Since we were talking about this in this thread, I figured I'd keep the conversation going here rather than create a new one.
Today I went to the range, and decided to time my rapid fire strings with a shot timer. Not all of them, but to just sort of spot check them to see where I'm at these days and if I could see a pattern. The reason that I stopped using a shot timer when training on rapid is because the timer adds additional stress. Under most circumstances I can ignore the timer, but controlled rapid fire is difficult, that any little distraction or mental stress got in the way of learning how to do it. For me at least, it had been a mental speed bump that was messing me up, so I stopped using it to keep it from interfering with my performance. I brought it back in from time to time, but hadn't been using it as a general rule when rapid fire training. Also, I typically don't begin firing in response to the beep. I hit the timer, load 5 rounds into a mag, the mag into pistol, come up on target, take a breath, and squeeze out the string. Basically isolating time to first shot from the problem of rapid fire. Again, while developing this skill, you want to minimize all other distractions in order to "find" the moments inside of the moments. Once you've developed the basic skill, pulling the timer back in, at least occasionally, will help out significantly in figuring out what's happening. But at the onset of rapid fire training it can work more against you than for you. At least for me anyways.
Today I put 150 rapid fire rounds downrange, in 5 round strings, at a target at 5 yards. Accuracy was a little bit sloppier than normal. The majority of my rounds were upper center mass inside of 10", although I did have several flyers.
Below are a a couple 5 shot strings that were more or less representational of how I was shooting. I noticed something very interesting though. There was a general pattern of increasing speed over the course of the 5 rounds. While doing this is a good way to train on increasing your speed (starting at a comfortable pace, and increasing your speed over a string of 15-20 rounds), this is not what I was trying to do here. I believe that this is something in my head, where I subconsciously hold back on the first couple rounds while being concerned with accuracy. The reality is, the best way to hold maximum accuracy is to maintain a consistent cadence. Introducing timing variations introduces inconsistency, and inconsistency is, well, inconsistent. Inconsistent timing will lead to inconsistent accuracy, and at these speeds, .03 seconds is a 30% change in speed. I need to make a point of emphasizing consistency at these speeds rather than speeding up during a string. That either means holding back just slightly to the pace I start at, or starting with balls-out speed rather than ramping up over the first couple rounds to get there.
Another thing I noticed is that the timing of my trigger stalls, where I start applying rearward pressure before the trigger resets, didn't cause as much increase in split time as I thought. My split times for stalls were all under .2 seconds, even though they felt like an eternity to get let off the trigger to reset and squeeze again. This also casts doubt on one of my presumptions about my "galloping" trigger technique - that trigger reset happens by leveraging my startle reflex to relax my trigger finger for a very brief moment to let the trigger out to reset. If I can squeeze the trigger, realize the gun didn't fire, let out to reset, squeeze and fire a round in .18 seconds, while *not* leveraging my startle reflex in response to the previous shot (since there was no previous shot I was responding to), I must be using another mechanism other than startle, that's still faster than my conscious raw reaction time. I'm going to have to spend some time thinking and reading about this, since I'm not sure how it's working. Another observation the timer made me aware of (that I should have been able to recognize even without it) was that trigger stall always happened after the 2nd shot or the 3rd shot. It never stalled after the 1st, and never stalled after the 4th. This is also the place in my strings where I was increasing speed slightly. One very common mistake people make is to increase muscle strength in response to moving faster. This makes me wonder if both my occasional trigger stall and accuracy issues aren't both related to consistency of cadence, and less about my weapon hand grip strength as I suspected.
My plan moving forward is to focus on consistency over speed, slow down a few hundredths, and see how much increased consistency effects my accuracy and trigger stall issues. That means, more work on the timer. I think I've pretty much gotten past the point where the timer interferes with my being able to do this, so hopefully I'll have a breakthrough in the near future by letting the timer tell me what's going on.
Anyways, I wrote this up for myself as much as anything else, to get my thoughts on today's session down so I can refer back after future range trips. Since we were discussing rapid fire techniques I figured I'd share with anyone interested. If anyone is interested in this, and would like to follow along with what I'm leaning about how o master this, let me know and I'll start a new thread.