Home Forums Hunting & Shooting Gunsmithing model 70 (classic ss) trigger question

Any reason for an occassionally inconsistent and greater pull weight on a loaded chamber? Trigger has been tuned and functions great for the most part. Breaks perfect and consistent if dry firing. Most noticable when shooting for groups on the bench.

Try flushing with lighter fluid. The only things I can think of are the sear may have become rougher from use or grit. A stoning and polish may fix this.

The sear on the bolt can seat differently in the action and create a different feel or pull weight. It could be a timing issue and the tension from the extractor could be enough to cause the trigger and bolt sears to engage differently. Hopefully a pro like Redneck who really knows will respond.

Thanks.

Open style trigger and that seems clean and fine.

Fooled with it again some this AM. Noticed that the catch for firing pin mechanism was starting to rub on the bolt release but that wouldn't cause it. Wonder if it might be how the claw puts pressure on the cartridge. When it happens it's noticeable enough to start the trigger squeeze over again. Been a long term issue.

PM Redneck.

He's a master M-70 gunsmith, posts here on a regular basis..

DF

Will do tomorrow. Imagine he might be preoccupied with football till then.

Tried it with a fired case in the chamber? Do so, and if it seems heavy, pull it with a trigger scale and record the reading. Could be you can then get a handle on cause and effect. eigh the trigger pull with the spring removed and the trigger set by holding it ahead with your thumb. I would be remiss if I did not mention; there may be a psychological component. GD

Pretty darn intermittant problem. Thought it might be a mental issue too but trigger pull on next cartridges will be fine. What I should do is when it happens is jack that shell out and reload it. Have two model 70s. The other one does not act up.

One thing I do is to polish all the engagement surfaces, on the sears and the extractor. I also use light pressure on the long portion of the extractor to very slightly open this up. On my middle bores I swap out for a Williams extractor if it did not come with one already. Some models are made from cast steel and I have greater faith in the machined ones like the Williams. Bolt timing is a job for the pros as it can entail re-welding the bolt or opening the bolt action stop cut out and a screw up here is major.



There is always that factor, the nut behind the bolt may be loose.

Never, ever touch the sear's engagement surface.. Only the trigger can need reworking - and to do it right it entails machining.. That's a common Rem issue - not NH 70s... Whole different system...

PM sent to lostleader...

I'd like to hear the solution.

I've not had that problem, but am always interested in such matters.

DF

Thanks Redneck will not do the sears again and you may have helped prevent someone from screwing things up. Would also like to hear the explanation.

Tried to get a couple of my M70s to do this and nada, they all seemed fine, but all of them have had a pro done trigger job too.

Uhmm.... this trigger was done by a pro (break at around 2lbs if I remember correctly) and it functions excellent in all regards except a sporadic but perceptible change in pull weight ....and this is not a huge change. Safety function is has not changed. It's happened often enough to know it is not my imagination or finger causing it. I doubt I would notice it hunting though.

Something is changing pressure or an angle somewhere. I will have it looked at when I put the next barrel on or decide to retire it, if not before.

BTW the old style open model 70 triggers seem to adjust just fine (not by me) and are probably my favorites but I am not a long range or competive target shooter.

Thanks for the replies.

Show me a pic of that trigger - specifically from the top, showing the platform and notch; roughly 3/8" or so back from the tip.. Then one from the side view of that exact area.... Then I can tell you what kind of 'pro' did your trigger.... No flames, really, and seriously not trying to be a smartazz, but I can tell within 2 seconds whether or not it's been truly reworked or not...

Send it to my PM and I'll post back asap..

As to the sear - any, and I mean ANY, even extremely minor alteration (whether from polish or stoning or buffing) to that particular surface can result in a failure to hold the firing pin... Nobody will like the result.. That sear edge is hardened and must be left alone, period.. I had one rifle in a couple years ago that someone (owner? bubba smith?) slightly modified that edge.. Totally unsafe.. I tossed it out and replaced with a new one - THEN worked over the trigger... Problem solved.. FWIW..

Will do. Will be a couple days until till I get finished from a couple meetings.
Will PM you the smith.