AR Sponsor
Posted: 6/11/2010 5:25:49 AM EDT
|
The M16 construction is a marvel of interchangeability and modularity with the exception of one part, the FSB. Why is it that this part is essentially hand fitted? I find it incredulous that Colt could make literally hundreds of thousands of M16s and not have a standardized mounting procedure. Or am I wrong? Will an FSB from one M16 interchange with another M16, all things being USGI?
regards, Ralph |
| It's not so much that they were hand fitted,,but this was the process used by Colt.Undrilled barrel comes down the assembly line gets an UNDRILLED FSB slid on,put into a jig.Then a duel head drill drills both holes at the same time,then pins installed.Assuming Colt had more then 1 assembly line,it's possible the duel head drills could be ever so slightly different from drill to drill,then also have to account for who is jigging and drilling, how that person lines up the bits on the FSB,bit wear and such... Now just MY thoughts here,,if you were to find several barrels that came off the same line at about the same time frame,chances are good you could interchange the FSBs from on to another.. |
BTW,the above info was originally told to me by a very well respected member here,then CONFIRMED by the man who I got my unfired,in the box 1964 SP1.He worked for IBM at the time (1964) and was sent by IBM to Colt to tour the Colt manufacturing process.He confirmed to me that the above is how the FSBs were installed..He ordered the SP1 at the end of the tour when the tour guide asked him if he had seen the "new" available to the public semi auto AR15...He ordered it that day. Received it, visually inspected it,wrapped it back up in the plastic sleeve,and back into the box and put it away.It remains unfired and in my collection now  He told me that when he was shown the assembly line it was set up like this.Long building with a center hall.On the left and right of the hall there were no walls but chain link type fence.On one side the military contract full autos were being assembled,on the other side,the SP1s were being assembled... I gotta ask him if he has pics of that!
|
|
Quoted:
sniper, Thanks for that info. I suppose tolerances might tend to stack up and be slightly different. Got any pics of that SP1? regards, Ralph None on file at this time,but if I get a chance this weekend I'll put on the white gloves and take her out as I've had several requests lately.Especially wanted are pics of what I call the "toe" tag.The original tag hanging off the trigger guard that says the rifle is "self cleaning" and also the original price of $189.50
|
| Like m1sniper said, it's not that they were hand fitted, but each barrel has a FSB unique to it cause of the jigs used to mount it. If you take one FSB off a barrel & put it on different barrel there is the possibility that it won't be straight & will affect accuracy. |
|
Quoted:
I wonder how Springfield Armory got all of the M1 Garand lower bands to be interchangeable? It is drilled essential the same way albeit one pin instead of two. regards, Ralph Really, you never should have to remove that band unless the wood is broken. Some of those bands are pretty loose. Ive never had an issue making a random lower band fit on any barrel. the gun would still function even if the roll pin isnt there. |
|
Quoted:
I wonder how Springfield Armory got all of the M1 Garand lower bands to be interchangeable? It is drilled essential the same way albeit one pin instead of two. regards, Ralph Really, you never should have to remove that band unless the wood is broken. Some of those bands are pretty loose. Ive never had an issue making a random lower band fit on any barrel. the gun would still function even if the roll pin isnt there. |
AR Sponsor