Slam-fire vs Nonslam-fire Ithaca 37

[nhithaca]

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I have attached four photos of three different trigger groups; top one is from a mixed serial number Model 17 Remington, middle one is from an Ithaca Model 37 w/ serial number 806XXX, and the bottom one from the Magnum Model 37 shown in a photo on the Forum earlier with a serial number in the late 1970s/early 1980s. Also checked my one and only Ohio built gun and it is identical to this Magnum gun.

The Model 17 is/was equipped with a disconnecter as designed by JMB. It is the hooked shaped vertical piece in the photos. On this gun anyway, if you hold the trigger down while cycling the slide, it will not fire and will only reset if you cycle the slide again or simply press the slide release and repress the trigger. All Ithaca 37's are missing this part. My guess is that in redesigning and modifying the gun for ease of manufacturing and to reduce costs this feature (and some other minor deletions & changes) were deemed unnecessary and eliminated. It has to be remembered that at that time (late 1920s to early 1930s) the slam-fire was not considered an issue and was included in a number of gun designs that were being built at the time.

If you look carefully at the hammer of the Model 17 (top) and the earlier Model 37 (middle) you will see a little protrusion out the right side of the hammer which interacts with a notch on the slide release. On the early Model 37s this is the second "sear" that allows the hammer to remain cocked while the slide is cycled and will then drop the hammer when the bolt is in battery (and the slide release is reset by the bolt) without resetting the trigger. In the mid 1970s or so, Ithaca eliminated the slam-fire feature simply by removing the little protrusion from the hammer. If you hold the trigger down on a newly manufactured gun and cycle the slide the hammer simply follows the bolt as it goes into battery and the spring loaded firing pin prevents the gun from firing. The only way to reset the hammer is to cycle the slide again, ejecting the live round in the chamber. It is interesting that the slide release on the new gun still retains the little hook notch even though it is totally unnecessary.

While I have not done it, I think that if you want to disable the slam-fire feature all you have to do is file the little protrusion off the hammer and the gun will act like a new one. Again, it will not reset the trigger and fire without cycling the slide. Based on the price that I understand was quoted by the Factory in Ohio I believe that this all that they do; roughly 0.5 to 1.0 hours work. And, since the 3" Magnum guns use a different hammer, you can not simply replace a new style hammer with an old style hammer to get the slam-fire feature without additional work. As far as I know all the 3" guns did not have the slam-fire feature.

Just some added info for discussion.

[M-Tecs]

Thanks very informative.

[Char-Gar]

I have one of the slam-fire Police Specials, but have never slam fired it. I see no reason to disable that feature. It is there if I want it and not there if I don't want it.

[W.R.Buchanan]

I will have to call them and find out. If the disconnector doesn't prevent the hammer from going forward if the trigger is trapped, it is pointless. IE: if it doesn't work like a Semi Auto Trigger then I don't want it, and it would save me a trip.

I was told that the post 1975 guns had a disconnector that worked like it should. If the hammer follows the bolt then conceivably it could slam fire if the slide was ran fast. I'll find out by calling them.

It makes no sense to have a hammer following the bolt forward when the whole idea is to have the hammer stay cocked until the trigger is pulled again. This is the way any other Modern Pump Action gun works.

The whole purpose of the disconnector is to trap the hammer so you deliberately have to release the trigger to reset it, and drop the hammer onto the sear ready to fire again.

Randy.

[jaguarxk120]

Slam-Fire is not a correct statement. The Ithaca does not slam-fire, it
actually pump fires. If you watch the action closing the hammer does not drop until the bolt is in lockup.
Slam-Fire suggests that the gun will fire with the bolt going forward and not into lockup.
By the way why is "slam-fire" so bad, seems to be OK in the (great) Winchester Model 12.

[BadgerShooter]

I shot the Second Chance Combat shoots for a number of years, especially in the pump shotgun category. One year I tried a slam fire Ithaca and while it was darn fast, I couldn't get the control with it that I could with my 1300's Best time was under 4.5 seconds for 8 rounds of 00 buck. Bowling pins at 25' time started gun down with the RO firing a blank in the air, time stopped when the last pin hit the ground off the back of a 30" deep table.

Slam fire is fun and fast, but I could hit more in a similar time with a conventional pump. You can't miss fast enough to make it up! (Pump fire is the proper actual description - slam fire is just more fun to say)

[bowfin]

You can't miss fast enough to make it up!

