Mossberg 500ab

**Dirk777** · 25-04-2016, 19:51

No mention of the 500 ATP8?

**Epsilon** · 25-04-2016, 20:56

Just waiting for an endorsement, then my app for a 500 goes in.

**M43** · 25-04-2016, 21:12

Originally Posted by HvR

From my strong Google-fu 500A got the a single action bar and 500AB is fitted with a dual action bar.

It seems that the change was made purely because Remington's patent on dual action bars expired and that there weren't any inherent problems with 500A.

My 500A has dual action bars, in fact all the Mossberg 500's I have seen have dual action bars. Maybe some very early ones had a single, but I have not seen one like that. The design of the internals is also of such a nature that I cannot see how it could work properly with only one action bar, some stuff actually has slots to fit into the action bars on both sides (There are two flat metal pieces on each side of the receiver that actually need an action bar to fulfil their function...) Maybe the early ones were different.

**HvR** · 25-04-2016, 21:19

Originally Posted by M43

My 500A has dual action bars, in fact all the Mossberg 500's I have seen have dual action bars. Maybe some very early ones had a single, but I have not seen one like that. The design of the internals is also of such a nature that I cannot see how it could work properly with only one action bar, some stuff actually has slots to fit into the action bars on both sides (There are two flat metal pieces on each side of the receiver that actually need an action bar to fulfil their function...) Maybe the early ones were different.

From the 3 forums I saw original 500A manufactured from 1960 to 1971 were single action bars and 500AB model name came in with the first time they started using double action bars, but that then answer his second question:
Mossberg then most likely stopped changing model numbers and just denoted all 12 gauge model 500 as 500A.

**M43** · 25-04-2016, 21:28

Originally Posted by HvR

From the 3 forums I saw original 500A manufactured from 1960 to 1971 were single action bars and 500AB model name came in with the first time they started using double action bars, but that then answer his second question:
Mossberg then most likely stopped changing model numbers and just denoted all 12 gauge model 500 as 500A.

The one action bar activates the cartridge interrupter and the other actuates the cartridge stop, they are on different sides of the receiver, unless current 500's are a totally new design that replaced a previous design, there has always been two action bars. I also read the Wikipedia thing about early Mossberg 500's having only one action bar, but I have learnt that Wikipedia sometimes states unfound rumours as fact...

**HvR** · 25-04-2016, 21:53

Originally Posted by M43

The one action bar activates the cartridge interrupter and the other actuates the cartridge stop, they are on different sides of the receiver, unless current 500's are a totally new design that replaced a previous design, there has always been two action bars. I also read the Wikipedia thing about early Mossberg 500's having only one action bar, but I have learnt that Wikipedia sometimes states unfound rumours as fact...

http://www.shotgunworld.com/bbs/view...?f=58&t=398562

http://www.shootingillustrated.com/a...tion-take-one/

There were 2 more forum threads along similar lines that I've already closed.

**M43** · 26-04-2016, 08:16

I honestly didn't believe that there were ever any 500's made with a single action bar. But after some googling I found a photo of one.

I stand corrected.