Mossberg 500 Safety Button Issues

[ithaca49]

Over the past year I built from scratch a Mossberg 500 Persuader. Why? Well..... why not haha. I got a great deal on parts from watching ebay & gunbroker, and everything seems to work great, except for the safety.

I purchased a safety kit which included the plastic slider, detent plate, detent ball, spring, and screw. I also purchased the block that goes inside the receiver. When I assemble it all, the safety allows the gun to fire in the forward position as it should, and not fire in the rearward position.

However, when I fire heavy buckshot loads though it, the safety slides from the forward position to half way back, and then you can't pull the trigger for the following round until you slide the safety forward again.

I have to believe that this is from the recoil since racking the slide doesn't cause the bolt to hit the safety block (it actually used to hit the screw going through the block since it was too long, but I fixed that). I also noticed that when I installed the detent plate, the way the movement of the button felt was different with each orientation that I could install the plate in (some really stiff, some really loose, but you couldn't even feel the detents in the "stiff" installation).

I'm kind of out of ideas here, anybody have any ideas?
Thanks

 

[ugaarguy]

I have no idea. I'll leave this here for a few days, and if none of the Shotguns regulars come up with anything I'll move it over to gunsmithing & repairs.

 

[Steve C]

Do you keep your thumb on the safety when you shoot? This could be why the recoil is activating the safety. Normally the recoil shouldn't move the safety as the little detente should hold it in place and it doesn't have the mass to move from the recoil. The thumb and your hand however will move a bit during recoil and may be sliding the safety on.

The first step will be find out when the safety moves, is it after a shot, after a round is ejected or after it is chambered. Then see if you can figure out the "why" it is moving. That "why" may be the shotgun mechanism, or the shooter.

 

[Uniquedot]

Make sure the safety block is straight and facing correctly before fully tightening the screw. When you you put the detent ball over the detent spring make sure it stays there when you place the detent plate and safety button atop it. When you tighten the screw all these things must stay in alignment in their correct position.

 

[ithaca49]

Thanks for the replies! When I shoot, my thumb is off the safety. I did have a friend shoot it and he was having the same problem. Also, the block and the detent are all aligned like the should when I'm tightening it down.

I think I found the problem. The spring for the detent ball was short enough that only half the ball was exposed when you set it on top of the spring in the hole. I stretched the spring, and now the safety feels just as stiff and positive as on my other 500.

The spring they included in the kits they sell on ebay has more coils and is of a thinner gauge wire than what they show on Midway's parts page. So, I think it all just ended up being the spring.

 

[MattShlock]

The safety on the 500 is a) a yucky resin switch and b) precise. Mossberg won't even sell the parts to non gunsmiths and note the original one-way screw.

They have to be installed carefully and must lock up positively. Your issue is common for guys who install the safety but the ball doesn't get to the detent properly.

 

[M1GarandDeerHunter]

I had problems too. Mine came loose from shooting so I took it apart cleaned it and reassembled. It gave me grief in that it would stay in the forward fire position. Nothing I did would fix it. I took it to my friendly gunsmith down the road, and asked him to put a real steel safety on it, and please chuck the plastic, cheesy one. Works good now. And no more one way retard screws!

 

[ithaca49]

Yeah, I ordered an aluminum safety, new spring, extra ball, and a screw from numrich today. I think that will make it a lot better as well.

 

[Uniquedot]

Be aware that the aluminum one still requires the use of the detent plate whereas the steel button does not. Some of the aftermarket aluminum buttons are designed to use with out the plate. but the detent ball will wear on those.

 

[M1GarandDeerHunter]

Cool just learned something about the 500. The plastic safety is the only real problem I've had so far with these. Otherwise a great beater/utility/ general purpose shotgun. I think ordering a new safety thats metal is the way to fly.

 

[tnxdshooter]

I've got a Vang Comp metal one on mine and I love it. It's 10 times better than the cheap plastic one and seems to operate allot more smooth.

 

[MattShlock]

Absolutely correct -- the resin switch should be replaced day one with a metal setup. It is the only weak link in the great Mossberg 500 chain.

 

[ithaca49]

The detent plate that I ordered from Numrich is aluminum, but it says on their site that it doesn't need a detent plate. I may actually still use it so the bearing pops up farther in the switch to hold it more steady, but hopefully I won't need to.

Side note:

This whole story about the shotgun is kind of funny. I'm in college, but I have parents that don't like guns and since they're still supporting me that means no new guns (won't let me sell what I have to buy new, nothing). I had a very worn out old 500 (single slide rail) and I mentioned that I was going to buy some parts for it and they were ok with that. So, the parts I bought were: a receiver, slide tube, bolt, lifter, interruptor, mag tube, mag spring..... you get the idea. Now, the only thing from the original gun is the trigger and everything else except the receive is new lol

 

[Uniquedot]

but it says on their site that it doesn't need a detent plate.

I tried one of those I got from them without the plate and it wouldn't work. It worked fine with it, but the workmanship on the button was poor so I trashed that one too. Maybe you'll have better luck with it.

 

[tnxdshooter]

I'm telling you Vang Comp metal safety is the way to go and the bees knees.

 

[Uniquedot]

I'm telling you Vang Comp metal safety is the way to go and the bees knees.

I ended up going with an older brownells custom steel button on mine which has been on the gun for a while now. It has a slim profile and appears to be indestructible. The only downside is it's less comfortable to manipulate than is the plastic or aluminum buttons as it is not quite as tall. I despise those with raised thumb pieces as they look silly.