Troy look interesting, as does the Kalashnikov KSZ-223.

Just my $.02.....

I am pretty familiar w/ the Remington semiauto 742/740/7400 semi series which is very similar to the 760-series pumps. I owned a 740. The former are very popular in some states back east and the 760-series in PA with its millions of hunters where semi's could not be used for hunting. A good friend has a 760 in .30-06 and has killed a lot of game with it; elk, deer, etc.

For years I bought guns to learn the mechanism and understand the rifle and then sell it. Enjoyable and very interesting hobby of a sort. I couldn't get rid of the 740 fast enough. I've never seen a gun more obviously designed to cheapness of mechanical construction and less regard for long term function. Strong action, to be sure. I'll give them that. I did learn the gun and figured a method of accurizing it but cannot argue one word with the Remington sales representative that described them to a gunsmith/dealer friend of mine as:

"The Rifle that commences self destruction with the first pull of the trigger".

This...from a Remington sales rep!

You can find if you look hard enough raving reviews about their accuracy and such but this is frankly, mostly BS.

The gun served its purpose very well for gazillions of American hunters. My Father in law had a 742 from the early era for deer hunting in MI for many years and probably killed around 40 deer with it. Even had a custom stock made for it. His use fit well into the target market; 40 deer x about 10 shots per year of exclusively factory ammo "to check zero" for a grand total of maybe 500 bullets down the barrel for its entire career.This is the same category of use my friend w/ the 760 falls into. If your interest fits into the general concept you may find a 74/76-series gun to your liking.

1} Not shot a lot.
2} Shot at relatively short range.
3} Used with factory ammo unless you are fine with getting no more than 2 or 3 reloads from a case.

Could you get a reverse-lemon and trick yourself into a real dandy? Sure. Absolutely. I've heard of Vegas and Yugos that got good gas mileage and never needed a tuneup. But on the whole, I'd steer clear.

Now.....

An AK set up for pump action seems to me to be a VERY simple prospect to engineer and if it keeps the features of an AK except for the gas system, might be a winner. The troy looks very interesting, too. As with all these cobble jobs the theory can sound perfect while the execution should be executed, tho, tho who knows.

The Brit marketed bolt action AR's look very interesting, too, and as I understand it, some of those guns are dead reliable.

As for .300 BO not sure what your intended use is, but those that kill deer w/ AR's here that I'm familiar with {one fellow over on Arfcom has documented thousands} use straightup .223 w/ appropriate bullets. The .300 is a pretty lame cartridge EXCEPT for suppressed use which frankly might be of some real advantage to you on the farm there if that is your interest. {?} I say lame with a caveat. In the AR system it is better than the 7.62x39 as I've never heard of many 7.62x39 AR's that run well. So there's that. I REALLY like the 7.62x39 cartridge and had a CZ bolt and AK and killed varmints and deer and coyotes with the round. Excellent round and better IMO than the .300 tho the .300 is often compared with it. I guess I'm a little too hard on the .300 but my issue is in an unsuppressed AR I see little advantage ballistically, shorter range and much more expensive to shoot. That's my beef. I'd steer clear of a 7.62x39 AR at least based on every review I've investigated {reliability} and it seems mag issues are the primary bugger so a pump wouldn't solve that dilemma.