Drilling the TSX cavity for uniformity?


February 27, 2011, 11:39 AM
Got a question for you guys based on a working theory. I shoot a lot of Barnes TSX at game, as do some friends of mine. Sometimes it's a devastating wound channel & DRT, sometimes it appears to pencil right through. Different rifles, different loads, etc.. No argument there, plenty of threads arguing the subject.

The other day I took my box of handloaded 300 WSM w/ 180 TSX and sat it on the bench. I went to my Dremel tool drawer & found my micro- drill bits. While the smallest (IIRC ~.012") would slide all the way into the cavity on the TSX hollow point with some forcing & wiggling, the largest (IIRC ~.030") would slide in a few MM & then stop- and this stop depth varied bullet to bullet. So, here's my theory- the manufacturing process of the TSX causes an inconsistent cavity from bullet to bullet, which causes inconsistent expansion on game. Some are more open, while some are darn near pinched shut.

Since uniformity is consistency I'm toying with the idea of procuring some 1/32" drill bits (or there abouts to match the hole in the tip) and using my press to uniform the cavitys on all my TSX. What do you guys think? When these things open up I beleive there's none better. When they don't, well, a wounded Elk can run a looooong way. :cuss:

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February 27, 2011, 04:35 PM
What do you guys think?

Buy some Nosler Partition or Remington Core-Lokt bullets. :)

Other than that, if you get the cavity out of round or off center even a little bit, accuracy will be affected.

February 27, 2011, 05:09 PM
Get tipped TSX

February 27, 2011, 10:56 PM
Well, I've tried the partition, the TTSX, and a few others in this particular rifle & nothing comes close to shooting as well as the 180gr TSX. So, for the sake of this thread I'm stickin' with it.

Since I'd be using a drill press and set it to drill a fixed depth it'll be pretty uniform. Of course I'd test them to make sure the accuracy didn't suffer. Logistics aside, anyone have thoughts on the theory?

February 28, 2011, 07:29 AM
The theory is excellent. The execution is going to be the hard part. It doesn't take much "wobble" to ruin accuracy.

Let us know how it works out.

February 28, 2011, 09:01 PM
There are two schools of thought on shooting elk:
a) TSX into the shoulder
b) Ballistic Tip into the lungs

I have practiced at the range with both, many times.
I have practiced shooting mule deer many times.
I have concluded that I am a "shoot for the lungs" man.

February 28, 2011, 10:17 PM
Guys were reporting performing this mod a couple of years ago with good luck.

February 28, 2011, 10:44 PM
Thanks, Walkalong. I've got a lot loaded so I can do some drill / no drill testing for accuracy. Having used the drill press *a lot* my suspicion is that the bit will follow whatever small hole is already there, so if it was straight before it'll be straight after.

Interesting that it's been discussed before. I did a little searching but didn't find anything on it.

March 1, 2011, 07:17 AM
Minor changes to the front end of bullets will not affect accuracy. You can cut the frnt/point off a bullet at an angle withwire cutters and at 200yd there will be no practical difference in accurecy over unmoded bullets.

March 1, 2011, 07:19 AM
True, mangled tips won't matter much, but we are talking about a cavity reaching into the bullet. Looking forward to the tests.

March 1, 2011, 08:33 PM
what I have noticed with tsx bullets is that usually they are velocity sensitive, in that the "308" is covered by so many cartridges, that not everyone ends up liking them. for instance in a 300 whisper you may get one result, and in my 300 wby mag you'll get something else. I would be curious to know if you have the same issue repeatedly with one caliber or just a mix of results with one rifle? I know in my 243 with an 85 gr I get a pretty consistent opening every time. I'm not going to lie I never recover them. but from the pin size entrance hole and the heart soup that was inside I'm guessing they opened okay:D and have always had similar results

March 20, 2011, 07:32 PM
So I found some .040" (#60) drill bits & drilled a control set. They all now have a uniform cavity diameter & depth. I can tell from the feeling on the press that the overall depth is very consistent, but the diameter within the cavity seems to change. I'll report after I have a chance to test them out on paper & milk jugs vs. non-drilled counterparts. I know that this load normally will turn a jug of water into a floating cloud of water vapor...

March 20, 2011, 08:20 PM
On a similar note, I've had great success re-boring unseated hollowpoint bullets using a cam lock trimmer to hold the bullet on one end, and the bit on the other....works just like a lathe, and you are always centered.

This method can also be used with various jigs to make cast rounds into HP.

Excellent thinking.

March 20, 2011, 09:12 PM
I guess there's nothing like spending the big money for a bullet, and then having to "fix" it before you use it! lol


March 20, 2011, 10:00 PM
Well, there will always be a difference between mass-produced parts & hand-fit parts. Some of us just like to tinker. :)

March 20, 2011, 10:22 PM
I have drilled FMJ's into hollow point and never noticed much difference in accuracy (although it was in a pistol). Some of them were very off centered and it seemed to pose little problem, especially considering most of the accuracy comes from the spin on the bullet via rifling.

March 21, 2011, 03:56 PM
I read this thread all the way through, just to follow the poster and his ideas about this bullet. My first question: You use a hollow point bullet to hunt elk? I was always schooled in the thought, you used HP's for Pd's or varmints, not caring what they looked like after the bullet hit. You stated, "Sometimes its a devastating wound channel & DRT", yes, I can only imagine what kind of a wound channel it would make through the front shoulder of an elk, total waste of meat! I guess that means you have less to worry about wrapping and freezing, to each his own!

