View Full Version : Interesting 870 find at the local pawn shop

April 26, 2007, 04:51 PM
Well, I stopped by the local pawn shop tonight and they had just put out an 870 super mag 3.5" express. Here is the "weird" part. It has been subbstantially modified. The barrel was cut down to about 20" (very pro looking job....even beveled it). It has a new front bead on the vent rib and it has a mag extension. It now looks to be a 3.5" HD gun. They only want about $190 for it and it looks basically unused.

Anyone see any potential probs with the mods on a super mag? I thought you couldn't install a mag extension on an express. The gun is about $80 less than the same store wants for a brand new 870 EX HD gun.

What say you?

April 26, 2007, 05:23 PM
You have to remove the dimples on the sides of the mag tube and a extension will work.I used a file to remove the ones on mine.

April 26, 2007, 05:55 PM
Can you remove the extension after the mod, or is it a permanent mod? Only reason I ask is if I ever take it hunting (slug gun) and want to take off the extension because of the issue of plugging it for deer season.

Also, in cutting down the barrel, will that pretty much mean the gun is cyl bore? I have heard that it is unwise to cut down a shotgun barrel because the resulting pattern will look like a donut.

I am not very informed in this area.

April 26, 2007, 06:20 PM
any chance I could see a pic?Also I wounder if it would be legal to just add a wood dowel in the extended mag to make it hunting legal?

April 26, 2007, 06:25 PM
Once the Express "dimples" in the end of the magazine tube are removed, you have problems going back to a standard length magazine.

The dimples retain the Express guns magazine spring assembly and magazine cap.
With the dimples gone, there's nothing to retain the magazine cap and it can vibrate loose.
If the cap comes off, the magazine spring is free to fly out.

The best way of dealing with this is to buy an old style magazine spring retainer and a standard magazine cap.
The retainer is simply a steel "spring-cup" that fits into the end of the magazine tube and is held in by friction.
This retainer will hold the spring in.

For the magazine cap, you can wrap a turn of Teflon pipe tape around the threads of the tube and screw the cap on TIGHT.
You can buy an old style magazine spring retainer and a magazine cap from many parts sources, most any gun show, and many gun shops will have spares laying around.
These parts are not expensive.

When you cut a shotgun barrel off, the choke is gone, and you have a Cylinder Bore: NO choke at all.
This does NOT shoot donut-shaped patterns, that's what happens if you shoot shot out of a RIFLED shotgun barrel.
Until recently, slug and "riot" shotguns that were used with slugs and buckshot were Cylinder Bore.
Many newer guns use a Improved Cylinder bore because it usually give better groups and patterns.

A Cylinder Bore gun will be almost ideal for shooting buckshot, and slugs, so if that's what you plan on shooting, the gun will be perfect.

April 26, 2007, 07:07 PM
Sure sounds like its set up for HD to me. Slugs & buck should shoot great out of it like Dfariswheel said. Now all you need is to pick up a longer barrel for it for hunting birds or whatever, choked dependant upon your hunting needs, and...

I wounder if it would be legal to just add a wood dowel in the extended mag to make it hunting legal?

Thats exactly how you make it hunt legal and not have to mess with extra springs, caps and such. As long as they can't slip that 3rd shell into the mag tube you're ok.

April 27, 2007, 10:21 AM
I am not a huge fan of Super Magnum receievers which shoot the 3.5 shells. This is the only 870 I have read about which ever had feeding/jamming problems. I don't know if I would use it for HD. 3.5 shells were designed for steel shot. Using heavy shot in a 3.5 is overkill.

April 27, 2007, 08:20 PM
Also I wounder if it would be legal to just add a wood dowel in the extended mag to make it hunting legal?

Thats exactly how mossberg does it. The 500s have a dowel in behind the follower that limits the gun to two in the mag. It can be taken out for playing around and put back in for serious shooting to keep it legal.

April 27, 2007, 08:39 PM

Deaf Smith
April 28, 2007, 08:51 PM
3 1/2 magnum buckshot. Boy what fun that is going to be. Mini Claymore there.

April 28, 2007, 09:01 PM
I wouldn't even consider 3.5" buckshot for HD. Fill it up with 2.75's and go, taking heart in the fact that you can use 3 or 3.5's in a pinch.