thefiremeister Posted January 22, 2009 Share Posted January 22, 2009 How many rounds do you get to shoot when you chrono your ammo at a match? I've just shot local matches and we have not chronoed our ammo at our matches. I'm thinking about going to a regional match and need to know how many shots it takes to get your ammo to pass. I'm assuming a number of shots are averaged to get a power factor. Link to comment Share on other sites More sharing options...
Jman Posted January 22, 2009 Share Posted January 22, 2009 Match staff shoot your ammo over the chrono with your gun. They also weigh bullets so a power factor is determined. They collect five rounds usually and weigh two and shoot three. You need to know your PF before a match. Jim Link to comment Share on other sites More sharing options...
AlamoShooter Posted January 22, 2009 Share Posted January 22, 2009 (edited) The Rule book covers it very good in Appendix C2 pages 65 -on If you don't have a rule book it is available on line as USPSA.org the quick reply is -8 - Measure one for weight, & shoot three for speed (the)left over rounds in case you need to shoot them to bring up the average speed -OR- you can ask to measure one of them for weight Edited January 22, 2009 by AlamoShooter Link to comment Share on other sites More sharing options...
SingleStacker45 Posted January 22, 2009 Share Posted January 22, 2009 I generally shoot 5-10 for testing purposes. 5 if the speeds are consistent 10 if they are jumping around. If I shoot 10 I usually throw out the highest and lowest and average the rest. Mule Link to comment Share on other sites More sharing options...
XD Niner Posted January 22, 2009 Share Posted January 22, 2009 I usually shoot at least ten chosen randomly from the batch of reloaded ammo. Link to comment Share on other sites More sharing options...
thefiremeister Posted January 22, 2009 Author Share Posted January 22, 2009 Thanks for the info. I'm working on some loads right now and I'm getting an average of 167 from 6 rounds. My spread is about 55fps with once shot brass. I'll have to bump it up a bit. Thanks again. Link to comment Share on other sites More sharing options...
Larry273 Posted January 22, 2009 Share Posted January 22, 2009 Keep in mind that weather has something to do with it. Not that I would know...but I knew a guy who chrono'ed in Florida and found out that Barry Illinois is slightly colder, and things move slower...enough to make a difference. Link to comment Share on other sites More sharing options...
cnote Posted January 22, 2009 Share Posted January 22, 2009 (edited) Keep in mind that weather has something to do with it. Not that I would know...but I knew a guy who chrono'ed in Florida and found out that Barry Illinois is slightly colder, and things move slower...enough to make a difference. Some powders are reverse sensitive, and you get hotter when it is colder outside. You have to know the powder. Edited January 22, 2009 by cnote Link to comment Share on other sites More sharing options...
Flatland Shooter Posted January 22, 2009 Share Posted January 22, 2009 Thanks for the info. I'm working on some loads right now and I'm getting an average of 167 from 6 rounds. My spread is about 55fps with once shot brass. I'll have to bump it up a bit. Thanks again. Depending on your SD (standard deviation) you probably want to get your average up to around 170 to cover temperature differences, match chronographs and such. If you have a high SD, you may want to look at a powder that meters a little more consistently. Bill Link to comment Share on other sites More sharing options...
bkeeler Posted January 22, 2009 Share Posted January 22, 2009 (edited) I usually shoot 10 rounds to check for power factor before a match. All 10 rounds must be above power factor. It usually averages 170-171. @ around 60*F-68*F. Edit to add temp: BK Edited January 22, 2009 by bkeeler Link to comment Share on other sites More sharing options...
boz1911 Posted January 22, 2009 Share Posted January 22, 2009 I always shoot ten over the chrono to get my PF. I reccord the temp with the data in my book. I will try to test several times, both on hot and cold days to verify consistency. I never shoot through a clean gun, because I never take a gun to a major match that hasn't been shot after cleaning. Link to comment Share on other sites More sharing options...
Gregory_k Posted January 22, 2009 Share Posted January 22, 2009 5 rounds adjust powder so slowest fps hits 170 pf. Link to comment Share on other sites More sharing options...
basman Posted January 23, 2009 Share Posted January 23, 2009 Usually test 6 but load 20 or so. if they make the required PF i like to do some slow fire to watch the front sight movement, make note of your impressions. Link to comment Share on other sites More sharing options...
XRe Posted January 23, 2009 Share Posted January 23, 2009 I'll shoot batches of 10 in ladders to find a target load. The goal is 170 PF, and no single round under 165. When I have a load that meets that, I use it. When loading ammo for a major match, I'll load up 500 or so, then randomly sample 10 rounds from the batch, and chrono those in the same fashion. If I don't meet expectations, I just loaded up 500 rounds of practice ammo, and I start over Repeat as required... Like some others, I try to chrono my working load in various weather conditions, as time permits, so that I can understand what to expect out of it in hot or cold climates, etc... Link to comment Share on other sites More sharing options...
G-ManBart Posted January 23, 2009 Share Posted January 23, 2009 (edited) At the actual match they pull 8 rounds, as has been noted. When I'm getting ready for a match I'll shoot at least 10 rounds randomly drawn from a batch. If that gets me an average over 170pf I'll then load a bunch more and chrono them a couple of other times under different conditions to see what happens. My current load has done 172-173pf at three different major matches before and after Nationals. All were loaded with the same everything....same lot of brass, same lot of primers, powder and bullets. No changes were made to the press at all. At Nationals I went 166.1pf Edited January 23, 2009 by G-ManBart Link to comment Share on other sites More sharing options...
Tzygä Posted January 23, 2009 Share Posted January 23, 2009 I shot only 6 if every shot makes major if not I shot new 6 shot string. Normally well over major so no problems ever. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now