Is It Possible To Convert Small Pin Ar15 Upper To Large Pin???

[jschance]

Why not just get a new upper there cheap enough?

The problem with getting a new upper (which I will be doing) is they don't make an affordable, large pin upper. The only company I've found so far that offers a large pin replacement upper assembly wants $1,000+. If anyone knows of someone making large pin uppers, by all means let me know.

I will probably eventually just use an offset pin, it just seems like there should be a better way, especially for a 'hobby machinist' (that's why we've got all those machines in our shop, after all) ;-)

 

[Cactus Farmer]

Thinking out of the box, why not sell the "rare, vintage" part and get a proper part with the cash, as the "vintage,NOS " part should bring extra $$$ over the new and improved models?

 

[ScrapMetal]

Have you looked at the Daniel Defense "Big Hole Upper", though at the moment they appear to be out of stock?

-Ron

 

[jschance]

Thinking out of the box, why not sell the "rare, vintage" part and get a proper part with the cash, as the "vintage,NOS " part should bring extra $$$ over the new and improved models?

In all reality, that's probably the best bet. That, or pick up a small pin lower receiver and transfer all the bits and pieces from one to the other.

Have you looked at the Daniel Defense "Big Hole Upper", though at the moment they appear to be out of stock?

-Ron

Yeah, I looked at those, but between the high comparative costs, and the fact that I've never seen them 'in stock', it wasn't something I was ready to charge after. That, and I was hoping to find someone who had done the machining to convert a small pin upper to large pin.

 

[Jay-z]

Has anyone on here ever attempted to convert a small pin upper receiver to a large pin configuration? I know that the pins are not only different dimensions but slightly different locations. It would seem that with the correct machining set up, it would be possible to rebore the pin hole to accommodate the larger pin diameter and different location.

I've got a 'pre-ban' Colt lower that I need to build an upper for. I know there are offset pins available, but that seems like an awkward way to fix the problem.

Thanks.

Why not purchase yourself a 0% upper, then mill it to the specs you need. They are very reasonably priced, and makes for a fun project. Just my .02 Jay

 

[jschance]

Why not purchase yourself a 0% upper, then mill it to the specs you need. They are very reasonably priced, and makes for a fun project. Just my .02 Jay

So is a 0% upper just a block of aluminum?

Otherwise, where would one get an unfinished upper?

 

[Jay-z]

So is a 0% upper just a block of aluminum?

Otherwise, where would one get an unfinished upper?

It is a block of aluminum but it is cast in the form of the upper receiver. It is a raw forging. They do require a bit of machining but all of the instructions you will ever need are all over the web. Just Google 0% A.R. reciever. These are available in uppers and lowers, A2 with the carry handle or flat top A3. Jay

 

[Jay-z]

 

[jschance]

Hmmm, looking at the 0% uppers, I'm thinking a 80% lower might be my best solution.