March 24, 2011, 02:25 PM
788Ham, the TSX is a solid copper bullet and does not explode like their lead counterparts do. That is apples and oranges.

March 24, 2011, 10:00 PM
788Ham, the TSX is a solid copper bullet and does not explode like their lead counterparts do. That is apples and oranges. exactly

March 25, 2011, 09:41 AM
Thing is, NOT all lead core bullets explode!


November 20, 2011, 12:30 PM
Time for an update, I've done some testing.

Accuracy. I zeroed my rifle at 200 yds & ran a couple cold-bore groups with standard & drilled rounds, no appreciable difference. Same basic POI & groups around an inch off a good rest.

Milk jug test. Both drilled & standard rounds turn milk jugs & watermelon into vapor. Far more dramatic than the same test w/ a cup and core bullet, which just turns them into chunks.

Test on game. I've never seen a TSX recovered on a deer or elk broadside shot, I load for mine & a couple friends. This year we recovered a drilled round (w/ textbook X expansion) in the off-side hide of a cow elk after passing through a rib & lungs. The shot was ~275 yds. The follow-up round, which was standard & not drilled, went through the paunch & liver and was a complete pass through as usual.

Yes this is only one example, but I'm confident that the drilling did help to initiate expansion that would not have been as dramatic otherwise. That's the good news. The only bad thing I could think of is that if you had to trail the animal, 2 holes would be better than one..

November 20, 2011, 01:09 PM
Good Job!

November 20, 2011, 07:06 PM
Damage or lack of symetry in the front of a bullet will have little effect on short (300yd or less)range accuracy. Youncan cut off the front end of a soft point with wirecutters and still shoot sub inch groups at a 100. Ive shot 90# whitetails and the wound channel with aTSX under 3000fps will give a nice 1-2" exit wound and minimal meat damage, up the velocity and bets are off. I shot a 100# bushbuck and an 1800# eland with the same 160gr 7mm TSX and lost minimal meat with either. The exit on the bushbuck was abit over an inch and none of the shots on the eland were passthrus. Ive never had to drill the TSXs and have always had picture perfect results, and little meat loss. On the other hand Ive shot some of our small whitetails with the YSX over 3300 and bloodshot meat is staggering. I dont use the super light bullets anymore, an exception is say a 120 TTSX in 7-08 loaded to just short of 3000. This is a good load for young or smallframed shooters.

June 3, 2012, 08:00 PM
I did some drilling today to start getting ready (mentally!) for hunting season. Same lot of 180gr TSX I've had loaded up, using the .040" drill bits I mentioned earlier. After drilling 30 or so bullets I noticed a couple things.

First, the tip of the hollow point extends in only about .040" or so before my drill bit stops. Next, on some bullets it only takes mild pressure for the bit to releive this "pinch", but on the majority it takes a bit more pressure for the bit to drill through. This tells me that the amount of pinch is a little inconsistent. Third, once the pinch is cleared the bit can clean out the hollowpoint pretty easily down to oh a quarter inch or so which I think will solve the problem & allow the hydraulic forces to more consistently open the round.

In general I've read that speed is key with TSX & I tend to agree. I'm just thinking that this mod may help to hedge your bets on a long shot where the speed drops down or some other unexplained factor happens. Hopefully I'll get more chances to test it out this fall. :)

June 4, 2012, 04:33 PM
I've killed a lot of big game with a variety of bullets and the Speer Hot core has performed the most consistent in every manner. I shot a bull elk with a 130 gr. one from a .270 win. and the shot placement was horrible, straight up the spine. The bullet traveled up the back bone through ever single vertebra and stopped at the base of the neck. When I removed it, it still had over 90% of it's weight and was nicely mushroomed.

With shoulder shots my bullets have the normal small entry wound, but with a near dinner plate sized exit wound. The Nosler Partition has performed quite well also.


June 4, 2012, 06:22 PM
With shoulder shots my bullets have the normal small entry wound, but with a near dinner plate sized exit wound.

A 270 leaving a nearly dinner plate sized exit wound?

November 18, 2012, 04:11 PM
Another season under our belt, and some more on-game performance to report. My hunting buddy took a nice sized mule deer buck at about 100 yds with the 7mm-08 140gr TSX I load for him. I'd drilled the tips. It made a small entrance hole, vaporized the lungs, and passed through with a quarter sized exit hole. Bullet not recovered but expansion/ shock was obvious. The deer ran about 40 yds & piled up.

Next I took this bull at 248 yds with my 300 WSM 180gr TSX w/ drilled tips. It punched past the ribs with a nickel sized entrace hole, made a big mess of the innards (COD laceration to the heart) and then punched out the other side with a small exit hole. The animal dropped where it stood in about 4 seconds. Looking at the holes I think it started expanding instantaneoulsy & then lost some petals on the way through. Possibly the drilling was a little too effective in this case..?


The one thing I have noticed about the TSX through-and-throughs is that the small holes on both sides don't tend to leave big blood trails the way that monster holes from lead core bullets do. If the holes are higher in the cavity it'll often not bleed externally at all. However, if you put the shock into the vitals it still gets the job done right away negating the need.

Since full penetration is never an issue for me with the 180gr TSX I'm thinking of stepping down to the 165 gr for next year's hunt for a flatter trajectory. Might even try the TTSX again & skip all this drilling stuff. :)

Steve H
November 18, 2012, 04:42 PM

Interesting thread. by any chance have you called Barnes and talked to them about this?

November 19, 2012, 09:58 AM
I thought that the cavity in the front of the TSX was "+" shaped once you get into lower section of the cavity.

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