3" aftermarket barrel on 2 3/4" chamber

[Piedmont Plinker]

I do apologize if this a stupid question. I don't know much about shotgun construction.
Back in December I bought an 870 Wingmaster. I got a pretty good deal on it ($150). It's got a 30" or 28" (think it's the former), fixed choke barrel and is a pretty great field gun, but I wouldn't mind getting a shorter barrel for HD purposes. The gun's action is slicker than Gordon Gekko and the stock fits me very well...better than most tacticool shotguns I've handled.
A popular online retailer has Mossberg-made 18.5" 870 barrels for $85. I'd get one today except for one question. The Wingmaster has a 2 3/4" chamber. The aftermarket barrels are billed as having a 3" chamber. Will they be compatible? I would never fire a 3" shell in the Wingmaster's chamber--I'm just wondering if the barrel will fit and will be safe.
Thanks in advance.

 

[AI&P Tactical]

That means up to 3", so yes you can shoot 2 3/4" shells. The chamber in the barrel determines the longest shell you can shoot and the ability of your receiver determines the longest shell you can eject. If your receiver serial number ends in the Letter "V" you can only eject 2 3/4" shells. If it ends in the letter "M" you can eject up to 3" shells.

However, since you are asking about putting an 18" Barrel on it I assume you intend to use it as a Defense gun. Not a good idea unless you upgrade it with the flex tab conversion. The conversion is on all modern 870's and allow you to clear a jammed shell that gets stuck between the carrier and the breech bolt by racking the weapon back. Older Wingmasters with out the conversion means if you get such a jam you have to break the weapon down to clear. Not a good thing in a fight. A flex tab conversion kit cost $112 and involves a new breech bolt, slide and carrier.

 

[Virginian]

The 3" barrel will work fine on the standard receiver. I would also check function with 3" shells - see if a fired round will eject, and make sure it is a 3" round that opens up toa full 3". Quite a few actually made it out into the wild with the 3" ejector and ejector spring, even though they were 'V' receivers and supposedly had the standard parts. Percentage seems to have gone up as they got close to stopping production on the 2-3/4" guns.

 

[jmr40]

The barrel will work. Don't sweat the flex tab conversion. Yes, you could get a shell jammed, but you could also be struck by a meteor too. I've never had either happen to me.

 

[retDAC]

I had one of those jams while loading for trap. Not a hard mistake to make and a major inconvenience to clear.

Would hate to have it happen in an emergency situation.

 

[Virginian]

Since it is April 1, I am NOT going to say I have never had it happen to me, just that I haven't had it happen yet. Not in 55 years. I have cleared several for others. I am not going to do the conversion. I will take my chances. I understand the odds; it's safer than driving I-10.

 

[AI&P Tactical]

The barrel will work. Don't sweat the flex tab conversion. Yes, you could get a shell jammed, but you could also be struck by a meteor too. I've never had either happen to me.

This is dangerous advise. The people who say this has never happened to them are out there hunting or target shooting with an 870. They are not in a shooting fight for their life which is high stress and you can short stroke or error in loading. Having your life on the line for the first time is serious enough. Putting yourself in that position with the wrong firearm makes it worse. If that happens with a non flex tab 870 in your hands you have a firearm that is useless and place yourself at risk.

So, ignore the $112 upgrade because what? Your life and the life of the family you are trying to protect is not worth $112? Older guns need upgrading if they are going to be used for defense.

It is foolish to use a firearm with an inherent flaw as a defense gun. This is why the problem was corrected in modern 870's and only those with little to no understanding of the platform would give you such advise. You are going to get different types of advise on these forums. They are open and no verification of the persons background and knowledge on the subject is required. Also, no verification of anything they claim is required. So it is up to you to determine which responses are valid

Also, I have had it happened to me twice during loading. I have had to clear dozens on the range certifying Officers. So, yes it can happen to anyone even in normal use. I started in 1978 and was assigned as a back up in the Armory in 1980 and as a Range Officer. Our issue was the Old Wingmasters with 20" barrel bead sight, non flex tab. By 1990 all those were gone so the issue went with them.

 

[oneounceload]

One issue if you try to shoot 3" ammo MAY be ejection if the ejection port isn't long enough.

 

[Virginian]

Ejection port is EXACTLY the same size on 2-3/4" and 3" guns.

 

[oneounceload]

Which is why I said MAY; on some guns they aren't.....

 

[chas08]

I have one of these barrels made by Mossberg. It works fine on all the 870's in the family. Ranging from the Wingmaster with 2 3/4 inch chamber, all the way up to my Supermag. The Wingmaster however will not eject 3in. fired hulls on mine. As I understand it, that is a result of the placement of the ejector on that particular reciever.

 

[Sunray]

An 870 is an 870. Any 870 barrel will fit any 870 receiver. Even when made 20 plus years apart like mine.
Wouldn't shoot 3" ammo either. Not because of the ejection port though. Because it hurts. snicker.

 

[Piedmont Plinker]

Thanks. I'll look in to the flex tab conversion.
Again, as it is a 2 3/4" chambered, at least 30-year-old gun I wouldn't shoot 3" shells out of it.

 

[Virginian]

There is no difference in guns made since 1950. The maximum pressure of a 3" load is no higher than for a 2-3/4" load, just more payload. My main duck guns are 39 and 49 years old. Steel ages well.

 

[howards]

Who wants to use 3 in. shells for SD anyway when 2.75 well get her done?

 

[MCgunner]

Only experience I have is with a Revelation M310 (a Mossy 500 with another name). I traded for it when steel shot got mandated in 1980. I couldn't shoot steel through my trusty double without risk of ruining the gun. The original barrel was a C-Lect choke, so I bought a Mossberg 500 barrel for it, a 3" barrel. The original was a 2 3/4" gun. It fired 3" just fine. I had ejection problems only with Remington 3" back 25 years ago. It was the only ammo that would hang in it. I think it was the ammo, because it also had problems in a friends 500 which CAME with a 3" chamber. No other 3" ammo gave me problems in the gun.

 

[Drail]

What I was taught is that the size of the ejection port is the same on magnum and non magnum receivers. What is different is the location of the ejector. If the ejector starts to kick out the empty too early then it will not clear the port. There are very few things in life worse than a jammed pump shotgun. The Flex tab mod was a VERY GOOD IDEA. I also agree with howards - a 2 3/4 shell is more than enough power for 90% of users.

 

[Virginian]

The ejector spring and the step on the ejector are 1/4" farther back on a Magnum Model 870 to allow the shell to clear the front of the port. That is the ONLY difference in the receivers.