Ruger m77 tang safety issues

crapshoot

crapshoot

Well-known member
7mm rem mag
Action is bedded (by me and the only gun i have bedded so its probably wrong). Trigger is a timney and set quite light but doesn't fire by banging the gun on the butt or slamming the action closed.
BUT after some use, it has developed a hang fire. Sometimes you pull the trigger and the bolt drops maybe 1/4 or less of its travel but doesn't fire until you try to lift the bolt handle, then boom!
Wont do it with an empty chamber. Wont do it with a fired case. At least not the few times i tried to replicate.
Only does it with live reloads.
Cant advise about factory ammo as i dont shoot/have any.

What might be the problem and how do i fix it?
 
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Here's my thought. Since i can't duplicate the issue on an empty chamber or a fired case, im thinking it has something to do with the loaded round putting bind on the bolt itself. Either the shoulder isn't bumped back far enough or bullet seating depth is to far out.
If i had to guess, I'd vote shoulder bump. These are new peterson brass. Once fired in this gun. Resized with a .003 shoulder bump. Bullets are seated a min of .010 off the lands and sometimes more.
In reality neither should be causing the problem but i have noticed some slight stiffness when closing the bolt on loaded rounds which im also not understanding since case and coal specs should be less that the actual chamber.
 
Did you install the Timney Trigger, or someone else? I don’t have any explanation for what you’re seeing with your rifle, however I installed a Timney trigger on my 77 Mark II and had to file a small amount from the post on the safety so that the safety lever would fully close in the full safe position. This is a documented step in the Timney instructions for the installation. Maybe a bit too much material was taken off the post?

I’m not a gunsmith and haven’t a clue if that would ever create the situation you are seeing. Just throwing it out there as a possibility. Hope you get it figured out.
 
crapshoot said:
n reality neither should be causing the problem but i have noticed some slight stiffness when closing the bolt on loaded rounds which im also not understanding since case and coal specs should be less that the actual chamber.
Click to expand...
I'd take a look at this area. Sounds like bolt is not closing sufficiently to allow firing pin to drop. Not that familiar w/the 77's, but all bolt guns have a safety provision to prevent firing out of battery. Suspect that when you try to open bolt it moves enough to satisfy that safety feature (whatever you call it) and releases the firing pin.
ETA: I'd start w/ammo. Size & prime a once fired case and see if you can duplicate the issue. If so, try setting the shoulder back just a tad.
 
What hm1996 said, then do a base to ogive measurement and a good base to lands measurement to make sure your bullets are not too long. Depending on the consistency of your reloading, 0.01 off the lands may not be enough.
 
wildcat18 said:
What hm1996 said, then do a base to ogive measurement and a good base to lands measurement to make sure your bullets are not too long. Depending on the consistency of your reloading, 0.01 off the lands may not be enough.
Click to expand...
+1 If the primed case works as it should, about the only thing left is base to ogive is a bit long. There is the possibility if you are using an expander plug in in sizer, you could be pulling your shoulder forward as case is extracted from sizing die; if that is the issue, the failure should repeat itself w/the MT primed case.
Stretching the case can be eliminated by lubing inside necks before sizing or a carbide expander.
 
I thought about taking the bolt apart and checking for debris. Haven't gotten to it yet.
I even asked AI. It suggested backing out the overtravel screw a 1/4 turn, which i did. That induced more creep than i like into the trigger. Haven't shot it yet to see if there is any difference.

Thought about trying the sized/ primed brass to try and duplicate but haven't yet.

And i guess technically it's not a hang fire as the gun could sit there all day and never go off even after pulling the trigger so long as you didn't move the bolt any.
 
