m1917 cylinder problem?

[spad124]

Newer to the forum and I have a question about a M1917 I bought about 2 years ago.

Background: SN is 836XX. Numbers match on frame, cylinder, barrel, crane. She has the government proofs: eagle S1, flaming bomb so I take it the DOB is after the Army took over production. (I'll post pics as soon as I can.) I think she was reblued somewhere along the way, some of the proof marks are a little soft, mostly the flaming bomb on the left side of the frame. Plus, there the barrel has some pitting so she's seen some service somewhere.

Here's the question, groups are pretty large, 6 or so inches at 15 yards. ( I can hold 2-3 inches at 15 yards with my 686 or 10-8.) Often there is one flyer larger than that. In one of the handloading magazines there was a test to check throat size of a 45LC SAA (.452 or .454+)--take a .452 bullet only (no case) and drop it into each cylinder chamber from the rear. If the bullet sticks in the chamber, it is .452, if it passes through the throat it is larger.

The M1917 doesn't seem to have a throat in the chamber as it headspaces on the case mouth, but I thought the test might tell me if the chambers were at least of a similar diameter. So I took a Berry's 230 gr .452 plated bullet and dropped it in each chamber in the M1917's cylinder. Three chambers held the bullet and three allowed the bullet to pass through. Then I set the bullet in the forcing cone and about half the bullet would enter the cone.

Lock up seems ok, not new by any stretch of the imagination, but not worn out. A business card won't pass into the barrel/cylinder gap.

Could the accuracy problem be that the bullets are starting to go sideways before they contact the cone?

Any ideas on if that can be fixed?

Thanks

[29aholic]

I would give Cylinder & Slide in Nebraska (?) a call. They have worked on several 1917's for friends of mine.

[Muley Gil]

Most 1917s seem to shoot their best with FMJ hardball. What load are you using?

[Hondo44]

Originally Posted by spad124

Newer to the forum and I have a question about a M1917 I bought about 2 years ago.

Background: SN is 836XX.

The M1917 doesn't seem to have a throat in the chamber as it headspaces on the case mouth, but I thought the test might tell me if the chambers were at least of a similar diameter.
Lock up seems ok, not new by any stretch of the imagination, but not worn out. A business card won't pass into the barrel/cylinder gap.

Any ideas on if that can be fixed?

Thanks

If the case headspaces on the case mouth, there is a shoulder in the chamber for the case to headspace on. That shoulder is the beginning of the chamber throat. Only 'charge holes' do not have shoulders and that's why they aren't called chambers. The case must headspace on its rim.

There's a cure for almost anything:
Sounds like you have three chambers with over size throats. Can't make them smaller but you can hone the other three larger or have a professional ream them larger. But I wouldn't pay to have that done on that gun.
And/or just use bullets sized for the larger throats. You should slug your bore as well. IIRC, the 1917 bores are larger than .452".

1st test I always do with a misbehaving cylinder is shoot a group from each chamber and find out which one or more is the problem child. If they all are, you need bigger bullets for sure.

[spad124]

Thanks for the advice guys.

Muley Gil, I'm shooting standard 230 hardball or 230 LRN. At almost 100 years old with some wear I don't want to push it.

Hondo44, I appreciate the correct terms. I'll try your suggestion of group per chamber--and probably look for some larger diameter bullets.

I agree that given my M1917 isn't a collector piece it isn't worth having a lot of work done, and because it has all the original numbered parts and hasn't been bubba'd I'm not inclined to start replacing parts. But it would be nice to see if I can get a little more accuracy out of it.

I'll try to get some pics up tomorrow and will update with what I find out.

[Hondo44]

If you go to larger bullets, I would hone the three tight throats yourself with emery paper in a split wood dowel chucked up in your drill press or power drill otherwise the larger bullets from those three chambers will get squeezed down and just rattle down the bore and give you flyers.