JigSaw Posted February 21, 2012 Share Posted February 21, 2012 Hello all, I was out today to test my ammo before the Louisiana State IDPA match and thought I'd bring my load and findings to the masses. It seems like everywhere you look for load/test data it is always missing something. I'll do my best to give you every piece of data I have, and a description of the testing. I wanted to test my load under the current weather conditions, and then run the same test again under what I would think to be a "Worst Case" for the match. I don't want to show up and get DQ'ed for 2 or 3 fps. This load was developed last summer and stayed right on the edge of 125PF. 1 or 2 would be under the wire out of every 15. Once the weather changed my gun started cycling funny and a chrono test showed it well under 125PF. I bumped the load on my powder measure until the gun felt better, but have not tested it until today. Let me start by saying this is the load that works in my gun, and it may not be good, or even safe, for your gun. Load at your own risk, I'm not going to court due to your stupidity. The Goal: Develop a soft IDPA load that is close to the Power Factor limit, but will still allow most guns to cycle correctly in their stock form. I could and have tailored the load to my gun only and have a softer feel, but I started selling my ammo so functionality is key. It also happens that I like the feel and accuracy of the load the way it is now. The Test Scenario: I Loaded 4 mags w/ 10 rounds each. Placed two mags in my gun bag in the front of the car while running around today. The other two mags were put inside a zip-loc bag that was placed in a small cooler w/ 3 cups of ice and 1/2 gallon of water. Approx. 5 hours after placing the mags in the car I was at the range for the test. 1 of each of the hot + cold mags was to be tested after being inserted into the gun and fired as normal. The other two hot + cold mags were shot by the IDPA Chrono rules of raising the muzzle before each shot to help the powder settle. The Gun: I shoot an STI Ranger III in 9mm. It has a 4.15" bull barrel, and has ~15k rounds through it. I'm also using a mix of Tripp and Dawson mags if it matters to you. The Weather: It was mostly cloudy day w/ a ray or two of sunshine breaking through at times.(2/20/12) Brookshire Texas (West Houston) 64 degrees F winds @ 8mph SSE Humidity 78% Dew 57 degrees Psi 30.04in (approx @ sea level) UV= 1-low 4:14pm The Chrono: CED ProChrono, 9 months old, new battery, and clean sensors. The loading equipment: Hornady LNL progressive, Hornady die set, Lee factory crimp die, cases lubed w/ Hornady spray lube in a ziploc bag, range pickup brass w/ the crimped primers and foreign stuff removed. The crimp die was not set by any certain measurement. I start by using LEE's initial setup and then load 5 rounds w/ no powder or primer. I measure each round and then cycle it through my gun. I measure each round for the amount of bullet setback caused by the round being fed through the gun. I tighten the crimp and retest w/ new rounds until I have no more than .004" setback on any one bullet. The Load: 135gr 9mm Bayou Bullet Winchester Small Pistol Primer 3.71gr of Vihtavuouri N320 powder (the powder weight is an average of 10 cleaned cases fed through the press and then emptied on an RCBS 505 scale) C.O.L.= 1.160" +/- .003" The results: Hot mag fed through gun normally: 965 - 984 - 976 - 962 - 975 - 984 - 968 - 980 - 954 - 965 HIGH= 984 LOW= 954 AV= 971 ES= 30 SD= 10 Average Power Factor= 131 Cold mag fed through gun normally: 955 - 955 - 954 - 955 - 960 - 963 - 963 - 938 - 966 - 968 HIGH= 968 LOW= 938 AV= 957 ES= 30 SD= 8 Average Power Factor= 129 Hot mag fed through gun, muzzle raised to 12 o'clock before each shot fired: 984 - 970 - 975 - 955 - 991 - 975 - 992 - 973 - 981 - 978 HIGH= 992 LOW= 955 AV= 977 ES= 37 SD= 10 Average Power Factor= 132 Cold mag fed through gun, muzzled raised to 12 o'clock before each shot fired: 966 - 957 - 962 - 935 - 944 - 972 - 964 - 978 - 986 - 954 HIGH= 986 LOW= 935 AV= 961 ES= 51 SD= 15 Average Power Factor= 130 Conclusion: Not a single round was under 125PF (925fps) which is GREAT for the upcoming match. The round is a bit more snappy than when I had it down at the edge of 925fps last summer, but the gun operates much better w/ room to accidentally put pressure on the slide and it still cycle. It is tons lighter than any factory load I have shot (so much that I am blamed for shooting .22LR at times). I show no signs of pressure spikes and didn't think I would given the quality of the powder. I'm also amazed that the speed didn't nose dive after the rounds sat in the cooler all day. I have used a lot of other powders, and most of them would not even cycle the gun if I were to chill them in ice. I'm sure you could back off the powder a touch if you are running a 5" gun also, but that is all up to personal preference and how that might effect accuracy and felt recoil. On that note, these Bayou bullets are VERY accurate. I don't have a bench rest proof of it, but I'd like to think I could tell in my match scores. The gun is also a lot cleaner than when i was using Berry's and Titegroup. Cleaning was a must @ 400 rounds before, and now its well over 1000. NEXT UP......... 200gr. .40 s&w Minor w/ VIHT N310 for ESP (gona try to make a .40 shoot softer than a 9) Thank you, and enjoy Matt R. Link to comment Share on other sites More sharing options...
