Good Saturday afternoon, ya'll ! It rained last night and I sort of figured that would discourage turnout at the outdoor range that I frequent. Turned out I was right and I had the entire pistol line to myself for almost two and a half hours.
I went to just "have fun" and burn LOTS of powder, but co-incidentally to capture chronograph data for the factory ammo I took with me. I plan to use this data as sort of a "baseline" to measure my handloads against. To that end, I took THREE revolvers to fire my factory 38 Special loads through, two of which I've been using this past week to test my plated bullet handloads.
The three revolvers have, between them, a variety of barrel lengths that allow me to get a good "feel" for the impact that barrel length has on the velocities produced by both my handloads and factory loads. BUT.... It was the addition of this third revolver that has opened up another variable that I must sort out and consider. Can anyone guess what that might be?? Come on boys and girls, put on your thinking caps!
Give up? It is the level of force with which the hammer/firing pin strikes the primer, plus variations in the sensitivity of various makes of primers.
My testing of plated bullet reloads this past week was all done by firing both of my test guns double action. One of them is a S&W 642-2, so that's the only choice I have, but the other one I've been using is an older S&W "N" frame with a 6" barrel, so I had the choice of shooting it either single action or double action. I chose to fire it double action exclusively while testing my plated bullet reloads... I think that I was thinking "consistency" and "apples to apples" and those kind of thoughts.
Well, I hauled out my third test gun today in addition to the little 642-2 DA only airweight and the big heavy 6" barrel N frame. It is a S&W 686 Plus with about a 3" barrel. I decided to shoot it FIRST this morning, so I opened it up and stuffed in 7 rounds of factory Winchester 130gr FMJ "White Box" target ammo. I also chose to shoot it double action. Guess what happened? Every other round fail to fire. Upon examination, the primer strikes were too light! phooey!!! So, what to do? Light bulb moment. I've seen this before. I decided to fire everything in this 686 and the N frame single action. THAT worked like a charm for both Remington/UMC 130gr FMJ target ammo and the Winchester 130gr FMJ factory stuff. I put 50 rounds of each through each of the three revolvers that I'd "brung with me" and captured the data on the chronograph.
As a quick sidebar, let me 'splain something to any of you new-to-revolvers young whipper-snappers out there: Double action revolvers are, by design, "sprung" in a manner that typically yields a slightly lighter hammer strike when firing double action. When firing single-action, most DA revolvers will typically yield a heavier hammer strike. And that will USUALLY be sufficient to get ignition on ammo that will not RELIABLY fire with a double-action trigger pull. SO... The new-to-the-mix 686 Plus gobbled up 50 rounds each of both the Winchester and Remington target ammo in single action mode with no further misfires. I then proceded to test both factory loads through the N frame 6" barrel. It gobbled up 50 rounds each of both ammo varieties in both double action firing mode and single action firing mode, no misfires on anything. Hmmm... The 686 wants single action to reliably touch off the Winchester White Box stuff. It also went through 50 rounds of the Remington/UMS stuff in single action without a hitch. What about trying the Remington/UMC ammo in the 686 shooting double action? Check. It gobbled that up with only a single misfire.
The little S&W 642-2 airweight is double action only and has a REALLY stout DA trigger pull. It gobbled up 50 rounds each of both the Winchester and Rem/UMC stuff without a hitch. I wasn't suprised by that, I've put literally several hundred rounds of each through this little gun previously. That stout DA trigger pull on the little gun has yet to fail me a single time on anything I've put in it. Best way that I can describe shooting it is that it is a VERY RELIABLE HANDFUL to shoot. My target from this morning reflects the differences in "shootability" between the lightweight snub and the bigger revolvers. I'm more of a "minute of pie plate" shooter with the snub, and a "minute of teacup" shooter with the heavier revolvers (when shooting them all DA).
Now for the bottom line: The issues with the 686's difficulty igniting the Winchester White Box stuff in DA mode causing me to shift to SA mode for the two heavy revolvers uncovered an interesting pattern in the chronograph data. What I THINK the data reveals is that the Extreme Spread values and Standard Deviation number were LOWER when shooting the factory ammo in those two heavy guns in single action that when shooting them double action.
I am going to have to pursue this avenue a bit farther with my handloads to see if the ES values come down any while shooting single action. Also, I've been building my plated bullet loads with CCI small pistol primers, which are probably some of the least sensitive ones available (according to the interwebs AND my person experience in the distant past). CCIs are all I have on hand, but I think that I have a stash of brass that I've already primed with Winchester small pistol primers, AND I'm going to seek out some Federal small pistol primers to test also (Federal supposedly being the MOST sensitive primers as compared to CCI / Winchester / Remington. Again, according to the interwebs, Lee's reloading manual, and my own experiences).
So, I just got back from the range and haven't done an in depth examination / analysis of the chrono data I captured this morning. I'll do my "reply to my own post" thing here in this thread once I've finished my dive into the data.
