[MDWS]

That is what I forgot to comment on. Accuracy out of an 18" ARP barrel for a 3-shot group was 1.8" at 300 yards, 0.6 MOA.

Well that works for me. Too bad it loses so much energy out to 300, but it still expanded very well. Looks like a great <250 meter cartridge overall. Sure yo could push it to 350 or so, but my usually bad math says ideal for 250 or less. Good fighting round considering I can barely hit stuff past 250 with a red dot anyways.

 

[jwtharpe]

You are achieving 200 fps more with your load and a 22" barrel. What recipe are you using? I loaded a ladder starting at 33gr and went to 35gr of CFE223 in SSA brass with BR-4 primer with a 2.36" OAL. I stopped at 35 expecting to see pressure before then, but I didn't see any so I have loaded another ladder from 35gr to 37gr, 37 almost fills the case to the top and is heavily compressed, so I should see pressure before I get to 37, from the looks of it 2800 should be close to 35.4 or 35.6, I expect to see pressure somewhere around 36.I will try it this weekend. A friend of mine that shoots a M-1 told me I should try the powder but not to use a magnum primer because it caused him problems when he got close to max for his rifle, so that's why I used the BR-4's. This barrel does not seem to like the faster powders like the ARP does so I'm trying a bunch of "too slow" powders with it. I have gone through Benchmark, Re-10x, LT-32, and H335 and so far the CFE223 loads beat all of those, I think the main reason is because it is so dense. BLC2 is next after I get done with CFE223.

 

[OdDuMet]

The 90gr looks like a good short to mid-range round. The bullet performance looks great, but it's already below 1000 ft-bs at 200 yds.

I cant see any reason not to choose the 115gr for deer+ sized game. The 115 has better penetration AND better energy @ 100 & 200 yds. Way more of both @ 300yds. Usually lighter bullets will give you more energy, but less penetration. Here it is less of both. And the 155gr loads are less expensive to boot.

Please note, I say this after buying 400rounds of the 90gr and zero of the 115gr....grrr.

These Fusion bullets all look damn impressive overall. I wish I could buy the 115gr as a component. I'd probably switch to them from the 110gr Accubond, better expansion, but they still hold together. I do have a bunch of the 120's though I've yet to try.


ETA - Awesome work & thank you!

 

[ppapago]

Xman,

Excellent work sir. This is much appreciated!

 

[Xman]

The 115 has better penetration AND better energy @ 100 & 200 yds. Way more of both @ 300yds.

OdDuMet, double check the velocity and energies again. I used the velocity for a specific 115gr bullet tested instead of a 5-shot average. I updated the picture just after you posted. That brings the velocity down 50 fps and the energy with it. Either the 90 or 115 will do the job. Pick the one that is most accurate in your gun. The 115gr bullet was penetrating more because it has more kinetic energy plus it was not expanding as much as the 90gr at 200 and 300 yards.

 

[Xman]

I have gone through Benchmark, Re-10x, LT-32, and H335 and so far the CFE223 loads beat all of those, I think the main reason is because it is so dense.

I'll have to get some CFE223 as I expect it will work well with 130gr bullets which is a project I started planning for.

 

[OdDuMet]

It looks like the gap has narrowed but the 115 still has more energy and more penetration at all ranges tested. If the factory load of the 115 weren't so mild it would look about like the same as 120gr. i.e more energy at 300 than the 90gr at 200, plus more penetration at all distances. C'mon Federal release the bullet as a component!

I shoot a lot of pigs. Penetration matters a lot bec. the shots are often less than optimal...like running away ass shots. I like a bullet that expands a lot, quickly, so it does a lot of damage as well though, not just a high penetrating bullet. Others may have different wants/needs. These look pretty ideal for what I like.

I think I'd keep the 90gr to about 200 yds max though personally for deer .... maybe 250 max.

Anyway, I have a bunch of 90gr and dont plan on buying any 115gr unless they sell the bullet only. I'll kill some stuff with the 90's and see how it does.

Thanks again for all your work and sharing it.

 

[Xman]

OdDuMet, I agree that the 115gr would be better suited for hogs. However, I would not hesitate to use the 90gr on Southern deer with a broadside lung shot at 300 yards if conditions were right (animal was stationary and no high crosswind). The reason the 90gr did not have a lot of penetration at 300 yards was it expanded to a size larger than any other bullet I have tested - the larger the diameter of the expanded bullet the less it penetrates. My .270 GMX bullet at 500 yards will out penetrate one shot at 100 yards because expansion is so much less at 500 yards. I expect that the 90gr Gold Dot would penetrate both lungs but would likely be stopped by the far-side hide which is very flexible and easily "catches" and traps an expanded bullet. 1000 pages of penetration in the phonebook is an easy pass through on a broadside deer lung shot.

