lpdb185 1 Posted January 14, 2011 Report Share Posted January 14, 2011 i'm new to this and i am looking to convert a S12. i found THIS part for sale, but haven't seen any pics of it installed. can anyone verify that this would install just like other internal receiver blocks? i like the idea of it, but the screw holes just behind what i assume is the tang area are throwing me off. i haven't seen any other internal adapters that use those holes. anyone used this before? what would be the benefit over THIS ONE thats half the price? 1 Quote Link to post Share on other sites
KC913 324 Posted January 14, 2011 Report Share Posted January 14, 2011 The SGM unit replaces the rear trunnion and is held in place by screws. You have to drill out rivets and remove your existing trunnion and replace it with the SGM unit if you go that route. The holes that it uses are the rivet holes from the original rear trunnion. With the other unit, you just need to cut the tang (piece that sticks out and holds standard buttstocks in place) from the factory rear trunnion and it slides in. Go with the one you posted from MississippiAutoArms. Quote Link to post Share on other sites
jcarter1974 5 Posted February 15, 2011 Report Share Posted February 15, 2011 I'm in the process of installing one of these while doing a conversion (Carolina SS kit) on my Saiga 12 with the SAW grip. Here's what i've found so far: 1. Drilling out the rivets & removing the old trunnion/tang wasn't a problem. The holes that the new trunnion mount was supposed to use were too small for the screws to fit through. The instructions say "if the holes are too small, enlarge them using a 3/16 bit." Plan on having to drill to make them fit. 2. The SGM Tactical rear trunnion mount will not fit a mil spec buffer tube (1.148 O.D. (Overall Diameter)), only commercial spec (1.168 O.D.). I overlooked that but it's no big deal. Plus it didn't specify on the website I bought it from. 3. When installed with the SAW pistol grip, the bottom portion of the trunnion mount rubs against the reverse side of the heel of the hand (meaty part between the thumb & index finger). I only noticed this while fitting everything together during the conversion but it dug in enough to concern me. It could become very uncomfortable on a day at the range. We'll see. 4. The threads are really tight & almost feels like i'm stripping them when fastening them down. I shut work down late Saturday night & just haven't picked it back up. I'll keep you posted. When considering how to mount an M4 style stock, I thought it seemed like a nice clean design as opposed to some of the other stuff & it didn't require cutting the tang off. Plus I could easily slap a 2-piece QD sling mount on it easily too. I saw some of the tubes that fit the saiga rear tang but it looks as if you can't totally collapse the stock because of the tang being in the way. And you'd also lose tube space if you added the 2-piece sling mount. Plus as you know, sometimes it just comes down to personal preference. I've got 2 more S-12s on the way & I'm still up in the air on whether I'm gonna use the SGM Tactical mount on the other 2. Any other recommendations? Quote Link to post Share on other sites
jcarter1974 5 Posted February 16, 2011 Report Share Posted February 16, 2011 Here's some photos... SGM Tactical Rear Trunion Mount on Saiga 12 Quote Link to post Share on other sites
jcarter1974 5 Posted February 16, 2011 Report Share Posted February 16, 2011 (edited) SGM Tactical Rear Trunion Mount... Rubbing against my hand while gripping SAW grip Edited February 16, 2011 by Prez Quote Link to post Share on other sites
jcarter1974 5 Posted February 16, 2011 Report Share Posted February 16, 2011 Also, there's a mounting screw on the bottom of the receiver that gets in the way of the SAW grip on a converted Saiga 12. Quote Link to post Share on other sites
theplastik 67 Posted February 18, 2011 Report Share Posted February 18, 2011 Hey Prez, is there any possibility you could post more pictures of your SGM Trunnion Stock Mount? I'd like to see the full rifle view, especially dead-on on one side so I can see how severe the advertised "2 degree downward angle" is. Honestly, it annoys me that they are selling this and have no working pictures on the website and I doubt they have pictures of it installed for reference. Personally, 2 degrees downward is not "a perfect shooting position" for me. I currently have the CSS pignose which has no angle/cant and it's perfect except for the extra inch in length it adds to the overall rifle length. Thanks in advance. Quote Link to post Share on other sites
