I have been wanting to build a new, purpose built, rifle/sbr for deer hunting (and hogs for that matter) but just can't bring myself to make a decision. I was really liking the 8.6 blackout, (still do like it) but then changed my mind to the 338 spectre / razorback / insert various short action wildcat here and also the 350 Legend or 450 Bushmaster. What do you guys think and what opinions do you have?

The 450 is awesome. Great AR round and fun to reload too.

Comes down to the environment you plan to hunt. The lease I hunt is very thick and shots rarely reach beyond 100 yards, perfect for my 450 bushmaster. For the one area that is open with shots that can reach 200+ yards, 300 WSM.

I have a 350 legend and my buddy has a 450 bushmaster. Both kill deer. The 350 has less recoil. The Legend with 180gr Winchester sps are a bad combo for deer.

I picked up a 350L recently and plan to give it a try later this season

Now you can split the difference with a 400 Legend.

FOFITY

Just bought a ruger ranch v2 in 450 bushmaster. Been shooting one in 300bo since they came out in about 2016. Only shooting subs and suppressed. Shot the bushmaster 8 times this morning, so far very pleased with it. Just wanted to try a heavier bullet than the 300bo. Using the 395 hornady right now, gonna try the 425 maker bullet if I can find some. First impression it's a little bit louder than the 300bo, but still the bullet hitting the target and then the berm is much louder than the shot. Recoil was not unpleasant at all, just a little push, but obviously more than the 300bo. I think the new stock design probably helps mitigate some of the recoil. I bet it would kick like a mule with supers. Accuracy was great, left and right spread was almost zero, all shots would have been nearly through the same hole l/r, but a little spread vertically. I shot a group at 100 yds with shots 5, 6, and 7, 2 shots were half splitting each other top and bottom, 3rd was almost touching the other 2 straight below. Didn't have a chrony with me, but I'm sure the vertical spread is speed variation. Shooting through a hybrid 46, it's quiet, but probably would be really quiet with a can with more volume.

Like you I really wanted the 8.6, then was scared off by the troubles they seemed to have and considered all the others, but decided to really get better than the 300bo needed to get a much heavier bullet. 400 legend seemed promising but it's been 2 years and still no support, subs were promised from winchester over a year ago and still nothing. It seems to be dead in the water right now. Went with the bushmaster over 458 socom just so could use in a straight wall case state if the chance came up. Will have to let you know how it performs on deer in about a month.

That should be an awesome subsonic setup. 45 caliber frontal area and almost 400 grains should hit hard even at subsonic speeds.

Hornady's new 338 ARC should be a gem for shooting suppressed. Think the subs are 307 grain SubX.