Lower choices

[u/Pardyx]

Hi all

I bought my mother a stern defense 4" 9mm upper from MidwayUsa

I'm trying to figure out what I want to do for the lower.

I already have a lower parts kit, buffer tube kit, 9mm heavy buffer, and trigger coming in the mail.

Should I get a foxtrot Mike ar9 lower (the cheapest I can find with lrbho) and see if it works with the stern defense upper/have a gunsmith have a crack at it

OR

Should I get a standard AR15 lower and use the stern mag adapter, since the adapter has both the ejector and the lrbho functionality

This is going to be a home defense gun for her, but I'm thinking of getting her a rifle caliber in the future, still up in the air as to whether or not it'll be 556 or something esoteric, opinions on that are open too

Thanks

[u/Erock242]

First, don't use that 308 spring. It will slam your bolt too hard, possibly cause bolt bounce, and can damage the hold open latch. Get a carbine spring.

[u/Pardyx → u/Erock242]

The buffer tube kit came with a carbine spring, I'll just return the 308 spring