Hi-Power Jack Posted February 21, 2012 Share Posted February 21, 2012 Matt, great info - thanks for sharing. One question - would a hot/cold GUN affect velocity? You chilled and heated the ammo, but what effect (if any) would there be if the gun was hot or cold? And ammo corresponding. Just wondering ... Jack Link to comment Share on other sites More sharing options...
blu46and2 Posted February 21, 2012 Share Posted February 21, 2012 You might want someone to chime in here that knows a little more about me than reloading but I'm not sure it's safe to load .40 with N310. I load 9 MM minor with N310 and .40 Minor and Major using N320. Link to comment Share on other sites More sharing options...
JigSaw Posted February 21, 2012 Author Share Posted February 21, 2012 Matt, great info - thanks for sharing. One question - would a hot/cold GUN affect velocity? You chilled and heated the ammo, but what effect (if any) would there be if the gun was hot or cold? And ammo corresponding. Just wondering ... Jack I did not consider the gun temp since i was just wanting an assesment of what the ammo would do at freezing temp. I would assume the gun temp would play a role in the first few rounds at a match, but the heat would saturate the barrel and be more consistent throughout the day. BUT who knows, next time i'll freeze the gun too Link to comment Share on other sites More sharing options...
JigSaw Posted February 21, 2012 Author Share Posted February 21, 2012 You might want someone to chime in here that knows a little more about me than reloading but I'm not sure it's safe to load .40 with N310. I load 9 MM minor with N310 and .40 Minor and Major using N320. Maybe i'll start w/ a 180 lead and see how the brass does Link to comment Share on other sites More sharing options...
superdude Posted February 21, 2012 Share Posted February 21, 2012 nice data. you've shown that N320 is temperature sensitive since the "cold" velocities were statistically significantly lower than the "hot" velocities (using a t-test at a probability of less than 0.05). But tilting made no difference (statistically). you're going to upset all those folks who claim that N320 is not temperature sensitive. Link to comment Share on other sites More sharing options...
GlockCanMan Posted February 23, 2012 Share Posted February 23, 2012 nice data. you've shown that N320 is temperature sensitive since the "cold" velocities were statistically significantly lower than the "hot" velocities (using a t-test at a probability of less than 0.05). But tilting made no difference (statistically). you're going to upset all those folks who claim that N320 is not temperature sensitive. It is a lot less sensitive then most. Link to comment Share on other sites More sharing options...
Merlin Orr Posted February 23, 2012 Share Posted February 23, 2012 nice data. you've shown that N320 is temperature sensitive since the "cold" velocities were statistically significantly lower than the "hot" velocities (using a t-test at a probability of less than 0.05). But tilting made no difference (statistically). you're going to upset all those folks who claim that N320 is not temperature sensitive. It is a lot less sensitive then most. 2 fps is significant???? Not in my view. Link to comment Share on other sites More sharing options...
superdude Posted February 23, 2012 Share Posted February 23, 2012 nice data. you've shown that N320 is temperature sensitive since the "cold" velocities were statistically significantly lower than the "hot" velocities (using a t-test at a probability of less than 0.05). But tilting made no difference (statistically). you're going to upset all those folks who claim that N320 is not temperature sensitive. It is a lot less sensitive then most. 2 fps is significant???? Not in my view. don't you mean PF instead of fps? it's statistically significant. whether that means that it is significant in practical terms is a different issue. Link to comment Share on other sites More sharing options...
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