Shiloh Rifle Forums

Last Fall, I picked up my 40-65 #3 from Big Timber. All the shop was out to lunch, so we didn’t get to see any of the masters at work. Lucinda was trying to wait on us and thus put off her lunch. The rifle has a wonderful fit and finish (don’t they all) and though my wife disagrees, worth the 5.5 year wait.
I’m now going through the process of re-forming (45-70 to 40-65) and loading the Starline cases. The chamber is specially cut with an “Orville Loomer reamer” and I find that after compressing 50gr of Old E 1.5, the cases stop short of chambering by about a half inch. I’m only compressing the powder 0.2 inch, but it seems to be enough to change the case diameter. To isolate the cause, I took a sized case and chambered it to make sure it fit. Then I put 50gr into it and compressed it under a .060 veg wad. Now it refuses to chamber as I stated above. My next step was to seat a paper patched bullet and the run the completed round through the resizing die one last time. Now it chambers as it should.
Thoughts anyone? Is it common to have to twice resize a case in the process? I thought 50gr powder in this case would be good enough for fireforming and a little compression would help.
Bullet used BACO 415gr smooth sided, Money profile patched to bore diameter .400.
Dies used RCBS for Shiloh Sharps
Drop tube settles the powder about another 0.10 which provides for a little less compression and the case comes closer to chambering (head still sticks out and breech won’t close)

First off I hope you are using a compression die to compress the powder. Do not use the bullet as it will swell the bullet causing chambering issues.

If you are using a compression die already, simply charge (slowly using a drop tube to get more powder) the case to within 1/4 inch, seat a wad, then seat the bullet. Fireform the case for the next load, you should be able to get a little more powder this time. Experiment with varying degrees of powder. I am willing to bet you can get a lot more powder in the case than 50 grains. Even my grease groove bullets with minimal compression get 56-57 grains of Swiss 3fg. A paper patch bullet can be seated 0.125 inch in the case and work well if patched to bore diameter. Those loads accept even more powder.

Nice engraving by the way!

Mike in Seabeck, WA

I have a grease groove chamber. Your Loomer chamber is tighter in the neck to avoid working the brass as much. The bullets are not to be seated deep in the case. That may be the issue.You should be able to finger seat bullets into fire formed brass without resizing once you get to that point.

A couple of questions for clarification:

Will the formed cases chamber completely before dropping and compressing powder?
Will the formed cases chamber completely after expanding and belling the neck?
How specifically are you compressing the powder?
What is your bullet diameter, how much is the neck tension, and what is the neck diameter with the bullet seated?

I don't know the specifics on the Loomer chamber, but with a any chamber, you should verify complete chambering at each step.

You might want to do a chamber cast, which will allow you to determine where you might have interference fits.

As Michael has noted, you need to be using a separate compression die, and the 40 caliber caliber bullets are easily bumped up in diameter, causing interference with the throat when you try to chamber. This doesn't, however, explain why you can resize and chamber, since the sizer die would not likely size the bullet. Any reasonable load will not swell the case during compression.

My guess is that you are making sure the case completely enters the chamber after forming, but are belling the neck too much. The length of the neck is around a half inch, and you are probably getting interference between the bell and the chamber neck. Sizing the loaded case would remove the bell and allow chambering.

Clarence

First the Starline cases are a bit wide at the web so it best to get the .408 RCBS Shiloh Sharps dies to size your cases for your tight chamber.

My .40-65 Shiloh Sharps came with a tight bore and the nose of any bullets with .400 wide noses would not slide into the bore.

I solved the problem by having a custom mold with a .398 nose made.

I can forward you some if you wish to see if they solve your problem.

I use a compression die and compress 52.7 grains of powder .230 without swelling the cases and they fit in my tight chamber.

I use the .40 necking die (without the rod in it) to size my necks (with bullet inserted) to remove the bell.

