usmc1974 Posted February 15, 2023 Share Posted February 15, 2023 I was wondering, what you guys considered a good standard deviation. I'm using a Dillon 550C mixed military lake city brass, Hornady 55 gr.fmj bt bullet, Winchester small rifle primer, 27 gr. of shooters world match rifle powder, and over all cartridge length is 2.230 10 rounds is going into about an 1" group. I use a magna speed 3 chronograph My maximum velocity is 3053 My minimum velocity is 2964 my average velocity is 3007 But My Standard deviation is 26.0 Link to comment Share on other sites More sharing options...
dannyd Posted February 15, 2023 Share Posted February 15, 2023 That means 74% of your rounds are very close in velocity. When I used to chase SD I like it under 15, but using a Magna that's a real good number. Link to comment Share on other sites More sharing options...
Racinready300ex Posted February 15, 2023 Share Posted February 15, 2023 I like to be under 10 Link to comment Share on other sites More sharing options...
usmc1974 Posted February 15, 2023 Author Share Posted February 15, 2023 2 hours ago, Racinready300ex said: I like to be under 10 You can get under 10 with a progressive reloader? I do it all the time with my single stage press I haven't been able to do with a 550 dillon Link to comment Share on other sites More sharing options...
Racinready300ex Posted February 15, 2023 Share Posted February 15, 2023 (edited) 2 minutes ago, usmc1974 said: You can get under 10 with a progressive reloader? I do it all the time with my single stage press I haven't been able to do with a 550 dillon I load on a 650. I'm running cleanshot right now, and it's amazingly consistent. I have 4 lbs left and haven't seen any for sale in a few years. Edited February 15, 2023 by Racinready300ex Link to comment Share on other sites More sharing options...
usmc1974 Posted February 15, 2023 Author Share Posted February 15, 2023 1 minute ago, Racinready300ex said: I load on a 650. I'm running cleanshot right now, and it's amazingly consistent. I'm using shooter's world match rifle and it also is very consistent. You running mixed brass ? Link to comment Share on other sites More sharing options...
Racinready300ex Posted February 15, 2023 Share Posted February 15, 2023 1 hour ago, usmc1974 said: I'm using shooter's world match rifle and it also is very consistent. You running mixed brass ? Yup, at least mostly. I do nothing really fancy. I do typically pick out any stepped cases. I just bought a batch of brass that has a bunch of those and I didn't sort them. I'd expect kinda s#!tty results from the little bit I currently have loaded like that. Link to comment Share on other sites More sharing options...
HesedTech Posted February 15, 2023 Share Posted February 15, 2023 2 hours ago, usmc1974 said: You can get under 10 with a progressive reloader? SD is effected by the brass volume. Since you are using mixed brass it will be hard to get sub 10 SDs even with a SS press. 37 minutes ago, Racinready300ex said: I do typically pick out any stepped cases. I thought this thread was about rifle loading???? Never seen a stepped case in 223 or 5.56. Link to comment Share on other sites More sharing options...
Racinready300ex Posted February 15, 2023 Share Posted February 15, 2023 7 minutes ago, HesedTech said: SD is effected by the brass volume. Since you are using mixed brass it will be hard to get sub 10 SDs even with a SS press. I thought this thread was about rifle loading???? Never seen a stepped case in 223 or 5.56. Yeah, my bad I stumbled in it in the recent activity section and didn't notice it was rifle. Link to comment Share on other sites More sharing options...
usmc1974 Posted February 16, 2023 Author Share Posted February 16, 2023 6 hours ago, Racinready300ex said: Yeah, my bad I stumbled in it in the recent activity section and didn't notice it was rifle. 6 hours ago, HesedTech said: SD is effected by the brass volume. Since you are using mixed brass it will be hard to get sub 10 SDs even with a SS press. All my military brass is lake city 07 08 10 Trimmed 1.750 With no crimp. Link to comment Share on other sites More sharing options...
