Anyone ever use an SP-1 Lower to built an M4? If so, how'd it look? I'm at my wits end trying to get a legal all preban M4.

TS

WHy are you at your wits end?  Why dont you just use any preban lower?  Like a Bushamster or other lower.  What kind of problems are you having?

It will be fine.  Just use an offset pin and go for it.  If you hang enough stuff on it, no one will notice it's a slab side [;)]

Because I'm completely broke.  My wits don't have much length anyway.

TS

Mine looks GREAT!!! I'll try to post a pic tomorrow when I get home.

Screw the offset pin, especially if you think you might ever want to go with multi uppers. You can get an aftermarket large push pin. Large hole uppers are harder to come by but I just swapped a guy straight across... my small hole for his large hole flattop.

Cool idea.  Never thought of that.

TS

You made out on that deal, if it was a Colt large hole flat top.

Your comment about the offset pin makes no sense - are you saying to build all you uppers on large hole receivers?  Small hole is much more common, and the $5 pin works just fine, allowing you to put any small hole upper on a large hole SP-1 lower.

Yes, I believe I did. My upper was was sans barrel assembly but his was complete. He sent me his complete upper and I swapped his barrel assembly onto my receiver. He offered to pay me for my labor and return postage but I told him I thought I was already coming out ahead on the deal.



Yes, I'm saying to build all your uppers on large hole upper receivers... if you have a large hole lower. Yes, those offset pins work... well sort of... each time you open the receiver they turn and you often have to turn them around to the proper place so your rifle will close again. Swapping uppers is a PITA. You have to have 2 screw drivers to mess with them and risk scratching your rifle up in the process.

They make an aftermarket large push pin that sells for $5 or $6. They are slightly longer than the receiver is wide and have a detent ball in one end that keeps the pin from falling out of the receiver. I have a .223 M4 upper, a .22lr M4 upper, a 9mm commando upper and am now building another 9mm upper that I am going to suppress. Each are large hole and I can swap between them in less than 30 seconds including jacking with the sling. My life became much simpler after getting rid of the PITA conversion pin.

Colt large hole flattop uppers are hard to come by, but there is a company making aftermarket large hole flattop uppers. SP1 uppers are a good choice, especially for dedicated .22lr or 9mm as these don't don't have forward assist on them. Be patient and you can find deals.

Agreed, if you only have a large hole lower and intend on swapping uppers.  As we all know, that idea sound good on paper but you always end up buying another lower, or two, or three....[;)]

TigerStripe,

Here's the pics I promised.


[img]http://img.villagephotos.com/p/2003-6/209463/m4gery_01.jpg[/img]

more pics
[url]http://img.villagephotos.com/p/2003-6/209463/m4gery_02.jpg[/url]
[url]http://img.villagephotos.com/p/2003-6/209463/m4gery_03.jpg[/url]
[url]http://img.villagephotos.com/p/2003-6/209463/m4gery_04.jpg[/url]

Thanks FAM4, that M4 looks damn good,  It looks like in came from the factory that way!

Thanks,

TS