wingnut Posted November 12, 2016 Share Posted November 12, 2016 What is your minor PF goal. Link to comment Share on other sites More sharing options...
Jmo2011 Posted November 12, 2016 Share Posted November 12, 2016 For me it really depends on the load. Some finer granulated powders with very little sd I'll load at 130. For flaky powders that seem to deviate more I'll push closer to 135. Link to comment Share on other sites More sharing options...
Sarge Posted November 12, 2016 Share Posted November 12, 2016 7 points over seems to be a universal target. I think somebody did some fancy math on here once to figure out what works best but 7 over still made just as much sense if I recall Link to comment Share on other sites More sharing options...
MemphisMechanic Posted November 12, 2016 Share Posted November 12, 2016 (edited) 24 minutes ago, Sarge said: 7 points over seems to be a universal target. I think somebody did some fancy math on here once to figure out what works best but 7 over still made just as much sense if I recall It was even published in front sight. Two standard deviations (in FPS) over the minimum. So the more consistent your ammo's velocity is, the closer you can load to the minimum without failing chrono. 133-135 is my preference. Gun cycles a bit more vigorously, steel is more likely to go over, it's a bit more accurate in many cases with heavy bullets, and I just like the way it feels. You can't feel the difference between 128 and 133 with the same bullet/powder combo when a timer is ticking away. Edited November 12, 2016 by MemphisMechanic Link to comment Share on other sites More sharing options...
Sarge Posted November 12, 2016 Share Posted November 12, 2016 (edited) 1 hour ago, MemphisMechanic said: Two standard deviations (in FPS) over the minimum. So the more consistent your ammo's velocity is, the closer you can load to the minimum without failing chrono. I agree with everything you said but the only flaw I find in the FS formula is the dreaded chrono variation from match to match. How many times have we seen comments about," a chrono at section match XX read my ammo 5PF slower than last week at area X. Same temp, same time of day, same everything". Thats the reason I stay well away from PF floor. Edited: Another thing I like to do is keep track of all my low readings when doing chrono work. I typically load to single digit SD or very close to it so in theory it matters less , but I like knowing what would happen if I went to a major and just happened to grab all 8 rounds that were on the low side of the batch. Edited November 12, 2016 by Sarge Link to comment Share on other sites More sharing options...
MemphisMechanic Posted November 12, 2016 Share Posted November 12, 2016 (edited) Sarge, that was his reasoning for staying 2 SDs above 125.00 pf. The worst of the worst ammo would still be more than hot enough. A good example of why you need to ignore the "just load to 130pf and you'll be fine" crowd... is my Ramshot Compeition loads. I've posted the data in this forum if anyone wants to look, and every attempt results in SD's around 22-23. This has caused me to use that powder for practice ammo. If I were loading it at 133pf and three of my slowest rounds went over the chrono at a match? With "worst case scenario" weather plus a match chrono that reads slow, there's a good chance I wouldn't make PF. WST and other powders will give that exact same 135gr bullet a SD less than 10, which much much less velocity variation. Loading to 133 with it means much more cushion because now my slowest rounds clock above 130PF with an honest chrono. Edited November 12, 2016 by MemphisMechanic Link to comment Share on other sites More sharing options...
MemphisMechanic Posted November 12, 2016 Share Posted November 12, 2016 (edited) But that's far afield from my initial point. Even if I were able to somehow know the ammo would chrono exactly what I wish it to when I went to a Major (so I could get away with 125.01 PF ammo?) I'd still load to about 133-135pf. I like the way the gun runs, and how it feels, and that extra padding when it comes to tipping over steel. Most novices try to load the softest ammo they can get away with. A few seasons later, you're loading consistent ammo that's more reliable and a hair hotter because you learn that you don't shoot it any slower. Edited November 12, 2016 by MemphisMechanic Link to comment Share on other sites More sharing options...
