Let me first say that I am new to the world of AR's (New to the point that I dont own one) however I am not new to rifles in general. I would like to build an early style M16A1 type rifle, however there is one main hang up that is throwing me a couple curve balls.

I want it to be in .458 SOCOM

I have plenty of AK's and other rifles in smaller calibers as well as .308 so I mainly want this gun to be a project as well as used to kill the occasional hog. One of the main concerns that I am running into is finding the correct style Front Sight Base to fit. From what I have found the .458 barrels are .875dia at the gas block however the largest FSB I can find is .750 (other than a discontinued .936 DPMS base). Is there anyway to work around this? Another question is how to get the gas block to work with the triangle handguards? I understand some people have rigged up various way to make this work, some will use a low profile gas block and simply cover it up with the handguards , however I am not sure this is possible in this situation.

Other than these two factors I dont see many hangups in the build process. However having the correct look is important for me (especially since this is 80% a novelty gun) so if I cant work out how to get it to look like I want it to ill probably abandon the idea.

Have you considered having an FSB modified to accept the larger diameter barrel and act as the gasblock? Just an idea. Not sure there is enough meat in an A2 FSB to pin it in place, without turning the barrel down some. Getting into the danger zone one way or the other. There may be some craftsmen in this forum who could help with getting that sorted . (Not me BTW ).

Would love to see someone build a retro like this. In for pictures and specs when you get to that stage.

Would love to see someone build a retro like this. In for pictures and specs when you get to that stage.

I thought about it, but I read somewhere (and I was worried about it myself) that there isnt enough material in a .750 FSB to allow for you to take off the amount needed. So I am not sure if that is a viable option or now.

Where's MarkRSims??

http://www.ar15.com/archive/topic.html?b=3&f=123&t=465073  He started with this

http://www.ar15.com/forums/t_3_123/586781_Finally_finished_the_beast__as_requested__with_under_the_handguard_pics_added_10_5_.html    Later modded it to this


Very groovy, by the way


http://bpullignwolnet.dotster.com/retroblackrifle/ModGde/CrbGde/651.html  One could mix the two styles above and build a 651 or 652

Yep. I've seen others mount an FSB with a set screw, while using a gasblock behind it. Well, whatever you do. In for pics.

What gas system would a .458 socom need?   pistol, carbine, or rifle length?   Don't know if you'll know the answer to that if you're not familier with AR's.   For instance, the 300 blk round "prefers" a pistol length setup. You're wanting an A1 so maybe, just maybe......if your going with the 20" barrel, but can/could use the carbine length gas system, then maybe a suitable gas blcok could be machined for under the rifle length handguards, with some kind of faux frt sight out in front of the handguards. Might still look retro A1, but function with the shorter gas system under the handguards.  Just an idea off the top of my head....or out of my as..........

I bet you could weld around on a GI frt sight and then work the weld back down to a decent look........having the frt sight there for looks.  I would imagine that the Socom round needs a shorter gas system, like a carbine length.......but OP wants an A1 look so would use a 20" barrel and rifle handguards.

As far as I know, they only come in 16 inch barrels, which is bummer however if I can maintain everything else looking correct to the early style then I will be happy with a 16 inch barrel. From my understanding the .458 prefers a Carbine Length Gas system.

I am wondering if it would be possible to put on full length handguards over a slim gas block and have the FSB mounted towards the end of the barrel. So it would look something like a SBR M16A1.

Frankly, I'm thinking about one of those Turkish "AR" style 12 gauge shotguns for $399...

i recently seen on our EE boards someone selling 2 of those .935? sight bases...  you might have to go back a few days.. it might have been about 5 days ago.. and i don't remember if it was in used uppers or in the accessories threads.
sounds like a great project.. like to see pics when your done
Pete

Mark got a original Teppo-Jutsu, Marty ter Weeme barrel with a carbine gas system, i waffled till Marty was gone and had to buy a Rock River complete upper in midlength, (the only way RR makes it).




 

That's some nice work right there! I would love to build a .458 SOCOM...but I think I'd have to take up handloading also. Howzit shoot?

It's thumpin else to shoot.

soon as i grow a big enough pair. we're going to put it on my SOT buddy's F/A  lower.

good thing about that is a 20 rd mag only holds 7, so the people behind me should be safe.

I can remember back when the Retro Forum was intended to only discuss 'Retro' AR15's/M16's .... etc.
I used to enjoy those days .... and I really miss them.  

Retro to you may mean a strict clone or replica using only original parts.  Like you better use a '56 oil filter and 70 yr old tires on your '56 Chevy because if you use a modern ones it's not "retro" anymore.

In a word .... YES.
Excuse me all to hell, but I don't seem to recall socom 458's being used back in the 60's or 70's.  Please enlighten me if I'm wrong.

he's after the "look" of an old M16 with more horsepower, and a one of a kind oddity. I don't mind that too much. There are different levels of enthusiast's on this forum. Some are sticklers for every detail possible (that's their joy) and some just love the damned ol fixed carry handle.

I am wondering if it would be possible to put on full length handguards over a slim gas block and have the FSB mounted towards the end of the barrel. So it would look something like a SBR M16A1.

You got it.  Check MarkRSims thread above.  Definately a retroish hog stopper.  Hard to beat fresh swine but boneless loin at $1.88 lb smokes pretty darn good too.

Interesting request as I have my new RRA catalog turned to page 82 "The Beast" and all I wanted for x-mas is a .308 AR with a brake.  Have been looking at those .45 ACP barrel blanks.  Decisions! Decisions!

the 458 is bad medicine for sure, but I gotta tell you, I've killed many a pig with 5.56, head shots, they drop like a sack o potatoes and you don't ruin any meat.

http://s332.photobucket.com/user/michaelgrappin/library/ar15 i have a good set of handguards if your interested.

Tip Of The Day.......don't read the threads you are not interested in.