Ladder Test how-to

[wooltie]

I've been shooting ladders at 100-200 yards using a magneto speed hanging off the end of the barrel.  I like to see the point of impact, but I use the measured velocity to determine my charge weight.  I tune seating depth after I select the charge weight to tighten the group per Jasnt.    I've had success with this approach, it doesn't take a lot of range trips and reloading.  I've seen inconclusive results where higher velocity shots produce a lower point of impact relative to lower velocity shots, for whatever reasons.

Usually I find the flat spot in velocity where the variation between three loads is < 10 fps e.g. 2690, 2700, 2710 (so I'd pick 2690), but this last trial was different.  7 of 8 loads were all about 1" or less, while 1 shot was outside the group and that might have been me.  Here's the spread for 165g partition, H435055.0g-57.1g out of a 30-06. 

2743
2752
2765
2782 (probably go with this one)
2790
2806
2849
2841

Now I'll mess around with seating depth until I'm tired of making range trips.

I just haven't had luck starting with charge weight first.  I find the seating depth that works as a starting point, then pick the velocity, then return to tweakign seating depth.  Also a good way to find out how much work it will take for a a given bullet:

I loaded up four bullets (5 shot groups each), 2 grains under book max, seated .020", then shot them at 100 yards. 

One bullet groups touching, whereas the others were more dispersed, and some where like 1.5" groups.....so it's like "do I really want to mess around with closing a 1.5" group, or do I just go with the load with the sub-moa load outta the gate?"  All the bullets will kill just fine.  Now if only I could get those stupid accubonds to group...

[TooTallMike]

I've been shooting ladders at 100-200 yards using a magneto speed hanging off the end of the barrel.  I like to see the point of impact, but I use the measured velocity to determine my charge weight.  I tune seating depth after I select the charge weight to tighten the group per Jasnt.    I've had success with this approach, it doesn't take a lot of range trips and reloading.  I've seen inconclusive results where higher velocity shots produce a lower point of impact relative to lower velocity shots, for whatever reasons.

Usually I find the flat spot in velocity where the variation between three loads is < 10 fps e.g. 2690, 2700, 2710 (so I'd pick 2690), but this last trial was different.  7 of 8 loads were all about 1" or less, while 1 shot was outside the group and that might have been me.  Here's the spread for 55.0g-57.1g

2743
2752
2765
2782 (probably go with this one)
2790
2806
2849
2841

Nice !

I do a similar ladder and it has saved me a bunch of components.

For what you listed there I'd go with 56.1g. So you know if you have a variance of +/- .1 either way you'll still be in the sweet spot for low ES.
Then I tune for seating depth if I feel like I want to squeeze out a little more.

Happy shooting!

[Magnum_Willys]

Followed up 500 Yd Ladder with best loads at 965 yards.   Need to tighten up the vertical a bit and play with seating +/- .005 but can't complain too much with 5" groups at 965 yds.    Seen some chatter about the Proof Carbon barrels but this one seems to be a keeper and its 30". 

[jasnt]

I've been shooting ladders at 100-200 yards using a magneto speed hanging off the end of the barrel.  I like to see the point of impact, but I use the measured velocity to determine my charge weight.  I tune seating depth after I select the charge weight to tighten the group per Jasnt.    I've had success with this approach, it doesn't take a lot of range trips and reloading.  I've seen inconclusive results where higher velocity shots produce a lower point of impact relative to lower velocity shots, for whatever reasons.

Usually I find the flat spot in velocity where the variation between three loads is < 10 fps e.g. 2690, 2700, 2710 (so I'd pick 2690), but this last trial was different.  7 of 8 loads were all about 1" or less, while 1 shot was outside the group and that might have been me.  Here's the spread for 165g partition, H435055.0g-57.1g out of a 30-06. 

2743
2752
2765
2782 (probably go with this one)
2790
2806
2849
2841

Now I'll mess around with seating depth until I'm tired of making range trips.

I just haven't had luck starting with charge weight first.  I find the seating depth that works as a starting point, then pick the velocity, then return to tweakign seating depth.  Also a good way to find out how much work it will take for a a given bullet:

I loaded up four bullets (5 shot groups each), 2 grains under book max, seated .020", then shot them at 100 yards. 

One bullet groups touching, whereas the others were more dispersed, and some where like 1.5" groups.....so it's like "do I really want to mess around with closing a 1.5" group, or do I just go with the load with the sub-moa load outta the gate?"  All the bullets will kill just fine.  Now if only I could get those stupid accubonds to group...

that last 2 sure are close! I’d at least try those before you decide




Nice shooting magnum