Yes I know the 120 NBT is the defacto perfect 6.5 mm pistol bullet, but I wonder if anyone out there has experience with the 100 grain bullet in the 6.5 TCU.

Anyone out there with real deer harvest experience with this combo?

Yes, I've used it -- and it's nowhere near as authoritative as the 120 grain BT. I recommend against it, esp. in a cartridge such as the 6.5 TCU. It fares better in a 6.5x50R Bellm or a 6.5 JDJ due to the higher attained velocity, but even so, it's just not the best for the job at hand.

I forgot to add: If you must use a 100 grainer on deer in the 6.5 TCU, go with the Sierra Varminter HP. It's far from the best but does a better job than the 100 grain BT when it comes to shcok transfer and incapacitation.

The 100 Gr NBT is basically a varmint bullet. The 120 Bt is a game bullet. 6.5 TCU velocities are some what limited due to the small case capacity, so the 100 NBT may work fine at the slower velocities as a game bullet.

Another possibility might be the 100 Gr Nosler Partition. The front sections of partitions are pretty soft, so it may expand just fine even at low velocities.

Running some water filled one gallon milk jug tests with the bullets you are considering will tell you the relative expansion characteristics of the bullets you are considering, in your gun at your velocities. I would run two sets of tests; one at the shortest distance you would expect to get a shot and one at the longest. Seven one gallon milk jugs filled with water ought to be enough to stop and capture your bullets...Rusty.

Rusty Hook-

The 100 grain BT is not a varmint bullet; it is intended as a game bullet. And yes, the 100 grain Partition will work OK, but it, too, it not nearly as effective as moving up to the 120 grain BT.

Also, shooting water-filled jugs gives absolutely no indication of potential on-game performance. It may provide an interesting visual, but that's about it. I have a set-up that I use which comes very close to giving a parallel performance when it comes to game, but it's a little difficult to set up. For a very simple but effective test, get a Prestone anti-freeze jug (NOT a milk jug) and fill with water, leaving the jug uncapped. Set up a sheet of 1/4 or 1/2" plywood 12 feet behind it -- making certain, of course, the background is safe.

Now back off to whatver range you want to test the bullet at. Center-punch the jug. If the hole in the plywood is basically bore diameter, you'll likely get no expansion on a deer. If you notice many fragments, chances are it's too fragile for anything other than varmints. But if it's a relatively clean hole that's 60 to 100 percent larger than bullet diameter, it's opening well and will likely do fine on thin-skinned game.

OK, I'm convinced, I just had a few boxes of the 100 grainers and figured the extra speed may make up for the reduced weight.

Bobby you use a modified version of my expansion test.

I use 20 ounce coke bottles with a piece of card board behind it to capture bullet "shape" or later in the fall I use "osage oranges" "Hedge Apples" "Bodark" "Bodock" Bois D' Arc" fruit backed by a piece of cardboard.

For Varmint bullets oranges seem to be perfect to induce expansion.

The nifty thing about these methods as they measure impact effects on the expansion inducing medium (one would be surprised by the induced effects from different chamberings/bullets) and final bullet condition on the cardboard.

All just supposition and opinion of course. IF I could just harvest all of the deer allowed here in TN, I could back it up with real world data also.

Louis-Your method should give a very good representation of on-game performance. When I get serious and have the time, the method I use consists of a repeating assembly of 1" wet newsprint and 1-inch air pocket. On the very first facing, there's also a sheet of 1/8th" paneling material (rather soft), and every 5th facing is fronted & backed by a square of 100 percent cotton material (basically worn T-shirt). At the very back, an area where not-too-many bullets make it to, is a compression of shredded cotton garments, lightly dampened, to collect those stubborn, non-expanding bullets that punch right on through everything else.

I've tried everything from sawdust-silt mixtures to phonebooks to what-have-you, and this set-up, which I have used since 1985 or so, seems to give the closest parallel to performance on game. But for a quick evaluation, the prestone jug I mentioned earlier or the method you noted certainly lets you know if the bullet/load combo is worthy of further experimentation -- and both are fairly foolproof as well.

Bobby: I didn't claim that water tests would approximate performance on game. I mentioned comparative bullet expansion test results to determine if you would consider using that bullet compared to others on game. Of course a test medium that better duplicates flesh and bone is better and should probably be used insterad. It is also a little to a lot more trouble for some. Milk jugs are more readily available to me than antifreeze jugs. I stacked up 10 jugs and all bullets were captured in the 5th and 6th jugs. This was with 140 and 160 Gr bullets out of a 6.5 Minidreadnaught - better than 2500 fps with the 140s.

In shooting ground squirrels, I found the 85 Gr Seirra to be the most explosive bullet that I tried in 6.5. The 100 Gr Bt was not nearly as expansive as the Sierra but much more so than the 120 Gr Bt. This was in a 6.5 JDJ. A 6.5 TCU will not have the velocity potential of the larger cases and may not develop as much expansion with a 120 BT as a lighter bullet traveling faster would.

Thank you for being so kind as to provide your test medium and procedures. I am sure that they will benefitt many here. Respectfully, Rusty.