HesedTech Posted February 16, 2023 Share Posted February 16, 2023 13 hours ago, usmc1974 said: All my military brass is lake city 07 08 10 Trimmed 1.750 With no crimp. If you are on a quest to lower SD, good for precision rifle, what I do is use an RCBS auto trickler and instead of 55s use 69 & 75 grain bullets. Rifle loading for precision is a bit more taxing than pistol. Link to comment Share on other sites More sharing options...
Tom Freeman Posted February 16, 2023 Share Posted February 16, 2023 For mixed brass with a bone stock Dillon measure 15-20 would be ok. Done some measure tweaking about you will bring that down a little bit. Link to comment Share on other sites More sharing options...
usmc1974 Posted February 16, 2023 Author Share Posted February 16, 2023 1 hour ago, HesedTech said: If you are on a quest to lower SD, good for precision rifle, what I do is use an RCBS auto trickler and instead of 55s use 69 & 75 grain bullets. Rifle loading for precision is a bit more taxing than pistol. Thank you guys for all your help and information I really appreciate your knowledge. My 550 pretty much Throws 28.0 gr. that I'm asking it to every time. I started weighing every 5th Round, Of course my scale is a Hornady GS350 electronic With plus minus 1⁄10 of 1 gr. I'm also using a Basic 55 gr. full metal jacket boat tail bullet. I am not really trying for long range match rifle accuracy, but for 3 gun competition. I need to be able to hit an IPSC target out to 400 yd. The quest will continue. Link to comment Share on other sites More sharing options...
Davecoff13 Posted February 16, 2023 Share Posted February 16, 2023 If your reaching out to 400 you will want a heavier bullet that a 55 as it will stay more stable and be much more accurate at longer ranges than a 55 will especially with a 1/7 twist barrel which is pretty much the standard now. Link to comment Share on other sites More sharing options...
usmc1974 Posted February 17, 2023 Author Share Posted February 17, 2023 3 hours ago, Davecoff13 said: If your reaching out to 400 you will want a heavier bullet that a 55 as it will stay more stable and be much more accurate at longer ranges than a 55 will especially with a 1/7 twist barrel which is pretty much the standard now. My 55 fmj-bt's are going out to 400 yards pretty easy with my 16" armalite With a 1 and 9 twist barrel... Fact that push them out to 700 with a different bolt gun. Link to comment Share on other sites More sharing options...
outerlimits Posted February 17, 2023 Share Posted February 17, 2023 5 minutes ago, usmc1974 said: My 55 fmj-bt's are going out to 400 yards pretty easy with my 16" armalite With a 1 and 9 twist barrel... Fact that push them out to 700 with a different bolt gun. i luv nosler 55gr BT's. they go out to 700 just fine. sub moa out to 400 in my 16" JP. Link to comment Share on other sites More sharing options...
usmc1974 Posted February 17, 2023 Author Share Posted February 17, 2023 2 hours ago, outerlimits said: i luv nosler 55gr BT's. they go out to 700 just fine. sub moa out to 400 in my 16" JP. Long range 223 I use Nosler RDF 70grain boat tail hollow points G7 BC 0.211 Talk about kick ass down range ballistics. Link to comment Share on other sites More sharing options...
Sokam101 Posted May 3, 2023 Share Posted May 3, 2023 How accurate your powder charge is dropped will help a ton with SD Link to comment Share on other sites More sharing options...
PhotoRecon Posted May 3, 2023 Share Posted May 3, 2023 For SD I try for 10 or less... In my experience loads that have the best accuracy don't have a great SD. Using a Labradar yesterday I was getting a SD around 11 both with all LC and mixed brass, loaded with the same components. The brass has the primer pockets uniformed and the flash hole deburred from the inside along with the usual steps such as trimming etc. I took the Dillon powder measure off my RL1050 and use it in my single stage press to drop powder. I seat on a single stage. Also loaded 223 on the RL1050 with the same results. Link to comment Share on other sites More sharing options...
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