Recommend second caliber barrel?

[jjrothWA]

An upcoming gunshow may have a dealer with uppers fro about $90, I want to get a second caliber, thinking the .450 Bushmaster or the 7.62X39.
Present thinking is the .450 for being allowed in MI southern deer zone and its 300 yard range.

7.62X39 due to more availability, using SAMMI chamber or Mil-spec???

What are decent manufacturers to consider?

thanks.

[emmagee1917]

I went with several extra calibers in several uppers. Went with .300 Blackout in a SBR and a carbine and a .458 Socom in a carbine to start . I have suppressors coming in both calibers . I also went with a .50BMG upper and a " can cannon " upper . I'm now working on lowers for them all . It's hard to stop .
Chris

[Litt'le Lee]

I have 3 AR's in 7.62X39--one made with a 308 bore allowing more bullet choice--McGowen barrels--the other 2 a 16 in and a 20in stainless--all shoot great

[holdover]

built one in 6.5 Grendel, like the dime size groups at 300 yds.

[GA-Dave]

I second the grendel. I am very impressed with the cartridge.

[Dan in NH]

for the AR platform go with the 6.5 grendel

[Art]

7.62 x 39 is a good cartridge and inexpensive but can have feeding issues in some AR rifles. The .300 Blackout provides similar ballistics without the feed issues and has the bonus of using standard AR magazines. Unfortunately it also costs a bunch more.

[Litt'le Lee]

the 300 blackout--very expense--I'ts a pistol round !!--most 7.62x39 ar's are usually prone to BAD MAGS--i'VE NEVER HAD A PROBLEM--ASC 20 rounders

[emmagee1917]

the 300 blackout--very expense--I'ts a pistol round !!

Really ????? Pray tell , in which pistol was it introduced in ?0
Chris

[Darreld Walton]

I've been leaning towards the 458 SOCOM for a pistol build. Want something with ballistics approaching 45-70 to strap to a pack frame if I make it to AK for another moose hunt, while hauling meat, or to have around camp. My thoughts are that I want "rifle" bullets that will hold together and penetrate come hell or high water.
I've also been looking at building another upper and making it up as a .30 Carbine. Haven't been able to 'like' the Blackout, or Whisper, or whatever they're calling it these days. Same for the commie rounds, effective as they are. Might as well use those rounds in the weapons that were developed with them, and not have to worry about mags, or the odd bore size issues.
I figure that a guy HAS to have a 'dedicated' .22 upper!