Spring replacements

[impala59]

Continuing my look at replacement parts for my Ithaca collection, I have focussed on the trigger mechanism spring set. As gun parts from the US are subject to homeland security (it seems) and unavailable in the UK, I looked at what I could achieve buying locally 'on the bay' 

Most of what is available is metric (of course) so my initial exercise was to measure and look for equivalents or as near as possible. Without spending too much, I managed to get some spring stock and proceeded to cut to fit. In a model 37 trigger assembly there are 5 springs, 4 coil and one straight wire. I used my 1985 Deerslayer model as the measuring datum on the grounds that it is the youngest at 36 years old and hopefully the springs are closer to factory specification than some of the octogenarians I own.

I replaced each spring and tested individually for fit and comparable tension with the original. I bent the slide stop release spring with pliers. I then re-assembled the trigger mechanism for function test. The safety detent spring was satisfactory. The trigger spring created a touch heavier trigger pull which I reduced by removing half a coil. The mainspring (hammer spring) concerned me with regards to different coil spacing and wire thickness, but it performs flawlessly, I don't expect any light strikes! The slide stop spring and the slide stop release spring caused my first hiccup, while they fitted well and functioned perfectly out of the gun, when I re-assembled it the slide would not release after the hammer had fallen. Looking closer, it became apparent that the two springs work against each other depending upon the condition of the gun (cocked or fired) Adjustment of the coil spring by one coil solved the problem. This particular M37, being a later variant, does not have 'slam fire' or 'trigger override' but that aside the mechanism is identical to my earliest model (1940's) 

Next in line will be the internal bolt springs, top and bottom extractors and the slide release pin spring, The only other spring on the gun is the magazine spring and I use Nordic or Wolff springs as they are the best available. I will then be completely self dependant as far as springs go and can keep these old guns working as they should.

While carrying out this exercise, I used for the first time, the gunsmith assembly block bought from China on the 'bay for £8. Designed for the Colt 1911, it nonetheless proved a useful tool when knocking out and replacing pins on my trigger assembly. Its no jewellers anvil, being hard plastic and not steel but it makes pin punching easy and of course being plastic will not scratch the gun parts.

Edited November 30, 2021 by impala59

[John_R]

Well done

[Gordon R]

I am impressed.

[impala59]

As an aside, if any M37 owning PW members need a spring, drop me a PM as I now have plenty!

[TIGHTCHOKE]

Very clever, if you want to make your own spring block I have some offcuts that lend themselves to a custom job.  

[impala59]

3 hours ago, TIGHTCHOKE said:

Very clever, if you want to make your own spring block I have some offcuts that lend themselves to a custom job.  

Sounds a bit technical to me! Hence getting ready made in similar if not identical sizes🤪

[TIGHTCHOKE]

11 hours ago, impala59 said:

Sounds a bit technical to me! Hence getting ready made in similar if not identical sizes🤪

Just a hard block of nylon that you drill to your own requirements.

[impala59]

3 hours ago, TIGHTCHOKE said:

Just a hard block of nylon that you drill to your own requirements.

OK, after removing my stupid head, I'm with you now! For some reason I thought you were referring to winding my own coils🤪! I actually have some small offcut walnut blocks that I will drill to set the spring lengths