Max length of mag tube?

[The Janitor]

For standard 3" shells, how big of a mag can you use for any given length of barrel without it protruding past the end of the barrel more than an inch?

12" :: 4+1
14" :: 4+1
18.5" :: 6/7+1
20" :: 8+1
22" :: 8/9+1

Does this look correct?

 

[MAX100]

Tube extension lengths & capacity with 3" shells.


12" :: 4+1 - Extend past the muzzle 1/2" for 3" shells.

14" :: 4+1 - Even or shorter than the muzzle

18.5" :: 6/7+1 - (6+1) cap, even with the muzzle. 7+1 needs to extend 1.5" past muzzle.

20" :: 8+1 - 7+1 even with the muzzle. 8+1 extend past the muzzle 2".

22" :: 8/9+1 - (9+1) needs to at least extend past the muzzle 3". 8+1 cap even with the muzzle.


GC

 

[The Janitor]

Now, that isn't entirely universal is it?

This FN is 7+1

This 870 is 6+1


Both are sporting 18" bbls with 3" chambers.

 

[Riss]

Slight differences in follower, mag tube designs. That FN does look sweet.

 

[BADUNAME37]

I don't like it.

They tried too hard to make it look like an AR -- AND I'll bet it's heavy, maybe not though. I once had a SPAS 12. What a heavy & awkward piece of junk that was! I'd take my Moss 500 ANY DAY over that SPAS!

 

[MAX100]

Now, that isn't entirely universal is it?

Remington purposely limits the shell capacity in their shotguns by their tube extension design. An after market tube extension of the same length as the factory tube ext and uses all of the available tube space will get 7+1 capacity with 2.75" shells on a 18" or 18.5" barrel 870.


GC

 

[The Janitor]

Interesting. Why do they do that?


Also, that FN monstrosity is ankward to handle. Very unbalanced and the pistol grip is uncomfortable. The 14" version with a normal stock might be nicer.

 

[MAX100]

On the +2 Remington factory tube ext the indented ring for the mag clamp screw and the narrow end of the tube won't allow the follower to pass. This causes the loss of one round allowing only 6+1 capacity instead of 7+1.


GC

 

[BADUNAME37]

Interesting. Why do they do that?

Also, that FN monstrosity is ankward to handle. Very unbalanced and the pistol grip is uncomfortable.

Maybe they cater to 8'-9" high 525 pound GIANTS to carry the weapon!

 

[exflatlander]

I have a 6" extension on my Benelli Nova that gets me up tp 6 + 1 using 3" (7+1 with 2 3/4"). With the extension the tube is just a touch shorter than the barrel.

 

[Carl N. Brown]

Before I would criticise the FN on looks, I would rather handle one in the field first. Why stock and sight a police shotgun like an AR? Simplified training.

That said, check out the stock style of pump guns actually used to hit targets in skeet or trap and ask yourself why you don't see other styles.

ADDED: We are drifting off thread opening. I have found the number of rounds in a tube magazine often depends on the shells themselves. I have some rolled-crimp-with-overshot-card buckshot rounds that are rated for a 2 3/4 inch chamber that are longer than unfired 2 3/4 inch folded crimp shotshell or SuperX slug shells (fired, all three are within 2 3/4 unfolded). With the buck, my gun's magazine holds 4 but with the others it holds 5.