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Hi all,
I have a Winchester Model 70 ~ 1982 in 300 Win Mag. The spent cartridge gets harder and harder to eject finally getting stuck. It seems to happen on demand using 180 grain ammo (various brands) after 3 shots and with 150 grain after 20 or so rounds.
Any thoughts?
I guess the first thing to check - is the chamber for roughness . Just a question but after the rifle cooled down will the case be easily removed again for a few rounds or does it need cleaning before smoothly removing the case .
What part of ejection is becoming more difficult? Meaning how far is the spent case out of the chamber before the issue presents?
With the post 64 70's that I have had, disassembling the bolt and thorough cleaning / inspection/ lubrication has fixed many of the "wrecked" guns I have had in my possession.
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Primary extraction = Happens while lifting the bolt handle
Secondary extraction = Happens while pulling the bolt handle to the rear.
Ejection = Tossing the case from the rifle, after the first two have happened.
Sounds like you are having a primary extraction problem.
Check both the cam at the bolt handle and the cam that pulls back the firing pin. And cleaning, lubing, etc. as mentioned.
Bruce
It happens when pulling the bolt back. In fact the spent round was so hard to get out i had to use a wood mallet to pull the bolt back.
Lifting the bolt is ok.
Pulling it back is the problem, when able to pull it back it ejects from the chamber fine.
Cool barrel makes no difference.
A local gunsmith polished the chamber
Polished prior to or after the problem began? Are you experimenting with this as a new to you load in this rifle?Quote:
Originally Posted by Monty
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Has it done this as long as you've had it, or did it just start?
Loosen the center and rear trigger guard screws a bit and try it. Keep the front screw tight. The wood may have compressed and a screw is rubbing against the bolt.
While waiting to go shooting, check the end of the two rear screws to see if one is scraped, scarred, or polished instead of blue.
Bruce
Polished by gunsmith once.
He said it was the barrel
Yes, i have had it a while but have fired less than 300 rounds through it. I started shooting it recently.
At the very first it felt gritty as more rounds were fired though it, cleaned it thoroughly, then sat for a while. It seemed to improve but would do the same thing.
A loads are commercial ammo.
What is strange is that it will occur after 3 rounds of 180 grains like clock work. 150 grains after 20 or so rounds.
Thanks all
dont think it was polished correctly it NOT the barrel
take a 22cal bore brass brush put some of the BLUE scotch pad and a drill with some soda it will hone it
ONLY use the BLUE not green or red
Soda as in baking soda?
Blue dishwashing pad?
Thanks
Do you have a pic of the fired brass?
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Yes, I may, let me see
What may help you is to completely colour the outside of your brass with a sharpie prior to firing. My guess after your elaboration is that the greater recoil energy expended by the heavier bullet load is making the obturation of the brass engage a section of the chamber differently and more quickly than the lighter load. The sharpie should rub off more completely in that area. I wonder if the chamber is now slightly out of round after polishing? that would at least partially explain why it's becoming worse after multiple shots - unequal pressure on the case from a non-concentric chamber warming unequally around it.
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Attachment 289967
1st try
That is a good idea. The Gunsmith said something about a hotter load and brass catching was not uncommon in 300 win mag because of rimmed or rimless (may have that wrong) in the model 70 for that era (I think).
Measure a fired case at the shoulder, in the middle and then at the base in front of the belt. Do the same with a new or sized case. the polishing may have opened the front more than the back removing enough body taper to make extraction hard. There isnt a lot of body taper in a 300 win mag. A egg shaped chamber would also show in being stiff bolt lift.
The reason for the difference between the 180 and 150 weight bullets is probably not the actual pressure as both are loaded to basically the same pressure, but the pressure curve being longer for the 180 forming the brass in tighter.
Will a fired case that was hard to extract ( when removing ) easily chamber without being resized ?