Regarding Lower Receivers

[Precision]

This is a totally ignorant question, but as most of you know I'm a totally ignorant firearms enthusiast.

Is a typical AR lower receiver limited to only one caliber? For example, would a Lancer Systems L15 Billet Lower (http://lancer-systems.com/L15_2010.html) be able to accept 5.56 magazines as well as, say, .50 Beowulf magazines?

Totally ignorant. But I'll tell you why I ask. In the oppressive west coast state where I take up residence, I am planning on building a designated feral hog/large game AR in the future. Unfortunately, Alexander Arms (maker of my preferred caliber, the .50 Beowulf) does not ship lower receivers to California. I will have to buy an upper from AA and search elsewhere for a quality lower. I searched around and found the awesome L15, but then started wondering if just any old lower will take any old magazine. I decided that would have to be a definite no.

1. Which lower receivers (NOT Alexander Arms) can fire .50 Beowulf?
2. Is the above-mentioned L15 a good choice?

 

[spartan00054]

I don't know of a standard AR-15 receiver that will NOT accept the AA .50 BEO magazines. That's the big deal about .50 BEO, all you have to do is pull takedown pins, swap uppers and magazines, and your 5.56mm assault rifle is now a large-bore rifle suitable for hunting good size game or engine blocks. The cartridge was designed to put the biggest bullet possible in a cartridge that would fit the dimensions of an AR-15 magazine well and didn't require a bolt face that would exceed the dimensions of the upper receiver.

That lower has an interesting feature in that it has a modular magwell, but for the price, I'll pass. The modular magwell is just to help with the kind of quick mag changes you need in competition and whatnot, it does not, like some systems, allow you to put different size magazines in, i.e. Colt's CM901. Spike's Tactical is affordable and they make good stuff.

 

[MichaelK]

Just put together an AR in 6.5 Grendel. When you purchase your lower, you'll get one that has "Multi caliber" stamped on it instead of "caliber 5.56". You can pick up one from a shop for about 150$, or at a gun show for 99$.

I don't know if that is just a good idea, or an absolute legal requirement. Better to find out now before you're at the range and getting questioned by law enforcement.

BTW, the Grendel will accept a standard .223 magazine. The 6.5 Grendel cartridges fit in it, but don't feed properly. It's the feed lips and follower that are cartridge specific. The outer body shape is standardized.

 

[easy]

You need to go to Calguns!

http://www.calguns.net/calgunforum/index.php

 

[TonyAngel]

As long as you are talking about a standard "milspec" type of receiver, there are many different calibers that you can choose from if you are looking for something other than a .223. Most only require the proper upper, bolt and magazine.

Just be sure that you really want what you are getting. I had a .50 Beowulf for a while and it wasn't nearly as much fun as I thought it would be.

 

[Kerf]

you might try Model "1" sales. URL below. Good barrels and reasonable prices.

http://www.model1sales.com/index.cfm?fuseaction=category.display&category_id=652

Sorry. Disregard, wrong thread

Kerf

 

[helotaxi]

There is no legal requirement for the roll mark on the lower to match the actual chambering of the upper. Many, but certainly not all, stripped lowers come marked "multi" but there is no legality behind it.

 

[Tirod]

Overall case length is the key - AA designed the .50 to fit the mag limits and will go into any standard AR15 lower.

There are about 5 dozen calibers you can feed thru an AR15 lower. Usually, the barrel, bolt, and magazine are about all that's needed to convert. Mags themselves will likely need a new follower, and the ribs inside may need to extend to a different depth to optimize feeding. Some constrict the mag and jam it with other rounds.

Don't blame AA for not importing into CA, they have their idiosyncrasies, but it's likely the AWB provisions and legalities intruding into their profit curve. Making a special edition for just the one state can be costly, especially since the upper will pin onto ANY compliant lower sold there.