Some 77 factory triggers apparently did have an issue; probably does not affect the Timneys???
Notice to Owners of Ruger
M77 Bolt Action Rifles
Sturm, Ruger manufactured M77 bolt
action rifles from 1968 to 1991. The trig-
ger overtravel adjustment set screw
(shown on right) in a few of these rifles
may not be securely tightened and may
move too readily. This change in original
adjustment can, in extreme cases, either
cause the rifle to fire unexpectedly (with
the safety “off) or cause the rifle to not
fire at all. This may occur suddenly and
without warning.
Ruger M77 bolt action rifles pro-
duced in later years have this set screw
permanently secured. These rifles have a “T” inscribed on the underside of
the bolt handle. This condition cannot occur in any of our other firearms as
their trigger mechanisms differ. Please note in particular that this condition
cannot occur in Ruger M77 Mark II bolt action rifles, which are of an entire-
ly different design.
For your safety, we ask that all owners of M77 rifles (except those with a
“T” underneath the bolt handle) contact us, using the coupon below.
You will receive a new locking screw that will replace your present over-
travel adjustment set screw and detailed instructions for quick, easy instal-
lation. There is no charge for this service and replacing the screw will have
no adverse effect on trigger pull.
Do not use your M77 rifle until you have received and installed the
replacement screw.
SINGLE COPIES OF INSTRUCTION MANUALS FOR ALL MODELS OF RUGER FIREARMS ARE
AVAILABLE ON REQUEST - PLEASE SPECIFY MODEL FOR WHICH YOU REQUIRE A MANUAL.
STURM, RUGER & Company, Inc.
1 Lacey Place
Southport, Connecticut 06890 U.S.A.
ALL RUGER FIREARMS ARE DESIGNED AND MANUFACTURED IN RUGER FACTORIES IN THE UNITED STATES OF AMERICA
Please affix to a postcard and mail to:
Sturm, Ruger & Company, Inc., Dept. M77
1 Lacey Place, Southport, Connecticut 06490
NAME
(Please Print)
STREET OR P.O. BOX
CITY STATE ZIP
Number of M77’s owned: List serial numbers here:
Ruger M77 Rifle
Click to expand...
https://ruger.com/pdf/m77.pdf

Not sure how Ruger prevents firing out of battery on the 77, but Bill makes a good case for disassembling, cleaning and lubricating the bolt.
 
Id maybe try a few factory rounds if can get your hands some to just try it and that should answer the question as to whether or not its ammo or gun. Then go from there? Ive had the sizing die stretching brass via the expander dragging in the neck as mentioned above. Could be bullet seating depth? Carbon ring built up in the throat of the chamber not allowing full chambering? Messed/dirty up bolt lugs or the faces they slide on? Dirty bolt as mentioned is a possibility. Maybe bedding is actually tweaking the action enough to cause bolt binding? On the 3 screw actions like the 77, the middle screw can get tightened too far for best accuracy.....maybe its causing binding? Just thinkin out loud?!

Id start with factory ammo, actions crews and a bolt cleaning and go from there to checking the chamber for carbon ring, and the lug recesses? Interested to know what this really is......
 
Just for curiosity I googled "Ruger 77 fires when the bolt handle is raised". The answers I got were, sear/trigger engagement, weak or gummed up firing pin, faulty over travel adjustment screw. Sounds like something in the action more than ammo.
 
It could possibly
William Suter said:
Just for curiosity I googled "Ruger 77 fires when the bolt handle is raised". The answers I got were, sear/trigger engagement, weak or gummed up firing pin, faulty over travel adjustment screw. Sounds like something in the action more than ammo.
Click to expand...
I did the same but added in w/ timney trigger.
 
A friend of mine put a Timney in his Ruger 77. He had all kinds of issues but finally got it working. I'll check with him and see if his issues were similar to yours.
 
It could be binding issues with the action screws as well. My "bedding job " was the base of the barrel only. The factory stock was opened up to accommodate the christensen cf barrel and over time it would walk to one side and contact the stock. So i bedded like the first 1.5" of the barrel to keep it centered.

It may be time to take it to a qualified / certified gunsmith to have it properly bedded and trigger tuned.
 
You might also check if anything in the stock tang inlet area is causing a binding issue. The working geometry of the Timney unit is a little different than the factory unit. I just installed a Timney in my old Ruger flatbolt .308, and there are several areas where interference is possible .
 
I just tried the sized/primed brass and was able to duplicate once out of 3 tries so brass sizing isn't out of the question.
Adjusting the overtravel screw out a 1/4 obviously didn't fix anything.

@6GUNSONLY
Pretty sure nothing is touching any part of the trigger. I made sure to open everything up enough to clear all aspects.
 
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