I finally got around to fitting an eBay 40-65 high wall threaded barrel to an action.  It appears to be new.  I did a chamber cast and measured the bore (.408).  The shank was about .025 long.    By the time I cut it to the proper length the rim recess was too shallow.   I then cut the rim recess a bit (but not enough yet). I took a case and cut the rim thinner from in front of the rim to see how much deeper the rim recess needs to be.  I was able to close the block on this modified case BUT only if I hammered it in to the chamber. The web is too thick. I did fire a primer and the strike is centered but unless I want to shave some thickness off of every case I use, I think a quick few turns with a reamer is in order. I have a member loaning me a reamer so that issue should be solved.  But now I need to dig up a set of 40-65 dies.  I borrowed a Redding set and it sizes the web just in front of the rim to .501.  My chamber cast measures .498 at that point.  I see there are die sets marked Shiloh. I have read about old chambers that are larger but I am trying to figure out what to buy.  I see one vendor has RCBS dies in stock for Shiloh.  How do the Redding and RCBS dies differ?

Any advice would be appreciated.

Thanks   
Jack

Are you using Starline brass? If so, there is a band on them right above the rim. If you have a 45-70 or 45-90 sizing die, see if one of them will size them down. If neither one works, I have the fix for you.

Jack, I have 2 sets of RCBS dies for 40-65.  The "Cowboy" legacy ones and the Shiloh marked ones.  The Shiloh ones definitely squeeze it about 0.001 smaller at the web.  Without that it's sticky in my Shiloh's chamber.  I can make some measurements in a sec...

Jack- I went through trying to figure out 40-65 chambers, dies and reamers a few years ago. I liked what I read about the 40-65 Shiloh chamber, so I bought a set of RCBS dies for it. Then came the fun of finding the correct reamer to match it. Finally got PTG to find and send me a copy of their chamber drawing and I had them make me a reamer. If you want to PM me an email for you, I will forward their print.

The Shiloh 40-65 chamber is very good.  If it will clean up your existing chamber I'd definitely recommend it Jack.  My Shiloh 1:16 twist 40-65 is incredibly accurate.  I've talked to some of our local prone TR shooters that say my black powder targets at 300 would be reasonably competitive in their matches.

I think Shiloh gets their reamers from Pacific Tool & Gauge but I'm not 100% sure.

Chris.

Jack,  was kind of in the same boat as you when I had my 40-65   built. I have no idea what reamer he used. I do know that my CH dies woudl not size the cases small enough to fit into the chamber. Somewhere along the line I picked up a CH sizer die that someone had shortened up quite a bit. Once I ran the cases through that die they fit just fine. After shooting I just use the regular sizing die and that seems to work ok. I did go and check my fire formed cases and at the rim they meausre .497. 
I don't know if my die would fix your problem or not.
Sam

Jack,
I had the same issue when I tried to use some fired Starline 45-70 brass.  The problem went away when I finally got some new brass.  I did call RCBS a year ago to find out what the difference was in the Shiloh dies and the Cowboy dies.  The tech told me that the Shiloh were a little tighter and had a smaller expander plug.  I use the cowboy dies and my chamber is a DZ arms 40-65.   

Cheers,
Steve

Jack with the Shiloh chamber, a .409" bullet is a perfect slip fit.  At least in the two I have.  In the first one I bought the bullets fit so perfectly that when I pull them out you can hear a pop sound as the air is sucked into the case.  That's with Remington 45-70 brass sized down.   

Chris.