Hi guys,

I have a 12 ga Ithaca 37 that was made in 1954. It's pretty beat up in terms of wood and bluing, but its internals appear fine and it's always run 100% for me.

Recently I fired some buckshot through it for the first time ever. 2.75" loads of #4 buck. I found it extremely difficult to open the slide after firing each shot. Never had this problem firing buck from 870, 590, Winchester 1300, even Stoegers.

So, for those of you who know more about 37s than I do: were 1950's Ithacas not rated for modern buckshot loads? Should I not shoot them in this shotgun, or does this shotgun need work?

I'd like to try out some low-recoil Federal buck to see if weaker stuff cycles OK, but I don't want to damage this shotgun. It's worth very little, but it's fun as hell to shoot.

Mine is early 30's and has never had a problem with anything I have thrown in it

Well, that's not what I want to hear. If it needs smithing, it's probably beyond my abilities to do myself, and there's not many guys left who can work on these things.

PM me if you need a smith.


My buddy completely rebuilt mine after I bought it. He's slow but he does great work


 

Check to make sure your extractors are moving freely and that the forks of the shell lifter aren't bent, if bent they can push down on the shell during chambering and extraction making the gun cycle hard, worst case they can push the shell off the extractor leaving the shell in the receiver during cycling, jambing the gun or causing a new shell to drop onto the lifter while you've still got a partially chambered empty. They should recess fully into the top of the receiver as the bolt closes and opens. Also the barrel is installed on an interupted thread that locks as the barrel is pulled forward by the mag tube nut, sometimes if the barrel is tightened too much the guns headspace can grow a little and make extraction tough. I try to never overtighten the barrel on a 37.

In regards to ole Ithaca 37, any pitting in the barrel can be an issue as the barrels are relatively thin (the wood can also be an issue, but not what we're talking about here).

So, OP says the internals appear fine and gun has always run 100%. That being the case I tend to think the 00 Buck ammo is a bit hotter than other shells that have come before and maybe the chamber isn't all too smooth. First concern would be pitting in the barrel. After that might try some of those other shells that have always run fine then try the 00 Buck again, kinda get a good side-by-side comparison, see if you can narrow it down to just the ammo. Speaking of that, which brand/flavor 00 buck is it that has been giving you grief? From there I like to use a bore brush covered in 000 steel wool spun with a drill to smooth it all up.

Pitting in the bore?

Ammo being used?

Polish with 000 steel wool.

Thanks for the advice, I'll check those things out.

When you say "overtighten the barrel," do you mean overtighten the nut at the end of the mag tube? If so, that may be the problem. I've kept it as tight as I could get it by hand.

Thanks for the reply.

The ammo was Sellier & Bellot #4 buckshot with max dram equivalent load. Pretty high brass.

Polishing the chamber couldn't hurt, and I can see what you mean about why it's important. It looks pretty smooth and clean, but I'll give it a shot.

Thanks again.

My old Ithaca 37 didn't care at all for Sellier & Bellot, so you should try another brand after you give your shotgun a good scrubbing. It fired other brands without problems.

The S&B #4 buck that I have the box says 2&3/4" but they are closer to 3" so that could be a problem in a 2&3/4" chamber.

My father bought a new 37 in the 70's and it will get very stiff if it is not clean. It also is very picky with reloaded shells.

My dad traded an old Pontiac ('37 or '39) for his M37 12 ga. in 1953.  He deer hunted with his M37 and I never heard him talk about having issues with 12 ga. slugs.  Is buckshot "hotter" than slugs?

My M37 was made in the mid 60's and I've never had issues with slugs or buckshot.

We've never had issues with any of the 12 or 16 ga. Ithacas in the family, and there's quite a few between dad, mom, me and my brothers and my sons.

No broken/cracked stocks/forends, no bent internals, etc.

Make sure the shells are 2 & 3/4" before you fire them.  If they are longer then you may be creating extra/higher pressures when the end of the plastic case has no place to go when it opens up and the shot/shotcup have to squeeze past the crimped plastic ends as it leaves the chamber and heads down the barrel.

You can cycle the action, without firing it, by putting it on safe, loading the magazine tube and holding the button/lever on the front of the trigger guard back while you cycle the pump/slide to the rear/forward/rear/forward - repeat till empty and make sure it's on safe and your finger isn't on the trigger and it's pointed in a safe direction.  If it doesn't hang up/feel stiff then the internals may be okay.

When was the last time you lubed the internals?  We never took ours apart (my mid 60's M37 has been apart once in it's life time because I was curious what it looked like inside, not because it has to be take apart to lube.  We used 3n1 oil, now I use Mobil 1.  Drip some oil on the slide/action bar, the bolt, move the bolt to the rear and drip some oil on the extractors and the lifting arms and the shell stop/catch that keeps more than one shell from coming out of the magazine.  Get the oil in/on it and work the action open and closed several times.

The way it's made, unless you do something stupid, you won't get much water/outside dirt inside it.  We hunted rain/shine/snow/sleet (Michigan, Illinois, Arkansas, North Dakota, Texas, West Virginia, Tennessee (Air Force moves you around some) and as long as you treat them right, they last and work.  My dad's M37 has been cycled so much that if you hold the barrel straight up and push the release button the bolt/slide move to the rear like you pumped it.

