Graham Smith Posted March 27, 2011 Share Posted March 27, 2011 (edited) I need to load up some 9mm rounds to use in calibrating poppers. I don't load 9mm much any more but I have some MG 121gr bullets and some Titegroup powder. According to my prior load data, 3.8gr of Titegroup will put me right about at a 125PF with those bullets, and 3.6 gave me a rather inconsistent reading in the 115PF range. So I figure that 3.7gr should be pretty close to a 120PF which is what I need. Of course, I'll have to run these through a chrono when I get a chance but I thought I'd check to see if this sounded about right before I started. Edited March 28, 2011 by Graham Smith Link to comment Share on other sites More sharing options...
gm iprod Posted March 28, 2011 Share Posted March 28, 2011 I think you load is a littel heavy for my tastes to calibrate and avoid whinging. I calibrate poppers with 22lr 40gr Solid High Velocity to the centre of the round section at 10Y. Guaranteed to take a 9mm anywhere above 1/2way and go down. In NRA AP we use the same load at 25Y with a rifle, no arguments that way. I just shot a match and lost a plate and they had not calibrated the plates, tough shit on me as I did not ask if they had been calibrated and no one checked. Good solid hit to middle, no go. 10 points lost. Check them each day and you are sorted. Link to comment Share on other sites More sharing options...
Too_Slow Posted March 28, 2011 Share Posted March 28, 2011 (edited) Well it matches Appendix C1 Section 2 of the Rulesbook so it should be good if it actually makes that PF reliably. You may need to go with a fluffier powder that takes up more room in the case at those lower charges weights though. Brian Edited March 28, 2011 by Too_Slow Link to comment Share on other sites More sharing options...
kellymc Posted March 28, 2011 Share Posted March 28, 2011 I crono a 121 cast bullet the other day with 3.8tg and was at 125.2 Thats as fast as I have gone so far with 9mm cast. Link to comment Share on other sites More sharing options...
Flexmoney Posted March 28, 2011 Share Posted March 28, 2011 GS, You might specify that this is for USPSA? Perhaps post the rule book requirements... What gun it comes out of is important too. Before they changed (lowered) the calibration ammo, we used to use WWB out of a G26 (after trying it on the chrono). Link to comment Share on other sites More sharing options...
Graham Smith Posted March 28, 2011 Author Share Posted March 28, 2011 (edited) You might specify that this is for USPSA? Perhaps post the rule book requirements... Thanks. Too many new things are all flopping around in my brain demanding attention. USPSA Handgun Rules require that poppers be tested with ammunition that "should achieve a power factor between 115.0 and 125.0 to qualify. 9x19mm is the recommended caliber." Edited March 28, 2011 by Graham Smith Link to comment Share on other sites More sharing options...
Too_Slow Posted March 28, 2011 Share Posted March 28, 2011 Yeah I know what you mean Graham, I took the level one RO course at the end of Feb. and now have a lot of strange things running around in there too. Brian Link to comment Share on other sites More sharing options...
gng4life Posted March 30, 2011 Share Posted March 30, 2011 You might specify that this is for USPSA? Perhaps post the rule book requirements... Thanks. Too many new things are all flopping around in my brain demanding attention. USPSA Handgun Rules require that poppers be tested with ammunition that "should achieve a power factor between 115.0 and 125.0 to qualify. 9x19mm is the recommended caliber." When you say 3.6 gave you inconsistent readings, what was hi/lo/avg/es/sd numbers? Just to err on the side of caution, I would really try to get that load closer to 115 to alleviate anyone from complaining. If you get up to 126 or higher on average, then you are on the upper side of the parameters of the calibration ammo. A shooter would have a legitimate complaint then. However if you came up with 114 pf ammo, even though it's less than minimum - how can they really complain if 114 pf ammo is knocking down the steel and theirs can't? Just a thought... Link to comment Share on other sites More sharing options...
Graham Smith Posted March 30, 2011 Author Share Posted March 30, 2011 When you say 3.6 gave you inconsistent readings, what was hi/lo/avg/es/sd numbers? I don't have the numbers at hand, but I seem to recall I was getting a high SD and a range from about 112 to 125 with the median around 117. Just would not settle down. I'm going to load up some more starting with 3.5 and moving up but I wanted to check the numbers to see if I was in the ballpark with what others were getting with TG. I don't want to get the load so low that I have to use a special recoil spring to cycle the gun. Link to comment Share on other sites More sharing options...
JAFO Posted March 30, 2011 Share Posted March 30, 2011 (edited) When I started using Titegroup, I got the following with my lowest tested charge weight: Temp: 65 oF Sky: Clear Distance from muzzle to first screen: ~15' Gun: Sig P226, 4.4" factory barrel Primer: Fed #100 Small Pistol Bullet: 124gr Zero FMJ (Avg wt of 10 bullets pulled from the same box was 124.7gr. I used this weight for the PF calculation.) COL: 1.161" Mixed range brass All strings were made up of 20 shots Load 2 (3.9gr Titegroup): HI: 1018 / LO: 981 / AV: 998 / ES: 37 / Sd: 10 / Power Factor: 124 Sounds like you're in the ballpark. Edited March 30, 2011 by JAFO Link to comment Share on other sites More sharing options...
Allgoodhits Posted March 30, 2011 Share Posted March 30, 2011 Determine the proper load, then adjust the popper or falling plates accordingly. Then take a trigger pull gauge and consistently measure the poundage it takes to cause the popper or plate to tip. That then can be used as a repeatable, measurable means of calibrating. For falling Bianchi type plates, you will probably find that it is about 18-20 oz. My guess for poppers it will be about the same. The variation will be whether the plate is welded at 12 oclock on the axle or in front of the axle. Either way, once determined, it should be a repeatable and measurable means of calibrating in the future, without firing a shot. Now just get people to believe it! Link to comment Share on other sites More sharing options...
Graham Smith Posted March 30, 2011 Author Share Posted March 30, 2011 Either way, once determined, it should be a repeatable and measurable means of calibrating in the future, without firing a shot. Now just get people to believe it! Yup! Link to comment Share on other sites More sharing options...
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