M37 mag tube threads

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.270 WIN
Posts: 202
Joined: Fri Oct 23, 2015 2:14 am
Location: Mitcham, South London, England
PostPosted: Tue Sep 12, 2017 12:48 pm
Does anyone know the size/pitch/designation of the threads at each end of the M37 mag tube, the fine thread at the receiver end and the coarse thread at the mag nut end. (its a '71 if that is relevant)
I ask because I need to make a custom length tube for my competition gun (10 + 1 capacity) after a minor accident dented and bent the original custom tube. I have straightened the original and it works fine but it appears a little fragile (thin walled) and I should like to make a stronger repair/upgrade.
Here's hoping the Ithaca massive has the info!! :)
PostPosted: Mon Sep 18, 2017 9:15 am
Sorry...can't help with that measurement.

But, hang tight...some member here will know !
User avatar
.270 WIN
Posts: 202
Joined: Fri Oct 23, 2015 2:14 am
Location: Mitcham, South London, England
PostPosted: Fri Sep 22, 2017 5:15 pm
Ok guys,
I got a nice reply from Jeremiah at the Gun Co. and for those of you who may also need this info, here goes;
The magazine tube at the receiver end utilises a .986"-32 NS 3A thread. Threaded portion .447" long with a least 13 full turns. the mag nut end is .986"-12 SQ thread. Threaded portion .436" long with at least five full turns.
I will probably seek out a local, traditional engineering shop as these threads are quite obscure over here and some of the old guys you meet in these shops can do this sort of thing with their eyes shut!
So, a good result from a great company, I'll always be an Ithaca man!
PostPosted: Sat Sep 23, 2017 10:00 am
Thanks for sharing...

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