 

[Xman]

The Benefits of Ballistic Tips

This section is a bit long but I hope you will find it interesting. I learned a lot about bullet expansion and had fun doing this series. So let's begin.

There has been discussion on other parts of the forum regarding the benefits of plastic ballistic tips and what degradation would occur if the tips were modified or removed. I've always believed that the primary benefits of the ballistic tips are improved ballistic coefficient and "sales appeal". When pulled from the bullet's body, a ballistic tip is hiding a much larger hollow point/expansion cavity from the wind which obviously does improve the bullet's ballistic coefficient (BC) compared to the tip not being there. As an example, the 85gr E-Tip has a maximum expansion cavity of 0.130" (almost ½ the bullet's diameter), the 110gr TTSX is 0.100", and the hollow point opening of 85gr TSX, which doesn't have a ballistic tip, is less than 0.050".

After seeing how rapidly the monolithic copper bullets are opening up during terminal performance testing and on game I have shot, I have also thought that ballistic tips could be promoting bullet expansion on impact with the animal, forcing the bullet open quicker and to a larger diameter. As an example, I have observed Hornady's 130gr GMX is fully expanded before it enters an elk's chest cavity based on the entrance wound on the inside of the rib cage is as large as the exit side. To test the assumption that ballistic tips facilitate expansion, I modified several monolithic copper bullets, specifically Nosler's 85gr E-Tip, Barnes'110gr TTSX, and Hornady's 130gr GMX.

Two modifications were done to the 85gr E-Tips. One with the tip shorten and filed blunt/flat but still protruding some length beyond the bullet's copper body, and the other with the tip completely removed leaving the gaping expansion cavity. The 110gr TTSX and 130gr GMX had just their tips removed leaving their large hollow-points exposed. The tips were easy enough to remove on the 85gr E-Tips and 110gr TTSXs, not so on the Hornady 130gr GMXs or any lead-core bullets I have. I place a loaded shell into my single stage loader without a die in it, raised the shell so the ballistic tip was just exposed above the top of the press, and then held the tip with a pair of wire cutters as the case was lowered. The tips just popped out exposing the larger than normal expansion cavities. I did have to recheck seating depth and recrimp as some bullets moved. The tip on the GMX had to be drilled out.

To repeat the assumption going into this test is, with the ballistic tips removed or modified, expansion should be reduced. Below are the results of the modified bullets pulled from the bullet trap at 100 yards. The 85gr E-Tip and 110gr TTSX were shot from a 6.8mm SPC II. The 130gr GMX was shot from a .270 Win.

Note that these are monolithic copper bullets and the results below may not apply to jacketed lead-core bullets.

Go to the First Page for Quick Links to all the bullets tested.

 

[Xman]

Obeserved Performance: 85gr Nosler E-Tips

I was surprise! Both modifications of the 85gr Nosler E-Tips resulted in more expansion, especial when you figure in the effect of reduce BC on velocity (all impact velocities without the pointed plastic tips are estimates). The bullet with the ballistic tip removed was largest and you can see how the expansion cavity is stretched more. I was also impressed with the reaction of the water jugs on impact. Both modified bullets stop in the phonebook before they reached 1000 pages.

 

[Xman]

Observed Performance: 110gr Barnes TTSX

Barnes 110gr TTSX - Though not as significant, the bullet with the tip removed did expand wider and had a more stretched expansion cavity. The bullet with the tip removed lost one of its pedals which was next to the bullet after it penetrated through the 1500 pages of phonebook and 5 magazines. The unmodified bullet with the ballistic tip still installed lost two of its pedals in the water column causing it to loose significant frontal area, penetrating through the phonebook and 10 magazines. These are both significant over-penetration situations, especially at 100 yards (penetrations through just less than 1000 pages of the phone book should give you an exit wound on a broadside lung shot on Southern sized deer). Though some six8 hunters use the 110gr TTSX, it really is designed for the .270 Win. When shot from the higher velocities of a .270 Win (3400+ fps mv), there is a dramatic difference in expansion as shown in the photo below (.270 Win on the left).

The testing done with the 110gr TTSX in the six8 demonstrate the negative effects of limited expansion, which are less energy transferred and over-penetration. The picture below shows the foam-core board and the increased energy transfer caused by larger expansion (test conducted at 100 yards). Note how much larger the facture/shock area is around the 115gr Fusion impact which expanded to 0.7 inches. Another comparison is to look at the 110gr TTSX impacts and the 95gr TTSX which has demonstrated excellent expansion (95gr TTSX is superimposed in the upper left). The 95gr TTSX produced a slightly larger fracture/shock area at 300 yards than the 110gr TTSX did at 100 yards. This demonstrates why Barnes made the 95gr TTSX for the six8. The link below shows the results when hunting hogs with the 110gr TTSX in a six8 which were not favorable.

