Multi-cal lower question...

[SoCalshooter68]

This may be a stupid question as the lower is labeled as a muilti-cal, but can multi cal lower be used to put together and AR rifle in .308 or does it have to be a .308 lower? Does multi-cal mean you can only use it to configure in .223 or 5.56? Thanks for any clarification on this question and forgive my ignorance.

Med.

[69Mach1]

A .308 lower is needed. Then you have to decide which .308 lower/upper platform to go with since competing designs are not compatible.

[Saym14]

multi cal means multiple cals, more than one. so you could match any compatible upper, 9mm 22, etc.

[THT]

Multi-cal is just a marking. It has no legal ramifications whatsoever. You can use it with any caliber that it will physically work with

[SoCalshooter68]

thanks for the infor everyone...

[Saym14]

Multi-cal is just a marking. It has no legal ramifications whatsoever. You can use it with any caliber that it will physically work with

its also legal to use a 22 or 9mm upper on a lower marked 5.56 right?

[THT]

its also legal to use a 22 or 9mm upper on a lower marked 5.56 right?

Yes; caliber designation has 0 legal bearing.

[Acorn556]

I think the only reasong you'd need the 308 upper is because of the difference in the shape of the 308 upper. I don't think anyone makes a 308 upper to match an AR15 lower.

[Fjold]

I think the only reasong you'd need the 308 upper is because of the difference in the shape of the 308 upper. I don't think anyone makes a 308 upper to match an AR15 lower.

The 308 sized cartridges are too long to work on an AR15 lower (or upper).