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Posted: 11/11/2009 5:01:25 PM EDT
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Observations on the Barnes TSX bullets
The Barnes 70 grain TSX is a very long bullet for its weight and caliber. At a nominal length of 1.037” it is longer than the heavier 77 grain Sierra MatchKing. 
Besides being a long bullet, the 70 grain TSX has a specific gravity much lower than a copper jacketed/lead core bullet due to its sold copper construction. For example, the Hornady 75 grain BTHP has a specific gravity of approximately 10.3, while the Barnes 70 grain TSX has a specific gravity of only 8.9. The Barnes 70 grain TSX will be unstable from a 1:9” twist barrel with a gyroscopic stability factor of less than 1 at all velocities. The 70 grain TSX will only be marginally stable in a 1:8” twist barrel with a G.S.F. of 1.05 at 2500 fps. A 1:7” twist barrel will produce acceptable stability with the 70 grain TSX with a G.S.F. of 1.37 at 2500 fps. 
Barnes also makes a 62 grain TSX. It is even available in a factory load from COR-BON. Hand-loads using the 62 grain TSX consistently shoot slightly more accurately than hand-loads of the 70 grain TSX, at least in my barrels. The smallest 10-shot group from 100 yards that I’ve fired with the 70 grain TSX hand-loads had an extreme spread of 1.12”. With the 62 grain TSX hand-loads, I’ve been able to achieve sub-MOA accuracy for 10-shot groups at 100 yards. 
COR-BON 62 grain DPX 
This COR-BON load uses the Barnes 62 grain TSX bullet which has an all-copper construction. The bullet is much longer than a typical lead core/copper jacketed bullet of the same weight. This load had a muzzle velocity of 2963 fps from the 20" Colt barrel. The 10-shot group of record had an extreme spread of 1.75" and a mean radius of 0.61". 
As for the possible difference in terminal performance between the two different bullets, here is a quote from Dr. G.K. Roberts on the subject: “Keep in mind, that with non-fragmenting bullet designs, heavier bullet weights are not necessarily better, especially at closer ranges and from shorter barrels. As long as penetration and upset remain adequate, it is possible to use lighter weight non-fragmenting bullets and still have outstanding terminal performance. Heavier bullets may have an advantage at longer ranges due to better BC and less wind drift.” Can you tell the difference between the Barnes 70 grain M/LE TAC-X Tactical Bullet and the Barnes 70 grain TSX Triple-Shock X bullet? 
The picture below (courtesy of Dr. G.K. Roberts) shows the Barnes 70 grain TSX after being fired into bare gel (on the left) and after first passing through auto windshield glass and then into gel (on the right.) Dr. Roberts states that when the TSX passes through auto windshield glass "the jacket 'petals' fold back against the core, or the 'petals' are torn off; this results in a caliber size projectile configured a lot like a full wadcutter, leading to deep penetration." 
Courtesy of DocGKR 
Silver State Armory's 70 grain TSX load easily matched the reported muzzle velocity of the 5.56mm Optimized load. From a 16" Colt barrel with a NATO chamber, chrome lining and a 1:7" twist, the SSA load had a muzzle velocity of 2788 FPS with a standard deviation of 15 FPS. From a 20" Colt barrel it had a muzzle velocity of 2899 FPS with a standard deviation of 21 FPS. 
Snapshot 
As I previously posted, the Silver State Armory 70 grain TSX load had a muzzle velocity of 2899 fps from a 20" Colt barrel. This is a hot load. Factory loads using equivalent weight bullets, for example the Federal Gold Medal 69 grain Sierra MatchKing, generally run around 2750 fps from a 20” Colt barrel. Since the SSA 70 grain TSX load is such a hot load, I decided not to use my Krieger barrel, with its match chamber, to evaluate the accuracy of the SSA load. Instead, I used my 20” Noveske HBAR which has a chamber designed to fire the military pressure MK262 load safely, on full-auto, in hot environments. This barrel has a 1:7” twist. Using match grade hand-loads, this barrel turned in a 10-shot group at 100 yards that had an extreme spread of 0.726”. 
