Testing another 160: Need for Speed Part D

[pitted bore]

Post #1 - The Bullet

Summary of what follows: I used the 160-grain all-copper bullet from General Bullet Co. in a repeation of the tests from the Barnes bullet in Part C. (LINK to Part C). The General bullet goes about as fast as the Barnes bullet, but is a different design and performs differently than the Barnes bullet.

First, an acknowledgement goes to forum member rohk. He started reporting his good results with the General bullets and Enforcer powder 2-3 weeks ago, so I rearranged my planned test series and tried the General 160-grain bullet.

Warning: The loads and techniques described here may damage or destroy your rifle, or cause you serious injury or death. They were OK for me, but you and I likely do things differently. These loads probably exceed SAAMI pressure specs for the 450B. Keep in mind that this report is coming to you via the internet, a prime source of misinformation.

The General 160-grain all-copper bullet, their type #45-160, is not a duplicate or clone of the Barnes GAP bullet. (LINK to General Bullet site). Like the Barnes, the General bullet has a very wide and deep hollow point, but the cavity is shaped differently and looks almost hexagonal. The external dimensions also differ from the Barnes. The General bullet is slightly longer than the Barnes. The Barnes has its greatest diameter just below the ogive, and tapers inward toward the base. The General bullet has its full diameter for most of the parallel bore-bearing sides. The average of measurements of several individual bullets is shown in the photo.

Dimensions of General and Barnes 160-grain bullets

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The external differences make the General bullet a bit easier to hold in the 450B case. If there were a significant internal taper of the case near the mouth then the Barnes might fit better. However, both the Hornady and Remington cases have a straight, non-tapering portion for about a half-inch from the mouth. (Maybe the Barnes would work best with an unreamed 284 case?)

The .448-inch diameter is of the General bullet less than the usual .451 or .452 used with the cartridge. So, the fit of the bullet in the case mouth will have to be monitored carefully by others choosing to use this bullet. In my trials a couple of cases had to be run a short length into the Hornady taper-crimp die before seating the bullets, in order to hold the General bullet firmly.

rohk reported that his General 160s were a uniform .451 diameter. He probably was working with a different lot of bullets, so that's something that should be checked by anyone who decides to work with this bullet.

The following photos attempt to illustrate some differences between the two bullets:

General & Barnes bullets - cavity end view

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General & Barnes bullets - cavity end view 2

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General & Barnes bullets - bases

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edited for grammar & spelling

[pitted bore]

Post #2 - Loading & Accuracy & Velocity

I wanted to compare the General bullet's performance with the Barnes, so I loaded and tested it like the Barnes as reported in Part C. Cases were FL sized with the Hornady die. No case mouth expansion was needed to seat the bullet. Primers were CCI 41s, and powder charge was 51 grains of Enforcer. Bullets were seated to a COAL of 2.116", and crimped with the modified Lee 45-70 factory crimp die.

The 51 grains of Enforcer is about all of that powder that the case can hold and still have the bullet seat without a lot of compression. Internet sources say that Enforcer and Accurate 4100 are the same powder with different names.

Ctgs loaded with General & Barnes 160-grain bullets

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From the bench I shot two groups of 5 shots each at 100 yards using the Winchester Model 70 bolt rifle described here earlier. The mid-point of the chronograph screens was about 10 feet in front of the muzzle.

For the first five shots, velocities were 3129, 3143, 3162, 3162, and 3123 fps, for an average of 3143 fps, and SD of 18 and ES of 39. Group size was 1-1/4" for four shots, with a fifth unexplained flyer opening it to 2-1/4".

For the second five, velocities were 3134, 3151, 3156, 3110, and 3173, average = 3144 fps, SD = 24, ES = 63. Group size for 5 shots was 1-1/4". Photo of this second group:

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At 3142 fps, the General bullet was a little slower than the Barnes bullet at 3192 fps. Accuracy was very similar. Again, these are not tiny groups of bragging size, but they do show a tendency for snuggling.

There were no obvious signs of excessive pressure. The muzzle velocities here exceed all but a couple of max loads shown in the Hodgdon on-line reloading data site for the 300 Win mag and the 300 Weatherby with 165-grain bullets.

edited 05Aug12 to correct COAL

[pitted bore]

Post #3 - Expansion in Water

I tested a General bullet just as I did the Barnes by setting up a series of gallon (3.8 liters for our metric friends) poly jugs of water, and firing into them from 20 feet away. Here are before and after photos of the trial:

Water jugs before being shot

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Water jugs after being shot

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(Yes, I realize that a sample of size 1 is not definitive, but it's better to light a single small candle than sit around in the dark.)
The General bullet penetrated four jugs, one more than the Barnes. The bullet was found in the fourth jug. It had poked a hole through both sides of the fourth jug, but didn't make it through the back-side hole.