jcarter1974 5 Posted February 18, 2011 Report Share Posted February 18, 2011 Here ya go!!!: Maybe it's just me but my eye doesn't notice any angle to it. Also, Keep in mind that on my gun, the tube is only screwed in 1 turn at the moment. As stated earlier, I have a milspec tube & the trunnion mount only supports a commercial spec tube. I haven't had the time to get to the gun shop & buy a commercial spec tube. That may make a difference in the appearance of the angle. And even though my gun is in a rough fitting/testing stage, nothing feels uncomfortable to me. I agree with your statement that it's frustrating that they haven't posted any photos of the mount on an actual shotgun. It makes ya wonder what type of testing they did on it. SAW grips & Tromix conversion kits are pretty common mods for Saiga 12s. I would assume that they ran across the bottom screw problem. And it is pretty obvious right off the bat that bottom of the mount digs into your hand. I sent them an email asking if they recommend a specific setup for this mount a couple days ago. No response yet. I hope this helps... 1 Quote Link to post Share on other sites
theplastik 67 Posted February 18, 2011 Report Share Posted February 18, 2011 Here ya go!!!: Maybe it's just me but my eye doesn't notice any angle to it. Also, Keep in mind that on my gun, the tube is only screwed in 1 turn at the moment. As stated earlier, I have a milspec tube & the trunnion mount only supports a commercial spec tube. I haven't had the time to get to the gun shop & buy a commercial spec tube. That may make a difference in the appearance of the angle. And even though my gun is in a rough fitting/testing stage, nothing feels uncomfortable to me. I agree with your statement that it's frustrating that they haven't posted any photos of the mount on an actual shotgun. It makes ya wonder what type of testing they did on it. SAW grips & Tromix conversion kits are pretty common mods for Saiga 12s. I would assume that they ran across the bottom screw problem. And it is pretty obvious right off the bat that bottom of the mount digs into your hand. I sent them an email asking if they recommend a specific setup for this mount a couple days ago. No response yet. I hope this helps... Hey Prez, I appreciate the quick response! It looks like there's no angle and I may have to make this my next purchase. I currently have the Magpul UBR stock mounted on mine and it adds a bit of length so this might be perfect for the look and length I'm trying to achieve. Thanks a lot for the pic, it definitely helps. I didn't think the thread spec on milspec and commercial tubes were any different. A friend of mine and I both have the MAA stock adapter on our rifles and his is commercial and mines mil spec and they both seemed to work fine. It could just be the spec for your specific manufacturer for the tube you purchased. When I order one I'll check the angle with a tube installed and if I don't like it, I'll resell or install on my 7.62 if I'm not satisfied. Thanks again. Quote Link to post Share on other sites
frantacz 1 Posted March 2, 2011 Report Share Posted March 2, 2011 Any news? Quote Link to post Share on other sites
308SAIGA 55 Posted March 2, 2011 Report Share Posted March 2, 2011 2. The SGM Tactical rear trunnion mount will not fit a mil spec buffer tube (1.148 O.D. (Overall Diameter)), only commercial spec (1.168 O.D.). I overlooked that but it's no big deal. Plus it didn't specify on the website I bought it from. That is very strange, because both the Mil spec & commercial tubes have the same size thread diameters.... If I where to take my AR and replace my mil spec tube with a commercial tube it would fit..... Did you purchase a AR tube? Thanks Quote Link to post Share on other sites
jcarter1974 5 Posted March 2, 2011 Report Share Posted March 2, 2011 Any news? Response from SGM??? NEGATIVE!!! Not a peep. Did you mean news on the gun? No change. Still haven't bought another tube yet... Quote Link to post Share on other sites
jcarter1974 5 Posted March 3, 2011 Report Share Posted March 3, 2011 2. The SGM Tactical rear trunnion mount will not fit a mil spec buffer tube (1.148 O.D. (Overall Diameter)), only commercial spec (1.168 O.D.). I overlooked that but it's no big deal. Plus it didn't specify on the website I bought it from. That is very strange, because both the Mil spec & commercial tubes have the same size thread diameters.... If I where to take my AR and replace my mil spec tube with a commercial tube it would fit..... Did you purchase a AR tube? Thanks Why strange? Apparently from what I've read, the thread diameters differ from MilSpec (1.185") to Commercial (1.170"). See this link for details: http://www.ar15fornoobs.com/mil-spec-vs-commercial-spec-buffer-tubes Also, see this illustration: I have this UTG Leapers MilSpec AR tube I bought from Carolina SS : http://store.carolinashooterssupply.com/servlet/-strse-653/CAR-UTG-TLU001-MILSPEC/Detail It don't fit... Some folks say that their AR lowers fit both tube sizes but this combo aint gonna work.. Quote Link to post Share on other sites
