View Full Version : Auxiliary Cartridges

February 25, 2000, 03:10 PM
Dear Sir,
I read in "Alex Auxiliary Cartridge" website about a 22 Hornet cartridge made of mild steel which incorporates a .22LR cartridge into itself. I would like to make some of these auxiliary cartridges for myself; saving the expense and providing me with a nice project. I have access to and belive I have the required knowledge to complete such a project.
As it may be, turning or grinding the outside diameter to within .0005 is not a problem. My problem is the fit required on the .22LR inside the bore. Should the .22LR be a slight press fit or a running fit in the
auxiliary cartridge bore? How about head space for the .22LR; should I add an extra .001 on the auxiliary case or would that be too much?

Thank you very much for any info which you can give me.

George Stringer
February 25, 2000, 11:08 PM
Viga, I've stayed away from these type of projects but if it were me, I would machine the insert .002" less than the inside dimensions of the chamber. Then use Accra glass to hold it. That way it isn't really permanent. You would be able to apply heat in the form of a heated rod into the .22 chamber and loosen the glass if you wanted to remove it. George

February 26, 2000, 06:06 AM
Thanks for the input.
I guess I had this figured all wrong. I though these were cartridges (many of them) that you placed a .22LR cartridge inside and then feed like regular 22 Hornet cartridges.

If I have to semi-permanently put this thing in the chamber of my gun and cut a chamber into it; then I would tend to agree. I too would stay away from such a project.

Anyway thanks.

George Stringer
February 26, 2000, 06:48 AM
Viga, I have seen what you're talking about but have never fooled with them. I guess in thinking about it my question would be if it isn't a permanent/semi-permanent change how is the firing pin redirected from the center to the .22s rim? If you have that figured out then you could machine the insert to the same dimensions as the original cartridge and the .22lr "chamber" to normal chamber specs. In other words buy or rent a chamber reamer. Headspacing for the .22 would need to be done with headspace gages and I do recommend a plus .001" over the go gage to allow for difference in rim thickness from one maker to another. George

February 26, 2000, 03:39 PM
I guess in thinking about it my question would be if it isn't a permanent/semi-permanent change how is the firing pin redirected from the center to the .22s rim?

From what I understand from this web site the auxiliarys should work in a TC Contender just fine. I agree and I'm a bit skeptical on how the firearm accomplish this. Thats why I had included the headspace question. Since the Hornet cartridge is in an already headspaced chamber then headspacing the .22LR insde it would create alot of headspace. Would it be too much in that the .22LR would go slamming into the receiver/hammer?

Anyway thaks for the input.
You are indeed a fountain of knowledege.

James K
February 26, 2000, 06:13 PM
Hi guys,

Commercial adapters to fire .22LR in a .22 centerfire rifle have been made two ways. The first, like the Alex adapters, uses an auxiliary firing pin which slips into the adapter behind the .22 LR cartridge. There are a couple of ways to do this, and Alex actually uses a separate firing pin. Some have just a cylindrical piece of steel with a "tit" on the front to fire the rimfire round. Either way, you have to punch out the empty case (if any) and the auxiliary block from the front, load the .22 LR, then insert the block/firing pin. It saves money, but it is tedious and a pain in the neck.

Some of the adapters will feed like the regular cartridges, some are single shot propositions. It looks like the Alex would feed OK.

The other route is to drill the auxiliary round off center, so the normal rifle firing pin strikes the rim of the .22 LR, but this means the .22 LR bullet has to "turn a corner" which distorts the bullet and is not conducive to good accuracy. This is not really a DIY proposition unless you are a good machinist.

Reloading is actually cheaper.