The recovered General bullet weighed 130 grains, or about 81 percent of the original weight. The recovered Barnes bullet had weighed 122 grains, or 77 percent retention.

The expanded bullets differed notably in appearance. Here are photos of the recovered General bullet, side-by-side with the Barnes bullet recovered from the water test a few days previously. It's obvious that the rupture pattern and expansion characteristics differ between the two bullets.

Recovered bullets from water jugs

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Recovered bullets from water jugs

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Post #4 - Newsprint test

As with the Barnes, I tested the General bullet by shooting it into a tight pack of newspapers from about 10 feet away. The dry newspaper test is supposed to stress the bullet like striking pretty heavy bone. Although the Barnes bullet had penetrated about 6-7 inches into the pack, the General blew through the whole grocery bag, and generated a cloud of confetti downrange. The bullet was not recovered. The exit "wound" was pretty impressive.

Dry newsprint entry

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Dry newspaper exit

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This test needs to be repeated. Shotgun slugs at close range have been stopped by the pack of dry newspapers, and they stopped siringo's heavy lead 450B slugs that I shot in a test reported here a couple of years ago. I suspect the papers in this test were not packed tight enough. I'll try to add another report soon.

[pitted bore]

Post #5 - A Couple of Notes

I'll be the first to admit the amount of data is pretty meager, and scarcely qualify even as preliminary. The comparison trial with these bullets was a side product of the real object of the work, which was to find what velocities might be obtained. A thorough check on accuracy or expansion characteristics will have to wait for another time or another person. Both bullets seem pretty uniform, and might produce really tight groups with some tweaking. Both bullets went splat nicely, holding together when operating at three times their designed velocity; this result was pretty impressive.

I'm not sure what use there is for the results. It's sort of like building and running a Top Fuel dragster - fun, but not a lot of immediate practical application. Or maybe there are good uses for these, and I'm just not imaginative enough to think of them.

Forum member rohk had pretty good accuracy with the General bullets, and did not report any functioning difficulties with shooting them in his AR with a different powder at lower velocities and probably lower pressures. I have no idea what would be the result of shooting the loads described here in a semi-auto. Be safe!

--Bob

[Hoot]

Excellent work Bob!

I love the © looking at you from the butt. I think that goes to show these are not simply Barnes seconds.

The graininess of the expanded round suggests it is forged harder than the Barnes, or it is an alloy of copper with a little more zinc than the Barnes. That could also account for the complete passthrough on the newspaper. Without re-reading your other thread, in your opinion, can an actual AR15 upper 450b take the energy of tossing them at that velocity? Obviously, your bolt action is up to the chore.

Hoot

[pitted bore]

The graininess of the expanded round suggests it is forged harder than the Barnes, or it is an alloy of copper with a little more zinc than the Barnes. That could also account for the complete passthrough on the newspaper.

Hoot-
I know only what the General Bullet website says about their bullets: That they're solid copper manufactured by a proprietary process. If they used an alloy, then they should not describe the material as "solid copper". If their process differs significantly from Barnes, that might accounts for the differences in appearance that you noticed.

Without re-reading your other thread, in your opinion, can an actual AR15 upper 450b take the energy of tossing them at that velocity? Obviously, your bolt action is up to the chore.

I don't know the answer to that question. rohk was running the General 160s a bit slower with the same powder, Enforcer, and reported no problems with his AR.

My plans are now to keep searching for a magic powder or powders that will drive these 160s a bit faster without pressure problems. When and if I find it or them, then it will be time to find out about AR operation. More likely, with a jillion AR owners out there, some of them will find a good powder for the light bullets. I hope they share the knowledge.

--Bob

[bushmeister]

Great info! 3000+ @160 gr, thats fantastic!

[rohk]

I only ran two loads as i only had 10 bullets left, neither showed pressure signs. Both cycled the action flawless. Not really sure how much harder you could push a stock bushy but the 2750 load was very accurate.


160 gr. Ramshot Enforcer
49 gr. 49.6 gr.
ave. 2750 2787

[pitted bore]

I only ran two loads as i only had 10 bullets left, neither showed pressure signs. Both cycled the action flawless. Not really sure how much harder you could push a stock bushy but the 2750 load was very accurate.

160 gr. Ramshot Enforcer
49 gr. 49.6 gr.
ave. 2750 2787

rohk-

The raw numbers indicate that I got 350-400 fps more velocity for just 1.4 grains more Enforcer powder, but that's almost certainly not the case. Some of the velocity difference may be due to 10 more inches of bbl (your rifle has 16", right?), or to a smaller bore diameter (.451" vs .452), or to something else. I recall that you were moly coating the 160-grain bullets; this could also somewhat decrease pressures and velocities compared with an uncoated bullet with the same powder charge.

Please continue to share your new ideas.
Thanks.

--Bob
edited to correct bore diameters