AR15.Com Archives
 Mossberg 500 Bayonet Mount
rcr29  [Team Member]
11/24/2007 12:02:50 AM
I posted this in GD as well, but thought you technical forum guys might like it.

I have already posted pictures in this thread about my latest DIY project of making a bayonet lug shotgun mount for my newly acquired Mossberg 500.

The gun itself was purchased Wednesday for $106 at a local gun shop. The gun's price and finish led me to believe that it will serve well as a vehicle gun, which I was in the market for.

After talking with a friend about making this, we both concurred that it was possible to mount an M7 bayonet on the Mossberg. I had a bayonet, and an extra bayonet lug laying around, so it was worth a shot to see if the idea of mounting a bayonet on the gun was indeed feasible.

I started with a clamp on bayonet lug, which I had purchased durning the ban to go on a Colt HBAR that did not have one. The below picture is exactly what it looked like, prior to any modifications.



When my friend and I decided that we were indeed going to undertake this project, we came up with a plan to modify the 2 piece assembly to grasp the shotgun barrel. In its original configuration, the spherical opening between the two pieces was not large enough to accomodate the barrel of the shotgun.

Each piece was placed in a vise, serperately, and honed out using an pneumatic drill and conical sanding bit. While air power was used, the same result could be achieved with a typical battery powered drill.

Here are pictures of the upper and lower bands after modification:




After the 2 pieces were modified, and were able to fit around the shotgun, the stock bolts would not fit through the holes of both pieces due to the shotgun barrel. To clear the barrel, I substituted thinner and longer(since the stock hex head bolts were not long enough anyways) bolts to secure the 2 pieces around the barrel. Since the bolts would not clearance the barrel and go through both holes, the mid section of the shaft needed to be reduced in diameter. Iniitially this was done by grinding the side off of the bolts, only to see if it would work. Later I replaced these bolts with 1/4" hex head bolts(same as stock) that were longer than the factory bolts.

First run of the securing bolts:



The second and final set of bolts was reduced by chucking them in an 18V drill, and holding a file to them. Since I do not own or have access to a lathe, this seemed to be the most efficient way of reducing the diameter of the bolt.



After the bolts were modified to accomodate the barrel, a way to secure the bolts needed to be found. I wanted to use a nut, as this seemed to be an easy and economical solution. However, the round contour of the bottom piece posed a problem, since the nut would have all of the force on one side. This problem was solved by applying the lower band to a grinding wheel, to create a flat surface for the nut to contact. The nuts were also modified to fit against the sides, eliminating the need for pliers or wrench when assembling the 2 pieces around the barrel.

Flats ground into lower band using a grinding wheel.



Nuts modified by grinding one side down in order to engage vertical side of cut.



After all of the grunt work was done, it was down to prepping the metal for rebluing. For this I used a fine metal file, 150, 220, and wet sand paper. For blueing, I used Bircwood Casey's Cold Blue.

Metal After preperation. The nuts in the photo are new nuts for the hex head bolts.



After 2 cycles of cold blue and a nice coat of WD-40:



Here is the finished product mounted on the gun:






This was quite a fun, albeit time consuming, little project. The most advanced piece of hardware that I used was a grinding wheel, so this can be done with simple tools if you wish to undertake something similar.

Here is the list of parts that I used to make it, and their cost.

Clamp on Bayonet lug - I paid $20 years ago, CMMG has them now for $ 25.95
2 Hex head bolts with nuts - $0.50 from local true value hardware store.
Cold blue - I don't remember what I paid, but it is $9.25 from outdoor superstore.

For around $35 I had a fun little projet that was interestesting and quite challenging, not to mention it makes liberals everywhere wet themselves. We all know that racking a shotgun makes anyone within ear shot wet themselves, so imagine what you can accomplish by adding a bayonet.

Hope you enjoy.
M4Sherman  [Member]
11/24/2007 9:49:39 AM
Why is the bayonet on the side?

Edit: I see now that your mag is in the way
gungod223  [Member]
11/28/2007 6:21:39 PM
well we came up with a fix for that for the rem870/1100/1187




www.sjhardware.com
rcr29  [Team Member]
11/28/2007 7:12:50 PM
gungod, your guys' bayo lug kind of inspired me to do mine. I knew yours would not work w/ my mossberg, so I had to find something that would work on the bbl, not on the extension. Your lug looks awesome.
TacticalTim  [Member]
11/30/2007 11:48:19 PM
Lug that I designed and a kind friend of mine machined from a scope ring.

DocMike  [Team Member]
12/1/2007 12:06:10 AM

Originally Posted By TacticalTim:
Lug that I designed and a kind friend of mine machined from a scope ring.

i128.photobucket.com/albums/p195/Tactical_Tim/DSCN2525.jpg


Got any pics of that one installed? That looks like a nice clean mount.

Doc
TacticalTim  [Member]
12/1/2007 1:08:23 PM


Mounted on my win 1300 Defender
TacticalTim  [Member]
12/1/2007 1:17:04 PM

Originally Posted By DocMike:

Originally Posted By TacticalTim:
Lug that I designed and a kind friend of mine machined from a scope ring.

i128.photobucket.com/albums/p195/Tactical_Tim/DSCN2525.jpg


Got any pics of that one installed? That looks like a nice clean mount.

Doc


Patent Pending..... Dont get any ideas fuckers
DocMike  [Team Member]
12/3/2007 12:41:06 AM

Originally Posted By TacticalTim:

Originally Posted By DocMike:

Originally Posted By TacticalTim:
Lug that I designed and a kind friend of mine machined from a scope ring.

i128.photobucket.com/albums/p195/Tactical_Tim/DSCN2525.jpg


Got any pics of that one installed? That looks like a nice clean mount.

Doc


Patent Pending..... Dont get any ideas fuckers


Tactical, not to worry, I've got a Mossberg 500 so your mount won't work for me but, I'll say it again...that is a nice looking mount. That is one mount design that should be patented.

Doc
JaxxKat  [Team Member]
12/3/2007 1:53:45 AM

Originally Posted By TacticalTim:

Originally Posted By DocMike:

Originally Posted By TacticalTim:
Lug that I designed and a kind friend of mine machined from a scope ring.

i128.photobucket.com/albums/p195/Tactical_Tim/DSCN2525.jpg


Got any pics of that one installed? That looks like a nice clean mount.

Doc


Patent Pending..... Dont get any ideas fuckers

ok
TacticalTim  [Member]
12/4/2007 8:25:34 PM

Originally Posted By DocMike:

Originally Posted By TacticalTim:

Originally Posted By DocMike:

Originally Posted By TacticalTim:
Lug that I designed and a kind friend of mine machined from a scope ring.

i128.photobucket.com/albums/p195/Tactical_Tim/DSCN2525.jpg


Got any pics of that one installed? That looks like a nice clean mount.

Doc


Patent Pending..... Dont get any ideas fuckers


Tactical, not to worry, I've got a Mossberg 500 so your mount won't work for me but, I'll say it again...that is a nice looking mount. That is one mount design that should be patented.

Doc