To cure your problem at the botleneck just make a single lip cutter, called a "D" reamer by some. Turn the exact profile of the cartridge and grind off slightly less than half. Harden, polish and feed slowly , peck often as there is very little room for chips. Done well it leaves a beautiful finish  and exact profile.

I have A2 and W1 and O1 for tool steel stock in correct diameter.
Which is best for a reamer of this type?
I know about it, just afraid to do it.... but since IM hacking old barrels right now, I can't hurt anything of value, just wasted time and I have time!

Please advise

Only thoughts. All three of those steels can be difficult to heat treat well. If it's heat up and dunk in used motor oil heat treating, O1 may be easier to do than W1. If you can control the environment, then you may get less distortion with A1, if you think you have some critical dimension that you'd like to maintain. Best of luck with it.

Oh, a 30 carbine and a 3220 on left for comparison.
beltfed/arnie

Actually, the 30 carbine case was only in my Pic for comparison,as is the 32-20.
Of course, as you have been doing, a person looks at
all available alternatives in doing such a chambering with minimal expense. Been there done that.
My main suggestion is indeed the rimmed 300 BO concept
that you might change to a rimmed 32 BO, short off 357Mag
or long off 357Maxi
Also, if one did this, you  would want to use a floating pilot 300BO reamer, with an appropriate "32" cal pilot in place.

beltfed/arnie

Corerftech, I was told that when Charlie Dell designed his version of the 32/357 Mag he made his reamer from a straight taper reamer. Of course he was all about breech seating, but I'm told he made a fixed version of the cartridge by simply reaming the inside of the case neck to accept the bullet to the desired depth.   

If I were pursuing the cartridge you describe, And if I were only making one chamber and one forming die, I would probably use a tapered reamer for the cartridge body, then a straight reamer to get the neck section I wanted.  But then again, I'd probably be having somebody do it for me, so what do I know? 

Froggie

A #7 taper pin reamer can be modified to make the 32/357 (Dell), or the same case on the maxi if the rear of the reamer is ground to ~.380-.

Willis

I moved to TN since I started this thread and am still not settled, by a long shot. No machines are under power yet, but electrical is close to complete.

Was reviewing an 8mm RB represented a 8x33mm, doesn't exist. Well it does, the 7.92x33 Kurz, a cartridge I have heard of but never researched or reviewed. Holy Mackerel, its a perfect (nearly perfect) prototype cartridge for several reasons.

The Kurz is rimless but reviewing the dimensions, its actually a perfect 44-40 analog and the 44-40 is the perfect rimmed parent. Secondly, since it's OD is larger than .380, it can be used to form 38, 357M, 357MAX parented 8mm cartridges using an FL die. Apparently there is enough of a resurgence that Hornady produced a run of dies, cheap. I procured (on way) a set and will forge several 8mm wildcats using the die set and even the seater will be operable and proper. PTG has a reamer in stock, will have it altered to .379 body so that I can run as shallow or deep as I like for cartridges. At some point if a variant performs on the 38/357 body, Ill rent a KURZ reamer and attempt a 44-40 based rimmed variant that I can generate quick load data on.

A request, is there anyone with the Neconos QuickLoad software addition for designing cartridges that could generate a modified 7.92x33 Kurz file using a 38, 357, 357 max body (all three would be needed)???? Ill already be spending many bucks on reamer and several rollers for pressure testing (RSI system) and the extra $160 for the software addendum to my quick load is untimely. Ill post the same request in reloading on another thread.

Anyway, running QL on the real kurz cartridge with 165 gr lyman, I get about 19kpsi and 1800 fps (IIRC) on 17 grains of 4227 with a case cap of 29 gr of H20. I know that efficiency will go up radically on the smaller cases of 38 cal parents and density will near 100% which is optimal.

A question with a 19 degree holder as the Kurz forms, is it better to HS on rim or shoulder with this odd variant?? Should I form a 38 special (the minimum the die will draw) (regardless of the final dimensions settled on for reamer) to HS on rim with a loose shoulder so that I can set back a thou and use the rim seating flat to size after forming, or HS initially on shoulder tight?? The shoulder will be so small that its basically an Ackley as I intended initially. The shoulder is under .050 wide, its ultimately pretty SQUARE regardless of angle! Thanks for the feedback