View Full Version : How far can a magazine extension surpass the muzzle?

January 31, 2009, 02:11 AM
New question that popped into my mind.

I see these 4 round magazine extensions for shotguns, and if I estimate the best it can, I can say it surpasses the muzzle of the barrel by 2 inches if I installed it alongside m 18" barrel.

Is this safe? Is there a maximum clearance to how far the magazine extension can excede the muzzle before it becomes unsafe, seeing how the hot gases could now touch it.

January 31, 2009, 02:44 AM
Two inches is fine as long as the extension is secured to the barrel. Nothing worse than an extension hanging out there in the breeze.

Lee Lapin
January 31, 2009, 11:34 AM
Technically I suppose you could put on an extension long enough to reach out to the point where pattern expansion beyond bore size would impact it. That would be several feet, more or less. Muzzle blast is not going to hurt it.

But it IS gonna look really funny. A better idea than a rediculously loooooooooooooooooong magazine extension is to learn to load the gun on the run. The drill is usually referred to as 'shoot one/load one.' As world class shotgun instructor Louis Awerbuck says- "No magazine is ever big enough."

But if you want to do it despite the disadvantages of extra weight forward of the support hand, possible degradation of magazine reliability, and snickers from bystanders, be sure you use a really good magazine clamp to secure it to the barrel and give it some support...


Scattergun Bob
January 31, 2009, 05:26 PM
Not to mention that the longer the Mag extends past the muzzle the brighter the "here I am" sign for Murphy and his pack of trouble!::D

Good Luck & Be Safe

In our minds there is never enough ammo for our scatterguns "the zombie effect" yet in reality most scattergun shootings are 3 hit fights, 2 rounds of Buck and the enemy hits the ground.

January 31, 2009, 07:15 PM
dont forget the added weight of 12 gauge ammo, i can totally notice the difference of having 4 extra shells hanging on your barrel... slows ya down a bit...

February 1, 2009, 12:42 PM
You should see Jerry Miculek's mag extension. That thing must hold 15 rounds.

February 1, 2009, 02:54 PM
Not to mention that the longer the Mag extends past the muzzle the brighter the "here I am" sign for Murphy and his pack of trouble!:

learn to load the gun on the run

+1 to those!

Instead of a magazine extension that extends out, I keep 5 rounds on the stock and 15 on a sling. The sling is kinf of an iffy thing. The extra bullets keep the sling down and out of the way during use, but it adds a lot of weight and makes it hard to manuever. I took the sling off and now have it hanging where I can get to it if I have to. But if 5 rounds of 00 BK isn't enough I'm switching to the hi-cap .45.

February 3, 2009, 11:43 PM
Ive heard several people claim that mag extension tubes (sticking inches beyond the barrel) have no ill effects. This may be true. But, I personally prefer to keep the extension at muzzle length or slightly less.

First of all it seems, depending on the make/model of gun, this lessens the need for a barrel/mag tube clamp. Second, keeping the extension tube at or behind the muzzle just looks better IMHO.

If you need more rounds vs those afforded by a "practical" mag tube extension, consider either a receiver mounted or butt stock mounted shell carrier.

February 4, 2009, 05:41 PM
The longer tube extensions that add 5 are typically suggested for use with 26" or 28" barrels. The shorter +1, +2 and +3 extensions work with 14", 18" and 20", in addition to longer barrels. Since mine has 20", the extensions do not pass the front of the barrel, unless I tried to put a +5 extension on it, then it is, [just measured] 6" longer. By comparison, the +5 is 4.25" short of the 28" Full choke bbl on the other gun.

You can YouTube some IPSC action of shotguns w/ their extended tubes.

It becomes a matter of practicality. Suggest getting Ayoobs shotgun book and reading up on it too.

February 4, 2009, 11:35 PM
I have a mossberg 12 ga 20" barrel 1 + 7 and a 6 shell receiver shot saddle. If I need more then that it is time to retreat. Anymore ammo on the gun makes it a tad to heavy to play with and anything beyond the end of the barrel makes it to nose heavy

February 9, 2009, 11:28 PM
In IPSC 3 Gun , I have seen some that were almost 12" beyond the muzzle. I always watch to see when one day the shot/slug blows them downrange:D

February 11, 2009, 04:29 AM
No offense but I don't plan on putting my family's safety at risk betting that I can "load on the run", I'm fighting as dirty as I need to. I'm not a SWAT/Green Beret/Blackwater member nor am I Chuck Norris. I figure having more rounds at the ready is a significant advantage, and I'll take all the help I can get.

And as for giving away your position, we're talking two inches, not two feet. You should always use a barrel clamp.


Residue build up after 50 slugs and 50 00 buckshot. Cleans right up.


February 11, 2009, 08:48 PM
just get that mammoth muzzle brake, or that door breacher to even them up. i mean it cant really get much more mall ninja.

February 11, 2009, 09:11 PM
The rule of thumb for cylinder bore is 1" increase in pattern diameter per
yard. So if the clearance between the barrel and extension is 1/4", at
somewhere around 18" beyond the muzzle things could get interesting.

Evyl Robot
February 11, 2009, 11:32 PM
It seems to me that the possibility of interferance between the mag ext and the barrel is insignificant. The reason we cut the barrel short is so that the gun is more maneuverable in the house, as the overall length is shorter and negotiates corners with far more ease. That being said, the extension extending beyond the muzzle of the barrel kind of defeats the purpose of the short barrel. IMHO - If you have an 18-inch barrel, you need to be looking for a maximum of 7-shot capacity in the magazine, 8-shots for 20-inch, so on and so forth.


February 12, 2009, 06:19 PM
Nice setup, SiNNiK

February 13, 2009, 05:06 PM
Thanks T191032. I like it.