New Weekend Knowledge Dump...

... from Active Response Training. Some of the things that caught my eye:

• The ATF has ordered Ultimate Training Munitions (UTM) from selling its force-on-force training munitions to civilians--they can only sell to military and law enforcement from now on. No explanation was provided for why civilians can't have the items.
• A test of different power optics on carbines looking at time to first shot and split times. Interestingly, at least from up close out to 100 yards that the author tested, he found 5X to be the best magnification overall. And no magnification and 10X were the worst. His recommendation was to get a LPVO and set it for 5X for general use and that you can then adjust it if circumstances and time allow for something different.
• An article (with embedded video) testing slung to shooting transitions with a shotgun from three different slung positions and just using a simple carry strap. If you don't have a pistol grip or long magazine sticking down to catch on your sling or clothes, I've found Africa carry to be fast and useful (i.e., off-hand shoulder, muzzle down). You can even rack a pump-action shotgun while bringing it to your shoulder. 
• A couple articles that discuss why open carry is a bad idea: one mentioning it in passing and the other specifically on that topic. The problem with open carry is that (i) someone may see the gun and decide to steal it and/or (ii) someone may see the gun and decide to take you out first. 
• For revolver fans, a discussion on the advantages of the S&W K-frame (like the original M&P) for a defensive/combat revolver.
• A recommendation that the civilian concealed carrier use a handgun with at least 10-rounds capacity (although recognizing that there are times and circumstances when you may need something smaller).
• Armed carry at churches was not only common at or around the time of the Revolutionary War, it was often required under the law. Might be useful for any lawsuits challenging modern laws prohibiting the carrying of weapons in a place of worship. 
• A look at using the .22LR for self-defense.
• Paul Martin gives some early thoughts/lessons from the attacks in Israel. 
• A test and comparison of ported, slide-compensators, regular compensators, and bare/plain barrels in polymer, striker fired, concealed carry pistols looking at muzzle-climb and the time to shoot a 10-round string. And the winner was ... the heavier, 2011-style .45 ACP pistol. But the ported barrel was almost as fast.