I've been working on this comparison of Wolf, Brown Bear, Tula, and Federal .223 ammunition since July. I think those who read my blog will find it interesting. It should bring forth some real data to a number of discussions relating to AR reliability, wear, and the differences between types of ammunition...
There seem to be some errors accessing the site right now, but it should be accessible to all soon.
I have utilized several motion picture devices and a personal computer to construct the greatest video you have ever seen*
*involving an iPhone and sandwiches.
In this video, I cover my experiences with the Mossberg 500 and the Remington 870.
I also describe how I came to carry and use the Remington 870 from the age of 10. My experiences with the Mossberg are more recent.
I've been working on this video in my spare time for over a month - I'm not in love with it, but I'm fairly happy with it.
High speed video of an AK-47 in 7.62x39 being fired, including a video of it without the top cover.
In this video, it is fairly easy to see that both the Sig M400 and Sig 516 are cycling at approximately 830rpm and display a small amount of bolt bounce in stock configuration:
Please see my previous SHOT high speed video post for more information. Unlike the video in that link, the rifles in today's post are being shot by the same person. Here's some of what I had to say in that previous article:
The rate at which the bolt carrier assembly recoils rearward can have an effect on reliable extraction and ejection, even if extractor and ejector dimensions and springs are absolutely correct. The period of time during which the bolt is behind the stack of rounds in the magazine, neither traveling rearward or forward, has an effect on reliability in that the magazine may not have enough time to push the next round into place before the bolt comes forward again, resulting in a "bolt over base" malfunction that is most commonly seen on suppressed rifles, as they have much greater rates of fire. Also, high forward bolt carrier velocity can result in extreme bolt bounce, as noted previously, while low forward bolt carrier velocity could mean that there isn't enough force to overcome strong magazine springs, dirt or debris in the action, etc.