Handsome rifle! Hope you get the solution found.

lennies,
I like the simple lines of your engraving, looks very nice.

The Loomer chambers have a tighter neck designed for the PP bullets patched to bore diameter or a few thousands above bore. I use chambers tighter then the "Loomer" and I have the same problem.
What is going on is not from compressing the powder bulging the case, the problem is seating the .060" stiff wad that is a couple thousands over groove diameter that is pushing the soft annealed necks out that is causing your problem. I go through the same thing with my chambers for the .40-65 and a couple other rifles I chambered with my reamers that just except a PP bullet in a fired case.
This is what I do to solve this problem with the wads pushing the neck wall out till the cases re-harden. Instead of using a .060" hard fiber wad I use two .030" one first to compress the powder and the second seated by hand with a rod. What this does is, the tight oversized wad will create a dome that keeps the case wall from getting pushed out. If the .030" still does it cut some wads from juice cartons and use as many as you want if you feel you need a thick wad.
All this will stop when the soft annealed cases re harden. You might get some .40-65 Starline cases instead of resizing your .45-70 brass you will have thinner walls using the .40-65 cases.
Just full length size your brass a few times after firing and the cases will re-harden and the problem will not exist again unless you anneal again.
My chamber neck wall is .425" that is a lot tighter than the Loomer.

Kurt

That is pretty deep to seat a bore diameter PP bullet. In the majority of my PP rifles the loading process is pretty much to drop tube the case full of powder. Typically this will be within 0.060" of the top. I add my wad and then compress it so that the bullet sits maybe 0.1" to 0.125" in the case. That requires very little compression.

Are you using a lube cookie? If so it will eat up powder space. Start with a powder column that is barely compressed when you use your wds+lube cookie + room for the bullet to sit 0.1" in the case. For my .45 cal cases that means put enough powder into the case so that I'm about 0.2" from the top.

Chris.

My guess is that you are making sure the case completely enters the chamber after forming, but are belling the neck too much. The length of the neck is around a half inch, and you are probably getting interference between the bell and the chamber neck. Sizing the loaded case would remove the bell and allow chambering.

Clarence

A friend had the same problem, case would chamber just fine before loading with powder and bullet, but would not chamber afterward.

As, Clarence guessed, when I asked him describe his loading process, I noted he had a generous bell on the case mouth. I told him to take a loaded round put it in his press and run the ram to the top of the stroke. Then I instructed him to gently screw the sizing die down until he felt contact with the case. I told him run the ram down and then turn the die down about a 1/8 turn, and then run the ram back up. He could then remove the load round and try it in the chamber. At about a quarter turn of the die after the initial case contact (the bell was straighten out), the loaded round would almost fall on its own weight in the chamber. Problem solved.

38-72

Here is what a .060" wad does to my soft annealed case. I have to bump the shell in a sizing die to nock the bulge down so it chambers. I just use a couple juice carton wads till the brass hardens and then no problem with a .060.

Kurt,

I don't anneal my cases that soft. Seems to me you might be overdoing it a bit...

Clarence

Well Clarence I'm just a retired Plumber and don't know much about over heating brass or copper just enough to stick them together with a mix of alloy so they don't leak water

A taper crimp die should help with your issues.
https://www.ch4d.com/products/dies/tc

My hepburn's chamber (45-90) with norma brass is especially sensitive to case mouth diameter. Running a loaded round through one of theese
is very simple. Also great for putting a little pressure on a paper patch round.

I shoot a Shiloh 40 70 SS and use the factory crimp die every time.
This grips my PP bullets so they don't slide out.
I think, like others, that you are bulging the case.

Try a lighter powder charge by fit and try until they chamber
OR.

try seating the bullet a little further in.
I had that happen and had to order a second mold with a smaller diameter for my PP to chamber.
my PP has a .395 base and a .397 top to PP into the .400 bore Shiloh uses on their 40's

bore is .400, groove is .408

good luck...Ken