Ruger Old Model 77 Help

[Old Navy]

A friend of mine brought me his Ruger 77 ( with the angled front action screw) yesterday and asked me if I thought it was safe to fire. I asked why. Seems he tipped his horse over about ten years ago. He didn't get hurt but the pencil barrel was seriously bent. One of his hunting buds took it to someone to have the barrel replaced. Don't know who at this point. After bore scoping I could see a copper mine in the barrel and the caliber stamp on the barrel was almost at 12 o'clock. Took care of most of the copper but now I need to determine what kind of headspace he might have. Factory Federal ammo will chamber just fine. Problem one is I don't have headspace gauges. I do have the Lock-N-Load E420 bushing. Can someone with the headspace gauges give me some readings? I have an accurate venire caliper. The loaded ammo measures 2.104" consistently. I know this is a stretch. Just trying to determine if it is in the ball park. We only have one so called gunsmith in my area. I use that term loosely. The bluing on the the barrel looks great so someone had the right tools. Problem #2. I know there is a torque spec and sequence for tightening the action screw on this model. I had two of them back in the 80s. This model has the last inch of the barrel touching the stock. I learned the hard way about that. Sure could use that info. Thanks. Frank

 

[DRK]

95 in-lbs if not bedded. 65 in-lbs if bedded.

I run that on my rebuilt 77.

What is it chambered in?

 

[Old Navy]

95 in-lbs if not bedded. 65 in-lbs if bedded.

I run that on my rebuilt 77.

What is it chambered in?

Sorry I missed that. 7mm Rem Mag. One screw is first to be torqued. As I seem to recall it is the front one. Thanks DRK

 

[DRK]

For the little bit of $ gauges cost, I would get a go gauge and check it. You can always use shim stock behind the go gauge and the bolt face to make a no go.

You can look up SAAMI spec for headspace for the cartridge, many of them are 0-6 thou. Not sure what the belt mags are w/o looking.

 

[Dusty Stevens]

Problem is you cant measure a belted mag headspace gage like youre wanting to. Theyre only about an inch long. Put some tape on the back of a factory case until you feel pressure on it. If its more than about .006 you have an issue. With the caliber marking at 12:00 is the barrel loose?

 

[shortgrass]

If the rifle was mine, and I wanted to check headspace for myself, I do like Dusty suggested. As the rifle belongs to one of your friends, I'd buy or rent gauges. Huge difference between doing for yourself and doing for someone else.

 

[Will Henry]

The gauges will quantify headspace while tape will determine head clearance on brass. Of the two, actual headspace may be seen as the CYA measurement. A headspace measurement of .223 is within Saami specs, but head clearance on brass with a .223 HS measurement, is likely to be on the order of .008" or more. This is a little much. I have measured all sorts of magnum brass which was .214" or less to the front of the belt, so you can see the issue. Tape on a piece of NEW brass will give you a read on head clearance, and this is valid insofar as safety is concerned. WH

 

[Old Navy]

Problem is you cant measure a belted mag headspace gage like youre wanting to. Theyre only about an inch long. Put some tape on the back of a factory case until you feel pressure on it. If its more than about .006 you have an issue. With the caliber marking at 12:00 is the barrel loose?

I just did that last night. .004" longer than a factory round. A friend brought me three of his fired cases this morning. They were .006" longer than a loaded round. The bolt was very snug closing on them. Good to go. The barrel is tight. Evidently it was turned to fit and that is where the caliber marking ended up. I bought a uses XP once years ago that I found was shot out. The guy gave me a very good take off barrel to make it right. After setting the headspace the open sight holes were at 2 o'clock. No big deal. I scoped it and shot it in the Unlimited Any Sight class.

 

[std7mag]

I have 3 of the 77 MKIIs.
Went and downloaded the owners manual from Ruger.
They only say to "tighten the action screws", but don't specify a torque.

With the angled front screw, tighten front then rear.
I did mine to 35inlb with no problems since.

 

[jds holler]

I'll tell ya this -- If ya wanna get it up to 95 inch pounds, you'd better have a very grippy driver; both the one that holds the bit, and the guy who holds the driver. jd

 

[Old Navy]

Problem is you cant measure a belted mag headspace gage like youre wanting to. Theyre only about an inch long. Put some tape on the back of a factory case until you feel pressure on it. If its more than about .006 you have an issue. With the caliber marking at 12:00 is the barrel loose?

How does a gunsmith know what the actual headspace is?

 

[Will Henry]

He can use a headspace gauge and shims, or he can remove the barrel and measure. WH

 

[Dusty Stevens]

How does a gunsmith know what the actual headspace is?

The headspace is off the belt on a belted magnum

 

[jds holler]

The headspace is off the belt on a belted magnum

I get that, but if the shoulder is blown out to where it won't allow the bolt to close, it still seems like a headspace issue. I don't think I like belted cartridges. jd

 

[Old Navy]

The headspace is off the belt on a belted magnum

 

[Dusty Stevens]

I get that, but if the shoulder is blown out to where it won't allow the bolt to close, it still seems like a headspace issue. I don't think I like belted cartridges. jd

Then it was a bad reamer or a bad sizing die since it specs from the belt. If the actual headspace is correct but the shoulder is in the wrong spot it can only be a bad reamer

 

[Will Henry]

The tolerance for the base-to-belt measurement is relatively close but the tolerance for the belt to shoulder measurement is not so critical. When chambering for a belted cartridge, if you want to chamber to a standard (as you should) you chamber to the proper depth on the belt recess. Just as with a rimmed cartridge.
Now, with either a rimmed or belted cartridge, it is accepted practice to establish head clearance with the shoulder after the case is fireformed. This means the head-to-shoulder measurement may not be standard but it works to eliminate excessive clearance. WH