Home Forums Hunting & Shooting Hunting Rifles Heavy bolt lift on M77MkII

I have a stainless 30.06 M77MkII that seems to have a rather heavy bolt lift. I noticed this particularly when I acquired another M77MkII recently with a very light bolt lift and excellent trigger. I don't know if those two things are related but I love the new rifles' qualities in these areas.

My question is this. What causes a heavy bolt lift? Is it something easily corrected (by the factory)? I know the trigger can be fixed but I am amazed at how two rifles that I bought new are so different.

Am I the only one who has experienced this problem?

As a SWAG, I suggest you ensure the front bolt lugs are well lubed and try again. Otherwise, I'm at a lose and must concede to someone with more knowledge.

How heavy? If you didn't notice it until you got another rifle with a lighter bolt lift, it might not be that big a deal. Rifles, like any other mechanical product, are made to certain tolerances. One rifle with maximum tolerances might have a lighter bolt lift that one with minimum tolerances, with both being well within acceptable tolerances.

Another question is when the bolt lift seems heavy. Is it all the time, only when there is a cartridge in the chamber, or only after you've fire a round? The first would point to manufacturing tolerances, the second to possibly tight headspace, and the third to excessive pressure.

Finally, if the rifle is new, give it a chance to smooth up. The simple expedient of dry cycling the bolt several hundred times could do wonders. Just don't do it while you and your wife are watching TV together; you might not like the new use she finds to put your new rifle to.

I have a new Ruger M77MKII that I've only managed to put a couple of hundred rounds through. It started out a little on the stiff side with some noticable roughness, but it's already starting to smooth out. Another one that I've had for several years has smoothed up almost to the point where it's comparable to my pre-64 Model 70.

I had a similar problem with a .243 heavy barrel target, had a brass shaving/strand in the bolt face, just enough to make closing/opening the bolt very difficult, after I found the strand of brass was OK.

Another thought, the middle screw that hold the action to the stock (there are three, front middle and back). The center screw should be tight but not heavy torque, that can cause the action to bind.

Better make sure those lugs are galling--it makes you cry when it happens.

utah
Pretty sure you mean "not" galling?
art

Flashman,

I presume you mean when working the bolt, and not after shooting. This bolt motion is for primary extraction, and since this rifle is stainless steel I would check the lugs and cocking cam for proper lubrication.

I don't have one of these actions handy to look at, but I would like to hear what results you have with yours.

jim

Let me explain. The M77MKII cocks when lifting the bolt handle after the firing pin has been released (or gun shot). Thus the bolt lift is the re-cocking of the rifle. I believe the old Mauser design were cocked on closing the bolt. This particular rifle has been dry fired a lot over the years and has been used a number of times hunting. Bolt lift is not a problem for those shooting from the bench or who lower their rifle to work the bolt. However, when working the bolt from the shooting position immediately after shooting it is sometimes difficult to do if I don't grab it firmly and agressively work the bolt. My M70 and Savage Scout have much lighter bolt lifts. I thought the problem was inherent in the Ruger design until I received my new .270 M77MkII that seemed like a custom rifle right out of the box with a light bolt lift and excellent trigger. It is stainless, and yes, I lubed the lugs a long time ago. I guess what I am asking is there an easy fix or at least something I can understand so if I send it back to Ruger to fix I can at least point to a potential cause for the problem.

I had a 77MKII that had a terribly rough bolt lift/operation. I traced the problem to two things. 1) the right locking lug had a burr that rubbed the underside of the extractor 2) the band that holds the extractor in place and it's corresponding groove in the bolt were both very rough; it was like rubbing two pieces of sandpaper together. I filed off the burr and put lapping compound under the band and worked the bolt a gazillion times. Cleaned up all the lapping compound, and it worked much smoother. Shouldn't have had to do all that, but it worked pretty well. Still not as smooth as my M70...

Anyway, to check for similar issues, take the bolt out and move the extractor by hand. If it feels rough or drags, you'll know what at least part of the problem is!

Good luck!

Stainless is a little sticky to begin with and doesn't glide like good ole chrommoly. The suggestions so far are good.

I would check the cocking cam on the bolt body and the cocking piece on the bolt sleeve for roughness, burrs, and proper lube. After slicking up(don't change angles or remove metal) I would use a good moly based grease on these surfaces. When checking the cocking cam clean out the inside of the bolt really well, checking for debris or roughness inside the bolt body. Clean/lube the mainspring too. The extractor sleeve is another good place to look for roughness. Plateau Hunter

Thanks for the suggestions. I sighted it in today with a new scope.