. reports of lower extreme spreads were reported but flash holes needed to be drilled and tapped. small long tubes threaded with a small shoulder then fitted in and primer pockets re-cut. Then tubes removed and deprime then install back in the cases, again a lot of work for the gain.

[scattershot]

10 year old thread, Interesting exercise, but it sure seems like the long way around the barn.

[Alferd Packer]

Installing a .223 case inside a .308 case seems to be duplicating the .300 blackout which is a subsonic loading which is supposed to have military applications as well as some hunting situations using a quiet load to launch a heavy bullet to deliver more ft lbs of energy on target with a much quieter shot.
The smaller capacity of the new case shows a more efficient use of powders that would not be possible using a .308 case without the insert.

[RU shooter]

Seems like a lot of extra work to get the same results . I load 5-6 grs of Bullseye in the 30-06 with normal to heavy bullets and get the same accuracy or better than I ever got from my 300 blackout . So what does all this extra work gain me . Imo nothing .

[charlie b]

http://www.gmdr.com/lever/lowveldata.htm