Previous accuracy testing using hand-loads of the 70 grain TSX bullet proved the bullet itself to be capable of some fine accuracy. A 10-shot group fired from my Krieger barreled AR-15 at 100 yards had an extreme spread of 1.12”. 
The SSA 70 grain TSX load was tested shooting from a bench-rest at a distance of 100 yards. A Leupold Competition scope with a magnification of 45X was used for sighting. Wind conditions were monitored using a Wind Probe. Just for kicks, I did something a little different this time. I fired two 5-shot groups! Those groups had extreme spreads of 1.22” and 1.91”. I then fired a traditional 10-shot group, which had an extreme spread of 1.93” and a mean radius of 0.61”. I over-layed the two 5-shot groups on each other using RSI Shooting Lab to form a 10-shot composite group. The 10-shot composite group had an extreme spread of 1.93” and a mean radius of 0.63”. 
As I posted previously in this thread, a barrel with a 1:9” twist theoretically will not stabilize the 70 grain TSX. Today, I put the theory to test using a Colt 16” HBAR with a 1:9” twist. This same barrel will marginally stabilize the Hornady 75 grain BTHP, though accuracy is slightly diminished compared to a 1:7” twist Colt HBAR. I fired a 10-shot group of the 70 grain TSX round at a distance of 100 yards using the 1:9” twist barrel. Accuracy was terrible; the group had an extreme spread of over 3 inches. Several of the bullet holes were slightly oblong in shape and a coulple of the bullet holes were clearly “key-holed” demonstrating that a 1:9” twist barrel will indeed not stabilize the 70 grain TSX. 
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MOLON, thanks for that info. For me I would never use that bullet for SD only for hunting or blasting hogs (ground and pigs). Too much of a good thing in penetration for SD in MY opinion. But man that is one LONG bullet but sure is purty.
Now I didn't understand that gravity thing with regards to stabilizing and stuff but I did get out of it to stay away from the 70 gr TSX and go for the 62 gr TSX in my LaRue Stealth 1-8 twist barrel. Thanks again for a great review. Oh by the way did you ever get to do an accuracy test of the Buffalo bore loads you did a bit back?? Thanks Brian |
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This will probably sound like a stupid question, but since I didn't see it answered in the OP, I'm going to ask it anyway.
Given that the 62 grain TSX bullets are longer than standard 62 grain bullets (including both plain jacketed, lead core and SS109), how well do they stabilize in 1:9" twist barrels? What bullet weight of traditional construction does the 62 grain TSX compare most favorably to in terms of length? It looks to me like it may compare to a 69 grain OTM bullet, but I'm just guessing. |
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Just for kicks, I did something a little different this time. I fired two 5-shot groups! Those groups had extreme spreads of 1.22” and 1.91”. I then fired a traditional 10-shot group, which had an extreme spread of 1.93” and a mean radius of 0.61”. I over-layed the two 5-shot groups on each other using RSI Shooting Lab to form a 10-shot composite group. The 10-shot composite group had an extreme spread of 1.93” and a mean radius of 0.63”.
You sir, are some type of machine!!  
Nice post, Scott |
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The 62gr TSX will stabilize in a 1:9 bbl, it's what I shoot in my 1:9.
Seating depth makes a big difference in this bullets accuracy, much more so than in other bullets. I have seen it open/close groups by up to an inch! If any of you are reloading it make sure and play with this a bit, you'll be glad you took the extra time and shots in the long run. P |
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I have yet to do any testing of TSX's in 5.56. But I have shot, and seen shot, many elk with my 7mm-08 loaded with the 140gr TSX. Many have tried to "educate" me that that combo is too light for elk. Fortunately the elk never figured that out. The performance of the bullet is exactly as advertised. Deep penetration, rapid expansion and near 100% weight retention.