IDescribe Posted November 12, 2016 Share Posted November 12, 2016 Load for best accuracy between maybe PF132 and PF137, and call whatever that load is good. Link to comment Share on other sites More sharing options...
Sarge Posted November 12, 2016 Share Posted November 12, 2016 1 hour ago, MemphisMechanic said: Sarge, that was his reasoning for staying 2 SDs above 125.00 pf. The worst of the worst ammo would still be more than hot enough. A good example of why you need to ignore the "just load to 130pf and you'll be fine" crowd... is my Ramshot Compeition loads. I've posted the data in this forum if anyone wants to look, and every attempt results in SD's around 22-23. This has caused me to use that powder for practice ammo. If I were loading it at 133pf and three of my slowest rounds went over the chrono at a match? With "worst case scenario" weather plus a match chrono that reads slow, there's a good chance I wouldn't make PF. WST and other powders will give that exact same 135gr bullet a SD less than 10, which much much less velocity variation. Loading to 133 with it means much more cushion because now my slowest rounds clock above 130PF with an honest chrono. I'm with you. Indeed with SD in the 20's you have no idea what you'll get on any given day. SD is more important than many give it credit for. Link to comment Share on other sites More sharing options...
Sarge Posted November 12, 2016 Share Posted November 12, 2016 3 minutes ago, IDescribe said: Load for best accuracy between maybe PF132 and PF137, and call whatever that load is good. Good point also! I shot a load for over a year that had a very low SD and was right at 132 EVERY TIME. Come to find out it was grouping about 6-8" at 20 yards! Link to comment Share on other sites More sharing options...
MemphisMechanic Posted November 12, 2016 Share Posted November 12, 2016 (edited) 2 hours ago, Sarge said: Good point also! I shot a load for over a year that had a very low SD and was right at 132 EVERY TIME. Come to find out it was grouping about 6-8" at 20 yards! Was it a heavier bullet? Conversely, my 135gr load with an SD of 23 (velocities varied by 100fps)? 2.5" at 25 through an M&P with an Apex hand fitted barrel. Edited November 12, 2016 by MemphisMechanic Link to comment Share on other sites More sharing options...
jkrispies Posted November 12, 2016 Share Posted November 12, 2016 3 hours ago, IDescribe said: Load for best accuracy between maybe PF132 and PF137, and call whatever that load is good. +1. 135ish. If anything I'd err on the high side to ensure a healthy knock down on plates. That's my route after exploring the lighter end and getting frustrated at the local level where plate calibration isn't a priority. Link to comment Share on other sites More sharing options...
uewpew Posted November 12, 2016 Share Posted November 12, 2016 I load to 132pf Link to comment Share on other sites More sharing options...
Kraj Posted November 12, 2016 Share Posted November 12, 2016 Ive made 132 pf at home and every major ive shot my current load at and feel comfortable leaving it as is Link to comment Share on other sites More sharing options...
mjmagee67 Posted November 13, 2016 Share Posted November 13, 2016 I shoot for 128 to 133 it's where my load puts me. In all my chrono-ing I've never had a round give me a PF below 126!!!! So that's what load to. Link to comment Share on other sites More sharing options...
Sarge Posted November 13, 2016 Share Posted November 13, 2016 2 hours ago, MemphisMechanic said: Was it a heavier bullet? No, same bullet. That was when I first started and before I knew subtle changes can make a big difference. I tested different oals, crimp, charge, etc before finding the ideal load for accuracy and PF. Link to comment Share on other sites More sharing options...
Sac Law Man Posted November 13, 2016 Share Posted November 13, 2016 5% above PF is always a good rule to follow.. For me I like to stay in the 130-135 range.. Link to comment Share on other sites More sharing options...
Norone Posted November 13, 2016 Share Posted November 13, 2016 I ran mix from 125 to 140 and the one my gear liked was 132 and if I get the courage to do 11lb recoil spring I may do 128-130. Link to comment Share on other sites More sharing options...
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