If this statement was repeated 1,000 times more than it is, it still wouldn't be enough.

[W.R.Buchanan]

All my Mossbergs and Browning's have disconnectors in them. At Front Sight we do what are known as "Trigger Reset Drills." We do them with all types of guns, Rifles Pistols and Shotguns. I am pretty much engrained with trapping the trigger and then resetting it after the gun cycles or is cycled.

When trying to shoot Skeet with my Ithaca, I ran into the problem with the gun not having a disconnector and since I have been trained to trap the trigger I was discharging the gun when I cycled it. I obviously missed the doubles targets.

I don't want to break this habit of trapping the trigger because every other gun I shoot works this way. That is Glocks AR's, Mini 14, Kel-Tec, Browning shotguns, Mossberg shotguns, Even my two Over/Unders work like this. This took me a long time to get in place and I don't want to fool with it for one gun. I want the Ithaca to have a disconnector like supposedly happened in 1975 !

Randy

[megasupermagnum]

I love comparative photos like this. So if I understand you correctly, the newer Ithaca 37 and now Sandusky 37 never really got a trigger disconnector, they simply make it so the hammer will not cock unless the trigger is released. I.e. the hammer rides the bolt back, and never sets off the round. That's the worst of both worlds.

[Bmi48219]

Slam-Fire suggests that the gun will fire with the bolt going forward and not into lockup.
By the way why is "slam-fire" so bad, seems to be OK in the (great) Winchester Model 12.

I owned an early model 12 that the police took for ?evidence? after a self defense shooting. Apparently they were slam-firing it during the three years they kept it at the sixth precinct. When I got it back the shoulder where the back of bolt locks up into the receiver was peened back, I believe from the not fully seated bolt recoiling back against the locking recess shoulder.
From then on the first shot always wedged the bolt in solid, jamming the action. Shame of it was this was a low six digit all matching model 12 in very good condition. And the surviving perp had plead guilty five days after the incident. No reason to hold the shotgun for three years.
If you value your model 12 don’t ever slam fire it. If you’re thinking of buying one check the locking recess. If the bottom edge of the recess isn’t sharp pass on the shotgun.

[W.R.Buchanan]

OK After a talk with Pat in Service at Ithaca, I got corrected about how there is NO Disconnector in the later M37's.

If you trap the trigger the hammer follows the bolt down, but there isn't enough momentum to fire the gun.

This prevents the gun from "slam firing" in the conventional sense of the word. IE: Trench Gun.

So, I stand corrected. And now if I'm going to shoot skeet with this gun, I'll have to learn to punch the trigger.

Randy.

[jaguarxk120]

Now all you have to do is learn to load the gun with the open bolt
so you don't have to cycle a shell from the magazine.

Look at it this way, if you can load a M1 Rifle and not smash your thumb,
you can load a Ithaca 37.

[W.R.Buchanan]

I already can single load one , But it isn't fast enough to justify doing it.
It is faster to just stick it in the magazine and rack the slide.
It is faster yet to not run the gun dry in the first place.

Randy

[jaguarxk120]

I have no need to load that fast.

[W.R.Buchanan]

I have no need to load that fast.

The need for this generally arises when you are being shot at. Or simulating being shot at.

Then the faster you can send rounds back down range the less likely you are to get shot.

As of today, the risk of that happening here has increased due to the Invasion of Ukraine and the high probability of Russia already having people inside the US thru the Wide Open Southern Border, that can do harm to us here in the US.

Best to be prepared :mrgreen:

Randy

[centershot]

The need for this generally arises when you are being shot at. Or simulating being shot at.

Then the faster you can send rounds back down range the less likely you are to get shot.

As of today, the risk of that happening here has increased due to the Invasion of Ukraine and the high probability of Russia already having people inside the US thru the Wide Open Southern Border, that can do harm to us here in the US.

Best to be prepared :mrgreen:

Randy

I pray that jaguarxk120 is correct. As for myself, I contiue to prepare for the worst........

[McKorman]

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I have attached four photos of three different trigger groups; top one is from a mixed serial number Model 17 Remington, middle one is from an Ithaca Model 37 w/ serial number 806XXX, and the bottom one from the Magnum Model 37 shown in a photo on the Forum earlier with a serial number in the late 1970s/early 1980s. Also checked my one and only Ohio built gun and it is identical to this Magnum gun.

