I recently acquired a SSK Contender barrel in 6mmJDJ #2 and would like some suggestions for a hunting bullet. The prey will be Hill Country whitetail and an occasional feral hog. Throw in a coyote if they happen to come by during deer season, but no dedicated varmint hunting.

Good choices are the 90 gr. NBT, NAB, and 85 gr. NPT.
I'm really sold on the PT. With my 6mmAI last year I took 2 very large does at 400 yds., one at 150 yds., and a large javelina at 177 yds. All the deer dropped. The pig went 5 yds.
Not many people pay attention to the PT in small calibers (including me before last year), but I'm sold on it now.

Id like to try some partitions in a small six.

You ever try the sierra 85gr hpbt in one hitman? Has great rep in 243s.

Ive shot quite a few sierra 80gr single shot bullets in them and they shoot great, but only took one deer with it. It died. 😉 i think the sierra 80 gr blitz should be similar

Kyode, before 1978 when I was young, dumb and used rifles my go to gun was a left hand custom .243. I primarily used 85 gr. Sierra HPBT on groundhogs (about 800) and some on deer (about 10). Damage was awesome in both.
Once I got smart and switched to 100% handguns I had to try the Sierras in my 6mmAI. They did great on groundhogs. Damage on deer was about 75% of the rifle damage in tissue damage and exits. I tried 70 gr. BTs and they were great on 'hogs and actually not too bad on deer (at 400 yds.!). The 70s and 85s did not shoot close together and I really hate resighting my guns a lot.
In preparation for my javelina hunt I got the 85 NPTs and stayed resighted for a year with them. I was so blown away with their performance that I didn't bother using the 85 Sierras. I favored penetration with them to the possibilities of bullet fragmentation of the Sierras on angled shots. They did good on broadside shots, but broke up on severely angled shots.
So, my 6mm uses 70 BTs for varmints( little flatter trajectory than 85 Sierras) and 85 NPTs for deer. My days of testing for this gun are over. I'm not messing with what works.

My bullet of choice for deer culling and pig eradication when using my .243 Win is the 105gr A-Max.

I?ve felled a suitable amount with that bullet as has my boy and anyone else I lend the .243 to.

Assuming you have a fast enough twist, with the discontinuation of the A-Max, I would recommend the 108gr ELD-Match.

Another I?ve used in guns with slower twist has been the Sierra 85gr HPBT-Game King.

I doubt the 6mm jdj has the twist or capacity to handle the heavy bullets like a 243. I think its on the 225win case, but doc or OP will know.

The 6mm JDJ is on the .225 Win. case.
I saw the effects of a 6mm ELD-Match this year. A friend shot a heavy doe on my farm this year with a 6mm Needmore and ELD-Match. He dead centered the shoulder. The deer ran about 100 yds. The autopsy showed the bullet entered one lung, destroyed it, but completely disintegrated and did not make it to the second lung.

I?ve never had issues with the 105gr A-Max. Superb accuracy and terminal performance. Can?t say I?ve tried the 108gr ELD-M. But, being the same jacket thickness and core material as the A-Max, they should be as exceptional as I?ve experienced on so many deer and pigs.

I have about 1,000 of the 105gr A-Max left. Once I use them up, I?ll probably try the 108gr ELD-M. See if they perform as well.

Lots of pigs and deer to thin out. Life is good. 😁