Ruger M77 Accuracy Fix

Posted by: roundoak

Ruger M77 Accuracy Fix - 02/08/10 01:30 PM








A member of the the gun club was complaining the other day about the accuracy falling off on a M77 TS 270 Winchester. He did some of the usual stuff to try and remedy...scope base and ring screws, stock screws, clean barrel and etc. He shoots factory 130 and 150gr Ptd Soft Pt Core-Lokts and they always group about 1 1/2" at 100yds ever since the rifle came out of the box. He sighted the rifle in just before the 2009 November Wisconsin Whitetail season and after a couple of shots he had 3 - 5 inch three shot groups on the 100yd target. He hunted with it as is.

I had him bring the gun along with the targets to me a couple of weeks ago. Took the gun apart, got out a 1/4" round file and filed wood just a tad in the very back end of the front screw hole. Put it back together...tighten the front screw and snug tighten the center and back screw. Told him to go fire it and let me know.... 1 1/2" groups returned and my wife and I have a steak dinner coming.

I advised him to take gun apart and apply a wood sealer to the rasped area for piece of mind.
Posted by: hotsoup

Re: Ruger M77 Accuracy Fix - 02/08/10 02:08 PM

seems like you scratched his itch! good on ya! it's good to have a friend who knows how to make a rifle better.
Posted by: rahtreelimbs

Re: Ruger M77 Accuracy Fix - 02/08/10 02:31 PM

I take that the hole swelled shut???
Posted by: roundoak

Re: Ruger M77 Accuracy Fix - 02/08/10 03:21 PM

I believe the dynamics involved here is the the front guard screw is drawing the barreled action into the stock with down and to the rear torque. After the rifle is fired a number of times the dynamics compress the surface of the wood slightly and allow the screw to move a bit towards the rear making contact with the wood in the hole of the stock.

After checking the scope base and scope ring screws, experiment with the three guard screws and shoot a clean or dirty barrel try the accuracy fix before free floating or bedding the rifle or looking to the chamber or throat for problems.

Ruger recommends the front screw to be tightened beyond snug, the center and rear screw to be snug and back out 1/8 turn.

I have found M77s react differently to the screws so you need to experiment. In most cases hand tighten front screw, snug the rear screw and lightly tighten the middle screw just so it will not fall out.
Posted by: cumminscowboy

Re: Ruger M77 Accuracy Fix - 02/08/10 03:28 PM

I had a ruger mk 2 that sometimes shot ok sometimes not so good. one day I decided to take one of those heavy duty screwdrivers with the fat rubber handle on it, and just torque the front screw like a gorilla. next time out at the range the rifle shot a ragged hole,this was with just a little pressure on the pressure point most of it was removed. rifle continued to be accurate however POI would shift around a bit, not too bad but I am anal, so I had the barrel free floated and stock glass and pillar bedded, I lost a little pure accuracy however the rifle is more consistent depending on load and how clean the barre is, I get 5/8- 1-1/8" groups. I am happy with that, its become my go to rifle.
Posted by: GeoW

Re: Ruger M77 Accuracy Fix - 02/08/10 04:51 PM

roundoak, I like your style smile
Posted by: Bearcat74

Re: Ruger M77 Accuracy Fix - 02/08/10 04:57 PM

I floated my barrels in my 77's and tightened the front screw like a crazy beast. Mine all shot much better after that.
Posted by: roundoak

Re: Ruger M77 Accuracy Fix - 02/08/10 05:47 PM

Originally Posted By: cumminscowboy
I had a ruger mk 2 that sometimes shot ok sometimes not so good. one day I decided to take one of those heavy duty screwdrivers with the fat rubber handle on it, and just torque the front screw like a gorilla. next time out at the range the rifle shot a ragged hole,this was with just a little pressure on the pressure point most of it was removed. rifle continued to be accurate however POI would shift around a bit, not too bad but I am anal, so I had the barrel free floated and stock glass and pillar bedded, I lost a little pure accuracy however the rifle is more consistent depending on load and how clean the barre is, I get 5/8- 1-1/8" groups. I am happy with that, its become my go to rifle.


Glad to hear that you did not give up on the rifle.
Posted by: roundoak

Re: Ruger M77 Accuracy Fix - 02/08/10 06:15 PM

Originally Posted By: Bearcat74
I floated my barrels in my 77's and tightened the front screw like a crazy beast. Mine all shot much better after that.


