ES problem

[Brad Y]

The post on accurateshooter is only one of many. I did some searching on there and there is so much info. For someone very opinionated but new to technical stuff like me its still a huge learning process. 6 months ago I thought load development was trying a few different charges and seeing what shot well. We are so lucky to have magnetospeeds and experienced people on here like DaveMc that are pushing the limit in understanding the science and maths that explains what happens from primer ignition to impact on the target.

There are some highly regarded shooters that still prefer to use ES over SD. However some of those shooters that do load development at 100yds where I prefer to do it at 300. You will never get people agreeing on it. There are so many people that have done work in this area and all have enjoyed thier own successes and failures. It shows that load development is an individual thing and you need to do what you feel comforable with.

I recently saw a ladder test that was 1 shot of one charge, one shot higher, one shot higher etc. That shooter found 2 areas to concentrate on. The first string shot ok, the second shot a 60.9 which I would have killed for that day.

Geoff I would definitely take a good look at the 105 class bullets and stick with your 2213sc powder.

[saum2]

All very interesting reading & great article.
I've been thinking similar things like Richard said, similar to the 6x47 but.
Then why would you have a big case like the XC and use 105gn projectiles? Might as well use a BR or Dasher which are both very accurate. I'm thinking like Richard, the 1:8 twist won't cut it for the 115gners. I do have a 1.7.75 barrel somewhere that might work with the 115gners.
This barrel might just become a Dasher after all.
Although I'll give the 105 Berger's a go on the weekend just for one last chance.

[mike H]

Forget all the stastics,get down to basics,if it doesn`t shoot ,change something,powder ,primers ,bullets,when you have exhausted all that think barrel,gunsmithing,finaly yourself.All jokes aside,most rifle calibres/chamberings have basic recipes that work in most of them,if yours doesn`t you are the execption.
Hope you work it out.
Mike.

[bruce moulds]

mike,
it is also amazing how well a rifle shoots is influenced by the standard of the pimping application.
keep safe,
bruce.

[bruce moulds]

that is why s.d. is better than e.s..
s.d. suggests a truer relative e.s. than e.s. for that string does.
keep safe,
bruce

[AlanF]

To improve your scores, the best measure to go by is neither ES or SD. Its your SCORE.

[IanP]

Krakey

At what elevation ASL was the testing done

This is a discussion about muzzle velocity statistics, ES and SD in particular. The question in this quote from Richard about altitude, suggests it has some effect on muzzle velocity. The effect even at high altitude like the Raton range, (6,500') in New Mexico which is about to host the f-class world championships is immeasurable.

High altitude ranges used for testing muzzle velocities should correspond to sea level muzzle velocities. The "thinner air", (lower atmo pressure) means less drag on the bullet and the down range velocities are maintained longer because of this.

It seems many shooters assume a higher muzzle velocity at higher altitudes but the atmo pressure difference is insignificant compared to the pressure generated in the barrel, driving the bullet forward. I asked this question about the possibility of it being measurable and got this response from Bryan Litz.

http://www.usrifleteams.com/lrforum/ind ... y+%2Braton

Hope this helps anyone out there like me who wondered about this issue!

Ian

[IanP]

To improve your scores, the best measure to go by is neither ES or SD. Its your SCORE.

Alan, I found this over on USRifleteams.com and its perfect!

A small ES is good. A small SD is better. A small group is best.

Ian

[TOM]

Providing the groups in the right spot... Back to reading wind we go!

[bruce moulds]

let the target do the talking, in the end.
other factors also come to mind.
e.g. some barrels climb a little on the target, and allowance must be made for this, particularly in long strings.
this is often not noticeable in a 5 shot string.
know thy equipment.
for those not having access to a range like dave, and who have a barrel budget, club shoots can often accumulate good stats if you plot.
vert at least can be monitored and compared to a degree, even though horizontal stats have a human element to them.
keep safe,
bruce.