break-in

[john480]

while i was breaking in my m48 today,when i was getting to the last of the 3 shot then clean .the bolt was getting tight on the 2nd and 3rd round ,only with the spent round in .when i eject the round the bolt was fine ???????

 

[old #7]

What ammo are you shooting.
Is the chamber clean.
Can you be a little more descriptive in the events leading up to the issue?

 

[john480]

im using nosler ammo 180gr acc .i followed there break in 1 shot then clean for a total of 10 rounds .the 3 shot then clean for 15 round .i was using a bore guide .chamber is clean .

 

[old #7]

Try some gun grease like ,Tetra, on the back of the bolt lugs.

 

[john480]

well i shot the last 5 shot then clean to finish up the break in .all is fine i dont know why it was doing it ,but it not doing it now

 

[nickshultz]

I have a model 48 in 300 WSM also and have the same problem using many different types of ammo. It usually only happens once or maybe twice, but when it does it feels frozen. It only seems to happen with a spent round. Any advice? I hate to send my rifle back because I have it ready for the season. However, what happens if I need a follow up shot and it sticks?

 

[Nosler4]

Hmmm, I'll pass on those comments to the gunsmiths and see if we can get an answer. I'll get back to you.

 

[john480]

any answer??

 

[nickshultz]

I'm wondering the same thing.

 

[HunterJim]

I put a bit of grease on the cocking cam as well as the locking lugs. Primary extraction is from the cam, any sign it needs some lube?

jim

 

[Guy Miner]

Often what happens during break in, is that the shooter is cleaning between shots and the chamber gets a little wet with the cleaning solvent. It doesn't take much.

Then, when the next round is fired, the brass can't "grip" the chamber walls and the cartridge case is thrust back hard against the bolt face. This can act like an over-pressure situation. The bolt lift will be sticky, and ejection may be tough. Primers will appear flattened, and even the lettering on the case head may be flattened out a bit.

I understand that the old British ammo makers used greased-up rounds as proof rounds, producing much the same effect as we do, when we inadvertently leave a little moisture in the chamber due to cleaning.

Yes, I did this on one of my own rifles a long time ago. Learned right then and there the value of a clean, dry chamber!

Regards, Guy

 

[Nosler4]

Here's the scoop:

It sounds like a small piece of debris floating around somewhere in the bolt area, or a wet chamber. Recommend the following clean & lube procedure:

-Remove the bolt assembly and clean the locking lug area in the receiver very well.
-Clean the chamber in the barrel very well – make sure it is dry.
-Remove the firing pin/spring assembly from the bolt body.
-Clean the inside of the bolt body, the outside of the firing pin, and the striker cam areas very well.
-Place a small amount of gun grease on the back of each locking lug, on the front of the firing pin shoulder, and on the tip of the striker where it rides on the cam surface.
-Re-assemble the gun and dry-fire it 4 or 5 times to move the grease around on the mating surfaces.
-When cleaning the rifle between firings, make sure the chamber is kept dry. Solvent or oil in the chamber will cause symptoms of high pressure.

This should correct the issue.

 

[nickshultz]

Thanks!!!

 

[john480]

thanks again.i dont want to leave for maine bear hunt with out it.i purchased it just to take it there

 

[Nosler4]

Not a problem, let me know if that doesn't solve the problem.

John480-You going to send us some pictures??? :grin: