Model 70 Extraction Problems

[Buano]

I picked up a used Model 70 SS with BOSS in .300 Weatherby. It looks to be in great shape. it's VERY difficult to get spent (factory) shells out of the chamber. Unfired shells load and unload easily. I was using factory Weatherby 180 grain cartridges that fed in and out of the chamber without difficulty. Once fired we had to pound on the bolt handle to get the spent shell casing out.

What do I do now?

 

[ICANHITHIMMAN]

It would help to know what action you have?

 

[Buano]

It would help to know what action you have?

It's a Model 70 New Haven Conneticut, SS bolt-action that SEEMS to function perfectly until I try to extract fired cases.

 

[ICANHITHIMMAN]

It's a Model 70 New Haven Conneticut, SS bolt-action that SEEMS to function perfectly until I try to extract fired cases.

Ya that's not what I meant, there are two different Winchester actions. One based of the Mauser with a big external claw extractor, this includes pre 64 model, classic models and the new models. The other actions are called push feed actions and they do not have the external claw extractor, Winchester did this to cut cost.

Which do you have?

 

[Buano]

I have what I believe to be a "classic" withe the large claw extractor. I've attached pictures that should make it clear.

 

[ICANHITHIMMAN]

Yep that's a Classic nice rifles, most likely you have poor extractor tension. But there may be other issues. Short of shipping it off to the doctor, you can do a few checks by your self then if you got it from a shop take it back and say fix it.

Check the chamber for burrs, these will some times show up on your fired brass. You can also use a Q tip to see if anything may be in the chamber making it hang up on you. Make sure the chamber and bolt are clean and there is nothing in the recess on the barrel that the claw fits into.

If you think you need to ship it out call Kevin Cram at montoure county rifles he did my M70 for me.

 

[Buano]

I have checked the extracted cases. The only "marks" are extremely light and right above the base of the cartridge. These marks look like the case was expanded against the sides of the chamber & pulled out HARD, but there are no deep marks, gouges or indentations — only rub marks. It doesn't seem like there is a rough chamber, it acts like I'm WAY over-pressure with factory ammunition. Being WAY over-pressure with factory ammunition is what concerns me.


My thought at this stage is to polish the chamber with rubbing compound, a swab, and a drill on low speed. If that doesn't work it looks like time for professional help.

 

[ICANHITHIMMAN]

I have checked the extracted cases. The only "marks" are extremely light and right above the base of the cartridge. These marks look like the case was expanded against the sides of the chamber & pulled out HARD, but there are no deep marks, gouges or indentations — only rub marks. It doesn't seem like there is a rough chamber, it acts like I'm WAY over-pressure with factory ammunition. Being WAY over-pressure with factory ammunition is what concerns me.


My thought at this stage is to polish the chamber with rubbing compound, a swab, and a drill on low speed. If that doesn't work it looks like time for professional help.

I dont know if I would do that, I would ask a gunsmith

 

[Buano]

I dont know if I would do that, I would ask a gunsmith

Thanks. I was looking for others' thoughts before I did anything.

 

[BPreheim]

Is the bolt hard to lift after firing can you see a shiny spot on the case head. Where the ejector slot is? Are there any shiny rings on the case body

 

[Buano]

Yes, the bolt is hard to lift. The only marks on the case is right a above the base where there is a clear 1/4 inch that shows "rub" marks where it pulled out of the chamber HARD.

I contacted Winchester & they suggested I send the rifle to them for evaluation. That looks like my next step.

I wasn't at all pleased with what the Winchester rep told me over the phone — that this virtually always means there is rust or debris in the chamber. It's a stainless rifle that was likely unfired and we checked the chamber and found it to be smooth, clean, and shiny.

 

[BPreheim]

Where the bolt is hard to lift I would say it is high pressure this could be caused by a chamber or throat out of spec. It could also be caused by interior barrel Finnish or if it has been shot more than you think it could have a section of copper build up that you might not be able to see without a bore scope. The least expensive way to get it fixed will be to send it to Winchester. Have you tried a differant lot of ammo? It could be soft brass. We saw a lot of it when the WSM was first introduced.

 

[Buano]

Where the bolt is hard to lift I would say it is high pressure this could be caused by a chamber or throat out of spec. It could also be caused by interior barrel Finnish or if it has been shot more than you think it could have a section of copper build up that you might not be able to see without a bore scope. The least expensive way to get it fixed will be to send it to Winchester. Have you tried a differant lot of ammo? It could be soft brass. We saw a lot of it when the WSM was first introduced.

Weatherby brass is as consistent as anything ever produced so it's unlikely I'm dealing with soft cases.

I agree there is little chance it's anything but an over-pressure situation. The question is, "Why?".

My thoughts leaned towards a throat out of spec but for some STUPID reason I never suspected a copper buildup. Obviously this used rifle might have been shot a fair amount & cleaned up to where it looked to be unfired. A copper buildup in the barrel is something I should have checked. Thank you for reminding me to check the obvious!

 

[Buano]

I know the problem, now I need the solution:

The rifle has a VERY ROUGH barrel that loads up with copper FAST!!

After chemically stripping all copper from the barrel and Running some JB Bore Brite through it, it worked well for 3 shots with no signs of pressure. By shot #4 the bolt started to stick & by shot 6 I had to stop because I didn't think I would be able to extract shell #7 without tools. I was then WAY over pressure with factory loads.

What say you, oh great men of experience? Do I lap it, have it electro-polished, or...?????
What's my best option?

Eventually I do want to replace the barrel to add a few inches but I didn't plan on doing that any time soon.

Suggestions????