The 62gr TSX will be in my kids rifles for thier first deer hunts. |
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Quoted:
Molon, Isn't this pic from DocGKR the 77gr TOTM .mil barrier blind ammo? http://www.box.net/shared/static/5ckiji3pno.jpg If so, is this TSX ammo considered equivalently barrier blind? I'm guessing yes based on this pic. http://www.box.net/shared/static/piqgn00tvb.jpg Yes, that's Doc's pic (hence my "courtesy of" notation at the bottom of the pic) but it's the 70 grain load, not 77 grain. The TSX is a barrier load, but as you can see from the pics, the petals either fold-in on themselves or are sheared off when fired through auto glass. |
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Quoted:
Quoted:
Molon, Isn't this pic from DocGKR the 77gr TOTM .mil barrier blind ammo? http://www.box.net/shared/static/5ckiji3pno.jpg If so, is this TSX ammo considered equivalently barrier blind? I'm guessing yes based on this pic. http://www.box.net/shared/static/piqgn00tvb.jpg Yes, that's Doc's pic (hence my "courtesy of" notation at the bottom of the pic) but it's the 70 grain load, not 77 grain. The TSX is a barrier load, but as you can see from the pics, the petals either fold-in on themselves or are sheared off when fired through auto glass. Thanks. 
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Quoted:
Quoted:
Great post Molon. You mentioned the M/LE Tac-X bullet. Do you know if there is any difference in the cavity, or are they in fact the exact same bullet? Same bullet according to Barnes when I called them - it was done for marketing purposes. Yup. Tac-X next to a TSX.
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Quoted:
Molon Have you or anyone you know of preformed penetration test of the TSX bullet on various mediums. The Doc has. The problem with the TSX bullets is that when shot through autoglass, the "petals" tend to shear off, or collapse in on themselves.
courtesy of Dr. G.K. Roberts |
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Quoted:
What bullet weight of traditional construction does the 62 grain TSX compare most favorably to in terms of length? It looks to me like it may compare to a 69 grain OTM bullet, but I'm just guessing. The 62 grain TSX is longer than the 69 grain SMK, but shorter than the 77 grain SMK. 
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here my seven year old took this six point buck during the youth hunt back in October. Handload of Barnes 70grain TSX and Varget. Gun is YHM 1:7 twist upper on a Bushmaster lower. Leupold Mark AR scope 1x4. Before any of you start to think that I shot it for him, forget it. We practiced several times even out to 100 yards. He could actually keep about a 4 inch group at 100 yards with no problem on a rest. I felt comfortable letting him take any shot 50 yards and in. This guy stopped about 50 yards out, he dropped the hammer on him and the deer actually circled towards us and piled up about 30 yards out. The shot was slightly quartering to and he hit him just a little back( I had told him to shoot dead center shoulder). You can see in the pic where it exited. When we skinned it the hemmoraging was quite extensive for such a little bullet. In fact my father thought he may just start deer hunting with a .223 and barnes bullets. |
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Quoted: Quoted: Molon, Isn't this pic from DocGKR the 77gr TOTM .mil barrier blind ammo? http://www.box.net/shared/static/5ckiji3pno.jpg If so, is this TSX ammo considered equivalently barrier blind? I'm guessing yes based on this pic. http://www.box.net/shared/static/piqgn00tvb.jpg Yes, that's Doc's pic (hence my "courtesy of" notation at the bottom of the pic) but it's the 70 grain load, not 77 grain. The TSX is a barrier load, but as you can see from the pics, the petals either fold-in on themselves or are sheared off when fired through auto glass. And it is, in fact the same projectile correct? |
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Quoted:
Molon, Great info as usual. Have you tried the SSA 77 grain SMK load (it supposedly mirrors the mk262 load in performance etc).? Silver State Armory 77 grain OTM 
Silver State Armory is now producing a 5.56mm NATO pressure, 77 grain OTM load with velocities on par with the Black Hills MK262 load. This makes SSA the fourth commercial ammunition manufacturer to currently offer a 5.56mm heavy OTM round loaded to NATO pressure; the other three being Black Hills (MK262), Hornady (5.56 TAP) and HSM (5.56-17T). The SSA 77 grain load comes in simple brown boxes with nothing more than a “5.56” designation on it to give you a clue as to what’s inside the box. There is no indication of the bullet weight found anywhere on the box. This round is loaded with a 77 grain Sierra MatchKing without a cannelure. 
