OK that's a winner for sure!

www.argonautarmament.com

I considered it but didn't like the way it clamps to the barrel. I think the simpler design from Cavalry Arms is the way to go.

www.cavalryarms.com/SST-870.html

Innocent_Bystander:  Argonaut has a shorter rail similar to the Cav Arms model as well as the one depicted above.

I think the the only things to consider are price, guarantee, and what type of stock you prefer.

Has any one from ARFCOM tried either of these adapters out?

I have shot one of the Cav Arms adapters. A friend of mine has one. Very nice! I've been looking for an 870 as a result.

I really like the SST conversion, seems to cover all the bases without a bunch of extra stuff.

As I posted in the Armory section:

TheFNG and I met up with Russell at the range. Reasonably "cool" day to go shooting, seemed like it hovering right around 98 degress or so.

He had a 14" NFA 870 with a ZM folder on it (way cool) and what I believe was a 21" bbl 870 with a 7+1 cap.

I shot the NFA first. I only had Winchester SuperSpeed, 2 3/4", 3 1/4 dr, 7/8 oz, 8 shot shells with me. The recoil was fine even though the ZM stock did not have recoil pad on it. It seemed likethe followup was quicker, but I was just shooting at dirt. The cheel weld with the OKO was balls on on both shotguns. Lining up with the sight was quick and instintive.

On the 21", recoil was beautiful and smooth. Using this gun with the C1 stock made followups very quick.

On both the guns, this conversion looks great and just feels right. The SST870 has a lot of utility for the shooter who can appreciate a new and unique product for the market.

It seems like with wide proliferation of AR15s and their numerous accessories, this is the most likely eveloution for this popular shotgun. It's great that someone finally came out with it.

Good job Russ

Hello...

Innocent_Bystander: KevinB (who posts regularly on other areas of the board) has fired an Argonaut equipped 870. He penned some thoughts over on this thread:

www.ar15.com/forums/topic.html?b=3&f=12&t=167710&w=searchPop

Take care,

BrobeeBiter

i can't speak regarding this argonaut unit but i have had a chance to play with the SST-870 that Cavalry Arms is distributing...
it is SWEET!  i posted my Mossberg shotgun for sale instantly so i could get an 870 (which i had my FFL order today).  
it seems a lot of people are making the same thing now but the SST-870 was the first i saw in production and its got my vote....
of course, if any of the competition wants to ship me a free unit i can give a truly unbiased report!

Quoted: www.argonautarmament.com

I notice you are taking orders and are about to ship.  Can you tell us anything about the quantities you are making and shipping?

Hello!

urbanred: To answer your questions, we've already shipped the first batch, and were depleted of units in just a couple of days. The next batch of 150 are sheduled to arrive at the end of October. If you would like more information, please e-mail me at [email protected] as I'm not really free to discuss commercial issues on AR15.com(this is because I have not paid for the priviledge of advertising here).

I am free to discuss development and technical feedback, so anyone looking for that type of discourse is strongly encouraged to participate!

With the greatest respect,

BrobeeBiter

Hello All!

Testing Update: A local range ran a SigAcadamy Basic Shotgun course this past weekend, and while I was not participating (I took the course last year and while I really really wanted to participate again, it was suggested by people wiser than myeslf that the money might be better spent upgrading my shooting education with a different course), an 870 marine magnum was equipped with the AR15/870 Stock adapter, a receiver length rail from GG&G, and an Aimpoint was fielded by one of the course participants. Round count consisted of 75 rounds of slug, 75 rounds of 00 buck, and 100 rounds of birdshot.

As a slight diversion from the topic of the adapter, this course is EXCELLENT. Due to an extremely high round count, it is also a torture test for your 12 gauge (shotguns were breaking left right and center) and will definately unveil whether or not you have the mechanical kinks worked out of your pump gun or semi in addition to any handling techiques you may posess that make you more prone to any number of different mechanical stoppages. It is also a sound introduction/complete immersion into the operation of the shotgun and in my opinion provides a significant foundation upon which to build some serious tactical shotgunning skills. Improvements had been made in the target handling capacity of the range since I had taken the course as well...where I had shot almost all paper targets that required constant repair under the insult of 122 gauge annumition, reactive steel targets were employed this time around. A thourough and highly effective immersion in the world of the tactical 12 gauge that earns high marks with the Brobee.

Back to the topic at hand: the 870 marine magnum equipped with the Brobee adapter. Part of the course involves a stoppage clearing drill intended to clear a double feed on the 870. The drill is performed by striking at a 45 degree angle the butt of the shotgun against the ground with a considerable amount of force. When performed on the M4-style stock equipped shotgun, the plastic stock cracked (no visible deformation to the locking pin or holes machined in the buffer tube). The operator of the gun found himself quite surprised to find his aimpoint inches away from his face as the stock collapsed immediately afterwards under fire and reported increased, but not unmanagable recoil, however he cowboyed up and shot the remainder of the course of fire with the stock completely collaped (and did quite well accuracy wise if one is to believe what is around here quickly becoming urban-superheroesque-caliber legend!)

I'll take some photographs of the damaged stock and post them for all to see. It is probably relevant to note that two wooden stocks on other guns were cracked under the same drill (one on an 870 and another on a mossberg). I'm curious to see whether increasing the angle of the strike to 90 degrees still effectively clears the stoppage, as I'm currently speculating that on an AR15 stock equipped shotgun the 45 degree angle of the drill's current butt strike focuses force on the stock in a that might be avoided with some slight modification to the technique. I will be looking for a crappy stock to test the theory...

Images of the marine magnum equipped with an AR15-870 CQB Stock Adapter, a GG&G piece of picatinny rail, and an Aimpoint CompML2 with a GG&G canteliver mount:







Participants of the SigArms Basic Tactical Shotgun Course:




I'll get some photographs of the broken stock up later...

Take care,

BrobeeBiter

its hard to tell from the pictures but can the argonaut adapter use a pistol grip other than the A2?  
i hate A2's and have never used them on AR's...i sure as hell wouldn't want one on a shotgun.
the soft rubber Ergo on my SST870 is a dream to shoot....

IMO, buis is mandatory if you mount an AR style stock and optics on an 870.  The buttstock is totally repositioned relative to the bore which makes a conventional sight useless if the optics crap out.

For this reason I would only consider the full length rail from Argo.

I have practiced the same style drill in other shotgun classes I have taken and did not have this problem with the SST870.

I have been wanting to get one of your adaptors to do a side by side comparison.
Do you have an US importor for your adaptor yet. I do not want to take the chance of illegaly importoring a gun part, I have a job and security clearance to worry about.

Quoted: IMO, buis is mandatory if you mount an AR style stock and optics on an 870.  The buttstock is totally repositioned relative to the bore which makes a conventional sight useless if the optics crap out. For this reason I would only consider the full length rail from Argo.

i do not consider a BUIS to be mandatory on a shotgun for the role i intend to use it for.  lucky for me the OKO sight i have on my SST870 has built in iron sight backups which are more than adequate for the ranges i shoot at (if i can do slug headshots at 25yds i'm doing just fine...i don't keep slugs in the gun for SD anyways).
for me the best thing about the SST870 IS the fact that it Does reposition the stock alignment to mirror the dimensions of an AR15.  if i didn't want it the same as my AR15 i'd just get a Speedfeed stock for the 870....

I would Indeed expect the the repositioning of the stock to be a good thing/beneficial for recoil control.  (I haven't tried one of these first hand)  But, I would definetely want the Rifle sights option if I were to do this thing.