Different strokes for different folks... I was tempted to float a M77 barrel once or twice, drove me nuts. I kept pouring the loads through them and after about 375 rounds one rifle settled down...it is a right smart shooting Roberts.

The other M77, a 358 Winchester was sent back to Ruger and they re-barreled it...no cost. I had sent them every single load note and target...they sent a note back with the rifle saying they had never received such a large pile of notes and targets...and told me not to wait so long the next time I have problems.
Posted by: JustLucky

Re: Ruger M77 Accuracy Fix - 02/08/10 06:47 PM

Would a synthetic stock have the same problems?
Posted by: TomM1

Re: Ruger M77 Accuracy Fix - 02/08/10 08:16 PM

Ive done that little trich to a ruger or two. I really like Rugers but hate the angled mini recoil lug. I thought the answer to prevent compression would be some accraglass in the lug area. This works for a while, but eventually if the rifle has any recoil to it, you end up with split in the wood between the trigger and magazine box.
Posted by: roundoak

Re: Ruger M77 Accuracy Fix - 02/09/10 08:18 AM

Originally Posted By: JustLucky
Would a synthetic stock have the same problems?


Dunno...never owned a M77 with synthetic stock or discussed the matter with someone who does...perhaps others on this website can offer some insight.
Posted by: roundoak

Re: Ruger M77 Accuracy Fix - 02/09/10 09:28 AM

Originally Posted By: TomM1
Ive done that little trich to a ruger or two. I really like Rugers but hate the angled mini recoil lug. I thought the answer to prevent compression would be some accraglass in the lug area. This works for a while, but eventually if the rifle has any recoil to it, you end up with split in the wood between the trigger and magazine box.


Hopefully your experience is rare or exceptional. I have owned three M77 thumpers.. 358 Win, 338 Win and 35 Whelen and had them apart for trigger work and at least once a year for cleaning. Nothing that you experienced...still own the 35 Whelen and it has three times the number of bullets down the barrel then the other two. No wood stock issues yet.
Posted by: TomM1

Re: Ruger M77 Accuracy Fix - 02/09/10 07:48 PM

The two rifles Ive experienced this on were 30-06's. Maybe I got some soft wood? Two is a limited sample. I like Rugers just the same smile If you do end up with a split its an easy fix to epoxy a brass pin in there.
Posted by: ratso

Re: Ruger M77 Accuracy Fix - 08/09/10 07:16 PM

talking about accuracy changes in a ruger m77.i rcently bought a ruger m77 markII 223.it would shoot erratically any where between 2-3" at a hundred yards,often 1" but then would throw a flyer out to 5".i installed a timney trigger which i will say made a good improovment,but still gun was erratic with unexsplanable flyers.i found the screws to be very tight.it appeared to me that the screw before and after the magazine were pulling the action causing the magazine to act like a fulcrum.i took out my dremel tool and took off about 3-5 thousanths of an inch from the magazine where the the trigger guard and the magazine door touch the magazine,thus releasing the pressure of the magazine pushing against the action.now with all screws tight the magazine barely puts pressure on the action.next i floated the barrel in the synthetic stock.i"am not sure what did the most but next time shooting the gun was shooting less than 1" quite often less than 3/4" there were no more flyers except the ones by me due to a bad shot if you know what i mean.try to get the magazine to not put pressure against the action when all the screws are tight and you will see a great improvement in grouping and consistancy.hope this might help someone with an all weather m77 markII.i was about ready to toss this gun into the lake.now i have a consistant rifle that shoots 1" groups everytime i do my part.peace to all.ratso
Posted by: hotsoup

Re: Ruger M77 Accuracy Fix - 08/09/10 07:43 PM

i've owned and hunted with only 3 ruger m77s (1-30-06 and 2-270 win) since 1975 or so. all three shot around 1.5" until i had them bedded and floated. they all improved after that.
Posted by: ratso

Re: Ruger M77 Accuracy Fix - 08/09/10 08:00 PM

iam just glad that my guns performance greatly improved.went out today and shot three groups at 50 yds.that were dime size.i was pleased to say the least.i was shooting hornady 55gr.i know when i start loading things will get even more precise.
Posted by: ScottSpencer

Re: Ruger M77 Accuracy Fix - 08/09/10 08:14 PM

I have a synthetic stocked Ruger M77 Hawkeye in 280 Rem. Here is one of my latest groups, measured center to center. Nothing has been touched on the rifle since pulling it from the box.




