6.5-300 Weatherby Mag ammo?

I got 2 boxes from Sportsman's Warehouse a while back but had to ask them. It was in the back

I’m going to Simmons in Bastrop this afternoon, I’ll check there too.

Pendelton ammunition has some in stock

Sounds like you've got some good leads so far. I'll also suggest Steve's Outdoors in Magnolia, AR. Ph # 870-234-227. I won't be surprised if he has it, but it'll be expensive if he does. Save all your brass and strongly consider handloading at a later date (once you can find primers ). The current times are very frustrating for ALL handloaders. I've been looking for Reloder 17 gun powder for nearly 11 mos, but to no avail. Then 2 days ago I got an email notification at work about 1030 AM. My work filter blocks "gun sites" and I didn't have time to leave the grounds until about 330 PM at which time it was ALL GONE Good luck w/ your ammo. I'd be sure and use a controlled expansion and stout bullet like a Partition, Barnex TTSX, Scirocco, maybe Accubond or others. No Ballistic Tips.

As others have mentioned, if you get any ammo, be sure to retrieve and save all the brass, it’s worth about $2.00 a round for empty hulls.
Wildcat calibers are often harder to get than standard calibers but even more so during worldwide shortages like currently being experienced. If you aren’t real interested in getting into reloading, you might consider asking friends, co-workers, hunting club buddies if any of them reload and if so, would they be interested in loading for you for a reasonable charge.
Primers of any kind are almost impossible to get right now but someone already loading for a large rifle caliber may be willing to load you a box or two using their primers.

Bowie's in Natchez had it. Also I get most of my reload hardware there. Bought the rock chuker there too.

I got around 800.00 in my reloading setup including three different calibers of dies. I have everything but the tumbler. It is a very rewarding hobby and plenty of time at night to hone your skills. That 6.5-300 will be a booger when shooting 3 ladders at the range, better get a good lead sled and pad.