TexasCHLforum.com

That barrel-breakin procedure is one of the most hotly debated subjects in the sport.
I don't know if there is an absolute truth to it unless you are a benchrest shooter with an electron borescope and lots of time.
For me, break-in consists of shooting the first 100 rounds with moly-coated bullets.
And I've only done that with .223s.

In the price range you posted, and if Dad is buying it as a gift, I'd buy a name brand that uses the mil-spec lower.
S&W, Sig, Bushmaster etc. You can buy all of these with the railed forend but you may have to do that online.
Otherwise order it separately.