Warning

 

Close
Confirm Action

Are you sure you wish to do this?

Cancel Confirm
AR15.COM
AR Sponsor
1/19/2003 7:00:29 PM EDT
Is it worth it,have Oly plinker 16" A1 upper,I like flat top A4 better for opic.How much trouble to change?
1/21/2003 9:23:35 PM EDT
[#1]
I would say its worth it, especially if you find an A4 receiver cheap, as oppossed to just buying a J&T 16" A4 upper ($289.95 http://webcats.net/store/merchant.mv?Screen=CTGY&Store_Code=J&Category_Code=BU )and then having 2 to choose.

If you have the proper tools and some mechanical ability, its a very straight-forward conversion. Same with the lower assembly.
You may want to check the "build it yourself" forum, and search for links to the upper assembly pages.

For my first barrel/ receiver swap, I bought a copy of the US Marine Corps Tech manual (TM 05538C-23&P/2  It should be for sale just about everywhere for less than $10) and followed the instructions.

Some recommend a better wrench than the $12 mil-spec combination wrench, due to lesser chances of slipping, which I can sympathize.
Some would even debate whether you'd need a headspace guage in that you'd be using the same bolt carrier group and your original (presumably properly headspaced) barrel, but I leave that up to you.

The only real snag I've encountered is getting the gas tube loose from the front sight housing after drifting out the pin on a particular ASA upper. (no comments on ASA parts nec. I neither recommend nor decry them)

AR's are really fun to "mix&match" once you get into them.  Don't be too intimidated. Good luck.
1/22/2003 4:41:11 AM EDT
[#2]
Thank!I'll start looking for flat top upper.
1/24/2003 12:36:40 PM EDT
[#3]
Please don't go just on my say-so.

Its alot cheaper to buy the manual and/or read the posts in "Build It Yourself" forum here, and price the tools, [if you don't already have them,] and then decide whether to buy the upper receiver alone and change it yourself, or buy a complete upper already assembled for about $150 -$200 more.  

If you only plan to do this once, it may be much more cost effective to buy the complete flattop upper and barrel assembly [from J&T or others], and skip the tool costs.  This has the advantage of getting to choose which upper to shoot, fixed sights or scope, with just exercising the take-down and pivot pins.

FYI see http://www.ar15.com/forums/topic.html?b=3&f=4&t=144270 on the tools required

Someone else may have the exact link to the upper assembly page archived here.

1/24/2003 3:42:43 PM EDT
[#4]
Also, if you send your existing upper to Bushmaster and buy the flattop receiver from them, they'll install your existing barrel on the new upper for free (meaning: no labor charges).

-Troy
AR Sponsor