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big problem with ruger 77mk2


ejg223

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My friends factory Ruger in 6.5x55 is becoming a pain in the ...

After adjusting the firing pin she won't fire at all.

Maybe someone here can give us some advice.

 

To the history:

1) It started that the rifle would strike light occasionally (He watched the deer walk away, he he)

I took the bolt apart, it was badly caked up, stretched the spring a bit, put a nice clean radius on

the firing pin and set to protrude about 0.066".

This worked for about one season. (maybe 100 rounds)

At the end the crater in the primer was not very deep and terribly out of center.

 

2) I did a bedding job on his rifle and cleaned his barrel and chamber for a change.

Now she went to punching holes through the primer on factory lapua 156grainers.

Handloads where ok.

I looked at the firing pin, it was a bit rough and bolt was terribly gased up. Polished

the pin and cleaned the bolt.

3) 3 shots later bolt didn't move.

Piece of brass was stuck inside between firing pin and bolt. was about 2.5mm long and flatish.

asked on here about protrusion, learnt it should be 0.055" and shortened the pin.

Now she won't fire at all.

 

I presume the position of the bolt in the closed position is way to far back ? or?

No matter what the rifle was ever fed, she was never really accurate.

 

edi

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It's really hard to tell what is going on without a more exact description of your friends handloads. It's hard to tell with some fellows who have an irregular set of dies or for some reason are setting the shoulder back. I do believe you had the firing pin set too far out. The fact that the Factory ammo is igniting and piercing primers points to this.

 

From my vantage point far across the sea it seems to be a problem with loads. Reduce the firing pin protrusion and have him load some brass with a bullet snugged into the rifling. I am willing to bet it goes off every time. This will result in a case fireformed to his chamber and he should not reduce this formed round too much in sizing or he will work himself into the same problem again.

 

Like I said, without seeing your friends ammo it's hard to judge, but going on what you've described, this is my guess as to the problem. ~Andrew

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It's really hard to tell what is going on without a more exact description of your friends handloads. It's hard to tell with some fellows who have an irregular set of dies or for some reason are setting the shoulder back. I do believe you had the firing pin set too far out. The fact that the Factory ammo is igniting and piercing primers points to this.

 

From my vantage point far across the sea it seems to be a problem with loads. Reduce the firing pin protrusion and have him load some brass with a bullet snugged into the rifling. I am willing to bet it goes off every time. This will result in a case fireformed to his chamber and he should not reduce this formed round too much in sizing or he will work himself into the same problem again.

 

Like I said, without seeing your friends ammo it's hard to judge, but going on what you've described, this is my guess as to the problem. ~Andrew

 

Thanks Andrew,

my friend does not hand load yet, he just had 20 or so made up from another friend.

The problem is now mainly with factory ammo. Lapua at the moment.

I shortened the firing pin to protrude 0.055 which is apparantly correct. Now it only dents the primers ??? no fire

 

Before when the pin protruded 0.066" it put a hole through the primer. I think the recoil was

throwing the cartridge back to the bolt face and the pin punches the hole through the primer while doing so.

 

How much play can a cartridge have when the bolt is closed? Back and forth that is

 

I could check with a dab of plastercine or a bit of soldering wire that gets squeezed to the thickness of the gap between bolt and

cartridge head.

(we used to use the soldering wire trick to measure how close a piston goes to the cylinder head without taking it apart)

 

This rifle was bought second hand so one doesn't know if it had been messed with. I'll have a closer look at the bolt lugs.

 

regards

edi

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too much protrution like the amount you described normally shows as some rounds will fire and some wont and normally not a big enough dent in the primer, yeh I know it sounds strange as you would think greater protution would give greater dent but it would only shorten the throw

 

I have had to deal with this same problem with two guns, one worked perfect after reducing down to 48 thou

 

the other was a right pain and even after correction the protution which was too long to start and making it 51 to 52 thou it still had problems

 

the problem was fixed by examining the spring, which was bent and caused irregular speed of throw meaning some would fire and some wouldnt

 

I had to fit a new spring and sleeve the inside with a piece of tube to prevent the spring bending and binding on the walls when compressesd then the problem was fixed

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I see. I'd look to the lugs as well to see if some well-intentioned person hadn't lapped them out of place. First off, I'd find a 6.5x55 headspace gage set and see what that indicated. In any event, judicious handloading would get the rifle working again, at least. ~Andrew

 

PS: I don't have the chamber specs for the 6.5 handy but a quick look at a few other cartridges of military origin show about .010" from minimum to (absolute) maximum. A sporting rifle would be held to half of that, you'd think.~A

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Andrew & Silent,

now, I'll get the bolt tomorrow and I'll take a pic of the spring on the bolt.