The Model 17 is/was equipped with a disconnecter as designed by JMB. It is the hooked shaped vertical piece in the photos. On this gun anyway, if you hold the trigger down while cycling the slide, it will not fire and will only reset if you cycle the slide again or simply press the slide release and repress the trigger. All Ithaca 37's are missing this part. My guess is that in redesigning and modifying the gun for ease of manufacturing and to reduce costs this feature (and some other minor deletions & changes) were deemed unnecessary and eliminated. It has to be remembered that at that time (late 1920s to early 1930s) the slam-fire was not considered an issue and was included in a number of gun designs that were being built at the time.

If you look carefully at the hammer of the Model 17 (top) and the earlier Model 37 (middle) you will see a little protrusion out the right side of the hammer which interacts with a notch on the slide release. On the early Model 37s this is the second "sear" that allows the hammer to remain cocked while the slide is cycled and will then drop the hammer when the bolt is in battery (and the slide release is reset by the bolt) without resetting the trigger. In the mid 1970s or so, Ithaca eliminated the slam-fire feature simply by removing the little protrusion from the hammer. If you hold the trigger down on a newly manufactured gun and cycle the slide the hammer simply follows the bolt as it goes into battery and the spring loaded firing pin prevents the gun from firing. The only way to reset the hammer is to cycle the slide again, ejecting the live round in the chamber. It is interesting that the slide release on the new gun still retains the little hook notch even though it is totally unnecessary.

While I have not done it, I think that if you want to disable the slam-fire feature all you have to do is file the little protrusion off the hammer and the gun will act like a new one. Again, it will not reset the trigger and fire without cycling the slide. Based on the price that I understand was quoted by the Factory in Ohio I believe that this all that they do; roughly 0.5 to 1.0 hours work. And, since the 3" Magnum guns use a different hammer, you can not simply replace a new style hammer with an old style hammer to get the slam-fire feature without additional work. As far as I know all the 3" guns did not have the slam-fire feature.

Just some added info for discussion.

All my Mossbergs and Browning's have disconnectors in them. At Front Sight we do what are known as "Trigger Reset Drills." We do them with all types of guns, Rifles Pistols and Shotguns. I am pretty much engrained with trapping the trigger and then resetting it after the gun cycles or is cycled.

When trying to shoot Skeet with my Ithaca, I ran into the problem with the gun not having a disconnector and since I have been trained to trap the trigger I was discharging the gun when I cycled it. I obviously missed the doubles targets.

I don't want to break this habit of trapping the trigger because every other gun I shoot works this way. That is Glocks AR's, Mini 14, Kel-Tec, Browning shotguns, Mossberg shotguns, Even my two Over/Unders(mostly using those in my survival gear (https://gritroutdoors.com/outdoor-survival/) kit) work like this. This took me a long time to get in place and I don't want to fool with it for one gun. I want the Ithaca to have a disconnector like supposedly happened in 1975 !



Pretty interesting read. Do you know anyone who has filed the hammer? It sounds like interesting project though.

[Chena]

I have a 1947 vintage Featherlight in 16 gauge with the corncob fore end that is the best handling upland gun I have ever used. But my first encounter with the slam fire feature (function testing against a berm) was disconcerting to say the least. The transition from 870s took some time to rewrite the muscle memory. It helped to stick with the Ithaca to the exclusion of other pumps.

[Outpost75]

When you do this conversion and use plastic shells, what choke do you recommend for the magazine tube?

Asking for a friend...

[W.R.Buchanan]

OK an update to this thread,, I have successfully broke the Trap the Trigger habit, and Front Sight is no longer teaching it. I am shooting the gun tomorrow at our weekly Skeet Practice shoot and will be better this time than last. No misfires last time.

I patterned the gun last time I took it out and it appears to be shooting a little to the left, which means I will have to be leading the High House Birds a little farther. Going to switch the choke tube out to an IC tube instead of the Spreader tube, and see if that helps move the pattern.

Randy

[Outpost75]

To clarify my post #19 for those unfamiliar, the 37 flexes and applies rotational torque to the extracted shell, such that when cycled rapidly the rim of an ejected plastic shell may strike the exposed primer of the round in the magazine tube. There were miles of high speed motion picture film documenting this, which happens mostly in 16-ga. and 20-ga. guns when firing plastic shells. Much less often in 12-ga. There were multiple lawsuits about this. At Ithaca in the 1970s they had an old Army wall locker full of guns with blown magazine tubes.

