Using small pin upper on large pin lower questions

Claven2

Claven2

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Is/was there ever a C7 (not C7A1 or A2) configuration for mounting the Elcan over the carry handle, or were Elcans ALWAYS on the flat-top uppers only?

What sights have the CF issued wit hthe A2 style original C7 besides the BUIS?

Also, are any C7's being retained or are they all going to be upgraded to C7A1/A2?

EDIT: this thread has evolved - scale down to see the pin size discussions!
 
The original C7 was issued with a fixed carry handle, but the rear sight set up was that of the A1 (needed a tool to adjust for windage). There weren't any optical sights (I'm assuming you're enquiring about any optics that might have been mounted on the carry handle?) that were issued for general service - only iron sights. As far as mounting an Elcan on a fixed carry handle (aka A2) style upper, I don't think it'll work. The Elcan units are big enough when you put them on a flat top - if you put one on a rail mounted to a fixed c.h., you'll need a step ladder just to get behind the thing.... :D You've heard the term "cheek weld" or "chin weld" when people refer to the process of aquiring a sight picture through the optics on their AR's, well this combo would probably be pretty close to a "neck" or "collar bone" weld.... :lol:

hsld.
 
OK, well aside from an ARMS39 and an Aimpoint or Eotech mounted mid-bbl, what other non-iron sight options are realistic for an A2 upper? Doesn't have to be combat worthy, only workable at the range.

I was considering an ARMS #2 or clone and some spare millet steel rings to mount a spare VXIII 1.5-5 Leupie on it for now. Opinions?

Of course, I guess I could just look for a stripped A3 or A4 upper and use an ACOG or Aimpoint or whatever, but I'd rather not get into a total rebuild right now.
 
Best bet get a flattop...

With the ARMS#2 it makes a cheekweld next to impossible without a cheekpiece - a chinweld fine for CQB shooting but not condusive to good performance in the accuracy department.
The Cheekpiece like the Cherokee/Colt Delta HBAR version have their own pitfalls - however they do make scopign a A2 bearable.

Costwise by the time you get a set of low rings for your VariXIII - an ARMS #2 and the cheekpiece you will lookign close to a flattop in price -- plus when you get a flatop you will require 1.5" centre height rings anyway - and the lows will require you to get a raiser mount...
 
Re: Elcan on A2 upper?

Claven2 said:
Is/was there ever a C7 (not C7A1 or A2) configuration for mounting the Elcan over the carry handle, or were Elcans ALWAYS on the flat-top uppers only?

What sights have the CF issued wit hthe A2 style original C7 besides the BUIS?

Also, are any C7's being retained or are they all going to be upgraded to C7A1/A2?
Click to expand...

There was never any ELCAN config on the C7 model. They were introduced with the C7A1.
The C7 had the M16A1 sights,, and not the A2 sights.
The plain carry handle C7 will be retained. It is still mainly the Army that has the flat tops. The Navy is still with the carry handle C7 and will probably have them forever.
 
I went through the same thing last year--I had an early '90's A2 that I was reluctant to do a lot of work to but after a ton of research I wasn't satisfied with any of the alternatives. After I made the decision to go with a flat top receiver I found that the work to change uppers was not as big a job as I expected. I was helped out in doing the swap by one of the board members here (well, actually he did the work and I held the tools :lol: ) but it only took an hour or so and when it was done the fit was tighter and the rifle shot better than ever (although the Elcan probably accounted for some of that, too!) It was a tough decision at the time but I'm glad I made it--plus I sold the old A2 receiver on the Parts-n-Bits forum to help pay for the flat top.
 
Hmm... well maybe getting a stripped A4 upper and doing the swap is a mod I should consider. Anyone know where to get reasonably priced stripped flat-tops to fit a large-ring Colt lower? ;)
 
I got mine (a small-hole Armalite) plus the offset pin and other bits (dust cover, forward assist, springs) from Wolverine. I wanted to keep the old upper complete to make it a little easier to sell.
 
I was concerned about the conversion pin...mostly that there'd be extra "slop" in the fit, but in my rifle's case there was no problem at all. I've actually won a couple of the 300m NSRA Sierra ISU matches (in the Service Rifle class) with the rifle (my first rifle match wins, well, ever, in any caliber) since I swapped uppers. If pricing and quality are comparable, I'd probably go with a large hole upper, but I'd have no hesitation about going with the small hole/offset pin again.
 
problem I have wit hthe offset pin is that you have to remove the front pin before the rear, so you can't pivot up the barelled upper for easy cleaning like you can with a non-offset pin :?
 
The use of the offset pin once it's installed is transparent (to me at least :lol: ). I can still remove my rear pin (although it's a little tighter) and pivot the upper down the same as when I had the old upper.
 
The instructions on the Fulton Armory website say specifically not to do that as you can damage the receiver.

I stand to be corrected though...?
 
Hmmmm...interesting. Mine's Armalite on a Colt lower...I wonder if that makes any difference? I had not heard of having to remove the front pin for cleaning--that would certainly be a pain. More investigation is required!

EDIT

Ok, I checked the Oracle (aka Google) and found this PDF http://www.fulton-armory.com/CombiningColtLowers-withStandardUppers.pdf that suggests that there could be problems with incorrect installation. The way I read it, the risk is when you are taking the upper and lower apart completely, not when you are opening the two for cleaning (although I am not sure). I seem to remember when my rifle was being done that the other Gunnut helping out mentioned this to me...can't say for sure, though. Any thoughts, folks?
 
Well,

My thoughts on this (being the other gunnut mentioned above) are thus:

I had an offset pin attaching uppers to a lower I had. The issue that occured when the offset pin was slightly loose because of firing, it actually was able to rotate slightly.

This slight rotation of the offset pin allowed the upper and lower to spread slightly at the front, between 1 and 2 mm. Not much, but noticeable, and just enough to cause some of the ammo I was firing to get jammed into the feed ramp edge (those were with 45 gn and 69 gn Hollow points I think) jamming the round back into the cartridge case.

I know I mentioned this to you M-G when I setup your upper, but with the tight fit, we were unable to cause this rotation to occur with your rifle I believe?

The problem may have been a slight difference in the hole location with that old Colt lower of mine too. I found that it did NOT fit other large-hole uppers properly either. I measured the pin location on that lower once, but was unable to establish the correct dimensions for comparison.

Now, my problem with this led me to spend the $300 on a stripped lower from Wolverine, and slapped that in place. Problem solved for me. Also, since I use multiple uppers (including .22) I found it to be a real improvement in convenience for me, allowing me to just pop the pins to swap uppers.

So, bottom line. Be aware of the orientation of the offset pin when assembling the lower/upper, and ensure that there isn't a gap between the lower and upper when you're done assembling it after cleaning, and keep the pin screws tight to prevent them from rotating.

NS
 
Well, in talking to many folks on this issue lately, the consensus is the just leavethe colt as it is and anjoy it like this. Most people are advising me that turning it into an offset pin parts gun would lower the resale value as well.

I think I'll just enjoy her as-is and use this as an excuse to build a second AR ;) You know, just for the hell of it ;)
 
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