Forming 7mm TCU cases - issues

[Mr_Sheesh]

I've had the problem that, despite cleaning all lube from the RCBS expander for 7mm TCU, the darn thing gets lube in it again and unscrews, eventually impacting the head's web and bending the threaded rod, makes a mess of things.

I guess it's time for locktite! But first I need to get spares...

Oh wait, the die set seems to be out of production now, so no spare expanders are available.

-grumpy mode- C'Mon, RCBS, do right by us, please LOL

Hoping they will produce more or I'll have to figure out another alternative or ???

[FLHTC]

Deprime all your cases separately, then open your case mouth and size the case with the decapping stem adjusted up.

[EDG]

The die may be out of production but the decapping stem is a standard RCBS item.

I guess the 7mm expander button uses the larger 10-32 thread on the bottom and the 1/4-28 thread on top. If the 7mm TCU uses a special rod just buy a rod for a 7mmBR. It should be similar since it is also a short 7mm.

[mtnman31]

It may seem obvious, but there should be a nut on the stem to lock it down so it doesn't move. As was previously mentioned, you can get a replacement stem from RCBS. I've tried to straighten a bent stem before and never could get it perfect. Easier to get a replacement.

[FLHTC]

I believe the thread that RCBS uses is 1/4 24. I used to get mine at Lowe’s by the 18” length. 10 32 is smaller than 1/4 20 or 1/4 24

[Three44s]

Is the expander button coming lose or is the whole stem loosening and drifting down?

If the whole stem is the issue, two nuts jammed will stay put. A Nylock nut would as well.

If it is the expander button then I guess lock tite is the answer.

Three44s

[rockrat]

or put a little pipe thread tape on the thread. Use scissors to cut a piece narrow enough to work

[gumbo333]

Years ago forming 7tcu from once fired .223 brass, just reloaded with a light .223 load under a 55 gr blem, load long, shoot in the 7tcu contender. Maybe lost 2 in 40 with a split neck. Easy.

[shaggy357]

I have 1000s of TCU cases in my reloading room. 100s of each 6, 6.5, and 7 TCU for multiple guns. The only die issues i have ever had was in resizing military (or PMC) brass with crimped in primers.

My first TCU was purchased in 1986. I purchased 1000 military cases at a gun show and deprimed them with a depriming fixture and hammer. Then i used a crimp remover to swage out the crimps. I had 2 or 3 hundred each of different loads about a year later when i bought more brass. I had been sizing those first 1000 With no issues. So i did not deprime or remove the crimp in the new batch of brass. The first 100 or so of this new batch went fine...then i stuck a decapping pin through a primer. A few cases later i wrinkled a shoulder. More issues followed. I finally realized i had bent my decapping stem. RCBS sent me a new one at no charge. No crimped primers through my dies since. No die issues since.

Size brass to fit your gun, load a moderate load, and go shooting. Fireforming loads can be accurate, and are great for sage rats or general target shooting.

[NObamain2012]

Going from 22 to 7mm is a big step in one operation. I would consider necking up to 25 or 6.5mm first.

[FLHTC]

I do my 25 TCU in one step. They come out beautiful every time

[ulav8r]

I do my 25 TCU in one step. They come out beautiful every time

Not that I doubt you, but a statement like this means little unless you give all steps of your process and equipment used. If I use different equipment or process, I may get far different results.

[BK7saum]

One step from 0.224 to 0.257 should be an easy neck up with a tapered expander. Most of the TCU die sets should have a tapered expander, anyway.

[FLHTC]

I have a set of regular dies from CH. I run a 5.56 case right up into the sizer with imperial sizing die wax on it. After that, I put them in the wet Tumblr and they come out like brand new and ready to load.

[Mr_Sheesh]

My previous die set never gave me this issue, made a few thousand cases back then. Don't remember splitting any necks, those were made from 1x milsurp brass.

This time I'm using new starline brass.

The whole expander stem is coming very lubricated from RCBS, and both the shaft and the sizer have unscrewed even if I acetone washed the lube off before use.

Once it gets too long, the press' mechanical advantage turns the shaft into a non straight item, and that's not good...

I thing I'll try longer degreaser, soaking then locktite.

Anyone happen to know the part number for the threaded shaft? I have a few more units inbound, yay!