An AR?

[Lucas]

Excuse my ignorance but,  can you change a 5.56 into a larger caliber by replacing the upper?  Dont know much about them.

[Pathfinder]

Excuse my ignorance but,  can you change a 5.56 into a larger caliber by replacing the upper?  Dont know much about them.

That's the way. It works well for some calibers, like 6.5 or 6.8. For larger rounds, like the .308, you do need a new lower specific to that caliber cuz the magwell is too small on the 5.56 for the larger round. Most of the fiddly bits - rails, sights, stock, grips, etc. - are interchangeable.

Check out this thread for an interesting discussion on this topic: http://www.downrange.tv/forum/index.php?topic=1902.0

[HAWKFISH]

Yep. Bushmaster has an upper in .270. You can take your regular lower 5.56 upper off and put the new .270 on and then use a .270 26rd. mag instead of your normal 30rd. 5.56. Then you have a .270 AR. 

[Lucas]

Are most brands interchangable?

[Pathfinder]

Are most brands interchangable?

yes, in general, parts from different vendors are inter-changeable (see below). That's why the AR platform is sometimes referred to as the Swiss Army knife rifle - many of the parts are interchangeable, especially the externals. The bolt and carrier are the only things besides the barrel that may change with the caliber change - unless you go to the really big bores like .308. With the 6.x, the magazine followers will change too. There are also small differences where you might not expect them, such as civilian vs. military mounts for stocks and buffer tubes.

But a huge cottage industry has been set up feeding the AR mania, selling everything from BUIS (back-up iron sights) to little rubber strips that cover rails to make them smoother and more comfortable to hold to magazine followers to ambidextrous safeties - all after-market.

Study up, search the internet, take everything with a grain of salt - lots of self-appointed "experts" out there. Read, read some more, ask questions - like here - especially when you read where 2 authors say different things about the same subject. It helps if you have an idea of what you want - 5.56, 6.x, .50 Beowulf, .50 BMG, .270, .22 - whatever. Then pursue it and drill down while keeping an eye on the big pictue too.

Most of all, for heaven's sake, have fun!!

[Sponsor]

[Lucas]

How easy is it to change from a 5.56 to 6.8?  Parts and time wise.  Would it be "easy" to change between the two, or would I just be better off spending the extra dough on another rifle?

[Pathfinder]

How easy is it to change from a 5.56 to 6.8?  Parts and time wise.  Would it be "easy" to change between the two, or would I just be better off spending the extra dough on another rifle?

I'm planning on buying a complete upper for the 6.8 - the most expensive parts are the barrel, bolt & carrier anyhow. I figure it's best to just get a complete upper and not worry about fiddling around with mounting a barrel, etc. when I want to swap out.  In fact, I'm building a 6.8 on an AR stripped lower, mostly to teach myself the details, building the lower out and all. Then adding a complete upper.

Price-wise, a complete 6.8 upper can set you back as much as a complete 5.56 rifle or carbine - I've seen them from $600 to $1500 and that's just for the upper. By the time you're done, building as I am, you could easily drop 1500 and up on the complete rifle. But then, it is a 6.8 and not the 5.56, and these tend to be more expensive anyhow.

[AR 15 Rep]

We also have them in 7.62X39 that fit on the AR lower.  The best way is to get the complete upper and then to switch them out to the AR 5.56 only takes a few seconds to switch them out.

[DDMac]

Found'em on your site Rep. What about magazines??
Mac.

[tombogan03884]

If you go the complete upper route it's real hard, push 2 pins out, push 2 pins in and thats it.