Re: TRG-42 vs AI AW vs TAC-300
I'm not flaming you....just giving you a heads-up on how it is round here.
If I wasn't away travelling I could post you the link to the enhanced SH search engine so you can do some digging.
On the AW - had mine for a long time (.308 though) so not really qualified to do a .300 comparison.
What I can say is it is hands down the best rifle I have ever bought (and that includes my GAP - both are very evenly matched on accuracy...at least in my hands as I don't profess to be skilled enough to push them to the extremes of their capabilities....others here can and do so may give you a different opinion).
It is built like a tank, will take more punishment than I can or would ever want to give it, and still keep on turning in sub .5 MOA accuracy (that is a comment on my abilities, not the rifle - I am sure it is capable of much better). The action works relaiably no matter what and I've never had any problems with it due to dirt or rain.
AW's are heavy rifles so depending on the configuration or intended use, be prepared. Range use....no problem. Hunting....maybe not ideal. Duty....that's what it was designed for.
You should get behind the AW stock to see if you like the ergonomics (some do, some don't). Many will praise the calibre change capabilities too - not a feature I use (or that may interest you?) but I don't know if either the McM or the TRG do this.
Don't rule out the AE either (if they do it in 300??) Or a custom build on the AICS.
LoneWolfUSMC has published a great review on the AE he has (look him up in the user list). IMO a lot of what he writes there holds true for the AW.
On the cost - again there are a lot of threads here about the comparative cost of the AW to the TRG - I don't think it is as clear cut as some would have you believe. If you include the AE in your evaluation, then the price is still further removed as an issue. There are some great deals to be had on the AW/AE these days in the UK (same in the US?) so don't get too hung up on this....and I'm guessing if you are looking at these rifles/calibre then price may not be your most important criteria
Others will mention perceived fragility of the TRG stock, the bipod mechanism, cost of accesories etc. etc. It really comes down to what you are looking for in the rifle. I don't know the McM at all, but both the AW and the TRG are highly respected and proven, accurate rifles. You can't go too far wrong with either of them.
But for me "buy once, cry once"! I know the AW and I'd be very happy to recommend it to you as a good, solid rifle that does what it does 100% reliably without any dramas, day in day out, rain or shine.
I shoot it from 100 out to 1000 and it's a keeper and even after a lot of years it is still a joy to shoot, never disappoints, keeps me honest and always encourages me to up my game.
Good luck with it whatever you do.
(jetlag....isn't it a wonderful thing? Hope this is not too much of a ramble...)