Ruger M77 from 1978

ksubuck

Handloader
Jun 25, 2014
362
56
I have started breaking in a new M77 in .243 for my father in law. He managed to put 12 rounds down the tube in 37 years. I loaded up some light rounds using IMR 4350 and 95gn SSTs to warm it up and fire form some brass.

I am not liking the bolt function, it is super tight to open and close the lugs, The bolt binds if you don't draw it straight back or advance it straight forward, and it scars the brass badly when ejecting. Every edge in the action is razor sharp, even the tang safety is sharp. I had 4 misfires in 50 rounds. Could be brass or primers because the firing pin struck a decent mark on the primer. But it seems to have some accuracy potential.

What all do you suggest in terms of breaking a Ruger in and accurizing it? Polish the edges a bit in the action? Polish the lugs? Shoot it a bunch more to accomplish the same? Does free floating the barrel and bedding the action help these rigs out much? The angled action screw has me scratching my head a bit.

I also see there was a trigger recall a while back related to a set screw that backs out and can allow the trigger to release when the safety is released. Any in home fix for that? Locktite?

Thanks for any input
 
Take a little emery cloth to the feed rails. Work the action about a hundred times or so. It will smooth up.

The recall was about the rear screw being too long and interfering with the safety. I can't remember if Ruger sent out new screws or did a full recall. If your safety works fine now it shouldn't be an issue but call Ruger and see what they will do for you.
 
I bought my wife one back in '82, I don't know the born date. This rifle was in 7X57, a classic case of buying someone else what I really wanted.
The best I could get was around 1.5" using IMR 4350 and 140 gr. Nosler PT's, but the gun averaged around 2.0".
The angled screw was the reason I never bedded the rifle and your right every part had sharp edges and burrs. Inside tooling marks were everywhere. I was a young toolmaker and every Ruger I'd owned was like this. I had polished them all to one extent or another but this was one to many.
I wrote Ruger a letter complaining about all the burrs and general poor inside finish. They didn't deny it, but instead replied "If we took the time to clean up all the tooling marks and burrs, then we couldn't sell our products at an affordable price. As is, most people are satisfied with the products we sell.
Our feeling is, if someone is sophisticated enough to recognize this problem then they are sophisticated enough to fix the problem themselves if so inclined."
The answer satisfied me and this was not the last Ruger I would purchase.
 
I bet that 7x57 had a long throat and would have shot better with heavier/longer bullets.

I would break the sharp edges that bother you and mark the brass. Work the action as stated and shoot it. Check the bore for copper fouling and clean it as necessary. I would also disassemble the bolt and clean & lube it. As far as bedding & free floating each rifle is different. Don't let that angled screw scare you, you bed it just like any other rifle. If you decide you want to bed it do that first then evaluate if you want to float the barrel. I have many Rugers and have exactly one that is free floated. Torque on the diagonal and two trigger guard screws can be critical. Especially the diagonal screw. You need a inch-pound torque wrench. Here's what I do...

Stock Screws: -
The sequence and torques are:
1. The diagonal screw, torque to 50-90 inch-pounds. (If it is a flat tip screw replace it with an Allen or Star Head
Bolt)
2. The aft trigger guard screw, 30-50 inch pounds.
3. The forward trigger guard screw, also to 30-50 inch pounds.
The torque placed on the diagonal screw will have an effect on barrel harmonics by changing the upward pressure
on the barrel at the raised area at the fore end tip in the barrel channel. This screw pulls the barreled action down
and back against horizontal and vertical bedding surfaces. It also serves to position the magazine box and locate
the hinge on the floor plate. This is why adjusting the diagonal screw often (not always) results in having to adjust
the trigger guard screws to maintain operation of the latch.
If I have decided I need to do this to get a rifle to shoot or if I am removing the stock on a good shooting rifle, I
record the torque values on disassembly.
On reassembly I adjust the diagonal screw torque from high to low in 5 in-lb increments. Just remember it's 50 in-lbs minimum and 90 in-lbs maximum on the diagonal screw; 30-50 on the trigger guard screws. Then just
“balance” the torque on the trigger guard screws ensuring the magazine box is positioned correctly and that the
floor plate latches and unlatches properly. Ruger generally uses the upper limits when assembling. But some
experimenting may be helpful if you want to tweek the last little bit of accuracy out of the rifle.
 
I have a M77 from this era and absolutely love but then I did have it bedded right after I got it because the forearm warped during hunting season and it would almost shoot around a corner. And the action is very smooth with out doing anything to it so I guess I got lucky on that part. After opening up the barrel channel and bedding it it has been a very accurate rifle and is my go to rifle when I hunt deer for the time being but my M70 35Whelen Imp is slowly gaining that place.
 
Thanks for the ideas. This is the first Ruger bolt gun I have worked with. I took down the bolt and cleaned, lubed, and reassembled it. Not too much grime or old lubricant in it. It is still stiff but is improved. Gonna keep working the action to see if that helps. I do see a significant scuff on one lug when compared to the other lug.

I did run the main action screw up to 50 ft/lb before I fired the gun, while leaving the guard screw and rear action screws at 30 ft/lb.

Touched up a few sharp edges with emory cloth. Seems to extract and eject slightly better and has reduced scoring on brass.

Plan to run OCW tomorrow using 70gn BTips.

I think this rifle will do fine once it is borken in completely. It has 58 down the tube and when cleaned it isn't holding much copper. All it has to do is pop yotes at up to 400 yards.
 
I traded an M1 Carbine for an identical rifle ( 243) during 1979 and it too was just like you described! I used a bit of Emory cloth also and it was OK, but still pretty sharp. It's saving grace was it was a "shooter", didn't matter what you ran through it! My dad sold it later to help during his house building project, but it was OK by me. I always thought it was a bit heavy for it's caliber. Back then, Ruger paid $17 per Outsourced barrel! Si it was always a gamble as to whether they would shoot or not!
 
Put a little lapping compound on the lugs and it'll even itself out some. I've noted the same with most Rugers, sharp edges and such but I've been very lucky that most have been excellent shooting rifles after a little break in.
 
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