[Texas by God]

By plastic shells, do you mean Activ type?
So interesting, I've never heard of it. I was wondering what you were referring to.

Sent from my SM-A716U using Tapatalk

[Outpost75]

By plastic shells, do you mean Activ type?
So interesting, I've never heard of it. I was wondering what you were referring to.

Sent from my SM-A716U using Tapatalk

All modern shells with plastic tube vs. paper, which does not present the problem.

[W.R.Buchanan]

To clarify my post #19 for those unfamiliar, the 37 flexes and applies rotational torque to the extracted shell, such that when cycled rapidly the rim of an ejected plastic shell may strike the exposed primer of the round in the magazine tube. There were miles of high speed motion picture film documenting this, which happens mostly in 16-ga. and 20-ga. guns when firing plastic shells. Much less often in 12-ga. There were multiple lawsuits about this. At Ithaca in the 1970s they had an old Army wall locker full of guns with blown magazine tubes.

OK this one is new to me, I don't see how this can happen as the spent hull can't separate from the Extractor/Bolt until the lifter pushes it down and that happens nose first.

Also having a little problem with the "Flexing" and "Rotational Torque" part and how that would influence how the hull is ejected.

I just got thru playing with mine and when the shell is ejected it is separated from the bolt/extractor by the lifter pushing it down nose first.

Is the hull being ejected so that it turns around on the Lifter so that the topside of the Rim as it was previously positioned in the chamber then strikes the next primer on the way out ??? Mine is a 1940 M37 12 ga. and I have not seen nor heard of this, but I think I can see how it could happen on the smaller gauges as the hull would rotate quicker on its way out, but it would have to hit the next shell before the shell trip released it onto the lifter? Or is it hitting the next shell after it is released? or the released new round is hitting the spent round before it can be fully ejected and pinning it against the front of the fire control group. Then the magazine spring would be actually providing the force necessary to set off the new round?

Maybe a timing problem?

Ithaca obviously fixed this problem because they are selling M37's in 12,20,28 ga. now.

Where can i see the high speed pics?

Randy

[W.R.Buchanan]

I have a 1947 vintage Featherlight in 16 gauge with the corncob fore end that is the best handling upland gun I have ever used. But my first encounter with the slam fire feature (function testing against a berm) was disconcerting to say the least. The transition from 870s took some time to rewrite the muscle memory. It helped to stick with the Ithaca to the exclusion of other pumps.

I have been fighting this for some time, and the fix is to stop trapping the trigger.

We were all taught this at Front Sight for every gun we shot there. It was called a Trigger Reset Drill and it was done for Pistols Rifles and Shotguns.

I complained about it the last time I was there because I was starting to use my Ithaca for Skeet shooting and it would slam fire if you trapped the trigger. So will a Model 12, neither one of which they will allow in Tactical Shotgun classes. Well I opted out of Trigger Reset drills which essentially broke the habit of trapping the trigger, then they got the idea and told everybody to only do it for that drill..

On these two styles of shotguns you punch the trigger which is how I was taught to shoot a shotgun 50 years ago. I still catch myself Trapping the trigger on my O/U sometimes. but hardly ever.

This is just a habit you have to break, and there really isn't any other way around it.

On the post 1975 Ithaca the hammer follows the bolt down if you trap the trigger, but there isn't enough force to slam fire the next round. This results in a loaded gun with the hammer down so you get to rack the slide and waste that round and then line up for the next shot. On the earlier guns like mine if you trap the trigger the hammer stays back until the bolt is closed and locked then it releases and fires the gun.

The hot tip is to not Trap the Trigger on any shotgun in the first place.

Randy

[Outpost75]

OK this one is new to me, I don't see how this can happen as the spent hull can't separate from the Extractor/Bolt until the lifter pushes it down and that happens nose first...

Mine is a 1940 M37 12 ga. and I have not seen nor heard of this, but I think I can see how it could happen on the smaller gauges as the hull would rotate quicker on its way out, but it would have to hit the next shell before the shell trip released it onto the lifter?

CORRECT

....Ithaca obviously fixed this problem because they are selling M37's in 12,20,28 ga. now.

Where can i see the high speed pics?

Randy

Was on 16mm movie film taken in late 1960s. Have no idea where it would be now.