Let me know if any of you have had experiences with primer ignition / primer sensitivity where it has had significant impact on your velocity extreme spread values and your velocity standard deviation values.
I went to just "have fun" and burn LOTS of powder, but co-incidentally to capture chronograph data for the factory ammo I took with me. I plan to use this data as sort of a "baseline" to measure my handloads against. To that end, I took THREE revolvers to fire my factory 38 Special loads through, two of which I've been using this past week to test my plated bullet handloads.
The three revolvers have, between them, a variety of barrel lengths that allow me to get a good "feel" for the impact that barrel length has on the velocities produced by both my handloads and factory loads. BUT.... It was the addition of this third revolver that has opened up another variable that I must sort out and consider. Can anyone guess what that might be?? Come on boys and girls, put on your thinking caps!
Give up? It is the level of force with which the hammer/firing pin strikes the primer, plus variations in the sensitivity of various makes of primers.
My testing of plated bullet reloads this past week was all done by firing both of my test guns double action. One of them is a S&W 642-2, so that's the only choice I have, but the other one I've been using is an older S&W "N" frame with a 6" barrel, so I had the choice of shooting it either single action or double action. I chose to fire it double action exclusively while testing my plated bullet reloads... I think that I was thinking "consistency" and "apples to apples" and those kind of thoughts.
Well, I hauled out my third test gun today in addition to the little 642-2 DA only airweight and the big heavy 6" barrel N frame. It is a S&W 686 Plus with about a 3" barrel. I decided to shoot it FIRST this morning, so I opened it up and stuffed in 7 rounds of factory Winchester 130gr FMJ "White Box" target ammo. I also chose to shoot it double action. Guess what happened? Every other round fail to fire. Upon examination, the primer strikes were too light! phooey!!! So, what to do? Light bulb moment. I've seen this before. I decided to fire everything in this 686 and the N frame single action. THAT worked like a charm for both Remington/UMC 130gr FMJ target ammo and the Winchester 130gr FMJ factory stuff. I put 50 rounds of each through each of the three revolvers that I'd "brung with me" and captured the data on the chronograph.
As a quick sidebar, let me 'splain something to any of you new-to-revolvers young whipper-snappers out there: Double action revolvers are, by design, "sprung" in a manner that typically yields a slightly lighter hammer strike when firing double action. When firing single-action, most DA revolvers will typically yield a heavier hammer strike. And that will USUALLY be sufficient to get ignition on ammo that will not RELIABLY fire with a double-action trigger pull. SO... The new-to-the-mix 686 Plus gobbled up 50 rounds each of both the Winchester and Remington target ammo in single action mode with no further misfires. I then proceded to test both factory loads through the N frame 6" barrel. It gobbled up 50 rounds each of both ammo varieties in both double action firing mode and single action firing mode, no misfires on anything. Hmmm... The 686 wants single action to reliably touch off the Winchester White Box stuff. It also went through 50 rounds of the Remington/UMS stuff in single action without a hitch. What about trying the Remington/UMC ammo in the 686 shooting double action? Check. It gobbled that up with only a single misfire.
The little S&W 642-2 airweight is double action only and has a REALLY stout DA trigger pull. It gobbled up 50 rounds each of both the Winchester and Rem/UMC stuff without a hitch. I wasn't suprised by that, I've put literally several hundred rounds of each through this little gun previously. That stout DA trigger pull on the little gun has yet to fail me a single time on anything I've put in it. Best way that I can describe shooting it is that it is a VERY RELIABLE HANDFUL to shoot. My target from this morning reflects the differences in "shootability" between the lightweight snub and the bigger revolvers. I'm more of a "minute of pie plate" shooter with the snub, and a "minute of teacup" shooter with the heavier revolvers (when shooting them all DA).
Now for the bottom line: The issues with the 686's difficulty igniting the Winchester White Box stuff in DA mode causing me to shift to SA mode for the two heavy revolvers uncovered an interesting pattern in the chronograph data. What I THINK the data reveals is that the Extreme Spread values and Standard Deviation number were LOWER when shooting the factory ammo in those two heavy guns in single action that when shooting them double action.
I am going to have to pursue this avenue a bit farther with my handloads to see if the ES values come down any while shooting single action. Also, I've been building my plated bullet loads with CCI small pistol primers, which are probably some of the least sensitive ones available (according to the interwebs AND my person experience in the distant past). CCIs are all I have on hand, but I think that I have a stash of brass that I've already primed with Winchester small pistol primers, AND I'm going to seek out some Federal small pistol primers to test also (Federal supposedly being the MOST sensitive primers as compared to CCI / Winchester / Remington. Again, according to the interwebs, Lee's reloading manual, and my own experiences).
So, I just got back from the range and haven't done an in depth examination / analysis of the chrono data I captured this morning. I'll do my "reply to my own post" thing here in this thread once I've finished my dive into the data.
Let me know if any of you have had experiences with primer ignition / primer sensitivity where it has had significant impact on your velocity extreme spread values and your velocity standard deviation values.
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