Hornady Superformance/260 Rem/Barnes Match Burner Load Experimentation
I first heard about Hornady Superformance ammunition and powders over a year ago, when pulling targets at a rifle match. "Word in the pits" was that significantly higher velocities were possible without increased pressures. Naturally, I was interested, if only to have slightly better long-range performance - the main attraction was to try something new and supposedly better. However, I've been pretty busy, and wasn't able to try them out until recently.
Even then, Hornady hasn't made it easy. There is a decent selection of Superformance ammunition, but official load data for the Superformance rifle powder is very slim. It'll supposedly work for .22-250, .243, and .300 WSM, but the other calibers they list might as well be .299 Macedonian Hoplite or .17-50 Weatherby BMG Accelerator - the powder as currently marketed doesn't have a broad appeal. To be fair, Hornady says that the "magic" behind Superformance only works in a few calibers.
I thought I'd try Superformance powder in my .260 Rem-chambered Remington 700 VLS. It has a 26" barrel, which tends to help me achieve higher velocity numbers when loading with Varget. However, since there was no load data for Superformance in the .260, or any other 6.5, I wanted to be careful.
As for projectiles, I normally use Hornady SSTs - 129gr, for this caliber. In this case, I bought the relatively new Barnes Match Burners, which are lead-core HPBT projectiles from the normally-lead-free Barnes bullet company. At around $27/100, they're significantly cheaper than Sierra MatchKings ($36/100 or so) or Berger VLDs ($42/100).
These Match Burners are 140gr, which are pretty darn long when it comes to the 6.5/.264 diameter, and have a G1 BC of .586. This would roughly correspond to a G7 BC of around .300, but I don't know for sure. I'm planning to do more shooting with them - especially since they're cheaper and my reloading dollars go farther. Their general appearance is more confidence-inspiring than SMKs, even if the uneven meplat on practically every SMK doesn't affect accuracy. However, for my initial tests, I wasn't concerned with accuracy, precision, trajectory, or anything but the most basic question every handloader asks when trying a new load.
That question is, of course, "Will this load cause hot, sharp chunks of steel to enter my face at extremely high velocities?" Since there was no load data to work off of, I used Hodgdon's data for 4831, because 4831 is close to Superformance in terms of burn rate, reduced it, and started from there. Since the load for a 140 was 44gr of 4831, I started with 42gr. I also loaded three each at 43, 44, and 45 grains of powder.
Although only three shots would limit my ability to determine how consistent the powder was with each load, it would give me a ballpark figure - and if I saw problem signs with the lighter loads, such as the hardened steel of my 700's receiver causing facial disfigurement and/or death, I wouldn't have to pull down 30 or 40 useless and dangerous handloads.
As it turned out, though, my rifle did not blow up. Nor did I see any of the classic high pressure signs, so I might try pushing it a bit farther. However, I'm not seeing amazing performance so far - the 42gr load averaged 2585fps, the 43gr 2612, the 44gr 2669, and the 45gr 2743. For what it's worth, Hodgdon says 44gr of 4831 behind a 140gr Nosler Partition is good for 2715fps - no minimum load is listed.
My normal 129gr loads with Varget are in the 35gr range and I see mid to high 2600s with the 129gr SSTs - nothing to write home about, but it's still a pretty flat-shooting and low-recoiling load. Speaking of that, while Hornady says recoil isn't any greater with Superformance, basic physics says that a projectile of the same weight fired in the same rifle but traveling at a higher speed will have more recoil than that which is traveling at a lower speed. It might have been because I knew I was shooting progressively hotter loads, but I thought I noticed greater recoil with the 45gr load than, for example, the 42gr load.
STANDARD DISCLAIMER: Please be smart when reloading, and don't kill yourself or endanger your ability to attract a suitable mate - then again, if you're really dumb and prone to doing things like blowing up your own rifle because you loaded 50 grains of pistol powder in a rifle, maybe you'd be doing the world a favor by not reproducing.
300 AAC Blackout Subsonic Velocity Data
As mentioned previously, I am working with a series of 300 AAC Blackout uppers courtesy of Deliberate Dynamics and Rainier Arms. These uppers have Noveske stainless steel barrels and will be run through a series of tests to determine their suitability for various purposes, both "military" and "civilian." Jim of Deliberate Dynamics did the shooting today, while I "shot" photos. I particularly like this shot, which shows what I believe to be a bit of flame coming out the ejection port along with the case.
8" Noveske 300 AAC Blackout
One of the first things we wanted to do was see what the performance of the 220 grain subsonic load was from these uppers. Since we had 8", 10.5", 12.5" and 14.5" barrels at our disposal, a good chronograph, and factory ammunition, it was a fairly easy task. These are preliminary numbers, and will be followed up with more thorough data analysis - but for now, they're pretty solid.
14.5" Noveske 300 AAC Blackout Chronograph Data
I've been loading 300BLK for a few months now, but I think most people will be interested in the performance of factory ammunition. In this case, it was Remington R300AAC8 - the aforementioned 220 grain subsonic stuff. Although supersonic loads - and factory brass - have been promised for a very long time now, it's disappointing to see that they have not been forthcoming.
