i know this has been covered....

AR/M4 AR General Discussion
1

i know this has been covered before but i cant find it anywhere. i dont know if maybe im just typing the wrong thing into google and/or the search bar. so i apologize in advance…i know

feel free to explain it here or post the link…i do not have a problem reading and searching to learn.

I am new to the AR world and have yet to own one, just messed with a few and love the way they shoot.

I have seen “modular” ars that can swap from cal to cal with just swapping out the upper…but cant most ars do that as well? what makes it fall into the modular category instead of just a regular ar?

thank you and sorry

2

Nothing, the uppers are all interchangeable.

You can take pretty much any 5.56 lower and put any upper on it.

3

The modular ARs would be those like the MRP where the barrels can be swapped without a vise. Just remove two bolts, swap barrel lengths/calibers, and you’re done.

4

Are you possibly referring to these?

http://www.mgi-military.com/

The lower can be switched for different calibers and mag styles such as 9mm, AK mags, belts etc.

5

ya that looks like one

as well as the colt 901
http://www.coltsmfg.com/Catalog/ColtRifles/ColtLE90116S.aspx

bushmasters carbine
http://www.bushmaster.com/catalog_xm15_BCWVMF16FMC.asp?zoom_highlight=modular

those are the ones that i know of.

but ya, so the only difference in those a regular ar (besides cal) are that you do not need a vice to swap uppers?

thanks

6

Two switch uppers you only need to pop two pins on any AR. On the LMT MRP you don’t need to remove the upper. You remove two bolts and remove the barrel itself. Buying complete uppers is expensive. Buying a different barrel for different purposes is much cheaper. The new Colt modular rifle allows the lower to accept both .308 and .556 uppers. So you could use all barrels compatible with both platforms. The Colt is the way to go for maximum modularity.

7

No not really. As KC said, you would not need a vice to swap upper on a standard AR. The actual lowers on the modular guns are different than a standard AR, from what I’ve seen. The magwells are usually removeable to take different inserts.

For example, the 9mm AR usually needs a magwell block if it is not purpose built for that small of a mag. So they have an insert that accomodates that. Switch that out (and the barrel or upper) and you can shoot something entirely different. Its interesting, but it seems they have issues getting a solid production line going.