A second target....

Posted by: ratso

Re: Ruger M77 Accuracy Fix - 08/10/10 06:38 PM

Today i tried some nato rounds in my 223 mark II.the best icould do at 100yrds.was aboedut two and a half inches.they were 55grn .Has anyone used these bullets and achieved any better results?I know there is quite a difference of opinions as to whether one should shoot this ammo in a non military gun do to larger chamber pressures involved.non of my shells stuck in my chamber nor were any of the primers bulged as would be exspected if exstreme pressures were existant.also there seemed not to be any headspacing problems as the bolt closed when loaded just fine and exstraction was just as normal.
Posted by: CAFR

Re: Ruger M77 Accuracy Fix - 08/12/10 09:30 PM

IMHO, you should NOT shoot 5.56 NATO ammo in your rifle. Unless your chamber wad reamed larger than spec, you're courting disaster. There is a good reason that calibers are stamped on rifles. Stick with .223 ammo.
Posted by: chris112

Re: Ruger M77 Accuracy Fix - 08/15/10 01:44 PM

From what I have read, the military standard for accuracy is 4" at a hundred yards. That isn't very good when the rifle might be capable of less than an inch at the same range.
Posted by: gddir

Re: Ruger M77 Accuracy Fix - 08/17/10 08:11 AM

Own 6 of the Ruger M77 Mark II's. All stainless, all synthetic stocks. 7mm, 30.06, .270, .243, (2) .223's. All will shoot 1" consistently, with the exception of the 7mm. This thing has been bedded, floated, trued, stock changes, pressure point--no pressure point, trigger job, different scopes, different mounts, various action screw settings, enough different varieties of ammo to have junked the rifle, and bought a Weatherby. (I'm stubborn). 3" at 100yds. is an "awesome day". I have one thing left to try (install back in original stock) and see if somewhere along the way I have created my own nightmare. If that doesn't work--she's a goner!
Posted by: bracer

Re: Ruger M77 Accuracy Fix - 08/18/10 04:59 AM

Check the bolt locking lugs. I have had two rifles where only one lug showed any contact. After having a gunsmith lapp the lugs the accuracy went from about two inch groups dowh to a bit under one inch groups.
Posted by: roundoak

Re: Ruger M77 Accuracy Fix - 08/18/10 07:09 AM

Originally Posted By: gkdir
Own 6 of the Ruger M77 Mark II's. All stainless, all synthetic stocks. 7mm, 30.06, .270, .243, (2) .223's. All will shoot 1" consistently, with the exception of the 7mm. This thing has been bedded, floated, trued, stock changes, pressure point--no pressure point, trigger job, different scopes, different mounts, various action screw settings, enough different varieties of ammo to have junked the rifle, and bought a Weatherby. (I'm stubborn). 3" at 100yds. is an "awesome day". I have one thing left to try (install back in original stock) and see if somewhere along the way I have created my own nightmare. If that doesn't work--she's a goner!


If you are going install the barrel/action back into the original stock (that has no modifications), why not contact Ruger and send it to them, or consider this?

The stock has a pressure point on the tip of the forend, then the barrel does not touch stock until near the action. Increase the length of the pressure pad with plastic steel or as one guy at the local gun club did, use Bondo. I increased the pressure pad length of a wood stock and it turned the gun into a shooter. If I recall, the overall length ended up at 1 1/8 or 1 1/4 inches. This is not my idea, rather I picked up the trick from a local gunsmith who advised the process manipulates barrel vibration and it is just another tool in the tool box to make some of the Ruger's - shooters.
Posted by: Coyotejunki

Re: Ruger M77 Accuracy Fix - 08/18/10 07:49 AM

I had a Ruger 77 MKII in 223 that would shoot a three shot group with two touching and 1 flyer, making about 1.25" groups. Never could get rid of that flyer. Pulled the barrel and had Pacnor make it a 17 Rem. which is what I really wanted at the time. As a 17 Rem it shot 5 shot groups easily under 3/4" and usually around 1/2".

Later I bought another M77MKII in 243. It shot around 1" pretty consistently. Decided I wanted a 22-250 so I had my favorite gunsmith rechamber that original 223 factory barrel to 22-250. Now that 22-250 shoots around 3/4" and sometimes better. Never had any action work done to the 22-250 just a barrel swap and rechamber.

Rugers can be really nice rifles IMO. I did glass bed both rifles and free float them.