Trimming Jackets

[Little Doc]

I have been following the swaging threads for a while. some really interesting stuff here.
the 22 rimfire jackets seem to have a lot of interest. i have not seen anything on trimming the jackets so they will all be the same length. sure would be interesting to hear what different folks do in this regard, or if they do not do it.
a little background here. about 1975 i purchased swage dies and a ram for a rcbs rockchucker from SAS (Ted Smith)in oregon if memory serves me well. i also purchased a jacket maker die for the 22 brass. made my own core mould and core cutter. after making some bullets i had a conversation with Ted and he had a jacket trimmer he made. i never bought one as $$ were verry short in those days. i made a jacket trimmer by making a pilot for my forrester case trimmer that would only allow the jacket to be trimmed to the desired length. i never came up with a good way to hold the jacket while trimming..it did work well but was slow and your fingers got real tired and sometimes the cutter would get into your finger. a collet of some type would be really good to hold the jacket i think. anyone got any ideas here? anyway the trimmed jackets made much better bullets. What do you folks do here or what thought do you have? i still have this setup and it still works well.
m

[Ammosmith]

I have been struggling with this too. I came up with a jig for trimming 22 magnums that were not derimmed but the length still varies. I just got a mega Mite press and I am making jackets as fast as I can get my hands on brass. So. some ideas I have been thinking of.

The one that seems to seem the most logical is the Lee cast bullet sizing die. They make one in .224"and .225". Why not use the .225" die set it up like a trim die. After seating the core run the jacket/core combo up the die after you have adjusted for jacket length and go over it with a fine file? The next case pushes the first one out.

The other idea was to setup a mandrel for the Lee trimmer and chuck it in a 1/2" drill. The finger thing is still an issue.

Another idea is to drill a hole into bar stock and have a threaded piece to adjust jacket length. Another file trim die setup. Corbin sells a pinch trim die but at nearly $400 I need to wait.

[Little Doc]

ever thought of a pair of plyers with a hole bored where they clamp to an object. a hole that is just the same size as the jacket or .0001 smaller. just enough to hold the jacket while being trimmed. this would also allow pressure to push the jacket to the cutter. have had this thought for a while but not acted on it. may give it a whirl. if this could be automated it would save a lot of time and fingers. what do you think.
m

[Ammosmith]

Interesting idea. I am trying to come up with a quick way too. I think the .224" cast bullet sizer from Lee would be pretty fast. I will be looking into that one too.

[sagacious]

Trimming jackets is not really necessary with the fired 22lr jackets. The need for trimming can largely be obviated by sorting the brass by manufacturer, and it's especially nice if one can get a large quantity of brass from the same lot and manufacturer.

After the bullets are swaged and finished, one can then sort them by weight, if desired. It costs nothing at all to sort brass, and goes a LOT faster than trimming each and every jacket.

Good luck. :drinks:

[BT Sniper]

The lee bullet sizer would have to be cut in half at the spot inside where the .225 sizing portion gives way to a larger section of the die since the .225 does not run all the way to the top of the die. Could be done though as I have thought about this very thing severial times.

[Ballard]

How do you lube your case before de-heading? It is my opinion that a lot of the variation in jacket length may be caused by cases being lubed by hand, and the amount of lube varying. Some go through the dehead die nicely, some "sticky".

[elk hunter]

Years ago a customer wanted a way to trim 22 LR cases to make lighter weight bullets for his Hornet. I made up a collet and pilot that fit in his case trimmer and he bought a cutter head that would do 17 caliber cases so that it was small enough to trim the derimmed cases. I'm sure it wasn't fast enough to do production work but it got him where he wanted to be with his bullet making. I would think that pinch trimming would be much faster, but I would think that variation in case wall thickness would effect overall length, since I haven't tried it I can't really say.

[Rat-Man]

I use a pilot that I made from a broken drill bit, #10 for my de-rimmed cases, that fits the Lee case trimmer cutter. That is chucked up in a 1/2 drill chuck that I have attached to an old benchtop belt driven belt sander. A 1/2 inch drill in a vise would work just as well for those that happen to have one.

My latest solution to the case holding has been a 7/32 R8 mill collet (just happens to be the right size for my die set), just slide one in and squeeze tight while the cutter trims to length.

I would think that a fellow could just drill a hole the right size in the end of a cheep pair of pliers, then sand off a little of the inside faces so that they would close on and hold the jacket tightly. I have never tried this, but I think that it would be a handy way to hold them and probably faster than my current way.

I think trimming is the fastest way to make consistent length jackets. I sort by manufacturer first and work with one brand at a time and there is still a good bit of length variance after de-rimming.

I spend a lot of time trying to keep weight variance to .1 grain or less, but from past experience you could just use whatever cases you happen to pick up, and cram in a core for the average weight your trying to make, and still be within .3 - .4 variance. That is better that some brands of bulk bullets and not as good as others, but they will still shoot pretty good.

Rat-Man

[deltaenterprizes]

Interesting thread, I am working on making 6mm/.243 bullets from 22/17 mag brass and that problem will soon arise.
I am better equipped than some, having a mill and lathe with a 5C collet chuck.5C collets are threaded inside to allow the use of an adjustable stop. There are cheap import 5C collet blocks available for about $15 each in square or hex configuration or $30/set of 2. Cheap collets are available for $5 for fractional sizes and the adjustable stops are around $15.
CDCO is a cheap source for import machinist type items. DO NOT use the web site to order with a credit card, it is not secure.