IGOTGLOCKED Posted November 22, 2016 Share Posted November 22, 2016 Just bought a CE Pro Chrono Digital and was able to use it for the first time today. Had to use it indoors as the closest outdoor rage is 1.5 hours away... Also had to use extra lighting as I didn't have the optional lighting kits for it and had to fiddle with it until it had enough light to function. I didn't get any errors so I have to assume all went fairly well..? Shot four strings of 9 shots. Average ES = 40.25 Average SD = 13.75 Average fps = 788.5 I need 76.5 fps to get to obtain 865 fps to a minimum PF of 125 (for 9mm) I am using 145 grain rn Acme hi tek coated bullets 2.8 gr titegroup 1.155 oal. My question is --- How do I calculate how many grains more charge required to obtain at least minimum PF? Thanks in advance form IGG! Link to comment Share on other sites More sharing options...
MemphisMechanic Posted November 22, 2016 Share Posted November 22, 2016 (edited) You're at 114 PF right now. So... Load 20 rounds at 3.0gr Another 20rnd batch at 3.2gr A third set of 20 at 3.4gr ... and go back and clock them. I expect 3.0 to possibly make power factor or be a pinch below it. 3.2 will hopefully hit what you need. (Follow my advice as long as 3.4grains isn't over the book max. Pretty sure it isn't. But don't go over published loads just because some jerk on the web told you to.) Edited November 22, 2016 by MemphisMechanic Link to comment Share on other sites More sharing options...
Brooke Posted November 22, 2016 Share Posted November 22, 2016 I bet you end up at 3.3 to get about 130pf. The advice above is a sound way to figure that out. Link to comment Share on other sites More sharing options...
IGOTGLOCKED Posted November 22, 2016 Author Share Posted November 22, 2016 16 minutes ago, MemphisMechanic said: You're at 114 PF right now. So... Load 20 rounds at 3.0gr Another 20rnd batch at 3.2gr A third set of 20 at 3.4gr ... and go back and clock them. I expect 3.0 to possibly make power factor or be a pinch below it. 3.2 will hopefully hit what you need. (Follow my advice as long as 3.4grains isn't over the book max. Pretty sure it isn't. But don't go over published loads just because some jerk on the web told you to.) Thx Memphis - book shows 2.8 lead & 3.6 plated... 10 minutes ago, Brooke said: I bet you end up at 3.3 to get about 130pf. The advice above is a sound way to figure that out. Is there an advantage being at 130 vs 125 PF? Link to comment Share on other sites More sharing options...
Sarge Posted November 22, 2016 Share Posted November 22, 2016 3 minutes ago, IGOTGLOCKED said: Thx Memphis - book shows 2.8 lead & 3.6 plated... Is there an advantage being at 130 vs 125 PF? You have to leave a cushion. If you are loading for USPSA PF and don't make 125 at chrono, you shoot for no score. Link to comment Share on other sites More sharing options...
Powder Finger Posted November 22, 2016 Share Posted November 22, 2016 what reloading press? Link to comment Share on other sites More sharing options...
MemphisMechanic Posted November 22, 2016 Share Posted November 22, 2016 (edited) And as we discussed in the previous threads, slightly hotter ammo is pretty much always more accurate with heavy bullets like those. That's the main advantage. (I'm amazed how many people can tell you exactly what PF their reloads run, but haven't tested it for group size at 25 yds) Other advantages? It cycles the gun harder & more consistently so you don't run into feeding issues shooting one handed... and it taps steel a bit harder. You cannot feel the difference between 125.001 power factor and 132 or so when a timer is running. It won't affect your score. Novice reloaders always think loading to just over PF is the best thing since sliced bread. I did. I was doing it for a solid year. Go to your range and ask the local Ms and GMs what the load their minor ammo at. I doubt you'll find a single one who is at less than 130PF So let us all tell it to you again: LOAD TO AT LEAST 130 PF Edited November 22, 2016 by MemphisMechanic Link to comment Share on other sites More sharing options...