theplastik 67 Posted March 3, 2011 Report Share Posted March 3, 2011 2. The SGM Tactical rear trunnion mount will not fit a mil spec buffer tube (1.148 O.D. (Overall Diameter)), only commercial spec (1.168 O.D.). I overlooked that but it's no big deal. Plus it didn't specify on the website I bought it from. That is very strange, because both the Mil spec & commercial tubes have the same size thread diameters.... If I where to take my AR and replace my mil spec tube with a commercial tube it would fit..... Did you purchase a AR tube? Thanks Looks like Mil-Spec threaded items will fit both mil-spec and commercial, whereas commercial strictly fits commercial. Sadly, SGM has done this to somewhat force us to buy their ugly butt stocks. I remember what I did with my old AR adapter on my S223. I took a wire wheel to the thread (commercial) and oiled the tube (milspec) til it went all the way in. I have the SGM trunnion mount now, but I've yet to install it. I currently have the Magpul UBR stock and the thread is a tight fit, but I am able to bottom it out, plus there is less thread to get in there. Quote Link to post Share on other sites
jcarter1974 5 Posted March 3, 2011 Report Share Posted March 3, 2011 Good info Plastik. When you install the trunnion mount, let me know what you think about the bottom of the mount digging into the top of your hand. I'm curious what others think about this... I'm actually thinking of cutting the bottom off & duracoating the whole gun... Quote Link to post Share on other sites
308SAIGA 55 Posted March 3, 2011 Report Share Posted March 3, 2011 Why strange? Apparently from what I've read, the thread diameters differ from MilSpec (1.185") to Commercial (1.170"). See this link for details: http://www.ar15fornoobs.com/mil-spec-vs-commercial-spec-buffer-tubes Also, see this illustration: I have this UTG Leapers MilSpec AR tube I bought from Carolina SS : http://store.carolinashooterssupply.com/servlet/-strse-653/CAR-UTG-TLU001-MILSPEC/Detail It don't fit... Some folks say that their AR lowers fit both tube sizes but this combo aint gonna work.. I was once again misinformed, thanks for the clarification...... ......... Quote Link to post Share on other sites
theplastik 67 Posted March 3, 2011 Report Share Posted March 3, 2011 Good info Plastik. When you install the trunnion mount, let me know what you think about the bottom of the mount digging into the top of your hand. I'm curious what others think about this... I'm actually thinking of cutting the bottom off & duracoating the whole gun... I have noticed the long tab in the back. Honestly, I'm going to grind it off before I install it. Even when I get the pistol grip attachment plate from R&R, the tab will still be an issue. SGM has come out with a product that, generally and ergonomically, is a good idea and is something I have wanted for quite a while. Unfortunately, the execution is a bit poor. Quote Link to post Share on other sites
frantacz 1 Posted March 3, 2011 Report Share Posted March 3, 2011 I think if is "2 degree downward angle" severe.. I am using C-More Railway so I need "in-line" stock Quote Link to post Share on other sites
mailtonate 2 Posted April 19, 2011 Report Share Posted April 19, 2011 Is there a specific buffer tube that any of you have tried that works well with this SGM internal trunnion? I have purchased three (UTG, one from CSS, and one from Amazon) different Commercial spec aluminum buffer tubes and none of them will screw in more than two turns. Brownells has an AR receiver buffer thread tap that I was thinking about chasing the trunnion threads with, but I'd rather not spend an additional $60 + shipping. Any help is appreciated. Quote Link to post Share on other sites
theplastik 67 Posted April 20, 2011 Report Share Posted April 20, 2011 Is there a specific buffer tube that any of you have tried that works well with this SGM internal trunnion? I have purchased three (UTG, one from CSS, and one from Amazon) different Commercial spec aluminum buffer tubes and none of them will screw in more than two turns. Brownells has an AR receiver buffer thread tap that I was thinking about chasing the trunnion threads with, but I'd rather not spend an additional $60 + shipping. Any help is appreciated. If I had to do it again, I would use the buffer thread tap. Best bet is to go to your local gunsmith/dealer and ask if they already have one and get them to do it. All I did was use a wire brush on the tube and trunnion thread, oiled it and forced the damn thing in there. It helps that the UBR tubes threaded portion is half as long as the usual buffer. This trunnion is great, except for the thread and angle. Quote Link to post Share on other sites
Cobra 76 two 2,677 Posted April 20, 2011 Report Share Posted April 20, 2011 That's a hot lookin Saiga man! Quote Link to post Share on other sites
