Sorry I missed your phone call again, TDD. I was going to pm you a response to all of your questions but figured I might as well post it up here in case it answers questions for others.
This rifle was built in 2007 by Kirby Allen as a full custom build. At the time, Kirby didn't have his Painkiller Muzzle Brakes
and used Defensive Edge muzzle brakes. The brake was installed by Kirby. Shawn Carlock used to do all of Kirby's coating, so he was the one who teflon coated the rifle.
If I were going up to shoot a big Yukon Moose, this would be my rifle of choice even over a big 338. In all likelihood, your shots will not be long range. I would guess they will be within 300 yards, probably a lot closer as in less than 100 yards. You will also most likely be shooting in the brushy stuff commonly associated with bogs. This rifle with the 260 grain Nosler Accubonds would be perfect for such a scenario. If you were to go with a 338 RUM or 338 Lapua with a high BC 338 bullet like a 300 SMK, even if you hit the slightest twig, you will experience drastic bullet tumbling and your bullet will not go where you want it to. The 375 RUM with the 260 Accubond will be a lot less susceptible to that. If you really want to punch through brush, you could even go with the 300 grain A-Square Dead Tough. With the way this rifle handles, and with the kinetic energy it would deliver, it is the perfect moose rifle.
Even if you were to encounter a long distance shot situation, the 260 Accubond with a muzzle velocity of 3050-3100 fps and a BC around .473 is no slouch ballistically. With a 100 yard zero, you could get to 600 yards with about 11 MOA of elevation dial up. Supposing you had a 10 mph cross wind, you would need to dial about 3.5 MOA.
Comparing this to a 338 Lapua with the 300 SMK at 2800 fps and a BC of .754 with a 100 yard zero at the same range of 600 yards, you would need to dial 11.5 MOA elevation and for a 10 mph crosswind you would need 2.5 MOA.
So you can see, you don't really give much up to the 338 Lapua ballistically, and you gain a lot concerning knock down power, reliable bullet expansion, and brush-busting capabilities.
I have never experienced any problems with the Lawton receivers binding up due to dust or anything. I would say they are slightly tighter than a Remington receiver, but not much. I would venture to say that you would never have an issue with the Lawton binding up any more than you would with any receiver. In reality, I have owned BAT actions, and they are much tighter than Lawtons. That being said, if you are somewhat careful, I don't think you would have issues with a BAT, Defiance, or any of your tight tolerance receivers either. On a moose hunt, you would just need to be careful to keep the bolt oiled if encountering wet conditions as I'm sure you will.
The bipod pictured is a Harris model which mounts directly to the sling stud. If you were to take it off, you would find only a sling stud remaining. The only reason I pictured the rifle with the bipod is for convenience of taking the photo. It is actually not included in the sale. I always hunt with a Harris bipod on my rifles, but that is a personal choice. On your moose hunt, I would guess you would be shooting standing or kneeling with some shooting sticks -- much like hunting in Africa. I don't know whether a bipod would be very useful unless you could get above the bogs and shoot prone from longer distances.
With the 24" barrel, I settled with a mild load that gave me 3050 fps with the 260 Accubond. Since I was using this load in Africa, I made sure I had plenty of margin due to possible temperature variability. I would think 3100+ fps would be possible without any pressure issues.
I had this rifle set up with a US Optics SN3 1.8-10x44 scope and felt the setup was perfect. It didn't add much weight, is fairly compact, and is simply an indestructible scope. I think a Nightforce 2.5-10 would suit the rifle very well for a moose hunt as well.
I hope that answers all of your questions. Like I said earlier, I can't think of a better rifle for your moose hunt, and I'm not just saying that to sell you the rifle. The black teflon coating would be another plus since it would reduce the chances of rusting the rifle out in the wet conditions I'm sure you would experience.
Let me know if you have any additional questions. Also, feel free to try calling me again. I'm sure we can synch up one of these times!