Hi all, I have a 835 ullti mag that hasn't seen much use in awhile and would like to use it for a HD/Tactical project. I've been doing some research on barrels and stocks and would like some verification on what will work. I've been reading that Mossberg made an 18.5" security barrel for them, when I contacted them they said they had been discontinued so thats out.
From what I've been reading a 590A1 barrel should work??? anything else under 20"?
Stocks: some things I've read they have to be 835 specific, others say anything that fits a 500 will work??
Any info you guys can provide would greatly be appreciated.
Thanks.

I own an 835 18.5" security barrel; works great. They are chambered for 3 1/2" and under shells. I'm sorry to hear they were discontinued, but if you really want one, call back in six months. Sometimes they have renewed runs. The part number is: 12946MT



Any older style (pre ~2017) 590A1 barrels utilizing the 5-shot mag tube will work (please note that you CANNOT safely chamber 3 1/2" shells in 590 barrels, but they chamber just fine with 3" or 2 3/4". The stroke will be a little longer is all. You will also gain the ability to shoot slugs, as these are not over-bored like regular 835 barrels):

590A1 5-shot magazine barrel part numbers:
590a1 standard 18.5": 16025P
590a1 choked 18.5": 16017P
590a1 blade front-sight (GRS): 18925P
590a1 3-dot sights: 18915P
590a1 Breacher*: 17837MT
*sometimes used on 500 models, but still retains the ring attachment style of the 590a1 and can be used on 590a1/835s



For stocks, anything that fits a 12ga 500 will fit an 835. For the forearm, you need to check the length. There are two major types of forearm tube lengths: 7-5/8" and 6-1/2" (check Havlin Sales for more info). I believe most 835s (like mine) have a 7-5/8" tube, which will fit most police/tactical furniture. Just make sure before you order.

Source: I have half a dozen Mossbergs, including a 500, 590, 590a1s, 835, etc. I hope this answers your questions, if not, please ask for more details. This is a bad time to be buying barrels on the secondary market, but Mossberg customer service should still have a few 590a1 standard and choked barrels in inventory. I bought several a few months back. If you have the part numbers it helps a lot; sometimes they find things they didn't know were on the shelf. Be sure to double-check on the 5-shot magazine length; the new 6-shot length barrels will have the attachment lug too far forward.

Why not find a current production model that will take current after-market accessories?

People often post here trying to "tac out" some obsolete Sears and Roebuck cheapo. In reality it is cheaper and more practical to buy a modern shotgun and go from there.

While I somewhat see your point, an 835 is by no means a bottom of the barrel offering, and these parts are barely out of production. Certainly gun snobs may turn their noses up at any Mossberg, but I have found 835s to be high enough quality for my needs and infinitely customizable with low-cost options. If the OP is lucky, he may find a barrel for under $100 (there are still more of the old type barrels than new on the market) and some castoff Mossberg 500 furniture for very little. That's probably why he's asking in the first place: to see if it's economically viable. If so, this shotgun is one of the best candidates for what he's trying to do.

And then some of us just like tinkering and customizing our own guns, regardless of whether it's cost-effective. I certainly love Mossberg's for exactly this; have you ever encountered a gun as easy to work on?

But they ARE out of production and that is the bottom line.

That does not mean that the gun was a bad design, it or that it will not work as well as anything else, it just means that it is not supported by the aftermarket. People often ask where to get "tactical" accessories for a discontinued Stevens, High Standards or Sears shotguns that they picked up for $200 at a gun show. These guns were cheap precisely because they are obsolete.

The only parts out of production are the barrel and mag tube. Every other part is still produced and he already owns. If the OP so desires, he can order a new style barrel and six shot tube for well under the cost of a new 590a1. (However, then he would not be able to switch his existing barrel back without also switching back the magazine tube, a consideration for some.)

I will grant you that Stevens et al. are not good candidates for such a conversion.