Noveske 300 AAC Blackout
We encountered no functional issues, which was a good sign for both the caliber and myself, since I put the uppers together. The Troy mags, as well as PMags, fed the fat 220gr loads just fine. If you're not familiar with 300 Blackout, it uses 5.56 bolts and magazines, and a modified 5.56 case that's shortened 10mm and necked up to .30 caliber. The advantages of 5.56 mags and the strength of a 5.56 bolt, as well as .308 diameter projectiles, make this a much better choice than 7.62x39 for the AR-15 platform.
8" Noveske 300 AAC Blackout
As for the performance of the subsonic load, all shots remained subsonic, which is, of course, a good thing. However, this means that the guys with 8" uppers are going to be using a load that's a little slower than it could be, just so the guys with 14.5" and 16" uppers don't have that supersonic "crack."
12.5" Noveske 300 AAC Blackout
The 8" averaged 954fps, the 10.5" 993fps, the 12.5" 1014fps, and the 14.5" 1025. This is clearly a load that's optimised for shorter barrels. However, I wasn't impressed with the standard deviation - over 40 in all but one example. And the extreme spread was, well, extreme, exceeding 100fps in several cases.
14.5" Noveske 300 AAC Blackout
I would like to see more ammunition available in this caliber. Not only would more loads be nice, but I've never found Remington ammunition to be "the best," or even above average. Right now, though, this 220gr load is just about the only thing I can find, other than expensive Cor-Bon stuff, and 175gr CMMG ammunition that reportedly won't cycle in anything but CMMG uppers. I'll be loading various projectiles, but as I said above, hard data will be presented with factory ammunition. My final report will be a comprehensive evaluation of the caliber.
Electroless Nickel Plating Two Year Followup
It's been two years since I first started electroless nickel plating firearms, and I figured it was time for a two-year followup. The original post is located here. Although I posted that in October of 2009, I started using the kit in July of that year.
I am very pleased with the results. If you are familiar with the process, you may find the first few minutes of the video boring. If you aren't, it's a general description of the electroless nickel plating kit, which might be as good of a decision for you as it was for me.
As you can see here, Caswell was also impressed with my results.
AR-15 Carbine Action Spring Performance Differences
In the past, I have used high speed video to analyze various aspects of AR-15 operation. Today, I did some testing at the range with several action springs. This is intended to be an ongoing test, so all three action springs were brand new. They are:
- Tactical Springs/Sprinco "Blue" recoil spring
- Brownells M4 Recoil Spring - Chrome Silicon
- Brownells AR-15/M4 Recoil Spring
The test weapon was a 16" carbine gas AR-15 with a .063" gas port, H buffer, 5.56mm NATO chamber, M16/Auto bolt carrier, and AR-15 fire control group. The bolt carrier group was cleaned and wiped down with a dry cloth before the test. Two types of ammunition were used, Prvi Partizan M855 and Federal XM193. One magazine, a Lancer L5 20rd, was used for the test, and it was always loaded to 20 rounds at the beginning of each string of fire, which consisted of five rounds.
Rate of fire calculation is based on the time it takes for the bolt carrier group to fire, unlock, extract, eject, cock, feed, chamber, and lock, plus the time it would take for a standard M16A1 fire control group to allow the hammer to fall once more. These calculations are therefore theoretical, but this method has always been verifiable when compared to actual M16A1 high speed video testing.
The rate of fire was highest with the Springco Blue action spring (726rpm M855/680rpm XM193), median rates of fire were achieved with the Brownells Chrome Silicon spring (685rpm M855/667rpm XM193), and the lowest rates of fire occurred with the Brownells AR-15/M4 recoil spring (656rpm M855/626rpm XM193). The differences in cycle time and bolt carrier velocity between the three springs were always noted during the feeding, chambering, and locking portions of the cycle of operations; put simply, the lower rates of fire came as a result of reduced forward bolt carrier velocity. As forward velocity fell, so did consistency.
Relative to the other action springs, the Sprinco Blue action spring was very consistent overall, with a total cycle time standard deviation of .55 for M855 and 3.03 with XM193. The Brownells Chrome Silicon spring was not far behind, with M855 and XM193 standard deviations of 1.87 and 3.81, respectively. The Brownells AR-15/M4 recoil spring could not be considered as consistent, with standard deviations of 5.59 and 12.87.
Further testing will be conducted.
AR-15 Platform “Barrel Whip” Discussion
Here's some high speed video comparing why free floated barrels move during firing. The results shouldn't be very surprising, but the cause is a lot more simple than some might think.
The movement is not due to barrel fluting or piston/op-rod operation, but the simple act of a muzzle device placing uncontested force at the very end of the barrel. Because the barrel is free floated, it only has support where it meets the receiver. As a result, we see the barrel move a bit. When this same rifle has a muzzle device that does not place such force on the barrel, we do not see any movement.