I have a bushmaster xm15 a2 fixed carry handle . can I buy an a3 flat top upper and just swap out everything from the a2 .or is it better to keep the lower and just buy a complete upper

I put an Aero Precision Upper on mine, no prob. You can always add the separate combo/grip sight if you want later.

 

 

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Not to steal any thunder from Slick Willy, it depends on what your definition of "better" is.

You can never have too many AR parts, until you don't have room for them all.

With the right toolset, it's easy enough to swap the A2 upper components onto the new A3 upper.

The biggest thing to consider is that the A2 barrel assembly most likely includes a combination Front Sight Tower / Gas Block.

If your intention was, for example to put a nice scope on the A3, you'd want a low profile gas block without the front sight tower.

 

If you have the $, assemble a new Upper Half with the A3, a barrel and handguards / freefloat of your liking, and save the A2 upper for another lower.

Stripped lowers are fairly inexpensive, and it's pretty easy to put a complete lower together on your kitchen table with minimal tools.

 

This is the Joy of the AR platform!

Good luck

Easy to do if you have the tools. Remember your feed ramp combos esp for the upper.  No M4 feed ramp upper with a standard feed ramp barrel extension.

Can you guys recommend some places to buy stuff to build a separate a3 upper , id kinda like to get a stainless barrel not sure if theres some places to get pretty much everything one needs. Thanks for your guys help and suggestions John

You can always cut the sight off the A2 gas block with a dremel and cut off wheel. Personally I would just buy a complete upper of your liking.

 

Bravo Company is my suggestion where to start your search. Midwest PX, or Palmetto State Armory also has uppers. Rguns is another. There's plenty of places to order a complete upper from. Be sure to order one that's AWB complaint so it's legal in Jersey. Unless you're going to do your own complancy work on your own. If not then have the upper shipped to an FFL that your going have do the Jersey legal work.

 

Thanks deerslayer for the heads up on the companys.

Not to steal any thunder from Slick Willy, it depends on what your definition of "better" is.

You can never have too many AR parts, until you don't have room for them all.

With the right toolset, it's easy enough to swap the A2 upper components onto the new A3 upper.

The biggest thing to consider is that the A2 barrel assembly most likely includes a combination Front Sight Tower / Gas Block.

If your intention was, for example to put a nice scope on the A3, you'd want a low profile gas block without the front sight tower.

 

If you have the $, assemble a new Upper Half with the A3, a barrel and handguards / freefloat of your liking, and save the A2 upper for another lower.

Stripped lowers are fairly inexpensive, and it's pretty easy to put a complete lower together on your kitchen table with minimal tools.

 

This is the Joy of the AR platform!

Good luck

 

 

front sight post will disappear in any magnified rifle scope.. its like magic.. you won't even see it.. 

front sight post will disappear in any magnified rifle scope.. its like magic.. you won't even see it.. 

But it will still be there, to possibly interfere with mounting the scope in the proper spot

Ask me how i know.

If the front sight assembly is physically in the way for mounting your scope, something else has to be messed up.....

Remember your feed ramp combos esp for the upper. No M4 feed ramp upper with a standard feed ramp barrel extension.

This is a big thing with with Bushampster uppers. Make sure you get appropriate/corresponding upper. M4 cutouts in an upper mixed with a barrel extension that is lacking them is a recipe for headaches, cursing, and much frustration.

 

You best bet is to buy an entire new upper. BCM has over 2000 individual SKUs, each corresponding to a different upper assembly set up - varying rail, barrel, upper, combinations. You will find what you want, it will be priced fairly, and it will be high quality.

If the front sight assembly is physically in the way for mounting your scope, something else has to be messed up.....

 

 

THIS... 

I have a bushmaster xm15 a2 fixed carry handle . can I buy an a3 flat top upper and just swap out everything from the a2 .or is it better to keep the lower and just buy a complete upper

I just did that but I have the tools and experience to do it. By the time you buy the tooling to change out the upper from an A2 to a FT, you may be better off selling your upper and buying a new one to your specs.

FWIW

YMMV