Home Forums Hunting & Shooting Ask The Gunwriters Pressure CX v LRX v TTSX

Rick,

For now I'll just comment that after Swift "re-designed" the Scirocco, the head guy told me that the new version was "harder," so it wouldn't open up quite as wide and thus penetrate deeper.

A few months later the editor of one of the magazines I worked for told me the same guy had told him the Scirocco II was softer, so it would open up wider.....

Which is yet another reason I've been doing my own pre-hunting penetration tests for over 30 years....

John

I took some measurements of bearing length to the ogive at bore diameter for bullets I currently have on-hand, and found the following:

7mm 140 TTSX, bearing length: 0.477"
7mm 145 LRX, bearing length: 0.533"

6.5 mm 127 LRX, bearing length: 0.561"

6 mm 80 TTSX, bearing length: 0.342"

The bands between grooves on all bullets measured 0.068" in width.

The increase in bearing surface going from the 140 TTSX to the 145 LRX is very noticeable, as seen below. The bullets are aligned where the ogive is bore diameter.

The 250 lrx .338 has some crazy bearing length

Need 1:8 twist
My notes show 3019 fps with 58.5gr Rel26

Here is my data on the 130gr CX with H4831SC
58.5gr 2901 fps
59gr 2944 fps
59.5gr 2974 fps
60gr 2999 fps

and the 129gr LRX with H4831SC
58.5gr 2937 fps
59gr 2964 fps
59.5gr 2985 fps
60gr 3008 fps

I'll add a few data points on my 129 LRX load development. I found that using WLR primers apparently caused more pressure as seen in velocity over the Fed 210. Not surprising but interesting nonetheless.

129 LRX, Kimber MT, 24" brl

Re 16 - all with WLR
52 3009
52.5 3010
53 3071

H 4831
59 3060 Fed 210
59.5 3088 WLR
60 3064 Fed 210 Settled here

H 4350
53 3027 WLR
53 2994 Fed 210
53.5 3045 WLR Option 2
54 3142 WLR

IMR 4451 WLR
54 3125

Both the H4350/53.5/WLR and H4831/60/Fed 210 shoot a bit less than a inch. The H4831 load shoots a shade better than the H 4350, plus H4831 is really temp stable.

Hmmm...I have a couple just laying around that need some load development. Maybe a new barrel with an updated throat/leade design? Sounds like it might be interesting!

I messed with the 150gr Badlands Super Dozer also. Best group with that was 0.33 and 2980fps with Reloder 26. Have not retested that bullet yet, but it is on the list. Was having time constariants getting a load done for last fall and went with the Barnes, since I have had really good luck with them.

Really struggling to justify anything anything else, the Barnes will easily penetrate as much as the the heavier C&C, or bonded, and the Badlands has a 0.710 BC. Highest I have seen.

It has been known for quite a while--though apparently only among a relatively small circle of handloaders--that WLR primers are one of the hottest "standard" (non-magnum) large rifle primers. Among other sources of info, Art Alphin's A-Square company ran velocity/pressure tests with various primers in the same handloads back in the 1990s. The WLR performed closer to some magnum LR primers than other "standard" LR primers. The Federal 210 is among the milder primers.

Mule Deer,

I was hoping that you could give some advice on a related situation. I've got a new to me Ruger 77 Hawkeye, 7mm-08. I've started with the Hornady 139 grain CX and H4350. Hornady doesn't have data for the 139 grain CX and H4350. However they don't seem to differentiate between bullets of the same weight in other data. Since I have a lot of H4350, very little Varget, and H4350 is known to be a good 7mm-08 powder I decided to give it a try.

I used a modest load of 47 grains and ended up with an average of 2773 fps about 12' from the muzzle. There were no signs of pressure but due to the length of the bullet it is already a compressed load. Would you be comfortable with using this load? Would you consider going any higher on the powder charge?

Any thoughts on the matter would be appreciated.

Fraser,

Will provide some thoughts on that a little later.

Right now I want to post the following photo, of a sectioned .30-caliber 168-grain TTSX and a 175-grain LRX. They were the first pair of a closely-matched TTSX and LRX I found on my shelves. They have the same number and shank of grooves, which are very similarly located, and as far as I can measured have the same ogive.

But after sectioning them I found the hole behind the tip on the LRX is about .05" deeper than the hole behind the tip of the TTSX. Aside from the overall length and 7-grain difference in weight between the bullets, that's the ONLY difference I could find. This extra length would allow the petals of the LRX to be longer, providing some extra leverage for its petals to open at slightly lower impact velocity.

The extent of the hole behind each tip doesn't show up in the photo, probably due to too much glare off the copper. I might take another photo later, with the bottom of the hole marked, but for now will only observe that obviously this pair of bullets doesn't vary nearly as much as the pair Jordan photographed, and I doubt there would be any difference in pressure between these two except for the slight difference in bearing surface and weight. (Will also note that Barnes lists the G1 BC of the 168 TSX as .470, and the 165 LRX as .508, which ain't much.)

What this suggests to me is that no hard-and-fast rule about pressures developed by the LRX and a similar TTSX can be valid. (It also might suggest the same when comparing Hornady CXs, which are apparently made with an only slightly harder copper alloy than Barnes Xs.)

I have only had one critter catch a TTSX. A bull elk shot at 310 yards with a 168 gr TTSX did not exit. The entry wound was oblong indicating it struck a twig very close to the bull and tumbled. He went down right there and the innards were a train wreck. I surmise the twig was fairly close to the elk since the entry hole was at my point of aim. Obviously the TTSX didn’t travel far enough for deflection to be an issue. My buddy and I have also killed a dump truck load of elk and mule deer with 7mm 150 gr TTSX over the years. I took my first WT buck last season with a 175 gr LRX out of my .30-06 with DRT results.

