I received some brass from a fellow on another forum recently, most unusual brass in that it has Shiloh's head stamp and caliber markings.(40-70). It wouldn't fit my chamber so I resized it in my Lyman dies and was met with quite a bit of resistance in doing so. In fact, the cases grew about .012-.015". Most were 2.490" and after sizing, 2.502". After sizing, they dropped right into the chamber just by gravity. 

I decided to reload some of the cases and primed and then expanded with the Lyman expander that came with the dies which measures .408". My bullets are .409". Keep in mind there's no problems doing this and getting rounds to chamber when using the 30-40 Krag brass from BACO but with this brass there is a pronounced bulge right about where the base of the bullet is. This bulge shows up early on in the expanding process but seems to travel down when seating the bullet to it's base.

I measure the thickness of both the Shiloh brass and the Krag brass and they were for all purposes the same, plus or minus .001" at .012". The inside of the case mouth on both brass measures .408". What's going on? I see no reason they wont chamber but due to the bulge they won't fit. I can't figure what's causing the bulge. Measuring the case at the bulge is .437" whereas measuring a sized but non expanded or bullet seated case mikes at .428". Any ideas as to what's causing the problem? Am I missing something here?

Some of the cases I have from the stretched 30-40 Krag brass are 2.497-2.502". The other cases that's giving a problem are 2.490" on average but when sized they grow to 2.502-2.505". I had a couple cases of the Krag brass that measured 2.508" and drop right in the chamber so, it's not the length. I even tried anneal a few cases before resizing to see it that would help to no avail.

No chamber cast as yet. I haven't done that before and am a little skittish of "welding" the extractor, to be honest.

Did you try neck sizing,Just alittle at a time.Try a stripe of marker on the case it might tell were the tight spot is,hope this helps,Bob.

Compare the web diameters on the 2 different cases plus run a stripe of permanent magic marker the length of the case to see where it is rubbing.  If the web is too big, resize down to the case rim

The web diameters are .456" for the Shiloh case and .453" for the Krag brass. The die is all the way down about as far as it will go. It's lightly touching the shell holder.

At the case mouth with a bullet inserted the Shiloh brass measures .426" and the Krag mics at .429". that's sort of odd but that's what it is.

It does take a bit more pressure seating the bullet with the Shiloh brass given the same expander used with the Krag brass. I think I have several pin gauges that are .430-.432". If I can locate them I may try to see it the larger can go into the chamber. The expander is only .408" to accommodate the .409" bullets. I couldn't locate a .407" expander like I wanted.

This brass is fairly old as I understand it was made sometime back in the 90's. Don't know if that matters or not but I did try annealing a couple cases all to no avail...same results. It's been used 2-3 times and looks nearly new.

OK-found my pin gauges. First, I pushed the .430" into the chamber and it was like dropping a BB in a barrel. Went to the .432" and it went right in and the largest I had, a .433" also went in easily but not loose or tight to the point I couldn't retrieve it. I'm inclined to think maybe I could have inserted a.434" pin in the chamber and that may be what it is. Therefore, no reason for the brass getting tight with a .432" bulge. A .434" bulge yep, that may cause a little problem overcoming but, the chamber is tapered and the pins are not. I don't know if my findings with the pins are worth their salt.

I took one each of the Shiloh case and the BACO Krag brass and marked both prior to FL sizing. The Shiloh is on the left. You ca readily see where it was tight some .080 from the rim and where it rubbed the marker. However, both measure .452" in that area. Measuring just ahead of the rim below that shinny area the Shiloh miked at .456" whereas the Krag brass was .453". Despite that, both fell right in the chamber up to the rim with no assistance.

While the Shiloh rim on the left looks thicker, it measures .068". That's exactly what's called for with current BACO Krag brass for the Shiloh rifle. The problem exists when the expanding process is complete. That's when the Shiloh case won't go all the way in as it does when sized only due to the bulge.

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They go in the chamber easily, both of them until I expand. The Shiloh cases are a real pain to resize and there's a lot of resistance compared to the Krag case. Well, you can see where it gave a lot of trouble sizing. Going up into the die takes a bit of effort. Releasing is not as bad.

I just got a package from UPS a minute ago. Inside the package were 100 30-40 Krag cases from BACO...for the Shiloh. I dropped one in the chamber but it wouldn't go in all the way-lacked about 1/4" so I resized it. No problem sizing the case and I even ran the expander through it. It drops right in the chamber without any hangup or bulge. Looks like I may have to abandon using the Shiloh stamped cases and just contend to using the Krag cases I got today....shame.

The problem is the bulge from expanding it to accept a bullet. Once i expand and seat the bullet to length it won't chamber. I remove the flare prior to trying to chamber the round. There's no flare at that point. I only bell the case enough to get the bullet base started so it doesn't shave lead. The Krag cases do not bulge with the expander and they're no problem.

I haven't had a chance to take those problem rounds to the range as yet. I've had to run them back through the size die with bullet seated in order for them to chamber. Once fire formed things might be different.