It's a John Browning design.  It's forged steel.  It's stout as hell and will take a licking and keep going.  That man didn't design/build things that were fragile or didn't work correctly.

Good luck with it.  I only own three kinds of shot guns.  M37 Ithacas (too many to mention here), one Browning Auto 5 made in 1934 that looks rough and runs like a top and one Winchester M97 that also looks rough and runs like a top.  All three are John Browning designs.

It's starting to sound like the S&B might be the problem, even though it says 2 3/4" on the boxes.

This is the first buckshot, the first S&B, and the first European ammo of any kind I've shot through any of my 37s.

The chamber's clean, and nothing's bent inside, so I'm starting to think it was just the Euro ammo.

This buckshot isn't as hot as a slug, but it's a lot hotter than any of the birdshot I've fed it. Judging by recoil, it's somewhere in between.

The ammo was definitely labeled 2 3/4", but two posters above have said S&B 2 3/4" is not the same as other companies' 2 3/4". It sounds like the European ammo was the problem. I'll try cycling them through without firing them-- that's a good idea. Haven't tried that.

When I bought this shotgun in 2011, it was over a half century old. I wish I could have met the prior owner(s). It's clear they used this thing hard, killed about a million birds with it, wore off most of the bluing, put some good dents and scratches in the wood... but the internals are pristine. Even the inside of the mag tube was heavily oiled when I bought it. Everything's worn slicker than snot, without a spot of rust anywhere. It cycles smoother than any shotgun I've ever fired, including my other 37, made in 1973.

I can't let those old guys down, so I keep it lubed throughout, just like you described. Nothing's impossible, but I can't see lubrication being the issue.

Thanks for the detailed reply.

My dad's old M37 looks like the receiver and about half the barrel are nickel plated.  Worn by carrying is so many miles over the years.  I remember always trying to make sure I carried mine by the stock and forend just so I wouldn't wear off the blue.  Mine still looks almost new (had to refinish the wood though - something is going to wear).

Like I said, good luck with it.  They are incredible guns.  Light and reliable.   I need to take some pictures of mine one of these days.

Any hard to extract issue should start with chamber inspection. Several small pits or even light rust and a slightly higher pressure cartridge causes the brass to cling to the chamber wall in more places thus needing more force to cause ejection. Chamber hone or take a brass brush, cover with cleaning patch lubed up with some valve grinding compound. Electric drill and spin it in the chamber for a couple 20 second passes, re lube do it again.. Clean it out and inspect. That should take care of it. The object is to do the least amount of polishing as possable to achieve a smooth surface.
Next...was the cartridge case clean and Un damaged. Corrosion on the brass does the same thing in reverse. When it expanded the crud on the case got swaged up against the chamber wall.
Doubt full it is mechanical. 37 is one of the most bullet proof designs ever.

S&B is a funky size, due to being slightly longer unfired due to the roll-crimp that they still use. Fired cases are he same length as star-crimped shells, but my 37 didn't feed or cycle them as reliably as other shells. My Winchester Model 12, on the other hand, loved them and patterned better with S&B shells than any of the other 'cheap' 00 buckshot I tried through it.

Thanks for the reply. I was thinking of using a flex hone on the chamber until I read your post. A brush with a patch covered in rubbing compound/valve grinding compound would probably take less metal off.

Good info, thanks

S&B also has soft metal in the head portion of the case. It can deform and make extraction hard.

I had the same trouble with my 50's Model 37.  Sometimes the action simply locked up and I couldn't even rack the slide.

Finally I took it apart and gave it a SERIOUS cleaning.

Problem solved.

Try that first.

Yes I mean over tightening the mag nut. On a 37 the barrel is pulled forward by the mag nut to lock the barrel into the receiver unlike most pumps where the barrel is pushed into the receiver to tighten it. You can overtighten the barrel cranking on the nut too much and increase the headspace away from the bolt face allowing caseheads to expand in the unsupported (by the chamber) portion causing them to stick. My father taught me that the nut is secured in position by a ball detent and that you should snug the nut but not crank on it.

Did that last weekend, thanks to comments in this thread, but it'll be a couple weeks before I see how much difference it makes.

When you say serious cleaning, what did you focus on? I focused on the chamber, since everything else seemed to be in great shape and easy to clean. I might have missed something.

Thanks for the answer. I was pretty sure that was what you meant.

I've backed off the nut at the end of the mag tube by a couple clicks. I never considered that headspace would be an issue with a design where the barrel threads into the receiver and the mag nut pulls the chamber forwards, but now that you say it, it seems obvious.

Between having a clean chamber and proper headspace, I bet this old 37 will run great next time. Thanks to all in this thread.

I just soaked all the small parts while I attacked the chamber.  Made sure that everything that was supposed to move was cleared of years of gunk and the springs were ok.  Just did the exact same thing on my Remington Model 17 (20 gauge predecessor of the 37) as well.  Did wonders for the slickness of both.  I will be surprised if yours doesn't work better now that you've cleaned it.