In the market for a big bore upper: 50 bw, 458 socom, 450 bushmaster.. Not overly picky about which caliber.. Who sales a good value complete upper?  Mainly going to be a beater hog gun.. Thanks in advance..

If your going 458 Socom the Tromix is the only way to go. I went with 450 Bushmaster and had APF Armory build me the upper I am very happy with it.

.458 SOCOM or .450 Bushmaster, TROMIX is by far your best choice between price, shipping, customer service, and most importantly, QUALITY.  Personally my choice of caliber would be, and is x7, the .458 SOCOM for many reasons already hashed over dozens of times both here and on the .458 SOCOM forums.

Big-Bore, still prefer the .458 over the .375 Socom? If I was doing it all over again I think I would gravitate towards the .375 because of the better ballistics. What's your reasoning?

I did not mention the .375 because the OP did not mention it.  I try not to stray too far from the OP’s question and assume he has done his due diligence in narrowing down his caliber choices and has already decided on the three he mentioned.  Also, I assumed he is not a reloader since he only asked about well known and available factory offerings and there is only one company offering .375S factory loads, SBR.

For ranges up to 150-175 yards, the .458 is still my choice, but for ranges further than that, out to 250/300 yards, the .375 SOCOM is my choice.

Frankly, I’d hate to have to choose one or the other.  Where I hunt deer, shots cannot exceed 150 yards so I would still choose the .458, but if I had the chance to hunt where 250-300 shots could happen, then I’d grab the .375 for sure.

Is .50 Beowolf dead? I've seen a couple non Alexander Arms uppers that have the metric size of the propriety caliber.

I don’t think it’s dead by any means, I just don’t like it or the .450 BM because when I got involved in big bore ARs, the only .500 bullets were pistol bullets and the BM did not exist.  Also, I don’t like high power rifle cases which headspace on the mouth.  Last, standard mags normally don’t work and have to be modified.  Those three strikes and it was out of the running for me, and even though there are bullets now that will hold up, I still want my rifle cases to headspace on the shoulder and use un-modified mags.  Others feel differently and that is fine; to each his own.

I have had good luck with standard GI mags and 450 BM, but any of the polymer ones seem to have issues. Also if you reload you can resize 458 bullets to 452 and use them. So that's kind of a moot point. Ballisticly the 450 BM is the best out of the group, but only has a slight edge over the 458S. Not saying any of the big bires are bad. I would probably either go 458S or 450 BM at this point.

Commercially available ammo for the 450 BM is a huge plus as well.

I am not a reloader, so that has impacted  my decisions. I have had a Alexander Arms 50 Beo for approx 13 years. Always fun and effective  but Ammo has always a been the hitch.  Pricey and not always available , a friend helped me load up a supply but  supply is still limited.  In the past year , the local fun shop has been carrying 450 BM ammo for about 1/2 the cost of 50 beo and 1/3 the cost of 458 SOCOM, So 450BM  began to hold my attention. Then not long ago I came across Great Lake Fire Arms ( Seems to be a small shop out of Sparta Michigan) They offer sub $500 complete uppers  and Barrel Bolt Combo's for $200.  I decided on the Barrel bolt combo and built my own upper. No serious work up with it yet, but it everything seems like a good quality barrel and is certainly accurate enough for taking game and plinking.