Ithaca 37 Ejection Problems

[Andy]

Thanks rKing for dimension confirmation. No visible bulges in base forward of extractor hook

Do I understand right that you're saying that my barrel should interchange with anyone whose gun is 800000 or higher serial? And that if the barrel itself has a serial # then it isn't compatible with this receiver? Our of curiosity & for my learning's sake, what makes them not interchangeable, is it a mechanical fit/obvious issue or something more subtle where the wrong barrel would fit but not work well?

Any way to tell if this barrel on the gun was the barrel that came with the gun from the factory?

I might have a chance to try some barrel swaps with the other guys, that's a good idea to try to 100% isolate things. The shell sticks so hard in there with the barrel off the gun that I feel like it has to be chamber/ammo related though. Not wanting to take the chamber past SAAMI spec it may be time to admit defeat and say it's a gun that will always be picky on ammo, hate to do that though.

[2152hq]

If you have access to a finish chamber reamer,, by hand take the reamer and run it into the chamber with proper lube and remove any extra matr'l in the chamber.
If it's a factory spec reamer,,it'll leave you with a factory spec chamber.

It'll recut (or just trace) the forcing cone and the rim recess as well.
Any out of wack areas will be trimmed to spec. You'll not be harming anything by doing this as the reamer is factory spec.
Metal removal will be next to nothing,,swarf on the reamer will amt to some fine curls of steel most likely in a couple areas. But you may find an undersized area or two, maybe even the rim recess.
The chamber length may be a bit short and the forcing cone a little rough. Some shells run a tad longer, some shorter than the labled 2 3/4".
A long one unfolded into a slightly short chamber or the beginning of a rough forcing cone can grab as well.

Also, that plastic fouling can't easily be removed with simple cleaning and brushing techniques. If it could, then there would never be the problem in the first place.
A solvent is needed to disolve and cut through it in most instances to really get it out of there.
Stainless steel brushes, oil & steel wood and all that will simply brush over it.

The early M37 bbls had threads that were not universally timed during their production. The threads didn't start at the exact same position on every bbl.
(The frame threads were indexed to start in the same position on each frame however).

Each of these early bbls had to be fitted to it's frame individually. This was done before the forend lug was silverbrazed into position, not knowing where that 6'oclock position for the lug was to fall.
The bbl was numbered to the frame at the time it was fitted, then sent on it's way for the lug fitment, extractor cut, bbl markings, polishing ect. The ser# on it allowed the correct bbl to be reunited with it's frame when done.

To avoid the hand fitting and extra handling involved, Ithaca changed the process and began the universal fit bbl's. This simply indexed the threads on the bbls to a start point that matched the frame so any bbl when placed in any frame would fit & headspace correctly.

In the older frame/bbl combinations,,you can take an un#'d bbl or one with the wrong ser# and drop it into the frame and turn it in and draw it up tight with the TD screw.
All will seem just fine. They look OK, The action works,,
But the headspace can and in most instances be off, sometimes grossly off spec.
That was the reason the bbl was hand fitted on those to begin with.

I worked in a shop in the 90's that used to specialize in taking universal fit M37 bbls and reworking the threads so that they were a hand fit replacement bbl for the older Model 37's that used those fitted bbl's.
It involved TIG welding the threads and some complicated lathe work (at least from my standpoint!) by one of the resident cranky olde gunsmiths to get the NOS M37 bbl converted to a handfitted replacement for a customers vintage Model37.

[rking22]

Above is the whole story, great post! If your bbl has no serial number and your frame is 1975, then it fits and headspace should be fine, baring a factory defect. I like the idea of a chamber reamer, that would cleanip any issue, just dont cut additional headspace. My 16 ga tolerates cheap stuff with a good rim, hates stuff with a marginal rim. I have seen refetence to a "fix" but cant remember the details. Maybe 2152hq has insight thete????

[Jkrem]

My Dad has a 16 ga Ithaca model 37 gun made in the late 1950s. He bought it new, and he said it always fed great with 2-3/4 and 2-1/2” paper shells, but that he could never find a plastic shell that wouldn’t jam. Never hunted with it again, switched to his L.C. Smith.

[wv109323]

Will the gun cycle rounds without firing them? This would determine if the firing is expanding the hull causing difficult extraction.

[Andy]

Thanks for the detailed post 2152, lots of great info in there.

I really think the chamber must be free of any plastic residue at this point. I see just bare metal in there and can clearly see scratch patterns change in the metal from before/after when i polished it, so I suppose I could be wrong but I really don't see any evidence of plastic fouling in the chamber. I have also cleaned multiple times with shooter's choice and given it plenty of good scrubbing time with brushes, and denatured alcohol swabs after polishing, repeat over a couple sessions.

Very great info on the barrels, that is very useful to me thanks for passing on all that info.

A chamber reamer would be a good final option to try out, I have checked the forcing cone distance with the brownells gauge but that doesn't check for anything in the chamber other than that, so it is possible that a reamer would catch something.

The gun will cycle unfired rounds just fine and just to give more explanation on my earlier info I've run a whole box of 25 winchester AA (all brass bases) through it without a hiccup, as well as 6-10 old peters all brass. When using the all brass loads extractions is much more effortless of a pull on the slide (even compared to when the cheap loads do extract somewhat normally) A couple different brands of steel based loads all had problems to different degrees, with the federal top gun being the one I tested the most as it is the objective of this work to get it working with that specific brand/line of ammo.

So, I feel reasonably confident to say that this issue is related to some feature that is different between winchester AA trap loads and federal top gun trap loads. I speculate it is the brass bases contracting more after firing like many others have already mentioned, but I ought to measure a few fired cases today to get some actual data on that.

Thanks again for all the helpful input from everyone, even if I can't solve the issue I've already learned a lot.

[W.R.Buchanan]

That English stocked Featherlight is gorgeous.

Sent from my SAMSUNG-SM-G930A using Tapatalk

I paid $100 for that gun in 1973 it sat in my safe for many years until I finally got back to it. I bought the wood from Fajen in 1976 but never finished fitting it. A friend finished it and checkered it and it came out nice.

Ithaca completely reblued it and all the choke tubes for the Cutts Compensator, and replaced a couple of internal parts.

I showed it to the friend I bought it from as it was his fathers gun originally, and he offered me $1500 for it on the spot. I really like the gun so he won't be getting it back any time soon.

Randy

[Andy]

Little bit more info:

Metal diameter measurements on shells fired in this gun after all work was complete, measurement taken on flat part of the metal head closest to the plastic of the hull.

Winchester AA all brass head .808"
Federal top gun steel head .814"

Correction to an earlier post, I put a magnet to some old peters shells that ran fine in the gun and they were also brass-washed steel surprisingly (definitely not just the primer, whole head was magnetic). I don't have any left to measure the fired diameter of, perhaps it is just really small, thin steel heads that are the problem, not all steel headed shells?