Friend has a Rolling Block in .40-65 and I formed brass from .45-70 once-fired brass using Lee F/L dies. Loaded up the rounds, and then found they will not chamber fully. They hang up about .3" from being fully seated. Broke down a couple of loads and ran them through another F/L resizer and now they chamber. Did I miss a step? Dies and press were adjusted per mfr's specs for F/L resizing. 'Smith checked the chamber and it's OK too.

it is easier to just buy 40-65 brass from Starline.
That's what I finally did last fall.

Rich
DRSS

There are two contributing factors you might be dealing with.

1. It is a rolling block and it will not push an oversize case in.
2. The original 40-65 head was supposed to be a little smaller than the 45-70 head.

Due to the shape (long tapered body)of the 40-65 case you might be expanding it at the neck enough to cause some interference along the long body taper.

I have compared a lot of Lee dies with my other dies and I doubt it is the fault of the dies as much as it is a combination of the above.

If you examine the Starline .40-65 brass that Idaho mentions you will find the head of it is sized smaller right at the junction of the solid head. Look at the photos of Starline 40-65 brass on Midway or one of the other sites that sells Starline brass. It is sized specifically to prevent that problem.

40-65 chambers vary quite a bit too.
RCBS makes at least 4 different die versions.

1. Original Winchester version for .406 bullets
2. The Cowboy version for .408 bullets.
3. The Ron Long version
4. The Browning version

I once bought a set of the RCBS Cowboy dies on Ebay. When I got them the sizer had been cut off .040. I sent a email to the guy asking him why he sold me dies advertised as "like new" that had been altered. He said he got them from another guy that had cut them off to make them work with a rolling block.
My 40-65 is a Browning. The chamber has no taper for about the first 1/4 inch and then tapers to the neck. With the straight section it will chamber 45-70 brass fine from all the die sets below.
My dies include 3 sets of RCBS Cowboy dies, 1 set of RCBS for the original 40-65, 2 sets of Reddings, and 2 sets of Lymans.
The Reddings size the brass enough to use a .406 bullets like the RCBS type for the original chamber. So did a set of CH dies that I once used. The Lyman dies are very close dimensionally to the RCBS Cowboy dies.
The hard core BPCR silhouette shooters claim they get better accuracy results by forming Remington brass due to the thicker rim. I have 4 different brands of brass and the main problem is the shooter.
EDG

Some .45-70 brass is too large at the base, just ahead of the rim, for some .40-65 chambers. I shoot a Shiloh sharps in .40-65 and it has a fairly tight chamber. I never did get WW brass to work satisfactorily, even after shortening a form die to size it down AND sitting the case on top of the shell holder to run the case fully into the die.
Some measuring showed R_P brass to be a few thou smaller ahead of the rim. I tried some cases made from R_P and no problems. I made a quantity of cases this way then later ordered some from Buffalo Arms. They already had this figured out and make .40-65 cases from both makes of brass. This same problem will occasionally show in other rifles after firing the cases a while, requiring sizing them down all the way to the rim. A friend made a die for this by running a Morse taper reamer into a piece of bar stock until he had the right dia. you can avoid the forming issues by buying Starline but may need this latter tip.

Which rolling block ? My Lone Star Rifle RB in 45-70 has been chambered to take only Remington Factory rounds .Will not chamber Win or Fed.

add to the problem; RCBS also made 40-65 dies to take .410" bullets, to match their initial bullet moulds...ran me nuts with my Shiloh 40-65 for a year. It was a shame, their line of 300/350/400gr spitzers shot great in a Uberti/Dixie 40-65...well enough to win the WA state BPCRS championship one year.

It is sad that dimensions are all over the place. I cured the problem...rebarreled and chambered it for the old 38-90WCF. Probably NOT the answer you are looking for.

Rich
DRSS
Knowledge not shared is knowledge lost...

I have formed over 3000 40-65's from 45-70. If you order a Ron Long sizing die (marked RL)from CH or RCBS as it has a tighter taper. However, all of my rifles were chambered by Ron and Remington brass was the ONLY brass you could use as Winchester was thicker at the head. For what it is worth.

Dutch

Dutch--thx for the tip/info. My buddy (gun's owner) is going to borrow the sizing die from a friend that was successful at sizing the brass to a dimension which would chamber. I'll pass the info along to my friend--

For me, in shooting the Shiloh .40-65, the expander idameter is only an occasional issue. Above 90% of my shooting with it has been with black powder and with my chambeer being a close fit I do not resize the brass once fireformed. I use the expander only to give the case mouth just enough bell to be able to start the bullet without shaving lead from the bullet. When the cases have been fired enough to start to chamber hard, I resize the cases.

BTW, if you are into such things, .41 jacketed pistol bullets will shoot nicely in a .40-65.

I broke down all the loads that wouldn't chamber, resized them with a borrowed RCBS sizing die, and checked each piece of brass for fit. All of them slid right in like they were lubed with KY jelly. Reassembled the rounds and now I have a happy customer.

I recently acquired a Navy Arms HiWall in .40-65, and some unfired Starline brass, rather than re-forming .45-70 brass (as I had done in the past for an original M1886 Winchester rifle). In both instances, I found that the brass would not chamber in either rifle if only run through a standard RCBS .40-65 Shiloh Sharps sizer die, OR an RCBS .40-65 WCF sizer die. In both instances, the brass was too large in diameter at the base BELOW where the sizer dies ended at the shell holder. I have a .40-82 WCF sizer die (RCBS). I found that after lubing the brass LIGHTLY clear to the rim, if I pressed the case clear into the die, as far as possible, and then driving the case out using a punch made of a piece of steel rod, the brass would work just fine. This step only has to be done ONCE. Thereafter, just using the regular .40-65 sizer in the press will resize the body and neck just fine.

Hope this helps.