Spent the day working on my new 98 project.

It had, well still sort of has a sticky bolt lift. So, I made a lug lapping tool on the lathe out of the old barrel it used to wear. Never lapped lugs before so I thought I would give it a shot. Now there is contact on just over 50% of each lug. Not great, but it is better and at least its smooth.

Near the end of the day I started to fit the bolt handle to the rear receiver bridge so it would cam open a little smoother.

Now here's the thing:
I checked a Peruvian I had on the wall to see how smooth the lift is, as well as to motivate me, and the bolt handle does not even touch the rear bridge as it cams back.

So my question is, was this bolt handle welded a bit too far forward and does it need to not touch the bridge in order for the action to open smoothly?

-Spencer

Spencer,
this may SEEM dumb...

put a trigger in the action, cycle the bolt, and then LIFT the bolt with the trigger still unfired...

bet its easier

now, do the same, with an empty gun of course, and let the trigger down....

open.. should be hard...


On the rear bridge or an the topforward corner of the bolt handle, it rough/rubbing... a little dykem will help

jeffe

Yes, this is exactly what is happening.

Easier to lift when cocked.

Now, the rubbing is only oon the angled camming part of the rear bridge, not the flat beginning area parallel to the bolt.

So, should the bolt not touch?

-Spencer

Spencer,

Just a thought...have you tried stripping the bolt and cleaning/lubing the cocking piece/firing pin/spring assembly and the inside of the bolt? It doesn’t take much gunk in there to make cocking really heavy no matter how smooth the cams and lugs are.

The cocking cam is soft. It was annealed when the bolt handle was welded on. Harden the cam and bolt lift will be much easier. This has been covered many times in the past. Regards, Bill.

The bolt handle IS supposed to contact the angled part of the rear bridge. That is what starts the bolt (and cartridge case) rearward.

I figured the bolt hitting the rear bridge was the main form of camming the bolt open, but I wasn't sure.

Bill-
This sounds like a very possible culprit. The more I think about it, the more I can visualize galling marks on the bolt cam.

I completely disassembled every possible part, and I put a lapping paste of some moly/graphite grease and a bit of 600 abrasive on every possible rubbing surface and worked the hell out of the bolt backand forth and up and down trying to get things to slicken up.

Next time I go into work will be Tuesday to harden the cam area, so we will see then.

-Spencer

Spencer, I've got a Mauser that did the exact same thing you descibe. After searching though the archieves I found post by Jack Belk that mirrored what Bill Leeper said. He suggested useing a copper based anti-sieze compond on the cocking cam (found at most auto part stores). It works great and has fixed the problem on mine. A $2.50 fix that works!

Terry

Progress!

Thanks to Bill for the idea of hardening the camming surfaces.
So, today I hardened the bolt camming surface as well as the striker. I would say about a 75-80% improvement.
It is still not perfect.
At the beginning of the lift it is pretty stiff and then nice and smooth at the end.

I am thinking maybe it is the bolt shroud and something is rubbing in there. I have a commercial shroud laying around somewhere that I will try tomorrow.

-Spencer

How did you harden it?

Terry

Well, pretty simple really.

I have an old old jar of a white crystalline compound which I think is like calcium carbonate, by Herters. I applied heat from my acetelyne torch with the tip of the feather touching the bolt (NOT the cone, I don't want to weld now ) and then when it gets medium hot, I put it in the Herters stuff.
I then apply more heat and the compund sort of glazes over and forms a sort of burnt sugar coating. After the area turns a fairly bright red, it is quenched in water. This blows off all the crystalline matter.

Repeat for the camming surface of the striker.

You do not have to use this compound, but I have found that it does one helluva good job of case hardening and making the surfaces nice and hard.

What the compound does is it adds carbon to the surface of the material therefore making it harder than just heating and quenching.

-Spencer

Sometimes, if the cocking piece is a sloppy fit in the bolt shroud, this can cause some binding. Another possibilty is the groove in the tang. Regards, Bill.

More and more I think it might be the shroud.

You are correct in the assumption that there is a sloppy fit in the shroud, about a 1/16" travel before it contacts the cam surface of the bolt. The commercial shroud tomorrow might shed some light on the situation.

Thanks again Bill.

-Spencer

Well, less success than I thought with switching shrouds.

I tried about 3 or so and not much difference.

There is a bright side though:
While rummaging through junk outside in the shed, I found a commercial, Santa Barbara looks like, hinged bottom metal! Score!

I was going to experiment with making a spring loaded lever, identical in appearance to the Oberndorf style, only with an improved mechanism. Now I won't have to I guess!

-Spencer

Ooh. Ooh. Quick question.

The follower from the military magazine is about 1/4" too short for the hinged box.

The internal dimensions are roughly the same, with the hinged box being slightly longer.

Where would I find a longer follower, if such a thing exists?
I'm sure I've had this problem in the past but can't remember how I solved it.

-Spencer