A little Mossberg 351 KA help

[d4dave1]

Your bolt assembly is same as mine. My sear is square cut with no roundness at all(edges just cleaned to not be sharp).Could be the culprit for not re cocking.

Check to make sure the shell cut off bracket(u shaped piece on the mag tube) is functioning properly or the shells will hang up(if dirty) or sometimes feed too fast( if spring is broke/weak). Try moving the action slowly while watching the face of the bolt while shells are feeding. I would bet the shells aren't getting under the extractor during loading(from the picture with the shell in it). I have had more 22's with this issue than any other over the years. Alignment(as mentioned) is also a good possibility.
Very nice pictures. They show great details!

Scott....

I guess my question would be is it okay to try and square the edges on the sear back again or would that change the tolerances too much?

The cartridge cut off assembly is clean, and damage free as best as I can determine. I lubricated lightly with graphite lube. The mag tubes have been cleaned and lubed, inside tube and outside tube. After reading comments from Mossberg they recommended against removing the mag tube and cut off bracket because alignment is critical so I have not removed them, just cleaned and lubed. That doesn't mean that the previous owner didn't take them apart. I have watched carefully as the bolt closed and opened over the mag feed assembly and they look good to me....keeping in mind that I am not a gunsmith.
After today at this point I am considering replacing the sear/trigger/safety group if parts are available.

 

[Archer Sam]

Safety leaver is correct,outside washer is correct. Mine is firm to move back and forth.
Squaring the sear:I would try to replace it. Removing any material will likely make the surface soft(probably hardened at the factory)and could change things enough to make it unsafe. You can use a sear from a 351C,351K,351KA,352Ka or 352KB(Mossberg part#1300)

 

[d4dave1]

Safety leaver is correct,outside washer is correct. Mine is firm to move back and forth.
Squaring the sear:I would try to replace it. Removing any material will likely make the surface soft(probably hardened at the factory)and could change things enough to make it unsafe. You can use a sear from a 351C,351K,351KA,352Ka or 352KB(Mossberg part#1300)

Thanks Scott. The safety on this rifle feels like it is full of gravel when you try to use it. It sort of grinds and wobbles a bit, hangs up, refuses to move at times and just generally feels like something is not right.

I will dash off an email to Western Gun Parts and see if they have anything available for the sear and perhaps the safety parts as well.

And as a general note to anyone reading this; if you have a need for more pictures of the 351 KA I have a lot of pictures and would happily forward them to anyone who requests them. PM me and I can send them to your email if that works.
Thanks everyone for all your help, much appreciated.
Dave

 

[Archer Sam]

Try rubbing the mating surfaces on your safety with some 660-800 wet dry and oil.. May clean it up and make it smooth. I forgot to mention.The trigger pin(part #1445) looks a hair thicker than mine where it reduces in size. I ask because a 351K uses a different part #. Possible the wrong one is in your gun? Is it easy to engage or stiff?

 

[d4dave1]

Try rubbing the mating surfaces on your safety with some 660-800 wet dry and oil.. May clean it up and make it smooth. I forgot to mention.The trigger pin(part #1425) looks a hair thicker than mine where it reduces in size. I ask because a 351K uses a different part #. Possible the wrong one is in your gun? Is it easy to engage or stiff?

I might go tinker on the safety a bit today. I will try the wet/dry paper.I am hoping that you typo'ed and put #1425 instead of #1445 disconnector pin because I can not find a part #1425??
It is very conceivable that there might be one or more incorrect parts in the rifle. The safety is difficult to engage and feels wonky even when it does work.

Y-day I sent an email to Western Gun Parts to inquire about a few Mossberg 351 KA parts and today they replied that they have all that I asked for and a price list for them. So I have some new parts coming.

 

[Archer Sam]

You sir are correct! I can't read numbers. #1445 is correct. I'm glad they have all the parts you need. It's getting more difficult to find them as time goes on. I did have a guy who liked to tear every gun he got apart(likely ruined a lot of good collector pieces) who was a good source for parts but he has gotten out of the game. Numerich is a good source,you just have to make the order worth while. Last order i did I order with a friend of mine who wasn't too far from me to split the shipping costs.

 

[d4dave1]

Update:

I received my parts from Western Gun Parts in just a couple of days right to my mail box. I replaced the #1444 Safety lever, #1443 disconnector bracket, #1209 Safety pin, #1210 retaining ring, #1300 sear, #1320 disconnector, #R479 disconnector and sear spring.

Assembled them all carefully and lubricated the parts. With much anticipation went behind the shop to test fire the rifle.....and had the exact same problem. !#$%^&*
Back inside and disassemble, then VERY carefully re-assemble step by step. Back out side to try it again. Same thing. !#$%^&*

On the bench, carefully working the action and releasing the trigger watching what is happening. If you look at the attached picture you will understand the following.

The bolt comes back and "loads" up the action, the sear is dropped down against the top portion and the safety is enabled as the pin holding it in place is moved to the rear. After the action is "fired" and the bolt moves forward the sear should drop back down behind the crown (for lack of a better word) and in my action that is not happening. When it does not drop down the safety cannot be engaged and the trigger will not function for the next round. After a number of dry fires and basically going insane trying to figure out why the sear will not re-engage because it is properly assembled and lubricated I tried one more thing.

If I physically move the trigger forward after the dry fire round the sear re-engages and the safety functions as it should. I tapped the pin holding the trigger in place to better center it and lubricated it carefully. Better but still hanging up. After checking the trigger spring for proper assembly my thinking is a weak trigger spring.

I see if I can order a trigger spring #R306 from WGP and try it. I hope all these pictures and information helps someone some day.

 

[olivedrab]

Op, best of luck! Heres hoping the trigger spring does the trick!

 

[Archer Sam]

Is your trigger rubbing the wood anywhere?(may be hindering movement)Possibly binding the movement. Is the trigger spring under the mag tube but over the cross pin?

 

[d4dave1]

“For the want of a nail the shoe was lost,
For the want of a shoe the horse was lost,
For the want of a horse the rider was lost,
For the want of a rider the battle was lost,
For the want of a battle the kingdom was lost,
And all for the want of a nail.”

All of the issues and problems I faced with this rifle and the cause..........

The trigger spring was on TOP of the mag tube instead of under it where it belongs. The small amount of pressure difference on the trigger was enough to cause the sear to not return far enough to allow it to drop back into place properly.

Between the help I received on here and NinjaMidget's helpful videos on YouTube I FINALLY put all the clues together to solve the puzzle. The rifle ran through an entire mag 15 rounds non-stop just like a good Mossberg should.

Thank you everyone who gave me advice and patience. If anyone needs any pictures or follow up help with their Mossberg semi please feel free to buzz me and I will help in any way that I am able. A special thanks to Scott.
Dave.

 

[Archer Sam]

Glad you got her figured out and working the way she should be. We're all here to help each other. I've been in your spot many times and had people here help me figure it out to.
Scott...