mossberg 472 light primer strikes

[Rno1fan]

Hi folks;

new to your forum and really like what I see.

I am trying to repair a Mossberg 472 (Western Field 47) lever action 30-30. I have watched all the available instructions (that I could find) on YouTube; most are excellent. My problem is a light or no primer strike. Most often the hammer will not even lose on the transfer block. I have replaced the hammer spring tube which seems to be the most common problem. No joy. All parts are free moving- no hang-ups anywhere. I have lots of exploded diagrams for reassembly. Note: I am attempting to fix this gun for a friend who disassembled it and could not figure out how to get it back together. I can understand that; it is not an easy gun to reassemble if you were not paying attention when taking it apart. 

Anyway, I am confident that I have assembled it correctly (well, maybe not...the hammer pusher will only install one way, so it is not upside down ). It acts as though the hammer spring is not strong enough to push the hammer forward. If you hold the trigger in the firing position, it will easily close in on the transfer bar when pushed.

I tried an experiment. I took the old hammer spring tube, tapped the threaded end as far as the tap would go and then drilled the spring end through (5/16" drill in my lathe, so I am confident it is straight) and used the stock attaching bolt to compress the hammer spring a little tighter to see if a stronger spring pressure would cure the issue. All I accomplished was making the hammer harder to cock.

This gun has an action called a 'rebound hammer' and I have checked, by taping the transfer bar, that the hammer makes contact (when it does travel forward) and it mostly makes contact but still not enough to strike the primer with any force.

My friend said it fired consistently before he took it apart. 

By the by for those of you trying to disassemble one for whatever reason, the loading gate must be depressed a good bit before the action will drop out. It will fall past the gate then. The safety must be off and the hammer forward, hammer spring assembly removed (this will remain under pressure from the spring, so be careful. It is aluminum and it will wipe out the end threads if taken apart without maintaining forward pressure on the tube. Likewise, when assembling, it is not easy to line up the tube with the spring pressure so be careful when installing it to keep it straight) Once all of that is done, it will fall out if you hold your tongue right.

The videos on YouTube all blow past assembling the hammer 'pusher' part. One remarks on the hammer spring tube pressure issue, but nothing on assembling the 'pusher' part. I have even tried assembling it upside-down just in case. No joy.

I am at my wits end. Any help would be greatly appreciated.

[Tornado1982]

I’ve had the same issue with mine. Bought it at a show, brought it home and pulled it apart and cleaned it up and when I went to shoot it the hammer was too week to cool off a round. There is the piece that goes in the spring that creates the ball and socket. I added an extra to give more spring pressure but still nothing. Were you able to find anything that works?

[xtriggerman]

If your rebounding hammer has a slightly out of "bend" spring strut, it can cause light hits simply because there is too much rebound travel away from the firing pin. The way to check for this is with the hammer at rest, push it forward with your finger. It should just barely more forward AND be just about ready to touch the protruding firing pin. pulling the trigger should allow the hammer to now move into the firing pin.  If in the first step, the hammer moves more than 1/16th of an inch forward to its at rest trigger safety stop, The hammer strut needs to be bent slightly up in the middle. This will move the hammer closer to the trigger stop and thus, lessen its rebound resistance.  This is a strut tune that any gunsmith knows about and has performed on countless single shot shot guns and the like. Marlins have been know to have rough secondary firing pin spring contact on that firist FP. Its the spring that holds the FP downward with the lever down. Machine lines there give a drag to the FP. As noted above washering up the hammer spring can at times be the answer and most of all, check your head space, a lot of it can sponge the firing pin hit into no fire with a weak hammer drive.