NO.4 mk1/3 primer problems |
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Wileycoyote
Newbie Joined: March 02 2020 Location: U.S.A Status: Offline Points: 8 |
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Posted: March 02 2020 at 5:00pm |
I have recently acquired a gorgeous No4 mk1/3 but after a quick range trip 4 primers were punctured one was a light strike that fired upon recocking it buggared the primer after the second strike but the other 5 looked good a might shallow there was a bit of gas leakage from the bolt head and not knowing what to replace first I need some help my research leans towards a light primer strike and a firing pin/spring replacement what do yall think
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Goosic
Senior Member Joined: September 12 2017 Location: Phoenix Arizona Status: Offline Points: 8792 |
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Welcome from Phoenix Arizona.
1. Weak main spring. 2. Misshapen firing pin nose. 3. Debris in the chamber causing a higher then normal pressure upon firing. Unscrew the bolt head from the bolt and examine the firing pin tip. Make sure there is no build up of dirt and grease inside the bolt assembly as well.
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Honkytonk
Senior Member Joined: December 30 2017 Location: Brandon Mb Status: Offline Points: 4770 |
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Welcome from Brandon, Manitoba, Canada! I'm out of breath from reading your post!
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hoadie
Moderator Group Joined: March 16 2006 Location: Niagara/Canada Status: Offline Points: 9003 |
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Well, soon as I seen the pic of your ammo, it brought back memories.(Not good ones, either!)
I have posted here - a number of times - about a similar problem with that same ammo! Everyone had the opinion that I had / have a weak spring too..but that wasn't the case. My 1916 hit the primer & nothing happened. I took a 2nd shot at the deer (that was now running) & it worked ok. A close examination of the suspect cartridge revealed a very faint scratch on the primer.(Pin was fine as well). I re-chambered that same cartridge. Another opportunity presented itself, & the same thing happened with that same cartridge! . I gave the entire supply of that stuff away. I've never had that problem since. I will not use S & B ammo (BTW- the brass isn't very good for re-loading). |
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Loose wimmen tightened here
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Wileycoyote
Newbie Joined: March 02 2020 Location: U.S.A Status: Offline Points: 8 |
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Thanks for the responses! And after rattling my brain all day yesterday,yes my punctuation suffered. I just ordered the bolt disassembly tool and a new spring after a good cleaning. I dumped out flakes of primer from under the bolt head. I am just hoping it's not a headspace issue no bulging or separation occured.
Primers did not come back either they maintained their original position. Thanks again I've been worried sick about having to dive into a headspace headache. |
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Shamu
Admin Group Logo Designer / Donating Member Joined: April 25 2007 Location: MD, USA. Status: Offline Points: 17603 |
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I'm actually suspecting the striker itself! They're supposed to run forward under spring tension till the "stop Collar" on the striker strikes the Rear face of the bolt head, preventing further forward travel. The pin tip should protrude between 0.040~0.050" from the closed locked bolt face. My guess is this is not happening & the striker's forward moment is stopped by the primer itself, resulting in varying striker hits. The cure with my No5 was to replace the bolt head & striker with a pair the fitted each other. |
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Don't shoot till you see the whites of their thighs. (Unofficial motto of the Royal Air Force)
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britrifles
Senior Member Joined: February 03 2018 Location: Atlanta, GA Status: Online Points: 6539 |
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I agree with Sham, I suspect the striker protrusion is out of spec. You can get a fair measurement of the protrusion using the depth measuring end of a caliper. Screw the bolt head until it aligns with the bolt body rib and then measure how far it protrudes from the face of the bolt. If it is > 0.05 inches, it can be stoned to reduce the protrusion (make sure you retain the rounded profile). It's possible the back of the bolt head was ground down to increase the protrusion at some time, so the alternative is to fit a new bolt head (but check headspace if you do this). Or, as Sham suggested, look for a new striker that is a closer fit to your bolt head.
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Wileycoyote
Newbie Joined: March 02 2020 Location: U.S.A Status: Offline Points: 8 |
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The bolt head doesn't seem to have been ground but the firing pin is roughly protruding. .045 but it looks like the firing pin has been messed with in the past like it has been sanded at some point. I have ordered a new firing pin and spring for it to start there. It is also pretty grimy in the bolt body. The previous owner must have not been so kind.but I'm hoping some TLC helps it. Also the barrel is in amazing shape and has so much life left so I want to get her running.
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Wileycoyote
Newbie Joined: March 02 2020 Location: U.S.A Status: Offline Points: 8 |
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Update firing pin and spring were replaced and no more issues! The S&B ammo was fine too tried some ppu as well all flawless. I fired 30 rounds and had no light strikes no primer deformation and the brass all looked uniformed.
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Zed
Special Member Donating Member Joined: May 01 2012 Location: France Status: Offline Points: 5585 |
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That's great news! Enjoy your rifle.
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It's nice to be important, but it's more important to be nice!
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Shamu
Admin Group Logo Designer / Donating Member Joined: April 25 2007 Location: MD, USA. Status: Offline Points: 17603 |
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Excellent!
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Don't shoot till you see the whites of their thighs. (Unofficial motto of the Royal Air Force)
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Whitjr
Senior Member Joined: September 09 2018 Location: Piedmont, NC Status: Offline Points: 426 |
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welcome to the forum!
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Tonsper
Senior Member Joined: January 04 2019 Location: Northern BC Status: Offline Points: 110 |
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That is one monster of a long sentence. Can you say it on one breath?
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Waiting for first light. Shook hands with the devil.
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