IGOTGLOCKED Posted November 22, 2016 Author Share Posted November 22, 2016 23 minutes ago, Sarge said: You have to leave a cushion. If you are loading for USPSA PF and don't make 125 at chrono, you shoot for no score. IDPA, however the reason still stands true - thx! Link to comment Share on other sites More sharing options...
IGOTGLOCKED Posted November 22, 2016 Author Share Posted November 22, 2016 3 minutes ago, Powder Finger said: what reloading press? Dillon 650 Link to comment Share on other sites More sharing options...
MemphisMechanic Posted November 22, 2016 Share Posted November 22, 2016 29 minutes ago, IGOTGLOCKED said: Thx Memphis - book shows 2.8 lead & 3.6 plated... Then you should be fine loading up to 3.4 behind a bullet of that weight. Im expecting you to hit 130PF with 3.2 or so grains of powder. Likely no more than 3.3gr. But I like having those data points for the whole ladder from 115-135 or so, so I can extrapolate from it about how much of a charge I'd need to load for a specific velocity later on. Link to comment Share on other sites More sharing options...
IGOTGLOCKED Posted November 22, 2016 Author Share Posted November 22, 2016 6 minutes ago, MemphisMechanic said: Then you should be fine loading up to 3.4 behind a bullet of that weight. Im expecting you to hit 130PF with 3.2 or so grains of powder. Likely no more than 3.3gr. But I like having those data points for the whole ladder from 115-135 or so, so I can extrapolate from it about how much of a charge I'd need to load for a specific velocity later on. Agreed & will do. Most likely won't be able to get back to the range till early next week due to the long holiday weekend. I have to get there before it gets busy because they don't want anyone else in the bay (it's actually the LE bay) with me in case I have to go down range. Really great people there! Also, what am I able to learn and use now from knowing the ES & SD numbers? Thx again! Link to comment Share on other sites More sharing options...
IGOTGLOCKED Posted November 22, 2016 Author Share Posted November 22, 2016 20 minutes ago, MemphisMechanic said: And as we discussed in the previous threads, slightly hotter ammo is pretty much always more accurate with heavy bullets like those. That's the main advantage. (I'm amazed how many people can tell you exactly what PF their reloads run, but haven't tested it for group size at 25 yds) Other advantages? It cycles the gun harder & more consistently so you don't run into feeding issues shooting one handed... and it taps steel a bit harder. You cannot feel the difference between 125.001 power factor and 132 or so when a timer is running. It won't affect your score. Novice reloaders always think loading to just over PF is the best thing since sliced bread. I did. I was doing it for a solid year. Go to your range and ask the local Ms and GMs what the load their minor ammo at. I doubt you'll find a single one who is at less than 130PF So let us all tell it to you again: LOAD TO AT LEAST 130 PF Thx - got it - 130+ --- done. Link to comment Share on other sites More sharing options...
MemphisMechanic Posted November 22, 2016 Share Posted November 22, 2016 13-14 SD isn't stellar nor horrible. Pretty typical for a new progressive user with Titegroup Link to comment Share on other sites More sharing options...
Powder Finger Posted November 22, 2016 Share Posted November 22, 2016 1 hour ago, IGOTGLOCKED said: Dillon 650 not sure how easy with a 650 but if you can clamp it down just take it to the range and then you can bump up a half flat on the powder bolt until you get where you want. than leave it get your weight at home for reference. 550's work great for this. Link to comment Share on other sites More sharing options...
jwhittin Posted November 22, 2016 Share Posted November 22, 2016 (edited) GLOCKED, See this posting which will give you a simple way to know you will always meet PF. Bottom line is you should always use the STD to calculate the average velocity needed to make PF. I recommend adding a minimum of twice your measured STD to the average velocity required to meet PF for your bullet weight. There are two reasons why you DON'T want to just add a few power factor points. First is using just the average velocity measurement of your chronograph can introduce significant error as you don't know how accurate your chrono is (see this article http://www.appliedballisticsllc.com/Articles/ChronographChapter.pdf ). Whereas the difference in STD between chronographs is very small because it is a variance. Secondly, if your reloading process changes, it can cause you to fail PF. If you don't use your STD, you would never know (see example in the EB post given in the link above). Shoot with any questions! Edited November 23, 2016 by jwhittin Link to comment Share on other sites More sharing options...
