Hi all,
I was wondering What sort of ES and SD I need to complete in 600 and 1000 yards.
Thanks,
mitchell
I was wondering What sort of ES and SD I need to complete in 600 and 1000 yards.
Thanks,
mitchell
ES and SD
- Thread starter mitchellchandler_au
- Start date
mitchell
You don't need any particular ES or SD to be competitive at 600 and 1000 yards. What you need is a rifle/ammunition combination that is capable of competitive groups and scores. It may be argued that low ES and SD will get you there but not necessarily. If you get the small groups with the low numbers, great. If you get the small groups with high numbers, also great.
I'm confused by what waterdog said. Ballistic programs don't calculate ES or SD. They will you give you trajectory under different velocity conditions but keep in mind that real bullets fired at real targets do not always perform according to ballistic charts.
Ray
You don't need any particular ES or SD to be competitive at 600 and 1000 yards. What you need is a rifle/ammunition combination that is capable of competitive groups and scores. It may be argued that low ES and SD will get you there but not necessarily. If you get the small groups with the low numbers, great. If you get the small groups with high numbers, also great.
I'm confused by what waterdog said. Ballistic programs don't calculate ES or SD. They will you give you trajectory under different velocity conditions but keep in mind that real bullets fired at real targets do not always perform according to ballistic charts.
Ray
The reason I ask about these is because I have just started to check velocities and have found over 10 shots my 6mm br will give me an ES of 29 and a SD of 9 according to an online Sd calculator I used.
Thanks,
mitchell
Thanks,
mitchell
Mitch:
Now that we have set the boundries for ES&SD anything under 10 for the SD and this should give you about 25 fps spread, that will stay in the "X" at 1K, and your go to go.
NOW how do we get there from here???? what are you doing in loading that you are getting a 30sd, ya must be screwed onneck tension, wrong powder, bad ignition? tell us what yer doing and we can FIX it.
Clarence
Now that we have set the boundries for ES&SD anything under 10 for the SD and this should give you about 25 fps spread, that will stay in the "X" at 1K, and your go to go.
NOW how do we get there from here???? what are you doing in loading that you are getting a 30sd, ya must be screwed onneck tension, wrong powder, bad ignition? tell us what yer doing and we can FIX it.
Clarence
Hi clarence,
My reloading process is as follows:
after the case is fired I size my cases in my new RCBS rockchucker press using a redding neck bushing die. The chamber is .270 and the neck is sized to .265 and neck turned to give a loaded round of .268 or as near as I can measure.then I clean the primer pocket with a lee pocket cleaner and then insert a federal SR primer. The charge of 29.9 of varget is the weighed out with my hornady beam scale. After doing a ladder test 29.9 showed to be the best grouping charge.I then seat a 105 A-MAX on the lands with a redding comp seater.
I hope this helps.
My reloading process is as follows:
after the case is fired I size my cases in my new RCBS rockchucker press using a redding neck bushing die. The chamber is .270 and the neck is sized to .265 and neck turned to give a loaded round of .268 or as near as I can measure.then I clean the primer pocket with a lee pocket cleaner and then insert a federal SR primer. The charge of 29.9 of varget is the weighed out with my hornady beam scale. After doing a ladder test 29.9 showed to be the best grouping charge.I then seat a 105 A-MAX on the lands with a redding comp seater.
I hope this helps.
Yesterday I done some testing with the projectile seated .20 from the lands and the ES went to 19 fps with groups in the .250-.350 range at 100 metres. So I will test more today to validate the results I now have.
Thanks,
mitchell
Thanks,
mitchell
Cheechako, I just got back on here and read this post again.
I suppose the things I wrote about a ballastic program was confusing.
What I meant was this:
If you use a ballastics program, and know the velocity and BC of your bullet then you can change the velocity of your bullet on the program and look at the difference in the amount of drop at 600 and 1000 yards. I just did this for a Berger 140VLD 6.5 at 3000fps. The MOA drop was 24.4 moa. I changed the velocity to 2980fps,a 20fps difference) and the MOA drop was 24.8 moa. These readings were at 1000yds. Acccording to this ballastics program that would mean a 4" drop at 1000yds. At 600yds the difference in 20fps was just a little less than an inch.
I know in the real world it might be different, but one can get some idea of the importance in having as little velocity spread in their loads as possible.
Merry Christmas to all of you, and keep posting......
I suppose the things I wrote about a ballastic program was confusing.
What I meant was this:
If you use a ballastics program, and know the velocity and BC of your bullet then you can change the velocity of your bullet on the program and look at the difference in the amount of drop at 600 and 1000 yards. I just did this for a Berger 140VLD 6.5 at 3000fps. The MOA drop was 24.4 moa. I changed the velocity to 2980fps,a 20fps difference) and the MOA drop was 24.8 moa. These readings were at 1000yds. Acccording to this ballastics program that would mean a 4" drop at 1000yds. At 600yds the difference in 20fps was just a little less than an inch.
I know in the real world it might be different, but one can get some idea of the importance in having as little velocity spread in their loads as possible.
Merry Christmas to all of you, and keep posting......
mitch:
If that gun will shoot well jumped,think you got the decimal point wrong was it .020 or .200?) try this! use about .0005 neck tension,this is accomplished by the use of a Mandrel of the proper size on the inside of the neck, seat the bullet longer than the Leade by .020 and let that chamber seat the bullet,this is called soft seating and will align the bullet to leade better so as to reduce the TIR),IF you have a GOOD chamber? make shure to FL size the brass.
Some will tell you that to jam a bullet causes pressure spikes, I believe that to a degree, but if done properly any pressure spike will be minor and that is the reason for searching for the low SD's ya can't have high ES's and low SD's two 10 shot strings will tell you about ES's and SD's
Clarence
If that gun will shoot well jumped,think you got the decimal point wrong was it .020 or .200?) try this! use about .0005 neck tension,this is accomplished by the use of a Mandrel of the proper size on the inside of the neck, seat the bullet longer than the Leade by .020 and let that chamber seat the bullet,this is called soft seating and will align the bullet to leade better so as to reduce the TIR),IF you have a GOOD chamber? make shure to FL size the brass.
Some will tell you that to jam a bullet causes pressure spikes, I believe that to a degree, but if done properly any pressure spike will be minor and that is the reason for searching for the low SD's ya can't have high ES's and low SD's two 10 shot strings will tell you about ES's and SD's
Clarence
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