PDA

View Full Version : Moss 590 Comparison: 14" vs 18.5" vs 20" Models



powell556
03-02-2019, 12:15 PM
I own three Mossberg 590s, one in each size of 14", 18.5" and 20". The 14" holds 5 in the mag tube. The 18.5" also holds only 5 in the mag tube (because the mag tube is not flush with the barrel). The 20" holds 8 in the mag tube.

The required minimum length of a shotgun is 18" in the USA. Anything shorter and it becomes a "short barrel shotgun" that requires special paperwork and a $200 tax stamp.

I started out owning the 20" because I didn't want to do NFA paperwork and the 8-round capacity is 3 more than 5 of the 18.5" version for only adding 1.5" of length. A more fair comparison is that the 18.5" could hold 6 in the tube if I added a +1 extension, so the 20" holds 2 more rounds.

I figured 1.5" of length is almost nothing and worth being able to hold 2 more rounds on board. I later bought an 18.5" because of "balance" concerns with the 20" which is really long and heavy. I thought the 18.5" would handle better, and it does a little bit. But now that I realize my pump guns are relegated to home defense only, I don't know if balance actually matters. The duration of time I'd be holding the gun in my hands is minutes at most. I don't plan to slice the pie and clear my home, but even if I did, I'm not sure if 1.5" would make that much of a difference.

The 14" version that I put together last really shines. It seems like the sweet spot. The only "downside" if it can be considered one is the spread is a bit wider, as to be expected with with a shorter barrel shotgun. The 14" seems like the really sweet spot and I'm considering converting one of my other two shotguns down into 14" after getting ATF approval on a tax stamp.

I'm not sure which non-NFA full size I want to keep. Either the 20" or 18.5", I can see it going either way. I am leaning towards the 18.5" and buying a +1 to bring the mag tube up to 6. According to Mossberg's site, it appears all of their current gen 18.5" 590s are coming with a 6-round mag tube. So I'll compare the cost of a +1 to just replacing to a new factory 6 round tube (Which would be more structurally secure I imagine).

I had considered keeping the 20" as a dedicated "car killer" with 8 slugs in the tube. As a civilian, the need for that in the real world is almost zero but it could also see use as a bear/animal control tool. A dedicated slug gun. Although I do not live in bear country or even a rural area at all, so also fantasy. Since I don't intend to sell any of the 3 mossbergs I have, because I don't need the money nor the gun safe space, giving them specific roles could be useful.

Another alternative is keeping one of them as a dedicated 50-state legal travel gun. And in that case, I'm not sure if the 18.5" or 20" makes more sense. 2 extra rounds in the 20" for adding another 1.5" of length. Probably worth it, but given it's use as a travel gun it could be used around my car or in a small hotel room, then maybe the 1.5" does matter. And maybe the 2 extra rounds on board doesn't matter.

What I need to do, and plan to do in coming months is shoot the 18.5" and 20" more, side by side and see how they feel. Although as mentioned earlier in this post, maybe that doesn't matter, because in a real world situation, the gun will be in my hand a maximum of minutes, not hours, so balance may not play a role.

What I'd love to do is find a folding stock adapter that works with the Magpul stock (paging Aridus Industries) to convert the pump into a more compact size to store in the trunk of a car. Either on a 14" for in-state use or a 18.5" for interstate traveling, a folding stock on the Magpul would make a nice compact package.

How do the different shotgun lengths of 14", 18.5", 20" and >20" fit into your collection and what is your experiences with them?

RevolverRob
03-02-2019, 01:03 PM
An 8-shot pump may not be 50-state legal. I know a shotgun with a non-original condition magazine tube (i.e., didn't come from the factory as you bought it in that fashion) is not legal everywhere. Example, here in Chicago the law (city ordinance, no state-level preemption) clearly states that magazine tube extensions are not legal on shotguns (grey area is if the whole tube has been swapped). Now, is it going to be enforced? Depends. I don't think you want to be the test case. If I were going to convert one, I'd chop the 18" gun back and leave the 20" gun as is (because of tube extension legality issues in some places).

The other thing to bear in mind is that in a number of states, you cannot travel with a loaded long-gun (or handgun) in the vehicle. My next 12-gauge firearm is going to be a Tac-14 with a folding brace, which after some legal clarifications here in Illinois has now been determined to not be a "long-gun" and thus, can be loaded in the car with me (well "cruiser ready" as we discussed in another thread).

If you believe you're going to need a shotgun for animal (bear) defense - you should simply stop loading buckshot and switch to Brenneke slugs in every gun, regardless of length. I believe this is effectively how GJM operates with most of his shotguns.

HCM
03-02-2019, 02:48 PM
The 14" version that I put together last really shines. It seems like the sweet spot. The only "downside" if it can be considered one is the spread is a bit wider, as to be expected with with a shorter barrel shotgun. The 14" seems like the really sweet spot and I'm considering converting one of my other two shotguns down into 14" after getting ATF approval on a tax stamp.

Spread of the shot is a function of the choke and to a lesser extent ammo selection not barrel length.

A barrel with cylinder bore / no choke will spread more regardless of length.

If you cut down a longer barrel, cutting off the choke in the muzzle end it will spread more but it’s the lack of choke not the length that causes it. A 14” barrel can be fitted with screw in chokes and made to pattern just as tightly as any other barrel.

I’ve been using 14” barrel shotguns at work for 20 plus years. It is a very handy length. With modern smokeless powders there is little advantage to longer shotgun barrels.

