big problem with ruger 77mk2

[Andrew]

I don't know about wear in a rifle that is possibly less then a couple of decades old. I own dozens of rifles older than that which haven't "worn" to the extent that the FP is hitting off center. The extractor could be part of the problem if improperly fitted. I note that in the photo the extractor looks a bit tweaked. Is that the photo angle or is it really arched away from the bolt face? Out of curiosity, do you know if this rifle has ever had a case blown due to an overload? (what we call having been "wrecked"??) Can you get a photo of the rear of the bolt lugs?

 

If it were mine, I'd shoot it with some headspace adjusted handloads (bullet into the rifling) and see if they went off. If not, I'd work through the ignition train. Has the trigger been dinked with?? ~Andrew

[ejg223]

Martin & Andrew all ideas are very welcome, missed the extractor issue until

it was mentioned. I'm not a gun smith.

I don't think the rifle had many rounds through it yet. Lugs look very good

on the rear side. The wear is hardly visible, a little shiny line . I'll try to take a pic.

The extractor if in the closed bolt position would push the cartridge over to the side that the

print is indicating. Easy to push it over if the headspace is a bit off and the cartridge not

wedged into it's cone when the bolt is closed.

 

Left the bolt at work, I'll go at it again when back at work on Tuesday.

I must also collect the rifle and some empties to hold against the bolt face. Like eldon

suggested the indent test would also show offset.

 

One thing that strikes me is I took the bolt apart a year ago and the spring was not too bad then.

Really went down hill fast. Max 150 shot's in that time.

 

 

edi

[baldie]

This gun has been rebarrelled? i,ve never heard of a std ruger 77 in 6.5x55? is the bolt face diameter correct for the cartridge? or has someone shoved a swede on a gun that originally ran a bigger bolt face.

[ejg223]

Baldie , think it's the mk2. Looks just like the other swift and 25-06 I've seen.

No she hasn't been rebarreld. The heads of a 22-250 are a bit lost on the

boltface. I presume it's the correct size but could measure.

edi

[bob tail]

Chris, if you manage to travel the area, give us a shout.

 

If i ever get over their again i will certainly give you a shout ,take care.

[Redfox]

Is the rifle/barrel marked up 6.5x55? or is it really a 260 Rem? although the same as far as loads are concerned they are a different case/round.

Redfox

[ejg223]

Looking at the last targets one could expect a 6.5x55 cartridge in a ruger 30-06

 

I'll have a look, now that would be something!

 

The swede shouldn't be able to fit into a 260 chamber or?

 

I should also compare fired brass with a new one.

 

Red, that rifle has shot quite a few deer so far.

 

edi

[Redfox]

We are beginning to clutch at straws now Edi

Redfox

[baldie]

check the bolt number against the receiver number edi. Ruger dont list a swede in current guns, and i cant remember them making one [thats not to say they havent at all] but its a calibre the americans have hardly ever used, as its european.They have the short actioned .260 rem to go at. I wonder if it has the correct bolt in it?

[ejg223]

The speer manual used a ruger 77 mk2 with 22" for the load tests on the swede.

They mention ruger made em in 93.

 

Anyway I'm sure it will be solved. Headspace is my biggest worry.

 

edi

[ejg223]

Took some photos of the lugs on the pressure side.

They don't seem worn.

 

Then I did the plastercine trick. The strike seems roughly 0.8mm (0.031") out of centre.

All pictures are taken with the claw in the bolt closed position!

 

Reason is the claw not allowing the head into the centre.

 

The contact point is only the nose of the claw.

 

Seems if I reshape the claw, the head would be able to centre easier.

 

edi

[silentsoulsleave308holes]

yes ed that claw is def pushing it over mate, like I said I have come accross this before so get the dremmel out

 

the last one I did I got carried away and ground away too much and had to tig it back up but I am still using that one and its flawless

[eldon]

Looks like you've found the culprit.

Dress carefully and try often. The picture with the red arrows shows the problem nicely.

 

This doesn't entirely explain the damage to the spring but replace it anyway and the new one should have an easier time.

 

Good pics let us know when you've done it.

[Redfox]

It still doesnt answer the qestion as to how its happening. If the cartridge fits the chamber and the bolt fits the action how can it move over by so much? it shouldnt be able to.

As baldie says I would want to check that bolt belongs to rifle and I would look at stamping on the barrel.

