EDIT: SOLVED! (almost) ready for a Mossberg?

[JagerDog]

So you can't get the last shell in the mag at times? That's not a reliability issue IMHO. Sounds like you're out of room. Not all shells are the same loaded length.

Check the size of the shells. Some shells are longer than others. even though they are labeled as 2-3/4 they could be longer.

^^
2 3/4 is the size AFTER it's fired, so like mossy is saying the stack and crimp on different shells isn't always the same overall length.

Slugs and buckshot are often roll crimped. The loaded length is longer than a star crimp.

Then I had beretta 390 20g that couldn't quite fit 2 ea. 3" Winchester star crimped shells in the mag without modifying the plug. these were "stuffed" with very flat crimps.

[langss]

Before I knew Remington was having problems, I bought a Remington 870 Express Synthetic with a 20" barrel and a 3 shot extension at Big 5 on sale. I must have been lucky, because its only screwed up once, and that may have been because of the crimp on a reloaded shell. No I don't have more than a few boxes of factory loads through it, but it blasted several hundred reloads without any problem. No its not as smooth as either of the Wingmasters I own, or any of the other pump shotguns I own, but it works and so far has gone Bang everytime.

[MJB]

https://youtu.be/Gr9_SYMmEmY

[Snagglepuss]

Mossberg 590A is the model you are looking for if you wish to replace an 870 for home defense. The difference between the 590A and 500 is the trigger guard on the 500 is made of polymer and the 590A has a metal one. The 590A is the military contract shotgun by Mossberg from what I understand.

[DChartier]

I'm by no means an expert, but I plan on getting a Mossberg 590A1 for my birthday with the Magpul stock (http://www.mossberg.com/product/590a...-series-51773/). I've spoken to several local gun stores about it and posed your exact question of what's the 870-equivalent Mossberg. They tell me that the Mossberg 500 is the 870 equivalent; they equated the 590 to some other Remington, although it may have been some police version of the 870 such as yours -- sorry, I'm not too familiar with the Remingtons.

From an in-store handling perspective the 500 and 590 didn't seem to be that different to me other than the barrel weight and some features to increase strength and durability (e.g., changing some parts that are plastic on the 500 to metal on the 590A1). I'm sure others with far more experience than I can provide better insights.

I have an 870 but it decides when it will allow you to feed the last round into the OEM extension. I've tried everything, and the last round won't insert into the tube but about every 4th time. I've done all the tips, tricks, suggestions... the thing feeds, cycles, and fires like a bank vault, but I can't have an unreliable gun for home defense.

So I was set to buy another 870 as a replacement, maybe an 870P, but I heard their quality control is a dumpster fire. And now I hear that Mossberg just announced they've banned Dick's as a Mossberg retailer, so I'd like to support a manufacturer that's on our side.

So questions I guess: I've never owned a Mossberg, so is it xyz model over an 870 Police? If so, which model of Mossberg?

[strakill]

I'm by no means an expert, but I plan on getting a Mossberg 590A1 for my birthday with the Magpul stock (http://www.mossberg.com/product/590a...-series-51773/). I've spoken to several local gun stores about it and posed your exact question of what's the 870-equivalent Mossberg. They tell me that the Mossberg 500 is the 870 equivalent; they equated the 590 to some other Remington, although it may have been some police version of the 870 such as yours -- sorry, I'm not too familiar with the Remingtons.

From an in-store handling perspective the 500 and 590 didn't seem to be that different to me other than the barrel weight and some features to increase strength and durability (e.g., changing some parts that are plastic on the 500 to metal on the 590A1). I'm sure others with far more experience than I can provide better insights.

For all intensive purposes the difference between the 500 & 590 is the magazine. The 590 as well as the A1 variant has a removable end cap to secure the barrel to the receiver (much like the 870) whereas the 500 has a captured nut attached to the barrel. OP would have to figure his needs and wants for the shotgun before making a decision.

[Tere_Hanges]

Did you remove the dimples from the mag tube when you installed the extension?

http://www.shotgunworld.com/bbs/viewtopic.php?t=53267

My 870 express has been 100% reliable. I also used to have Mossberg 590 that was 100% reliable. I liked the Mossberg more because I prefer the safety location and the action gets crazy smooth after its been broken in. If I need another basic shotgun I'll get a Mossberg.

