Airforce Piccanty rail modification…
thought I would field this one past the fine folks here…
Hate the stock set up on the AF rifles. Building a sidecocker 9mm and plan on removing the carry handle nonsence and fitting it up with a full length 1913 Piccanty rail. Picked up a 32″ 1913 extrusion but would like to hear some ideas on permenently installing it.
leaning towards after cutting the handle off having the existing rail milled rectangular witha matching mortice cut on the underside of the 1913 rail.
At the front the new 1913 rail will be secured to the tube with a series of screws with two more screws at the rear then finally TIG welded along the seam and fiinish machined prior to bead blast and Ceramic coating.
Does this sound like a good route on this?
Have a Swan Sleeve with the pop up rear and a Troy Arms folding front sight that will be going on this rig which will also allow use of my throw lever ARMS optics bases. Site plane will be perfect as I am using one of Marmot Militias drooped ETACS with a 68ci JDS bottle
All Replies
Riverside,
If you completely screw it up, so that it is nothing but a throw away. Your talking about a frame that cost 235 from Air Force, or about 130 if you get a reasonable deal on a used gun and sell the parts you do not need. Add to that your rail cost.
To me that is a very reasonable risk for what you will learn, and the potental rewards you will gain if it works.
These are Air Force Rilfes, not works of art, not pieces of history that can’t be replaced.
I say go for it.
In 1981 I cut the handle off my AR 15 and screwed and glued a piece of bar stock to it , then I put a weaver base for a Marlin 336 on top of that.
It was a gamble, I knew it was possible for I had seen it done in SOF for the first time.
Look where that impossible job has evolved to.
Good Luck,
Roachcreek
Riverside…I have worked with many different welders ..some were great at their craft and some …well let’s just say they had a hard time remembering not to touch while it was still glowing….if your confident in your abilities I say go for it but you may need to straighten your frame when your done or it may be good as is when your done…keep us posted as I am thinking a weaver rail is next on my list as well
Lord Guys…
its not like its my first time around the block these jobs
can something crack or wrap under heat…sure
is it something that commonly occurs?
only if you are a serious meathook
done many a weapon with thinner metal & more critical dimensions…I mean try welding cut AR lowers, uppers or 1911 frames
Heck you ever MIG welded on restoration panels on cars? I Have rarily had warpage issues. Its all about going slow
Before A3 AR uppers were commonly available how did folks get flat top uppers? Yeah same way I am proposing with the AF tube…the cut the carry handle off and then screwed and silver brazed a 1913 rail in its place, SWAN was doing this in the 1980s! I can’t see all the hand wringing over doing the same to an AF frame
Actually if this is done right the strength should be superior to the stock frame as there is quite a bit more beef to the 1913 rail than that spindly AF carry handle.
As far as wanting an AR look…that has ZERO to do with it, it is all about getting a 1913 flat top on an AF frame. Have one of Davids stocks btw, wonderful work but that wont get me a 1913 rail either and I am not a great fan of the Marauder…having a big bore breech in .308 made for the Marauder tube
YN: how has your flat top mod held up? Mine will of course be longer but the same basic idea. Thinking on running a rear screw directly into the steel bushing the tank screws into for increased rigidity
as i understand it, you’d remove the carry handle and weld a 1913 picatinny rail in place of it?
what i know of welding (which is not a great deal..i know basic oxy-acetylene, brazing and arc welding but not much beyond) you’d have to have lab conditions, no less than perfect, in order to minimize warpage to such thin aluminum.
as it is, the AF frame is not as rugged as an anvil, railroad spike or an M1 Garand, but it never the less, is fairly rigid for what it’s designed for. why risk it’s integrity? why not look to another rifle like a Benjamin Discovery or Marauder to add the rail to? it could be accomplished with almost no welding and minimal machine work and in the end, costs would probably be lower…Dave Sosa makes a really nice machined, aluminum AR style stock for the marauder for only $149.00 as an example
not trying to argue or “rain on your parade”…but if you’re looking for the “AR” look, there are other ways available without “re-inventing the wheel”.