I know it doesn't look great. Jamie your'e not gonna run away are ya :)

 

What I never liked was that the firing pin and inside of bolt was always caked up

very bad even after only a few shots. Not sure if the primers where always puntured

because the cases where thrown away as usual. I'll have a close look at the

lugs also. Good to know, less than 0.01 play.

The problem we have here Andrew is we don't have that many gun gurus around.

Our local smith sold a rifle with a bolt that didn't even close... said it's fine . I wouldn't

bring a rifle to him.

 

Thanks to both of you

 

edi

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Now, got the bolt.

1) why would the inprint be so off centre?

DSCN1264.jpg

 

2) Protrusion, 1.4mm or 0.055" ( Should the tip be more square? with just a small radius??)

The tip seemed a bit burnt from going through primers. might just rework it.

DSCN1267.jpg

 

3)The spring is not very nice, especially up front where it seems to want to hop over.

I think it is rubbing on the outside diameter. not good. A new spring wouldn't go astray.

Where would I get one?

DSCN1268.jpg

DSCN1269.jpg

DSCN1271.jpg

 

If I get the rifle + bolt I'll try guess the head space.

 

edi

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Guest varmartin

That spring is knackered Edi.......

 

Thats your problem...Its week , coil bound and binds on the inside of the bolt.

 

A new spring will sort it along with a bit of carful work on the pin too as its a bit pointy.

 

Try `midway usa` for a new spring ??...link>>>Tubb spring kit

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Andrew & Silent,

now, I'll get the bolt tomorrow and I'll take a pic of the spring on the bolt.

I know it doesn't look great. Jamie your'e not gonna run away are ya :)

 

What I never liked was that the firing pin and inside of bolt was always caked up

very bad even after only a few shots. Not sure if the primers where always puntured

because the cases where thrown away as usual. I'll have a close look at the

lugs also. Good to know, less than 0.01 play.

The problem we have here Andrew is we don't have that many gun gurus around.

Our local smith sold a rifle with a bolt that didn't even close... said it's fine . I wouldn't

bring a rifle to him.

 

Thanks to both of you

 

edi

 

Who's your local gun dealer? ;) he's not in bandon or mallow is he?

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yeh the spring is naff mate, I would perhaps put the pin in a drill or lathe and polish the end more round and this may reduce it to about 50thou which is ok

 

from the picture the spring is binding/rubbing and the face looks ok in terms of its original machining looks true but for some reason the inprint of the case is off centre

 

from the picture also I would ask if it has had a recent new ejector spring/claw??

 

if it has.....lokking at the front on picture of the bolt face .....the highest point of the claw.....the bit sticking out to the centre of the face....maybe the point is pushing the case over to one side as these claws often need to be custom fitted ;):)

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Thanks Martin,

I think it's a special order for midway uk.

anybody got a spring ?

 

Jamie that make sense with the claw, in the closed position

I presume it would push the round just to that side.

But It also means that the brass is quite loose in the chamber

when closed. :)

 

and some rugers work real nice.....

 

edi

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We have an outfit here called Numrich arms. Factory main-springs are $1.50 US each. These are excellent folks to deal with and I believe they ship abroad, but if you can't find one otherwise, let me know and I'll mail one to you. Extractors are about $26US. Firing pins are not available.~Andrew

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Thanks Lads,

 

Martin, just tried midway uk but I think they only want UK customers.

