The UK's Finest Independent Forum for Shooters and Gun Owners. Est 2010.

Not as simple as first anticipated? I would have thought DPMS uppers would have gone on anything else? "Bob spec"..... Yeah aptly put. Previously owned three SSR15s, great rifles but I'll refrain from commenting on the man and his customer "service"....

safetyfirst wrote:All the SGC kits I've tried to swap round has turned out to be very well made but "Bob spec" not mil spec.

I've not successfully mated a SGC speed master upper or lower on any Cmmg or Lantac upper or lower!

I have a SGC V22 and would eventually like a centre fire upper for it and would like to know what are the major differences between a "Bob spec" and "mil spec" upper?

Technically milspec is exactly that not as tighter tolerances hence milspec. The easiest thing to do is if you want a straight pull upper send it to mark Bradley or Roger at syss and they will mate an upper to your lower.

From what I saw trying to fit his lower and upper to any part of my Cmmg or Lantac, the takedown pin holes just didn't line up, only by a tiny fraction though.

Sandgroper wrote:

safetyfirst wrote:All the SGC kits I've tried to swap round has turned out to be very well made but "Bob spec" not mil spec.

I've not successfully mated a SGC speed master upper or lower on any Cmmg or Lantac upper or lower!

I have a SGC V22

Not the one I sold your mate by any chance?

saddler wrote:

Sandgroper wrote:

safetyfirst wrote:All the SGC kits I've tried to swap round has turned out to be very well made but "Bob spec" not mil spec.

I've not successfully mated a SGC speed master upper or lower on any Cmmg or Lantac upper or lower!

I have a SGC V22

Not the one I sold your mate by any chance?

It is. He got bored with it, whereas I doubt my son will ever get bored of it...

safetyfirst wrote:From what I saw trying to fit his lower and upper to any part of my Cmmg or Lantac, the takedown pin holes just didn't line up, only by a tiny fraction though.

OK. So it's just the tolerances, I'll keep that in mind.