Uneven wear on bolt lugs

[AlaskaMike]

I found a used Ruger M77 stainless with a Leupold 3-9x scope for $750. I'd like to buy it, but I noticed that the face of the extractor is faily smooth, but the face of the lug on the other side of the bolt shows virtually no wear at all. I thought I've read somewhere that this would indicate the bolt isn't aligned the same as the barrel, and the rifle will probably group poorly. Is this the case? If so, is it easy to fix, or is this a rifle I should pass up?

Thanks,
Mike

[Bass Ackward]

Mike,

You could be entirely correct or you could be dead wrong.

There could be a casting error in the action where the locking lug recess isn't straight or entirely filled out. So alignment of the bolt with the threads in the action and thus the bore could be perfect for all we know.

The question is how can you tell?

Even if it is perfect, there is a negative. You only have one lug holding the pressure. And the working lug is going to increase in wear, so what you will have is enlarging head space at a rate higher than normal.

[fatnhappy]

I'd walk away from the deal. We're talking about a $200 scope (new) so for giggles, we'll saying you're paying $550 for a used ruger with a suspected problem. I believe $550 is steep for any used ruger to begin with, but then again I don't shop in Alaska. I will say my sister in laws little brother lives in Sitka, and he picked up a stainless ruger in .30-06 for deer and bear hunting, used, for something like $350 IIRC. The last used ruger I bought was $300.

[uscra112]

^This isn't all that uncommon in standard factory rifles. My 700 Remington was this way when I got it. A gunsmith can lap the lugs to equalize them, but it has to be done with real attention to headspace. Cockeyed lugs do hurt accuracy by making the bolt face cock slightly every time the gun is fired. This then cocks the cartridge in the chamber, and starts the bullet into the leed off-center. It's fixable, but the cost will add at least $100 to the net cost, maybe more. I'd keep looking.

[waksupi]

It's very common for factory rifles to have bolts that haven't been mated in. Takes too much production time. Have also seen some better quality rifles without all that good of contact.
For your purposes, it would most likely be fine. A handloader can deal with any increase in headspace. If you do lap the lugs in, and intend shooting factory ammo, you definitely should have the headspace checked. It will increase by several thousands.

[fourarmed]

It is hard to tell what you mean by "virtually no wear at all." You don't have to have full contact of both lugs in order to prevent torquing of the bolt face, but you do need to have some contact. You might blacken the bearing face of the lug with a felt marker and work the bolt several times with a dummy round in the chamber. If you don't see some bright spots on that lug, forget it. If you do, then you have to decide if the price is reasonable.

[versifier]

It's very common for factory rifles to have bolts that haven't been mated in. Takes too much production time. Have also seen some better quality rifles without all that good of contact.
For your purposes, it would most likely be fine. A handloader can deal with any increase in headspace. If you do lap the lugs in, and intend shooting factory ammo, you definitely should have the headspace checked. It will increase by several thousands.

I couldn't agree more. The more lugs involved, the less likely they're all making good contact. I have in mind specifically older Weatherbys and Rem 788's with multiple lugs. Even on my .33MOA .22-250, only three lugs out of nine make proper contact. On that rifle, it's obviously no big deal.
But, on the other hand, in your case with only two and one of them not even close to contacting, that would raise a red flag for me. The potential for a real problem is there. If it is to see a lot of use, it will need regular inspection by a competent gunsmith to monitor the headspace. It's not as uncommon an occurance as you might think. Lug lapping is time consuming and when done, it is done by hand and by a skilled craftsman to the action before it is barreled. This costs time and money and most manufacturers today bank on the closer tolerances possible (not always achieved :shock: ) with modern CNC machining of parts. If you are handloading and neck sizing for it, you may be less likely to have or notice a problem as the brass will conform to the chamber. You may notice over time that when you do have to FL size to move the shoulders back, you won't need to do it as often or as much. It is still a situation that I would prefer to avoid, and certainly fixable, but if it is cost effective to do so for you is your call.

[AlaskaMike]

It is hard to tell what you mean by "virtually no wear at all."

In this case it meant that the original machining marks were visible on the face of the lug.

I've decided to pass up the rifle. With the exception of the strange wear pattern on the lugs, it looked like my ideal general-purpose hunting rifle: .338 Win Mag, stainless with a Hogue stock, and a good Leupold scope. Not a gorgeous piece of art, but a functional, reliable tool. However, the price would only be okay assuming no problems with it. Factor in the strange wear pattern, and that tipped the scales for me.

Thanks for all the comments! I sure appreciate it.

Mike

[Four Fingers of Death]

My thoughts:

"Danger, Danger Will Robinson!!!"