 

Jamie,

Spring inside: 7.82mm or 0.308" outside: 10.65mm or 0.419" isch length around 4.33"

Firing pin where spring sits: 7.50mm or 0.295"

inside of bolt, just where I can measure with vernier is 11.8mm or 0.465"

that would be great if you have one.

 

Andrew, thanks for the offer. Might need to come back on that if we can't get one this side

of the pond. Customs don't mind lawn mower springs do they? :)

 

 

edi

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Enough said :)

I quite like the chap in bandon, he has helped me and I've helped him.

but he is not set up for smithing.

The fella from Mallow, bad news.

 

Have you been to the area?

 

edi

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What silent said makes good sense.

You could try this.

Get an old case with no primer in. Fill the primer hole with plasticene. Position it on the bolt out of the rifle and hold it tight to the extractor claw. Manually strike the plasticene using the firing pin in the bolt. Inspect your plasticene and see if it is offset. If so the claw is too big and dress accordingly.

 

The spring is obviously your main culprit for the light strikes. When I started reloading I never had a strike problem on factory ammo, with the first homeloads using CCI primers I had 6 misfires out of 24 :)

Changed the spring and thought I'd been sent the wrong one as it was about 1'' longer. Obviously it was harder to fit than the older one but not had any problems since. This was on a CZ 527.

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I quite like the chap in bandon, he has helped me and I've helped him.

but he is not set up for smithing.

The fella from Mallow, bad news.

 

Have you been to the area?

 

edi

 

Yes i have , i used to live in donoughmore just a few miles from coachford and i used to visit mervin in bandon quite often . He was always as good as gold but never very technical on the smithing side of things, but thats because he was a green grocer and not a gunsmith , (more bananas than smith and wesson), if you no what i mean. But despite that mervin was great to deal with and happy to help if he could, as for pat in mallow he should stick to selling buggies and pet food , useless and about as much good as a chocolate kettle. Nice to though that mervin has still got the shop going and i hope you get some results with the rifle problem.

 

chris :)

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One thing is for sure I'm learning a few things here.

Eldon, I only had 22-250 and 308 empties at work (as one would)

I just held them on and I'm sure the extractor will push a 6.5 across also.

Good tip with the plasticene.

No problem to reshape the extractor, I do a bit of precision manual grinding

under the microscope, and If I screw up I'll just give it back to my friend. :)

This offset might not happen with a push feed, or?

 

Chris I'm south of cork airport on the coast.

I think mervins health is going slowly, he has his shop closed

mondays and thursdays now, but still sails the scottish coast on his holidays.

He is also the safety officer of our gun club.

small world eh,

 

edi

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Glad to help as I'm sure we all are.

With the right case is the pin indent on the plasticene offset?

 

I've always found this a good site with a lot of ideas and information, collectively we could sort the world :)

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One thing is for sure I'm learning a few things here.

Eldon, I only had 22-250 and 308 empties at work (as one would)

I just held them on and I'm sure the extractor will push a 6.5 across also.

Good tip with the plasticene.

No problem to reshape the extractor, I do a bit of precision manual grinding

under the microscope, and If I screw up I'll just give it back to my friend. :)

This offset might not happen with a push feed, or?

 

Chris I'm south of cork airport on the coast.

I think mervins health is going slowly, he has his shop closed

mondays and thursdays now, but still sails the scottish coast on his holidays.

He is also the safety officer of our gun club.

small world eh,

 

edi

 

Edi its a small world in deed i never expected to be talking to someone from cork, i miss ireland alot and can't wait to go back one day. I'm sorry to here about mervin he's a lovely man with a heart of gold , it's a shame when things take there toll like that , i hope he's not to bad and he's enjoying semi retirement and that he has many years left to go. :)

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Guest varmartin

With a Mauser type bolt and the tolerances in question, I think the case will push the bolt over a bit not the other way round. So it will not affect case alignment. :)

 

Are you sure you want to re-shape the extractor ? I am uncertain if it will improve the problems with misfiring.

 

Has this rifle fired a LOT of rounds ? as the wear in the bolt indicates it has . That may be why the bolt face is not in perfect alignment with the case face ??

 

If it were mine, I would replace the spring first , then re- test firing and extraction ...

 

Just my thoughts Edi....

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