I've never shot Barnes bullets before, but am about to give them a try.
I have heard some horror stories about the early Barnes Bullets, but nothing other than excellent performance of the more recent.
What can i expect in terms of Cu fouling?

After solving more than 50 rifles for them I would say you have a better than 95% probability they'll be just like and other bullet. I have only seen one really bad rifle that fouled enough more than it did with gilding metal jackets that something had to be done. Dyna bore coat fixed that.

Finding seating depth to get the best accuracy out of them might well be much harder though.

Start with a clean barrel, and you won't have any problem. If you have jacket fouling from other bullets, it can build up quicker.

Fouling is minimal.

I like the TTSX over the TSX in most applications.

That said, I like lead core bullets better than either.

TTSXs are just about the only bullet we use and haven't seen any unusual fouling issues. For me they are very accurate and kill great.

The early ‘X’ bullets were, in my experience, very inconsistent. I used the blue coated ‘XLC’ version to take several coyotes and one antelope. On one coyote the 160g XLC blew a golf ball sized hole through the back of a coyote, another zipped through with no visible entrance or exit. At least both animals died instantly.

An unfortunate antelope buck was not so lucky. Two XLCs through the lungs caused it to lower its head and cough up blood, then lay down. While down it always kept its head up as it if was just soaking up the morning sun. I circled around for a closer shot, which I took about 20 minutes later. Just before that shot the buck struggled to its feet and tried to walk away. A third shot hit the heart and ended its misery.

After that I used the remainin XLC bullets for targets only. When the TSX came out I found them very accurate in my rifles but couldn’t bring myself to use them on game. Some reports of failure to expand, along with pictures of recovered TSX bullets reinforced my decision.

When the tipped MRX bullets came out I found them to be very accurate as well and gave them a chance on game. While holes were not as big as with some lead core bullets, no animal I took with the MRX took more than a few steps, including elk. The MRX was replaced by the TTSX, which we (no, not the royal ‘we’ but rather my family members and I) have been using for antelope, deer and elk. The results so far have been 100% positive – great accuracy, wound channels that show evidence of expansion, and no animals going more than a few steps with many (at least half and maybe more) dropping straight down. I’ve driven a couple of them lengthwise through deer.

Fouling hasn’t been a problem. I generally don’t scrub a bore until accuracy deteriorates and my .257 Roberts, which has seen more TSX and TTSX bullets than any other rifle, is still going strong.

I've used .277", .284", and .308" TSXs on several elk with success, despite claims that they don't open as reliably as the TTSXs. The TSXs appear to work as well as Partitions.

I've tried a few of the TTSXs in the .270 Winchester and .308 Winchester, but always got slightly better accuracy with the regular TSX versions.

The one pictured in the attached file below was a 7mm-08 TSX shot into a hog. Was a quartering too shot that went in front shoulder and stopped in hindquarter. So that was a good 20" it traveled and the hog didnt go 5 feet.
2 weeks later shot a 180# buck broadside less than 45 feet away. Had good exit and buck went about 75' before piling up.

I found them in federal premium on sale for $20 a box and I stocked up well.

My son has killed quite a few critters with the 25-06 and 80gr TTSX including a huge-bodied bull moose, a smallish brown bear, a largish bull caribou at 340 lasered yards, a couple deer, and a mountain goat... Very few recovered bullets.

One deer was bedded beside a rock. Bullet went through, stopped at the rock and got hung up in the hair.

The moose stopped two. One went through a huge joint and hung up in the matching bone on the other side. Another was the final shot in the neck at a long angle. It still took out a long stretch of vertebrae.

Thanks for sharing your experiences, guys.
Looking forward to giving them a try.

With the plain copper (not tipped) versions, regardless the grooves or not, I think that the level of and ease of expansion is affected by the shape of the ogive. Early XFBs were 'fuller' in profile and tended to open flat like the fourth picture. The sleeker profile of the XBTs and later XFBs seem to need more speed to open well. The pics above of animal recoveries; the pic below of 'media-teed' bullets.



A few 150 grain bullets I tested on a tidal mud flat; the 'mud' was a matrix of sugar sand, mud, and heavy grass roots: 155 yards- 30-06. L-R: GMX, TSX, TTSX, E-Tip, AccuBond.

Whatever you do, recall that even Hornady users had issues with the old 52 and 53 grain hollow point varmint/target bullets not opening reliably due to the smallish opening on those hollowpoints. All of these solid copper projectiles are a harder, tougher material than most lead core alloys are and will be somewhat less reliable in their expansion properties. Tips seem to help considerably.

The LRX are another very good option if you want to go on the heavier side for the caliber.

None of the monometal bullets are very quick killers and they still suffer from occasional failure to expand issues.

TFF

Going to try out some 286 TSX bullets in the 9.3 to see how they do. Might have to try one on a black bear this year.

I've been gradually switching over to them in some applications. I find they shoot about as well as anything else and I've only recovered one so far: 130gr TSX / 270 Wby from a 6x6 elk.



I mostly buy the TTSX version now...

I have loaded TSX bullets in 30-06, 6.5 Swede, and older XFB in my 405 Win. In the '06, I have loaded 150, 168, and 180 grainers. Took moose and deer with the 150 and 168. I fi d them very accurate and they kill real efficiently and quickly. No issues with fouling.

I've been shooting a 140 gr. TSX out of my .270 WSM at 3250 fps and have shot several bull elk(through the ribs) and haven't gotten a bullet back yet. Holes were good, not huge. But my rifle loves this bullet and no fouling to speak of...I'm going to continue to use them.