You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an alternative browser.
You should upgrade or use an alternative browser.
gr variation ?
- Thread starter rebs
- Start date
did you chrono the load workup or shoot a ladder at 300 or better ? If so how wide is the velocity node? There is no rule of thumb, I have seen nodes .5gn wide and others only .1gn. One thing I have noticed is that the smaller the powder charge the smaller the nodes as a general rule.
the answer you want is in the ladder or chrono record. If you don't have one to go then go burn some powder at whatever distance you will be typically shooting and check for vertical spread and/or get some velocity data
edit - also consider the accuracy of your scale. A scale will generally be accurate plus or minus 1 of its smallest resolution. For a RCBS Rangemaster that would be .1 so a reading of 25.0 could be anywhere between 24.9 to 25.1. In the big scheme however over a series of 15 loads the differences are negligible. Lots of ammo loaded on a Chargemaster or equivilent will be shot this weekend and no one will notice plus or minus .1
the answer you want is in the ladder or chrono record. If you don't have one to go then go burn some powder at whatever distance you will be typically shooting and check for vertical spread and/or get some velocity data
edit - also consider the accuracy of your scale. A scale will generally be accurate plus or minus 1 of its smallest resolution. For a RCBS Rangemaster that would be .1 so a reading of 25.0 could be anywhere between 24.9 to 25.1. In the big scheme however over a series of 15 loads the differences are negligible. Lots of ammo loaded on a Chargemaster or equivilent will be shot this weekend and no one will notice plus or minus .1
Last edited:
Rebs: It would be expresed as + or - 1/10
You would not be more than 1/10 off your baseline.
You could be as much as 2/10 off between rounds of course.
The whole thing gets mucky, when I am doing load runs, I use 5/10 between the lots to ensure there is a large enough variance to see.
I will test down to 3/10 but no closer.
I don't have the references but that seems to be where a change occurs is at about 3/10 above or below specified charge.
You would not be more than 1/10 off your baseline.
You could be as much as 2/10 off between rounds of course.
The whole thing gets mucky, when I am doing load runs, I use 5/10 between the lots to ensure there is a large enough variance to see.
I will test down to 3/10 but no closer.
I don't have the references but that seems to be where a change occurs is at about 3/10 above or below specified charge.
No need for pistol beams, the old school beam balances are pretty darn good straight from the factory. A few mods on one that was not abused and it performs better than a 600 dollar electronic and can be fine tuned even farther.
My Lyman's linearity is plenty good enough for me straight from the box. It is off by .1 gn at 260.9 gn using its calibration weight. At 50 gns that would translate an error of .02 gns or about the weight of a kernel of Varget. I can live with that.
It's precision is excellent also. I just weighed 5 gns of powder in the pan and removed the pan 10 times and each time the needle returned to zero plus or minus a needles width which is maybe a milligram or about the same as a AD Fx scale.
Scott Parker over at Accurate Shooter forums can tune a old Lyman M5 or RCBS 5 -10 even finer.
http://bulletin.accurateshooter.com...eam-scales-for-precision-and-repeatability-2/
My Lyman's linearity is plenty good enough for me straight from the box. It is off by .1 gn at 260.9 gn using its calibration weight. At 50 gns that would translate an error of .02 gns or about the weight of a kernel of Varget. I can live with that.
It's precision is excellent also. I just weighed 5 gns of powder in the pan and removed the pan 10 times and each time the needle returned to zero plus or minus a needles width which is maybe a milligram or about the same as a AD Fx scale.
Scott Parker over at Accurate Shooter forums can tune a old Lyman M5 or RCBS 5 -10 even finer.
http://bulletin.accurateshooter.com...eam-scales-for-precision-and-repeatability-2/