jwhittin Posted November 22, 2016 Share Posted November 22, 2016 GLOCKED, In your case, you need a minimum of 850 fps to meet PF. Your STD is 14 fps so 850+28=878 fps (say 880 fps) which is now your desired load velocity. As a general rule, using 2*STD gives you a 90% confidence level you will meet an official PF test using only your first 3 rounds. If there are additional unknowns then add 2.5 or even 3*STD to ensure you meet PF. Link to comment Share on other sites More sharing options...
IGOTGLOCKED Posted November 23, 2016 Author Share Posted November 23, 2016 16 hours ago, MemphisMechanic said: 13-14 SD isn't stellar nor horrible. Pretty typical for a new progressive user with Titegroup Regarding the 650, perhaps I just need to keep loading more to learn more (unless you have suggestions) however I can change powder if that would help? Link to comment Share on other sites More sharing options...
IGOTGLOCKED Posted November 23, 2016 Author Share Posted November 23, 2016 16 hours ago, Powder Finger said: not sure how easy with a 650 but if you can clamp it down just take it to the range and then you can bump up a half flat on the powder bolt until you get where you want. than leave it get your weight at home for reference. 550's work great for this. Interesting concept, not sure if I would be comfortable with that, however what a great idea! Link to comment Share on other sites More sharing options...
MemphisMechanic Posted November 23, 2016 Share Posted November 23, 2016 Is any powder slipping out of the cases when you index to the next station? Is your powder measure kept at least half full? Link to comment Share on other sites More sharing options...
IGOTGLOCKED Posted November 23, 2016 Author Share Posted November 23, 2016 8 minutes ago, MemphisMechanic said: Is any powder slipping out of the cases when you index to the next station? Is your powder measure kept at least half full? No powder spilling out when indexing, I installed that aftermarket bearing which stopped that. Yes I keep the hopper topped off and well over half full. Thx! Link to comment Share on other sites More sharing options...
MemphisMechanic Posted November 23, 2016 Share Posted November 23, 2016 You can obsess over this... Or go shoot groups with your ammo. If it's accurate at 20-25yds and makes power factor? Then whittling down your SD with hours spent in the reloading room is going to make your OCD feel better. But it won't make you shoot any better. Link to comment Share on other sites More sharing options...
IGOTGLOCKED Posted November 23, 2016 Author Share Posted November 23, 2016 20 hours ago, Brooke said: I bet you end up at 3.3 to get about 130pf. The advice above is a sound way to figure that out. Thx, I'll let you know! Link to comment Share on other sites More sharing options...
IGOTGLOCKED Posted November 23, 2016 Author Share Posted November 23, 2016 (edited) 1 hour ago, MemphisMechanic said: You can obsess over this... Or go shoot groups with your ammo. If it's accurate at 20-25yds and makes power factor? Then whittling down your SD with hours spent in the reloading room is going to make your OCD feel better. But it won't make you shoot any better. Me obsess, surely you jest! Edited November 23, 2016 by IGOTGLOCKED Link to comment Share on other sites More sharing options...
Brooke Posted November 24, 2016 Share Posted November 24, 2016 (edited) On 11/22/2016 at 3:37 PM, IGOTGLOCKED said: Thx Memphis - book shows 2.8 lead & 3.6 plated... Is there an advantage being at 130 vs 125 PF? Absolutely. Each round, each environment, and each test chronograph vary a little. In order to comfortably pass a chrono at a major match you must be a little above the minimum 125. Most people shoot for 132 to 135 pf on their chronos to have a safety factor. It is imperative to do this. You will fail if you don't. Edited November 24, 2016 by Brooke Link to comment Share on other sites More sharing options...
jwhittin Posted November 25, 2016 Share Posted November 25, 2016 Brooke, Why don't you use your STD as explained above? As I point out, if you don't know your STD you can fail at any time if you just add a few PF points OR your chrono is off. Just curious. Link to comment Share on other sites More sharing options...
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