[deadshot]

Went and bought a Mossberg 930 and recently a 590A1 and I could't be happier. Both shotguns work perfectly right out of the box and the quality is top notch.

Yep the 930 runs flawlessly.

[Tere_Hanges]

Yep the 930 runs flawlessly.

Yeah, thats what I want.

[crufflers]

Mossberg 590A is the model you are looking for if you wish to replace an 870 for home defense. The difference between the 590A and 500 is the trigger guard on the 500 is made of polymer and the 590A has a metal one. The 590A is the military contract shotgun by Mossberg from what I understand.

For all intensive purposes the difference between the 500 & 590 is the magazine. The 590 as well as the A1 variant has a removable end cap to secure the barrel to the receiver (much like the 870) whereas the 500 has a captured nut attached to the barrel. OP would have to figure his needs and wants for the shotgun before making a decision.

Yeah the 500 is tough enough and lighter IMHO. Mine has a metal trigger guard - maybe it's a really old one. Smooth action, really nice trigger, great safety.

A 930 Home Security is probably the best value in a semi-auto I've seen. I think it took $450 to get the shotgun before tax and fees with a $7 pic rail and I put a FF3 on it. Pretty nice reliable shotgun and holds 9 rounds at the range IIRC... chambered and ghost loaded. Looks like the semi counterpart to my plain old standard stock bead sight 500, except with a shorter barrel.

For the price it is a steal. Sure, I'd love to have a FN SLP.

https://www.budsgunshop.com/catalog/product_info.php/cPath/2084_2108/products_id/21092/MOSSBERG+930+HOME+SECURITY+12+GAUGE

[Dan_Eastvale]

Almost? No.. Always ready for 590A1..

[drinktothat421]

My 870 tactical runs like a dream with the factory mag extention. Try a notric compents mag extenion. I cant stand the feel of the moss 500. Go for a 590.

[drinktothat421]

The 930 is a nice choice too i had a jm pro it was nice just too long.

[drinktothat421]

If your in the FN slp market. Id take a look at the barretta 1301 tactical. Adrius induesties make some bad *** parts for it. Magpul stock Adapter amd magpul ak forend adaptor and if you like red dots a Co witness mount. Or the the M4 at tuners is 1800.

http://jerkingthetrigger.com/2017/10/24/sneak-peek-aridus-industries-zhukov-handguard-adapters-for-the-beretta-1301-and-rmr-crom/

[pratchett]

Thanks for your help everyone! I've just about decided on a 590A1, but I'd like to respond to some of your questions. Seems respectful to do so if you took the time to ask, and at least they'll be recorded for the next guy with the same problem. From Google, it sounds like it's a known issue.

Sounds like you're out of room. Not all shells are the same loaded length.

I ensured that all shells are 2 3/4", by measuring and also by going through multiple different boxes of ammo from different lot numbers and different manufacturers. I'd tend to agree with you, but one time every round slides forward like a hot knife through butter, and the next time it locks up hard on the second to last round. The next 3 times it locks up hard and won't accept the last round, and the next time time it's throwing a hot dog down a hallway. And these are all with the same handful of shells! It's enough to make you question your sanity.

Define "everything" because it sounds like the crappy OEM follower is catching where the tubes connect.

You're right: the OEM follower is a plastic toy, so I replaced it with a GG&G. Both have the same issue.

Check the size of the shells. Some shells are longer than others. even though they are labeled as 2-3/4 they could be longer.

I ensured that all shells are 2 3/4", by measuring and also by going through multiple different boxes of ammo from different lot numbers and different manufacturers. I'd tend to agree with you, but one time every round slides forward like a hot knife through butter, and the next time it locks up hard on the second to last round.

Did you remove the dimples from the mag tube when you installed the extension?

I didn't, because it didn't have any. It came from the factory with an OEM extension tube. So, I bought another Remington OEM tube assembly. Same problem.

Someone online commented the cause might be the tube was installed as one piece instead of as separate pieces. It can create a "gap" or "ledge" by installing as one piece; however, if you install the extension tube nut prior to the extension tube you can eliminate it. Sounded promising, but also didn't work. The final thing I tried, per recommendation, was to debur the edges where the fore-end tube meets the extended magazine tube within the extension tube nut, but again - no joy.