The Accurate Reloading Forums
Pre-64 M70 Problems

This topic can be found at:
https://forums.accuratereloading.com/eve/forums/a/tpc/f/9411043/m/692105605

06 July 2006, 08:14
Michael Robinson
Pre-64 M70 Problems
I would appreciate any help that anyone may be able to give me on some problems I am having with a modified pre-64 Model 70 action.

This action has been worked on as follows:

1. Action trued and lugs lapped (I think).
2. Factory swept bolt handle replaced with welded on straight bolt handle.

All well and good, but the action suffers these problems:

1. Three position safety sticks in rearmost position (i.e., all the way off). I mean really sticks. Won't move forward without much applied force.
2. Trigger pull is heavier, too heavy by half.
3. Bolt handle torques upward when trigger is pulled.

What happened and what needs to be done to fix it? A plus would be the recommendation of a good smith to fix what the last smith screwed up.

Thanks.


Mike

Wilderness is my cathedral, and hunting is my prayer.
06 July 2006, 08:32
DavidReed
When the lugs were lapped the relationship between the sear and cocking piece was altered. This affects the safety and trigger with the effects you described. Pretty common to M70's worked on by those not thinking of the big picture. I've even seen this on out of the box M70's, both pre and post 64's. A few of my own too.

This is an easy fix for a smith that knows the M70 trigger. Most likely the sear and cocking piece will need to be ground down a few thousands. Mark Penrod has a deserved reputation for his work on M70's
06 July 2006, 09:05
Michael Robinson
Thanks, David.

Would that also explain the bolt handle torquing upward when the trigger is pulled, or is that something else that is purely bolt handle related?


Mike

Wilderness is my cathedral, and hunting is my prayer.
06 July 2006, 09:57
DavidReed
MR,

I'm pretty sure the sear to cocking piece relationship also affects the bolt handle torquing up when the firing pin is released. A few of my M70's exhibit this to varying degrees also. None too severe though. For a better explaination of the dynamics I would defer to a true M70 expert such as Jim Wisner.

However I believe a complete tune and timing of the trigger and safety together should alleviate the problems you are describing.
06 July 2006, 10:45
hart
It looks like the bolt has rotated a little past where it is supposed to stop when closed, possibly because of work done to the bolt handle. The end of the cocking piece does not line up with the bottom of the cocking notch and when the cocking piece drops it automaticly rotates the bolt to line it up.
07 July 2006, 04:35
Michael Robinson
Thanks very much, guys. I now have a pretty good understanding of what it should take to put this right.


Mike

Wilderness is my cathedral, and hunting is my prayer.
07 July 2006, 04:44
jorge
MR: If you have the time, I'd strongly recommend Mark Penrod to cure all the maladies described. He saved my bacon on a pre-64 that was gooned up by an idiot smith down here in Florida.jorge


USN (ret)
DRSS Verney-Carron 450NE
Cogswell & Harrison 375 Fl NE
Sabatti Big Five 375 FL Magnum NE
DSC Life Member
NRA Life Member

07 July 2006, 04:48
malm
quote:
Originally posted by hart:
It looks like the bolt has rotated a little past where it is supposed to stop when closed, possibly because of work done to the bolt handle. The end of the cocking piece does not line up with the bottom of the cocking notch and when the cocking piece drops it automaticly rotates the bolt to line it up.


And..., almost every action out there exhibits this trait. There are things that can be done to correct this problem if it bothers you, but, from a practical standpoint, it does no harm on a hunting rifle.