RCBS and Lee don't have dies...

[2pats]

I've asked this before on other sites...most replies were either not serious or down right ...um..insulting. Any ideas on how to(neck) resize a 105mm. (aluminum) shell case? I have the case and empty projectile that I would like to assemble as a dummy round. This would make a great door stop for the gun room. Thanks for any advice, Pat.

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[Stevo]

How much does the neck need to be taken down and over how much length?

[2pats]

The neck ID needs to come down by about 2.8mm. The neck length is about 4mm. Thanks for the first...logical...reply to my question.

[buffdog]

Interesting. To make up a dummy round, you could insert a wood block inside the shell case,mark it at the mouth of the case, then measure on the shell how far you wish to insert it. Measure down from your mark the distance you need to insert it, make a line, then cut it off. This will allow the shell to go in, and not go in fully.

To resize it, measure the diameter of the shell, and the thickness of the mouth. Now comes the tough (read $$$ part) unless you have a friend with a metal lathe. You will have to make up a mandrel for the inside diameter, less a small amount. Then you will have to make up a split collar that is the diameter of the shell plus TWICE the mouth thickness LESS a small amount for holding.

If you have a friend with a wood lathe, find a piece of hardwood and try the above procedure. It will probably work for a one-off deal.

Next, insert the mandrel inside the case, put the split collar around the outside of the case, and clamp the collar together. Try the shell in the case. If not tight enough, you might have to take a bit more off the mandrel and reduce the collar diameter a bit to squeeze it down more.

That is what I would try. Good luck.

[Stevo]

The neck ID needs to come down by about 2.8mm. The neck length is about 4mm. Thanks for the first...logical...reply to my question.

2pats,
I'm a ham-fisted, bigger-hammer type of mechanic, so here's what I'd try:

You don't need to take it down much. Heat and force should be all you need. You could make up a steel/wood/aluminum "die", tapered to the size you need. Heat the neck with a tiger torch and beat the case into it. Alternatively, you could get a large metal hose clamp and progressively tighten it as you apply heat.

I don't know if either of those methods would work, but it's my $.02 worth.

Stevo

[desporterizer]

Might be easier to made a dummy projectile from wood at the right size & paint it. Wouldn't a practice or inert projectile be kind of heavy?

[Andy]

What is the required outside diameter?

Drill a hole through a piece of steel plate, smooth it, lube it, and pull it down over the empty shell casing for the length requiring sizing (i.e. neck size it).

[Stevo]

I hope you don't need to crimp it, too.

[buffdog]

Be Very Careful If You Apply Heat On It.....Aluminum Melts Very Easily.

Also, you mentioned that you wanted to use it for a door stop. If you do that, you better get everyone in the family a pair of safety boots. That sucker is going to be Top Heavy, and will fall over easily unless securely anchored down.

I like the idea of a wooden projectile. The Navy used them for practrice gun drills, and it would be a lot lighter. You could even pour a bit of lead or other weight into the bottom of the case, but do not fill it.

[that was loud]

I would also start with the heat and pressure method using a torch (lightly) and a suitably sized hose clamp to apply the pressure around the neck. That should shrink the aluminum enough for what you're after.

As for having your doorstop tipping over due to being top heavy - just throw a few pounds of sand in it.