Has anyone tried these? Their website states compatible with
conventional load data. Really? The bearing surface on these is
looooong! In my 7mm WSM, there would be more bearing
surface inside the case than in the neck!

For anyone who has tried them, do you get better accuracy with
the bearing surface close to the lands, or loaded like a
regular 139 Hornady at the book specs?

I didn't try them in 7mm but have been playing with some 165 gmx in my 300 win mag. So far I've been loading them with different slow burning powders alongside the 168ttsx. So far out of 4 trials I've gotten 2 great groups with the ttsx and 2 average ones. The gmx...not so good....not even one group that gets close to the ttsx.
Not sure if you can compare pressure but the same loads with the gmx crank out about 50fps more with the gmx over the ttsx.

Thanks, kraky. Have you noticed if the bearing
surface on your GMX's is longer than on your
TTSX's? There have been statements made on
different forums that it isn't so much a matter
of bullet weight or even length that requires a
tighter barrel twist, as it is the length of the
bearing surface of the bullet.

If that is the case, it could account for your less
than desirable groups with the GMX, and also my
apprehension that my 9 1/2 twist barrel will
even stabilize the 7mm 139's. These have a
bearing surface even longer than their 7mm
162gr A-Max, which they suggest a 1:8 barrel
twist.

Guess I'll just have to experiment with some
close to the lands and some further out. It
may be just a waste of some RL17 and some
hard-to-find primers!

My best 200yd group was with the 120gr TTSX,
followed by the 140gr VLD.

Interesting on the bearing area of the 139. I only compared the bearing area and ogive of the gmx to the 168ttsx. The gmx has about .050" more and it is "moved" forward so to speak. At first I really like it cause it gave me some seating depth play room over the ttsx and the clip on the 300 mag is limitted to just 3.350. On some of the last batches I seated the gmx really deep so the ogive position would match the ttsx. Accuracy improved slightly but still not a match to the ttsx. On the next trip to the range I'm gonna try identical loads and seating depth (at ogive) of the gmx and some cheap nosler 168 J bullets 2nds I got on sale.
My last batch of re19 seems real slow and I want to get them up to useable speed and see if things tighten up. All I can say is so far I'm a bit disappointed.

Looks like I struck paydirt today. I set the ogives flush to the case mouth and charged up a healthy dose of re19. Both the nosler J and the gmx cranked 3100fps for identical speed. It was a little windy but at 200 yds the last 4 nosler went into 1" at 200. I had 4 gmx loaded and they went into 2.1"@200. The group was right about an inch till the last shot with a hot barrel. We'll double check that load some more but looks like we're starting to see the light! Looks like I got the right powder and the right seating depth for now.
The gun is a tikka t3 and when you find the right load it is scary accurate...a better shooter than the operator.