[ARCHIVED THREAD] - A1 upper build

Posted: 6/14/2008 11:40:29 AM EDT

I have a A1 upper which came off of a 5.56 AR15. Can I build a 9mm upper with it? what modifications would need to be made?

Thanks.

Posted: 6/14/2008 2:10:42 PM EDT

[#1]

Quoted:
I have a A1 upper which came off of a 5.56 AR15. Can I build a 9mm upper with it? what modifications would need to be made?

Thanks.

Screw a barrel in place into the front, slide a bolt in the bore, and feed it with appropriate magblock/mag combination..

Posted: 6/15/2008 7:07:01 AM EDT

[#2]

so i don't need the modfied brass deflector and the 3/4 dust cover? what about the cross pin with spring i see in some of the pictures?

thanks.

Posted: 6/15/2008 7:16:02 AM EDT

[#3]

The cross pin and spring is for the ejector on Olympic Arms system of 9mm conversion. If you use a RRA/Colt style conversion you don't need that as the ejector will be incorporated into the mag block.

Posted: 6/15/2008 8:18:34 AM EDT

[#4]

Quoted:
so i don't need the modfied brass deflector and the 3/4 dust cover? what about the cross pin with spring i see in some of the pictures?

thanks.

No door or deflector here, std A3 flat top, now it sports an A1 with std style 11" barrel ang grips.

Old pic --

Posted: 6/15/2008 8:22:47 AM EDT

[#5]

thanks for the picture. that's what i wanted to see. did you remove the forward assist plunger? is it required? if so, what did you plug it with?

thanks

Posted: 6/15/2008 6:05:57 PM EDT

[#6]

Quoted:
Thanks for the picture. That's what i wanted to see.

Did you remove the forward assist plunger?
Never bought 1 to finish upper when it sported my 12" stainless bull barrel in 5.56mm, though the A1 upper used now has the assist plunger (had 5.56mm barrel in it for 18yr), I just left it in to fill the hole.

Is it required?
No, 9mm bolt not cut for assist, it would be a means to fill the hole for $12

If so, what did you plug it with?
With the flat top in the pic, be it an old (around 2003-2005 pic), I left the assist hole open.

Thanks

[ARCHIVED THREAD] - A1 upper build

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[ARCHIVED THREAD] - A1 upper build

[ARCHIVED THREAD] - A1 upper build