I found it to have slightly thicker neck thickness than Lapua, Hornady or Peterson, thus needing a larger bushing.
I had a box of FGMM once fired and loaded up a few fouler & sighter rounds to zero my scope and do a tall target test to confirm whether 20 MOA turret adjustment is really 20 MOA, then did load development with Lapua brass because I had 200, not 20 like the FGMM.
It has a looser primer pocket once fired than Lapua with 8 firings. Peterson is even tighter.
No digs on the brass but I'd wager the primer pockets loosening up will define it's life cycle in number of firings.
If it is really factory primed it may be new. Does the inside of the brass look new? Even that isn't definitive if the original owner cleaned with steel pins. I'd confirm whether Federal even sells new brass factory primed. If you can find it, then you'll know what the retail value is. Can you look closely to see whether the laquer sealant is actually on the primer too instead of just on the case? If really factory primed the sealant should be noticable on parts of the primer too.
I'm thinking that anything close to $1/case will be a halfway decent deal for the buyer and a nice pop for you, maybe a bit less because of the volume. Be prepared to be flexible.
Keep in mind that Midway has regularly had BBR-15 headstamp .338LM for $79/100 that was made by Lapua for Barnes Ballistic Research but I haven't seen them in a few months. I think it was a contract overrun that may not ever be seen again. Lapua is pretty much the Gold Standard for top shelf quality but ADG is getting a good reputation.