Good info, John. I wondered if the observed qualitative difference in pressure between the TTSX and LRX was due to my limited experience with direct comparison of various pairings of similar calibers and weights of the two bullet lines. It seems that is the case. It looks like relative pressure between the two bullet lines needs to be considered on a case-by-case basis. Thanks for the additional data point.

I have caught a bunch of Barnes bullets, but the vast majority have exited. It’s still based on a limited sample size, but I’ve recovered a higher proportion of the 6.5 mm 127 LRX than any other Barnes bullet.

Jordan,

The comparison between the .30-caliber 168 TTSX and 175 LRX was interesting to me as well.

Have used the 127 6.5 LRX more than any bullet from my Sisk 6.5 PRC over the past few years, and have yet to recover one. But as mentioned earlier, the big cow elk I took in December was quartering strongly toward me at 200 yards, and I put the bullet just inside the near shoulder. It ended up somewhere in the guts, and though I looked for it some, didn't find it. (Same thing happened with a 200-grain .30 Nosler Partition used on a 350-yard tail-bone shot on a raghorn bull elk around 20 years ago, but in that instance the bullet's path went into the chest....)

All of which indicates "further field research" is needed!

Good hunting,
John

John,

The last few animals that I recall having shot or seen shot with the 127 LRX include a very large MD buck, a small bull moose, and a medium-sized WT buck. The MD was shot quartering away, where the bullet entered near the second- or third-last rib and was found up against the offside humerus with a petal detached. The moose was shot on a frontal presentation, and the bullet ended up in the guts. We searched for that bullet for a while, but ultimately decided that getting the meat back to camp in the dark was more important. The WT buck was first shot on a frontal presentation, slightly from below, which exited the spine behind the last ribs. The buck fell while turning to run, and was up on his front two legs trying to crawl away for a second or two. A mercy shot between the shoulder blades ended it, and that bullet was recovered under the skin of the throat.

So of those last few critters, one 127 LRX exited, while three were caught. The moose catching the bullet on the frontal shot wasn’t shocking, but I was quite surprised to have caught the two Barnes bullets in those deer on non-lengthwise nor hard-quartering shots. My previous experience has been that monos are typically only stopped on shots that are steeply angling from broadside, but early results with the 127 LRX seem to counter that observation. In the last few years, I watched a few MD die to the 7 mm 145 LRX, which exited in all cases with various shot presentations and penetration depths. The most recent bull moose that I killed was with a 7-08 and 140 TTSX on a broadside shot from about 250 yards. The bullet exited and the bull trotted off about 80 yards before collapsing- pretty typical for bull moose.

As you said, further field research is required!

I was shooting 250 LRX out of my 340 Wby last night in prep for my bear hunt this weekend. The LRX are about 40 fps slower than other bullets with same powder charge. Accuracy was certainly acceptable. I doubt one will stay in a brown bear

To add a bit of info to the above, the 127s were all fired from various 6.5 CM rifles. The MD was shot at 285 m, the moose at 75 m, and the WT at about 110 m. The bullet recovered from the MD is below on the left, missing two petals. The bullet from the WT is on the right, all petals intact.

The photo below is a handful of the Barnes bullet's I've recovered. Top row, left-to-right: 7 mm 160 gr X bullet, THS into a wounded WT buck, recovered from brisket; (3) 7 mm 160 gr TSX, I don't recall the details but the bullet on the right has one remaining petal. Bottom, left-to-right: .243" 85 gr X bullet, recovered in offside front quarter from WT doe shot steeply quartering away; 6.5 mm 127 gr LRX, mentioned above (fired into a WT buck).

Jordan,

At this point in this thread I feel the need to repeat the essentials of a conversation I had with Randy Brooks 20 years ago, during a mule deer hunt in Sonora, Mexico--which happened to take place in the primary area where Jack O'Connor did most of his mule deer hunting. (Should also state that the hunt was not paid for by Barnes Bullets.)

This was shortly after the TSX was introduced, and I used a 168 from a custom .300 Winchester Magnum to take my buck. This wasn't because Sonora mule deer are huge-bodied (they're much smaller than northern mule deer), but because that was the rifle I had a U.S. Customs form for when the opportunity for the hunt came up.

Anyway, Randy and I had known each other for quite a while, and one evening around the campfire he mentioned that when he first designed and introduced the original X-Bullet, he thought that petals breaking off would help "killing power," due to resulting in more internal damage. But as the X became more popular, more hunters started bragging about how they sometimes retained 100% of their original weight--which was apparently considered a virtue.

Being an astute businessman, Randy gave his customers what they wanted, tweaking the bullets so they tended to retain their petals--and hence 100% of their . (Have also talked to several other gun writers who had the same basic conversation.)

Personally, as I've mentioned before, have never been able to tell any difference in the "killing power" of X-Bullets of whatever variety, whether they retained all their petals, some or none. (Same deal with other bullets that work similarly, going all the way back to the Combined Technology Fail Safe, which Eileen and I used considerably during the 1990s before the TSX appeared, because FS bullets usually grouped better than the original Xs.)

Anyway, how many petals remain on recovered Xs, TSXs, TTSXs and LRXs has remained a popular Internet topic for decades....

John

John,

Yeah, petal retention, or lack thereof, is a hot topic with lots of folks. Like you, I’ve never seen it make much difference in results, as long as the bullet expands and hits important body parts, so it doesn’t matter much to me. In fact, missing petals is often correlated with smashing heavy bone, which is usually correlated with shorter death runs, so if anything, missing petals means a higher DRT rate.

I point out petal loss in my above posts just for interest’s sake.

Awesome. I need to try mine with a few different powders. Let me know how it performs on bear.