Accurizing an M77 .22 Hornet

Ruger8r
Posts: 403
Joined: Sat Mar 28, 2020 1:28 pm
Location: Glendale, CA

Accurizing an M77 .22 Hornet

Post by Ruger8r »

Having already installed bolt shims, a Volquartsen target sear/spring and shimming the trigger and sear pins, I had to get into the stock and mounting hardware. The action looked slightly canted and the barrel was not lying straight in the channel. So it was probably quite unruly though I did not have an opportunity to shoot it.

Inspection of the mag liner revealed a small divit in the edge that fits into the groove along the bottom of the recoil lug. It's the little bright spot in the photo.
20200403_114050.jpg
The culprit was a high spot in lug groove where a casting line crossed it causing the two surfaces not to mate squarely. You can still see it after careful work with a triangle file.
20200403_113255.jpg
There was evidence that the barrel had been bearing on the channel too heavily. With a dowel wrapped in 400 grit sandpaper I slowly removed material until the barrel rested lightly in the center. You can see the channel in the bottom photo.


I also checked the the wood surfaces behind and above the recoil lug were flat and smooth. Here is the lug contact point before.
20200403_120220.jpg
Finally the area underneath the tang looked like it extended too far forward and was binding on the bolt release spring where it clips under the tang. Before and after a little work with a dremel photos are in a following post. Getting the hang of attachments.

After torqueing the mounting screws to spec it would be time to go out and punch some holes in paper except all the ranges are closed. So that's it for now - no range report. Please reply with comments or questions. I'll do a photo spread of the rifle a bit later.
Let's Ruger!
O
Attachments
20200403_120858.jpg
20200403_120138.jpg
Last edited by Ruger8r on Mon Apr 06, 2020 6:34 pm, edited 4 times in total.
"My greatest fear is that, when I die, my wife will sell my guns for what I told her I paid for them." Anonymous Collector
zebra55
Posts: 348
Joined: Tue Feb 02, 2016 6:55 pm
Location: Michigan

Re: Accurizing an M77 .22 Hornet

Post by zebra55 »

thanks for the post, I too have a 77/22 hornet and the barrel also rides slightly off center. I have shot it quite a bit and once in awhile it will throw a shot. I plan to use your advice and do some work on it...fortunately I have a range in my back yard...
Ruger8r
Posts: 403
Joined: Sat Mar 28, 2020 1:28 pm
Location: Glendale, CA

Re: Accurizing an M77 .22 Hornet

Post by Ruger8r »

Hello zebra55.
I highly recommend shimming the bolt as the first step if you haven't already.
The idea is to have the barrel resting lightly on at least half of that little channel support and not touching the sides.
Good luck. Let us know how it goes, please.
Range envy!
O
Last edited by Ruger8r on Sat Apr 04, 2020 9:32 pm, edited 1 time in total.
"My greatest fear is that, when I die, my wife will sell my guns for what I told her I paid for them." Anonymous Collector
Ruger8r
Posts: 403
Joined: Sat Mar 28, 2020 1:28 pm
Location: Glendale, CA

Re: Accurizing an M77 .22 Hornet

Post by Ruger8r »

Kinda screwed up the attachment thing in the OP. Here are the before and after of the tang area. I hope.
20200403_120858.jpg
20200403_123132.jpg
Hmmm. I get a notice about permission but I think it worked

BE CAREFUL not to remove too much material from the channel. You just want to level it to the barrel. GO VERY SLOW.

There may be something to the claim that the rifle can be fine-tuned by changing the relationship of the torque on the front and rear mounting screws within the spec range of 60-65 in/lbs. It could affect the barrel to stock channel contact pressure. I suppose. Sounds like lots of work and ammo on a private range with big optics and a good torque wrench. Seeking the ragged hole. What fun.
O
"My greatest fear is that, when I die, my wife will sell my guns for what I told her I paid for them." Anonymous Collector
Ruger8r
Posts: 403
Joined: Sat Mar 28, 2020 1:28 pm
Location: Glendale, CA

Re: Accurizing an M77 .22 Hornet

Post by Ruger8r »

It takes a good fitting drive bit to crank 65 in/lbs on the mounting screws without buggering them. I use a Weaver #142 (0.34 wide x 0.050 thick). It fits the slot perfectly.
Y'all probably know this already but I read on another thread how the poster couldn't apply spec torque because his bit jumped the slot. Made me cringe a little.
Here's the rifle I've been working on.
All fixed up and nowhere to go.
All fixed up and nowhere to go.
O
"My greatest fear is that, when I die, my wife will sell my guns for what I told her I paid for them." Anonymous Collector
Ruger8r
Posts: 403
Joined: Sat Mar 28, 2020 1:28 pm
Location: Glendale, CA

Re: Accurizing an M77 .22 Hornet

Post by Ruger8r »

An added benefit of better alignment of the mag well liner and receiver lug is that my magazines slip in and out much more easily.
O
"My greatest fear is that, when I die, my wife will sell my guns for what I told her I paid for them." Anonymous Collector
Ruger8r
Posts: 403
Joined: Sat Mar 28, 2020 1:28 pm
Location: Glendale, CA

Re: Accurizing an M77 .22 Hornet

Post by Ruger8r »

Pulled out my other 77 Hornet out to see if it has the same problem with the uneven surface on the receiver lug where it mates to the mag well liner. And, yes, it does. In fact it's a little worse. So I suspect all of them have that little casting line flaw in the receiver lug.
Seems to me that, until that little problem is corrected, any bedding work would be ill advised. Thoughts, anyone? Anyone?
O
"My greatest fear is that, when I die, my wife will sell my guns for what I told her I paid for them." Anonymous Collector
Ruger8r
Posts: 403
Joined: Sat Mar 28, 2020 1:28 pm
Location: Glendale, CA

Re: Accurizing an M77 .22 Hornet

Post by Ruger8r »

zebra55 wrote: Sat Apr 04, 2020 4:48 pm thanks for the post, I too have a 77/22 hornet and the barrel also rides slightly off center. I have shot it quite a bit and once in awhile it will throw a shot. I plan to use your advice and do some work on it...fortunately I have a range in my back yard...
Hello zebra55,
Just wondering if you ever got around to doing this and whether it made a difference and tightened your groups.
My local range is still closed, dang it!
Stay well.
O
"My greatest fear is that, when I die, my wife will sell my guns for what I told her I paid for them." Anonymous Collector
zebra55
Posts: 348
Joined: Tue Feb 02, 2016 6:55 pm
Location: Michigan

Re: Accurizing an M77 .22 Hornet

Post by zebra55 »

not yet my range is temporarily closed for turkey hunting
Ruger8r
Posts: 403
Joined: Sat Mar 28, 2020 1:28 pm
Location: Glendale, CA

Re: Accurizing an M77 .22 Hornet

Post by Ruger8r »

As the final bit of accurizing, I decided to float the barrel. So as not to remove too much material from the channel, I took it down in stages with a dowel wrapped in fine sand paper checking the clearance often. Once I had it as close as I thought prudent, I assembled the rifle and torqued both screws to the mid point of spec. Then, by adjusting their relative tightness, I was able to lift the barrel off the channel enough to allow a dollar bill to slide easily between them. I think this procedure works on the Hornets because the receiver lug acts as a fulcrum between the two screws.
I've remounted the Leupold Vari X 2, 2-7x28 Ultralight scope back on it (nice combo). Next trip to the range we'll see what affect all this work had on accuracy.
"My greatest fear is that, when I die, my wife will sell my guns for what I told her I paid for them." Anonymous Collector
Post Reply