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11/24/2010 7:12:59 PM EDT
Folks, I've read the 4 other related threads to this one but have a question.   My SP-1 upper is an orignal upper with the large pin.  I know that in order to use that pin, I would have to not only redrill the lower but also move the center of the hole.  Are the forgings that folks such as Nodak Spud use adequate for the SP-1?   Wondering how hard it would be to talk Mike or Harlan into making a run of lowers drilled for the SP-1?   Model number ND/SP-1?
11/24/2010 7:32:03 PM EDT
[#1]
There generally isn't enough material left to relocate the hole properly.

I don't know if the NDS forgings can stand to have the holes drilled in the proper place for a large hole. But a limited run of large hole lowers sounds like a good idea if it'll work.
11/24/2010 7:38:23 PM EDT
[#2]
Just buy the offset pin adapter for a few bucks.
11/25/2010 1:13:18 AM EDT
[#3]
Truth told if it were not that there are many transferable SP1 machine guns out there I would say enough. Someone has to end this .3125 pin hole madness. That and the oversized FCG parts? Come on. I sold the two Colts I had because of this. That and people were paying crazy prices for them too!
11/25/2010 2:51:52 AM EDT
[#4]
Quoted:
Just buy the offset pin adapter for a few bucks.


^^^^this^^^^ is the answer you seek.
11/25/2010 3:41:25 PM EDT
[#5]
I think I'm best served by selling the SP-1 upper and gathering parts for a 605 build.  I'd be happier there anyways and it will look more comfy with my 603 build.
11/28/2010 1:48:06 PM EDT
[#6]
I have an SP1 lower that was welded up and redrilled for small pin.  I have a USGI  M16A1 upper on it.  I use  one of the uncaptive pins from 601's etc.  That is another option.
11/29/2010 3:03:19 AM EDT
[#7]
Just 2 pennies thrown in.I contacted both Victor and M60Joe and asked about welding SP1 lower holes closed and redrilling.Both can do it,,,BOTH do NOT recommend it,and don't want to do it.They can both install semi permanant bushings for lowers.As for uppers,I have a bushing installed in the original upper that was on my Palmetto Arms car15.Until I became educated on ARs,I never knew it was there and I've NEVER had a problem with it.
11/29/2010 4:25:00 AM EDT
[#8]
I have several barreled uppers set up on SP1 upper receivers that have offset bushings, glued in place with black RTV, that work just fine on any lower I care to pin them onto...but I also have a couple that are loose on all but one or two lowers...I just chalk it up to stacking tolerances and live with it.

It's like anything mass produced for such an extended period of time...sometimes the ones that are "close enough" to specs are allowed to slip through..especially when times were a bit lean
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