UNM1136
03-02-2019, 09:47 PM
I used these guys:

http://aimprotactical.com/aimpro_tactical_mossberg_performance_shop.htm

Forcing cone lengthening/honing, bore polish, magnaporting and screw in chokes, on my original barrel.

Didn't have the barrel fully snugged down when I test fired. Reinstalling the tritium front sight was a challenge due to how thin the barrel was at the muzzle for the new chokes.

I would do it again, but if you use these guys they weren't fast, they didn't answer emails, and they didn't answer the phone.

You can tune and tweak your 14 to your hearts content.

If I had a 14" I wouldn't need another mossy pump. I currently use my 20" M590a1 for everything: teaching, patrol, breaching, hunting. I just inherited my Great Granddad's Browning A5 that is already plugged, so that will become my hunting shotgun.

pat

GJM
03-02-2019, 11:10 PM
After using 14 inch shotguns for ten years, 18 and 21 inch shotguns feel like a musket.

Bigghoss
03-03-2019, 12:36 AM
I've not had the pleasure of using a 14" shotty but going from a 20" to an 18.5" on my mossberg was a slight but noticeable improvement.

Gater
03-03-2019, 07:25 AM
Running a 14 inch barreled shotty was revelatory for me--it really is a sweet spot. I have an 18.5 inch 590A1 (currently with a Vang +1) that I have seriously considered going the SBS route on, but the NFA process is new to me.

OP, your comment on the six round 590 tubes piqued my curiosity, since my recollection was that when Mossberg originally went to 6+1 18.5 inch 590A1s in 2016 (along with a railed forend), they used a flush mag extension (by Choate, I think). After poking around, it appears they are indeed using a 6 round tube now. Unfortunately, I think that will mean that the older barrels like mine aren't compatible with the new mag tubes. On the plus side, if you have a new production gun (or upgrade to the new tube and barrel), I think the six round tube with a flush fit +1 will get you to 7+1 with an 18.5 barrel.

Paul Blackburn
03-03-2019, 08:48 AM
Easy button is to buy a shockwave and put a Ergo adapter and a SBA 3 Brace on it.

powell556
03-07-2019, 10:46 PM
Is there any reason to own the 20" Pump 12 gauge? Or was it a silly purchase and should I either sell it for another 18.5" or replace the barrel and mag tube with 18.5" version and sell the 20" ones? Assuming I decide not to SBS another shotgun.

M2CattleCo
03-09-2019, 09:06 AM
I've played around with a 20" 590A1 a few times and it's a heavy, unwieldy beast.

I MUCH prefer an 18.5". I really like a regular 'ol 18.5" Mossberg 500. Very light and handy, but brutal recoil.

03RN
03-10-2019, 09:42 AM
35991
I like them all.
I used a 20" in the Marines and like the capacity, the bayonet lug, and it just balances right in my hands.

My 18" 590 has a surefire forend on it and is my bump in the night gun with a +1 wilson extension.

My shockwave gets a lot of use hunting, training, driving around, etc.

My 18" 500s sit around the house in various locations.

powell556
03-10-2019, 09:59 PM
35991
I like them all.
I used a 20" in the Marines and like the capacity, the bayonet lug, and it just balances right in my hands.


What do you think of the bayonet on there? Any usefulness in any niche situations?

03RN
03-10-2019, 10:47 PM
What do you think of the bayonet on there? Any usefulness in any niche situations?

Scared some Philippinos once or twice.

Sammy1
03-11-2019, 07:55 PM
I have a 14 inch and 20 inch. The 20 inch has ghost ring sights and is setup very nicely as a fighting shotgun and it's great for competitions. The longer and heavier barrel on the 20 inch does make follow up shots a little smoother. I recently got the Dept. to purchase a 7 shot 590 18.5 and it is a decent setup. I don't think, in my hands, it's as easy to shoot as the 20 inch but I have more time withe the 20 inch gun.

ricky_bobby
03-25-2019, 11:05 AM
Running a 14 inch barreled shotty was revelatory for me--it really is a sweet spot. I have an 18.5 inch 590A1 (currently with a Vang +1) that I have seriously considered going the SBS route on, but the NFA process is new to me.

OP, your comment on the six round 590 tubes piqued my curiosity, since my recollection was that when Mossberg originally went to 6+1 18.5 inch 590A1s in 2016 (along with a railed forend), they used a flush mag extension (by Choate, I think). After poking around, it appears they are indeed using a 6 round tube now. Unfortunately, I think that will mean that the older barrels like mine aren't compatible with the new mag tubes. On the plus side, if you have a new production gun (or upgrade to the new tube and barrel), I think the six round tube with a flush fit +1 will get you to 7+1 with an 18.5 barrel.


This is correct - I bought the "non A1" 590 "Tactical" model #50778 back late last year (the A1 model is #50776, the Marine A1 model is #50777) - for $260 delivered to my FFL - comes with a 6 round tube which is about 2" short of flush with the end of the barrel - I bought a S&J +1 extension which came with their follower and spring, for $55, and now I can easily have 7+1 capacity with 2.75" shells -

Since Mossberg went up to 6+1 with the 18.5" models and I can easily add a round while keeping it as compact as I can without the NFA, the 20" Mossbergs serve absolutely no purpose for me now

People may think that "its only 1.5" but it makes a difference in the shotgun feeling nose heavy and for room clearing etc, the more compact the better -

Highly recommend the newer 590/590A1 18.5" platform as its a step up from the 500 series with their 5-shot tube/barrel screw setup, which can't be expanded in capacity easily unless you change out the barrel and magazine.