Forming 25-20 SS from .223

[Danth]

There was a post a while back on swaging .223 to 25-20 SS. Can't find it. Anyone have this info? Thanks, Dan

[Eddie Southgate]

How would that work without a rim ?

[Danth]

The rim is formed by swaging the base.

[ndnchf]

This is not mine, but I saved it off the internet. I've not tried to do it.


Converting .223 brass to .25-20 SS and ultimately .22 Lovell

First expand the necks to about .25 cal. ID. I used a long tapered expander I made for a Lyman M die. Lee expanders can be made to work.

Swaging the body down is the hard part. I used the neck of a 7x57 sizer die to do the swaging. This brings it down nicely to .311" diameter. Being a bit small has an advantage I'll bring up later. Don't be tempted to use some other 7mm die. The 7x57 has a fairly mild shoulder angle, and this is important to getting good results.

To do this, I made a punch approximately the shape of the 7x57 case body to push the case up into the neck far enough that the rim of the .223 was almost touching. (See photo.) The tip of this punch went through few iterations. The nose has to be about .005" concave, to curl the rim forward just a bit, and it has to have a pin that enters the primer pocket to keep it from collapsing. This eventually required that I machine the concave tip, and then press the pin into a hole. The pin was made from drill rod, and "shade tree" hardened with a propane torch. Diameter .172". The shank of the punch has a shoulder that contacts the mouth of the die to positively establish the depth. For my die, the distance from shoulder to face of punch is 1.592". The punch is also made from drill rod, but is not itself heat treated. It has held up for about 250 pieces of brass with no apparent change.

Using the 7mm die and the long 7x57-shaped punch has the advantage of keeping the everything aligned so that the base of the .223 case isn't forced out of square, and keeps the case fairly concentric in the die. This is important. A much earlier attempt using a drill bushing as the sizer failed rather badly in this regard.

I did the pressing in a benchtop hydraulic press, with a bolster that had a 7/8" hole in it. Had two steel jam nuts tightened together at about the midpoint of the 7mm die. Press the case in with the punch, back off, flip it over, and press back out using a length of 1/4" drill rod. My press' gauge was registering about 5000 psi at the end of the pressing-in.

I used anhydrous lanolin generously for lube. Today I would use Assemblee Goo, a kind of vaseline(?) grease you get at NAPA. Used during assembly of automatic transmissions. Tough, but requires a solvent wash to get it off. Imperial Sizing Die wax I have never tried, but it comes with positive recommendations from those who have.

Now you have a long, almost straight case with a fillet at the base. (See photo.)

To machine off this fillet, I make a spud from any old bit of steel, chucked up and turned with a pilot pin to enter the primer pocket. This needs to be snug, but not a press fit. I make this new each time, to make sure it runs dead concentric with the lathe spindle. Make a mandrel about 2.5" long that is a close slip fit in the mouth of the case. It needs a little tit on the nose to enter the flash hole, to keep it (the mandrel) running true. The outer end has a 60 degree center. Insert the mandrel, then press the case against the spud with the tailstock ive center. Press hard. If the cuts on the brass are light, it will not slip.

Use these to machine off that fillet. I only had a small and none too accurate Prazi bench lathe in service when I did these, so this was a bit fussy. Keeping the tool from touching the rim is essential - it is already too thin. The fact that the sized body is .311 is a boon here. I could leave the cross slide set to cut to .3125" (my Krag/Lovell has a very tight chamber!), and it rarely touches the body. (I back it off in Z-axis rather than move the slide in and out - the Prazi's cross slide isn't all that repeatable. A hard stop on the bedways kept it from touching the rim.)

From there it's straightforward. Rough trim to length. Form in a .25-20 die, then O.D. turn the neck to a thickness that will work in your gun. (Mine has to be a scant .010" for the Krag-Lovell.) Form again in the .22 Lovell die, and recheck length. Fireform and you've got a case. Note: use a .25-20 or a Lovell case adaptor in your press. The .223 may not accept the swaged cases, because the rim is curled forward, thus acting thicker than it is.

These cases are hell-for-strong, but have much less capacity than old commercial .25-20SS brass, and less even than new Jamison brass, also. Reduce loads about 1 grain to start.

Rims are thinner than commercial .25-20 SS brass of any make. Also smaller O.D. Headspace may be an issue. Extraction may be an issue. Be aware.

[kootne]

20+ years ago, this is how I did it; necked up, swaged body down in a bunch of steps, trimmed base/web to blend to body in a lathe, crimped rim forward to thicken, FL sized, trimmed to length. I made all the dies except the FL die. Used 1045 pump shaft because I had it, quenched them in water. It is a big job, although now that I have made a set up and use my 16" shaper to form brass it would go a lot faster.

[turtlezx]

wow all that to make shell thats dedication plus

[kr54]

Would this be any easier going through intermediate steps?

[BS2]

296770
My first try at reducing 223s.
Only two bushings and a trim job on the lathe.
1.800 long