The cartridge is charged with ball powder. The primers are crimped in place, although some of the crimps are so shallow that I needed magnification to see them. The primers are not sealed. As mentioned, the bullet does not have a cannelure, but there does appear to be a slight taper crimp on the case mouth that leaves a small indentation on the bullet. There is no sealant at the case mouth. 
The SSA 77 grain load was chronographed using an Oehler 35-P chronograph with “proof screen” technology. All velocities listed are muzzle velocities, as calculated from instrumental velocities using Oehler’s Ballistic Explorer software program. All strings of fire consisted of 10 shots each. Colt barrels in the lengths of 20”, 16” and 14.5’ were used as the test vehicles. All barrels used were chrome lined, NATO chambered and have 1:7” twists. Atmospheric conditions were recorded using a Kestrel 4000. Temperature: 74 degrees F Humidity: 58% Barometric pressure:30.15 in Hg Elevation: 950 feet above sea level 
The SSA 77 grain cartridges had a nominal length of approximately 2.250”. All rounds used in this test session fed, fired, extracted and ejected without any malfunctions. There was definite primer flattening noted on the fired caseheads, but no significant ejector or extractor brass flow marks. 
Finally, here’s the data! 
At one point during the test session I noticed an unexpected visitor on the range. The big guy pictured below was sitting on the berm about 10 feet above the target frame watching me. 
Accuracy Report Following my usual procedures, an accuracy evaluation of the Silver State Armory 77 grain OTM NATO load was conducted shooting from a concrete bench at a distance of 100 yards. The test vehicle used for this evaluation was a Noveske barreled RECCE. The 16” Noveske Recon barrel is made of stainless steel and has the 5.56 Noveske Match Mod 0 chamber, a 1:7" twist and polygonal rifling. The barrel is free-floated in a LaRue Tactical railed handguard. 
The fore-end of the RECCE was rested in a Sinclair Windage Bench Rest with the aid of a modified Sinclair fore-end stabilizer. The butt-stock was stabilized in a Protektor bunny-ear bag. Sighting was accomplished using a Leupold VARI-X III with a mirage shade attached. Magnification was set at 25X and the scope was adjusted to be parallax free at 100 yards. The lower receiver used during testing has a Geissele match rifle trigger in it. 
Atmospheric conditions were recorded on a Kestrel 4000. Skies were sunny and the winds were breezy. Wind conditions were continuously monitored using a Wind Probe which was positioned approximately 33 yards from the muzzle. Temperature: 77 degrees F Humidity: 51% Barometric pressure: 29.87 inHg Elevation: 950 feet above sea level 
Prior to firing the SSA 77 grain load, I fired a 10-shot control group from 100 yards using a hot hand-load seated with Sierra 77 grain MatchKings (the same bullet used in the SSA load). That group had an extreme spread of 0.97”. 
Three 10-shot groups of the SSA 77 grain OTM NATO load were fired from 100 yards using the described set-up. Those groups had extreme spreads of: 1.92” 1.60” 2.03” for an average extreme spread of 1.85”. Those three groups were over-layed on each other using RSI Shooting Lab to form a 30-shot composite group. The mean radius of the composite group was 0.54”. For comparison, three 10-shot groups of Hornady’s 75 grain 5.56 TAP previously fired from the same Noveske barrel had extreme spreads of: 1.03” 1.42” 1.20” for an average extreme spread of 1.22”. The 30-shot composite group formed by over-laying those three groups on each other had a mean radius of 0.37”. The composite groups of the two different loads are shown below for visual comparison. 
Lastly, for the Internet Commandos in our viewing audience I fired a 3-shot group of the SSA 77 grain load from 100 yards. That group had an extreme spread of 0.80”. 
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