theplastik 67 Posted April 21, 2011 Report Share Posted April 21, 2011 That's a hot lookin Saiga man! Thanks man. It was a lot of work, time, and money to get this how I wanted. All that's left is to have the excess receiver holes filled, Left side charging handle, barrel shortened to 18.2 OAL, and coated. Then I'm done and can call it quits on pimpin' guns. Quote Link to post Share on other sites
Cobra 76 two 2,677 Posted April 21, 2011 Report Share Posted April 21, 2011 Awww man don't quit on us bro! I told my dad I was gonna stop drinkin and he called me a quitter! lol Quote Link to post Share on other sites
mailtonate 2 Posted April 21, 2011 Report Share Posted April 21, 2011 Is there a specific buffer tube that any of you have tried that works well with this SGM internal trunnion? I have purchased three (UTG, one from CSS, and one from Amazon) different Commercial spec aluminum buffer tubes and none of them will screw in more than two turns. Brownells has an AR receiver buffer thread tap that I was thinking about chasing the trunnion threads with, but I'd rather not spend an additional $60 + shipping. Any help is appreciated. If I had to do it again, I would use the buffer thread tap. Best bet is to go to your local gunsmith/dealer and ask if they already have one and get them to do it. All I did was use a wire brush on the tube and trunnion thread, oiled it and forced the damn thing in there. It helps that the UBR tubes threaded portion is half as long as the usual buffer. This trunnion is great, except for the thread and angle. Thanks for the reply! I think I will call a few gunsmiths around here to see what they would charge me before I sink the cash on the tap. I just can't see myself using that tap more than once. Very sick Saiga!! One of the coolest I've seen. I especially love the look of that R&R magwell. Quote Link to post Share on other sites
theplastik 67 Posted April 22, 2011 Report Share Posted April 22, 2011 Thanks for the reply! I think I will call a few gunsmiths around here to see what they would charge me before I sink the cash on the tap. I just can't see myself using that tap more than once. Very sick Saiga!! One of the coolest I've seen. I especially love the look of that R&R magwell. Thanks a lot. I think I'm kinda stuck on AR ergonomics, which is why it looks the way it does. Quote Link to post Share on other sites
poptart 3 Posted April 27, 2011 Report Share Posted April 27, 2011 (edited) I'd like to see a regular ace style replacement trunnion even better an ak74 style folder, wouldn't have to be an exact copy but something russian looking...it definitely would sell Edited April 27, 2011 by poptart Quote Link to post Share on other sites
C_1 0 Posted May 1, 2011 Report Share Posted May 1, 2011 The thread on the tube and trunnion should be the same; mil spec or commercial. The different diameter they are referring to is the actual tube part that the stock slides onto. A commercial stock, will be lose on a mil spec tube, and a mil spec stock wont fit on a commercial tube. So its either the trunnion's or tube's thread thats out of spec. I think its probably the later. Try a quality AR receiver extension (buffer tube) from VLTOR or LMT. A Stag, Spikes or CMMG will do too. Hope this helps. Quote Link to post Share on other sites
mailtonate 2 Posted May 3, 2011 Report Share Posted May 3, 2011 The thread on the tube and trunnion should be the same; mil spec or commercial. The different diameter they are referring to is the actual tube part that the stock slides onto. A commercial stock, will be lose on a mil spec tube, and a mil spec stock wont fit on a commercial tube. So its either the trunnion's or tube's thread thats out of spec. I think its probably the later. Try a quality AR receiver extension (buffer tube) from VLTOR or LMT. A Stag, Spikes or CMMG will do too. Hope this helps. I ended up ordering a 1 13/16" - 16 tpi AR receiver tap from Brownells http://www.brownells...VER_TAPS___DIES. The tap took quite a bit of material out of the trunnion. All of my buffer tubes (mil spec and comm. spec) now thread effortlessly. I also ground the bottom tab on the bottom of the trunnion flush to match the receiver. The trunnion buffer tube threads are definitely out of spec. So be aware that you will have to spend some extra cash on a tap or be creative and use a wire wheel like Plastik did above. 1 Quote Link to post Share on other sites
Chirpinsquirrel 3 Posted January 20, 2012 Report Share Posted January 20, 2012 Sorry to bring back an old post, but would this trunnion fit a Romanian RPK? Quote Link to post Share on other sites
Goose 95 Posted June 30, 2012 Report Share Posted June 30, 2012 SGM Tactical Rear Trunion Mount... Rubbing against my hand while gripping SAW grip How important is the part that sticks down in your hand, think it could be grinded off?? And also, how does the removal of the old trunnion work with the side mount on the other side of the gun? Grinded?? Ground?? Lol I'm kinda drunk sorry Quote Link to post Share on other sites
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