 

[Xman]

Observed Performance: 110gr Barnes TTSX

Barnes 110gr TTSX - Though not as significant, the bullet with the tip removed did expand wider and had a more stretched expansion cavity. The bullet with the tip removed lost one of its pedals which was next to the bullet after it penetrated through the 1500 pages of phonebook and 5 magazines. The unmodified bullet with the ballistic tip still installed lost two of its pedals in the water column causing it to loose significant frontal area, penetrating through the phonebook and 10 magazines. These are both significant over-penetration situations, especially at 100 yards (penetrations through just less than 1000 pages of the phone book should give you an exit wound on a broadside lung shot on Southern sized deer). Though some six8 hunters use the 110gr TTSX, it really is designed for the .270 Win. When shot from the higher velocities of a .270 Win (3400+ fps mv), there is a dramatic difference in expansion as shown in the photo below (.270 Win on the left).

Update: subsequent testing has shown that barrel twist rate can effect bullet expansion. These were shot with a 1:11.25 twist. 110 TTSXs shot from a .270 Win with a 1:10 twist captured at the same velocity (longer distance) expanded much more. The evidence suggests that, if a bullet doesn't expand rapidly enough to shorten its length and increase its diameter, it becomes unstable afer impact and yaws before it can fully expand. Thus the faster 1:10 twist rate allows the bullet to remain more stable on impact and reach its full expansion.

The testing done with the 110gr TTSX in the 6.8 demonstrate the negative effects of limited expansion, which are less energy transferred and over-penetration. The picture below shows the foam-core board and the increased energy transfer caused by larger expansion (test conducted at 100 yards). Note how much larger the facture/shock area is around the 115gr Fusion impact which expanded to 0.7 inches. Another comparison is to look at the 110gr TTSX impacts and the 95gr TTSX which has demonstrated excellent expansion (95gr TTSX is superimposed in the upper left). The 95gr TTSX produced a slightly larger fracture/shock area at 300 yards than the 110gr TTSX did at 100 yards. This demonstrates why Barnes made the 95gr TTSX for the 6.8mm. The link below shows the results when hunting hogs with the 110gr TTSX in a 6.8 which were not favorable.

http://68forums.com/forums/showthread.php?25986-17-hogs-down-120sst-vs-110ttsx&highlight=Barnes

 

[Xman]

Observed Performance: 130gr Hornady GMX

Hornady 130gr GMX - the GMX with the tip removed did expand to be larger than the unmodified tipped bullet, 0.563" vs 0.525", and also expanded so much that it bottomed out the expansion cavity. However, during removal of the tip's shank from the expansion cavity, the drill bit did touch and slightly cut into the internal copper wall. I believe that is why the bullet's expansion became lopsided. All GMXs I have tested previously and pulled from game have been symmetrical.

 

[Xman]

130gr TSX vs 129gr LRX

This post has been update, 23 Jul 2013. During analysis to better understand the dynamics of monolithic bullet expansion, I found a significant error in my test data. I had mistakenly switched some of the recovered bullets. My apologies to Barnes Bullets and my fellow forum members. The picture below has been updated and the analysis revised. Additional analysis showing that kinetic energy, not velocity, is the correlating factor determining expansion can be found at the link below.

TBD

A revise report follows.

Here is another comparison of like bullets with and without ballistic tips shot from a .270 Win. Both these bullets are unmodified. One is a Barnes 130gr TSX hollow-point that is produced without ballistic tips. The other is a new Barnes .277 129gr LRX with a ballistic tip that is advertised to have a lower opening velocity, down from 2100 to 1600 fps. The LRX has the "new" cavity design that is claimed to be similar to the 6.8mm 95gr TTSX (you will see later that they are not quite the same). These tests were conducted at 100, 300, and 500 yards. I expected the LRX to out expand the legacy TSX which turned out to be the case at 100 and 500 yards but they expanded the same at 300 yards. The 130gr TSX did well, , especially considering the smaller expansion cavity, but the 129gr LRX provided the largest recorded expansion of any monolithic .277 bullet I have tested, an impressive 0.611" at 100 yards and still doubling in size at 200 yards. BTW, I have already tried the 130gr TSX in my 1:11 twist 6.8mm and it wouldn't stabilize. Stability calculations said it wouldn't but I tried anyway.

 

[Xman]

An opposing approach - Let's Add Tips!