Ruger did list a 6.5x55 in 1993, they also list the 260 rem which is the same size head, however the 264 winchester magnum and the 6.5 rem magnum have heads which are 1mm bigger and if the bolt head was originally made for these cases it could then move over and give this effect, the bolt certainly doesnt look worn in any way, interesting, keep us posted Edi.

Redfox

[silentsoulsleave308holes]

with mauser actions,,,,it is possible to chamber the round and it get pushed in straight but the bolt have enough play to get pushed over to one side

 

my ph 7.62 shoots the muts as most of you know but you should see the bolt slop I have,,,,,,,,,I get firing pin strikes all over the place, some centre, most off to one side just as your clay check one so I wouldnt worry too much about the offset pin strike

 

 

picture that your round is chambered and so snug in place, now in the lug area there is a little room to move the bolt side to side and is held in place by the backside of the front lugs and not on the sides of the lugs

 

there is a little play in the chamber if the rounds are factory or full length sized and so the the problem with your bolt may cause the round tilt a wee bit whilst in the chamber and cause in-accuracy

 

if they are fireformed then the round will be held tighter in the chamber and so not shoot as bad but would exaggerate the bolt tipping problem that the claw is causing

[ejg223]

Thanks for the replies lads,

just picked the rifle up this eve. Bolt at work, can't win.

Rifle is a 6.5x55 and No. on bolt is also the same. I remebered the no.

 

If one thinks what could be the case when firing this rifle. I presume

the bolt might be on relative good center position with a round chambered,

the claw will (like silent said) tilt the round in the loose chamber

because the headspace might be on the large side.

Then when firing, the round will want to square up with the bolt face and

chamber. What a wobble! The bullet must also first straighten out. juck

I'll try measure the play in the chamber tomorrow.

 

edi

[ejg223]

Hope not to bore the tits off some of you.

Trying to guess head space, wanted to see at what position a factory cartridge sits

in regards to the bolt.

 

Took a nearly new (two strikes no fire) Lapua mega cartridge, pulled the head

and poured the 47.5gr powder out. Turned the head down so that the extractor claw would not interfere.

 

 

Put a dab of oil on the head and threw it into the chamber, a few taps with the cleaning rod to make sure

the brass is in as far as it would go without force.

Then put a small blob of plastercine onto the center of the bolt and inserted the bolt and closed.

Result looked like this. Headspace looks ok to me, not much play at all. Just not square.

 

 

My guess would be, to put in a new spring, make the claw fit and back in action. or?

 

edi

[Andrew]

Say! I just got back here after a few days away. Interesting developments.The pressure of the extractor isn't a huge worry. There should be a little bit of pressure but perhaps relieving it would help.

 

I also looked at Ruger's web site. They did chamber 6.5x55 in the 77.

 

The thing caught my eye in the photos is what looks like a small crack in the bolt in the photo of the extractor tip pressing on the cartridge. Is that for real?? Or just an illusion? If so it may be worth contacting Ruger and shipping it home for an inspection.~Andrew

[ejg223]

Andrew, I didn't see that one now. But I actually wanted to throw it into the crack check soup

anyway because around the lugs it looked a bit suspect, probably nothing. But it only takes a minute

to check under the fluorescent light.

It would be a nightmare to go through the rigmarole of paperwork to get the bolt to the states.

 

edi

[Andrew]

Yeah, and actually, they'd want the entire barreled action. That tiny crack isn't a problem in itself but it may point to a larger problem with the metallurgy of the bolt. Bolts shouldn't crack, anywhere, at any time. ~Andrew

 

PS: The few cracked bolts that came into my shop were the result of some catastrophic over load. Had a fellow bring in what was left of a 7mm Spanish Mauser he'd managed to fire a 308 in. When I hammered the bolt open the bolt head had cracked off! (It had also blown the floorplate/triggerguard out of the gun, stripping the screws and shattering the stock. No injury to the shooter. God must watch out for fools....)

[ejg223]

Bolt in soup (metl check) showed no signs of cracks up front.

What I had seen where scratches from deburring.

Further back was a little bit of a "crack" where a square piece is

inserted, possibly welded and riveted from behind.

Now where is that spring?

edi

 

[ejg223]

A big thank you to Andrew,

spare Ruger springs arrived from over the pond.

 

edi

[ejg223]

New spring fitted and a few shots fired without a problem.

 

Thanks all for your input.

 

edi