JMO… 🙂
Synopsis: Understand your concerns with TIG wich is why I will likely opt for the Coral aluminum brazing rods as one can run those with a propane/Mapp torch
So exactly like I said…. but longer….
the aluminum frame will be prone to what is refered to as hot cracking. tig welding or putting a torch flame to your frame is a bad idea. most welded joints that need to keep their tolerances are machined AFTER welding. one must also consider the heat affected zone.
WELD AT YOUR OWN RISK.
Ken
YN: No will be a straight flat top configuaration with a 21″ 1913 rail so I can use AR 1913 sighting elements which I have a rather wide variety of and also cover the no longer used top cocking slot
Synopsis: Understand your concerns with TIG wich is why I will likely opt for the Coral aluminum brazing rods as one can run those with a propane/Mapp torch
I have made a few tooling fixtures for making custom bicycle frames and the items that were welded were horribly tweaked from the heat. We stopped welding stuff unless it was machined after welding and even that had some issues.
I even think my trirail is tweaking the frame out of line. The machining on the trirail lacks. I wish they would bring this frame up to the current technology and add the weaver rails. I bet they would sell a third more without the dovetail. I have to shim mine to get the scope to line up with the barrel, so the scope can’t be removed without having to get the shim back in with tweezers… The weaver rail on my 10/22 is awesome, I can remove the scope and put it back on without any poi change.
Check out what this guy did…
Like this (but with the tri rail replaced with a single taller picatinny)?
Already aware of frame flex & rigidity issues once the carry handle is cut off. Also aware of issues with warping…rewelded many a receiver in the day. May not use TIG rather instead go with the Coral aluminum brazing rods we used to restore AR10 demilled lowers at they are low temp and flow well.
Yellow, like your idea but the carry handle still has to go! Still it saves aditional machine work and give more area for the braze to flow into. The secret of keeping warpage at zero is work side to side in small areas over time.
Heres how it is currently mocked up without the 1913 rail
Picatinny is wide enough for you to cut a straight sided channel the width of the airguns dovetail on the underside. Attach it with screw’s the same as mounts are attached to firearms receiver’s.
That way there is no material removed from the frame – just a few screw holes and its also lower so it looks more like factory instead of just something bolted on the top.
Riverside,
Removing the material on the top of the frame will allow the whole thing to flex more than it already does, remember this this is basically a thin tube. The material on bothe the top and bottom add rigidity to the overall structure.
I would advise against welding the entire length, or for that matter at all. The warping would create havoc with the piece. Any amount of welding will warp it, causing some impossible to control dimensional changes.
If you think that removing the top and adding a rail is a good idea and you will be farming out the machine work, why not have the rail and top surface milled for a dovetail. A few setscrews in the rail will hold it in place.
Just my thoughts, I’m sure others will chime in with their thoughts.
Stick
Dayum… 😯
sounds good to me.
Buy some batteries for your camera, we need pics.
- You must be logged in to reply to this topic.
Subsonic: Hear what you are saying but this isn’t as great of rocket science as its often made out to be. Spoke with a buddy a few weeks back that does aircraft welding in TIG, he figured it would be a pretty easy job and his work is far better than mine.
Every so often I see Gun people getting all worried about this kind of work. Well its been done for decades, here is an example from the 1970s. Years ago Seventrees offered their ASP rebuild of the M39 S&W to government agencies. They started with this:
and turned it into this:
there was an incredible amount of welding that went into these guns. Owned several over the years, carried one for a year
anyways this work is dead common. John Norrel and others remanufactured M16 lowers from scrap cut military lowers and these are still running today in the CIII world
in contrast brazing a 1913 on an AF frame is dead simple…
Roachcreek: Thats exactly my point, its not as tho I have a shortage of AF frames here…last count I think I was up to 6 of them give or take…LOL