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. One of the first things… Read More
Category: Tests
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… Read More
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… Read More
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… Read More
A Test of Rifle, Caliber .223, AR-15 – From 1960
Aberdeen Proving Grounds 1960 AR-15 Test Linked above is a PDF report from February, 1960, about some early AR-15 testing. I've had it for a while but don't believe that I've discussed or posted it in the past. There's a large amount of technical data, to include precise gas port diameter and location, distance the bolt travels before unlocking, precise travel of the front sight post per notch moved, and so on. It also includes multiple 10 shot group accuracy testing, 6000 round endurance testing, extreme heat and cold testing,… Read More
Clearing Malfunctions
Ah, the dreaded "double feed" - something you need five hands, special tools, and a blessing from Odin to clear quickly, right? Watch as this shooter clears and fires 8 rifles in just over 3 minutes - 4 of them while blindfolded. Two each of the following malfunctions: - Bolt override double feed - "Dead man's chamber" - Stovepipe - Empty case override
Does Nickel Boron Reduce Heat?
We've been bombarded with a variety of coatings and platings over the past few years, most of which are called "proprietary" and given a cool name. In reality, there aren't a whole lot of finishes or metal treatments out there. Many are just variations on a theme, such as all the derivatives of nitrocarburization and nickel plating. Nickel boron is related to electroless nickel plating and electroless nickel with teflon (also known as Robar's NP3) with regard to the plating process. Nickel boron is reported to provide "permanent dry lubricity".… Read More
Heat Dissipation: Insulate or Circulate? Gas Tube or Op-Rod?
Standard disclaimer: I'm not a scientist and this was not a scientific test. Any conjecture on my part is purely an uneducated guess. As I've written before, POF-USA provided me with two of their upper receivers - one is of their standard P-415 design and the other is actually operated via a standard gas tube. It's called the RDIK. This gave me the opportunity to compare how each handled heat. That is, just how effective are all the design changes POF has made to the AR receiver, barrel nut, and… Read More
Federal XM9HA Chronograph Test
In a recent AR15.com thread, it was claimed that Federal 9mm ammunition identified as XM9HA was a contract overrun of 147gr HST hollow point projectiles loaded to the impressive velocity of 1180 feet per second. That's 9mm Major territory - and beyond. It was also reported that this ammunition had a high rate of failures to feed or failures to fire in a variety of handguns. I was recently sent a small quantity of this ammunition for testing via a chronograph. It was requested that I use a Glock 19… Read More