So, if pulling the ballistic tips on monolithic bullets improved expansion, what would happen if ballistic tips were added to bullets that were originally designed not to have ballistic tips? To find out, I tested an 85gr TSX shot from a 6.8 and a 130gr TSX shot from a .270 with bullets modified to accept ballistic tips. Bullet expansion was worse with the tips installed and nowhere near the performance of the unmodified bullet. However, this really was not a valid test and more a schooling in how important expansion cavity design is. All bullet expansion stopped where the drill-bit stopped making the cavity to accept the ballistic tip. You can even see the original Barnes expansion x-cavity which continued deeper into the bullet. All these bullets modified with tips added over-penetrated, especially the 130gr TSX + tip which didn't expand much at all and was too long to remain stable after impact. It yawed and finished its deep, over-penetration tail-first (just like the Berger .277 VLDs). The real take-away here is how good a job Barnes did in their TSX expansion cavity design which achieves so much expansion from such a small cavity.

 

[Xman]

Final Piece of Analysis

To complete the search for knowledge and understanding, below are cross-sections of several 6.8/.277 monolithic bullets. You can see the expansion cavity in the E-tips and GMX are the largest. All the other bullets are pure copper where as these two are 95% copper/5% zinc - the same alloy used in copper jackets for lead-core bullets. An alloy of 95% copper/5% zinc is harder which is likely the reason the E-Tips and GMX need the larger expansion cavities. Here are a couple of interesting aspects to note. The 95gr TTSX, 110gr TTSX, and 129gr LRX all have different size blue ballistic tips and associated expansion cavities. The 95gr TTSX expands at lower velocity because it has the largest expansion cavity of the Barnes tipped bullets. You can see there is less copper structure around the expansion cavity of the 129gr LRX when compared to all the other Barnes bullets. This is likely the reason the LRX is claimed to expand at lower velocity even with its smaller expansion cavity and why it is losing its pedals during expansion. Finally, notice how much smaller the expansion cavities are for the non-tipped TSX bullets yet their expansion is typically as good as or better than the tipped bullets within their designed speed/energy range.

 

[Xman]

Conclusions

Thus, from the results of this testing where every bullet with its ballistic tip removed expanded more, and the fact that monolithic bullets with ballistic tips require larger expansion cavities to achieve similar expansion to monolithic hunting bullets produced without ballistic tips; it can be concluded that the addition of the ballistic tip does not promote expansion for monolithic hunting bullets. Again, these results may not be applicable to jacketed lead-core rifle bullets that have ballistic tips.

So, now there is another reason to remove ballistic tips other than wanting to use up some of your longer .270 bullets and have them feed through your AR magazine. From a terminal performance perspective in short range situations less than 100 yards, the advantage of removing the ballistic tips can be more expansion and reduced risk of over penetration. I do not recommend or see where it would be worth the effort to remove the tips on the 130gr GMX or 110gr TTSX as they are designed for .270 Win velocities. However, specific to Nosler's 85gr E-Tip, with the tip removed it becomes a more effective home defense round (note, leave the seating die depth unchanged so the bullet seats the same giving plenty of magazine clearance).

For those that need lead-free bullets for hunting, the heavier longer 130gr E-Tip could potentially become an option in the six8 assuming it has the same effective expansion cavity design that the 85gr E-Tip has. I need to test the 130gr E-Tip to verify performance but predict with the tip removed, it should stabilize in a 1:11 twist as the calculated stability factor improves to 1.26. The 130gr E-Tip would provide deeper penetration when hunting hogs with the six8 and possibly an advantage in areas of dense brush. Besides the advantage of being able to stabilize the longer 130gr copper bullet, there should be less chamber pressure and more powder capacity because the bullet can be seated longer in the six8 case which should also result in a higher muzzle velocity. Just remember to stay at least 0.050" off the lands to avoid pressure spikes.

Note: the bullets with the ballistic tips removed fed from the standard six8 AR magazine ok but should be cycled through your specific action multiple times to ensure reliable feeding if you choose to do this. I do have my feed ramps modified so they continue down into the upper receiver (see example below) which could be benefiting reliable feeding with these modified bullets (can't find the forum member that provided this tip and picture.

 

[WiscTJK]

Great work add usual x-man. Have you had a chance to shoot up the 110 gr tsx I sent you? I am wondering if the will over penetrate similarly to the 110 ttsx.

Thanks for all your hard work on this.

Todd

 

[Xman]

WiscTJK, 110gr TSX is the next testing I'm going to accomplish. I should get it done this weekend. I also want to see if the 130gr E-tip will stabilize in a 1:11 barrel with the tip removed and whether it will provide sufficient expansion in the 6.8 as it is a bullet designed for the higher speeds of a .270 Win.

 

[jwtharpe]

I'll have to get some CFE223 as I expect it will work well with 130gr bullets which is a project I started planning for.

Got the 120's up to 2950, node was at 2890 for .4".