Need ladder test help

[micahb]

I have a Remington 700 SPS tactical AAC-SD 308
I tried a ladder test today with
Federal once fired neck sized brass
Cci br2's
178 amax's

C.O.A.L 2.910
And powder ranging from
40-40.5-41-41.5-42-42.5-43-43.5-44-44.5

I'm confused I know the concept behind doing this but my ladder test doesn't make sense

Help plz

 

[Bob 964]

Re: Need ladder test help

At what distance? Did you keep the same point of aim for all shots? How much time between shots? Is this the back of your target?

 

[Bob 964]

Re: Need ladder test help

I forgot to mention that the 0.5 grain increments may be too much. I suggest you use 0.3 grain increments.

 

[micahb]

Re: Need ladder test help

400 yards
Same poa
Yes it's the back of the paper so you can see it better
The paper is still oriented properly up is up

 

[GreenMonster]

Re: Need ladder test help

You've got about 4" vertical spread and maybe 4.5-5" wide, pretty good at 400yds. I try to discount any left to right spread and just look at verticle dispersion for nodes. Assuming all were "good" shots, I see a node from 41.5 - 42.5. 43 breaks higher than the rest, and 43.5 a little lower.

I shoot my ladder 3 times, once forward ( increasing load charge) then backwards ( decreasing load charges) the from the middle (#6,7,8,9,10,then #1,2,3,4,5) this helps me believe I allowed all the charges to have about the same barrel and shooter warm up on each shot. I compare all three groups and hope that there are consistent results.

1/2 a grain is a little bit large but okay to start with. Shoot your ladder 2 more times and then, if all looks well try .3 grains from 41.5-42.5. It might look the same, or clarify things a little better. Distance helps but you're already at a good poke, I see no need to move it back any further, it would be more beneficial to hold out for the best possible weather/wind conditions instead.

Good luck!

 

[GreenMonster]

Re: Need ladder test help

Stole this from another thread, great article.


http://www.accurateshooter.com/technical-articles/long-range-load-development/

 

[X-fan]

Re: Need ladder test help

With that big of increment you should see a fairly even horizontal dispersion....There is no such pattern in your test.

It looks like something is messing with your results.
What was the wind speed and direction like?
What sort of aiming point and scope?
What sort of shooting rest or setup are you using?

 

[micahb]

Re: Need ladder test help

I started off by shooting twice at steel at 400 to make sure I was on target the 2 rounds where 1" apart

Then started the ladder test
3 min between shots
Caldwell rest
Absolutely 0 wind the whole time
Konus 8.5x32x52 scope

I will say this I don't know why but I shot about 15 round before the test and they didn't group well like 2" at 200 and last week I was shooting 1" at 200 with the same load so im real confused

 

[micahb]

Re: Need ladder test help

The target

 

[MMAJunkie]

Re: Need ladder test help

I normally use .3 gr steps and maybe even less as I approach the limits of that cartridge

 

[micahb]

Re: Need ladder test help

I just can't understand why 44 is 5" lower than 40.5

 

[mattlewis]

Re: Need ladder test help

don't mean to be rude here, i'm just trying to help. no offense meant...

are you weighing your powder or throwing it? looks to me like you may have some reloading inconsistencies.

or you have a scope/mounts that won't hold zero.

or you have a faulty shooting technique.

and after all that, it's still a 5" group at 400 yards with a factory rifle. i'm not sure i'd care! LOL

anyway, the ladder test is about barrel harmonics and powder charges, right? it may be accurate that 44gr is 5" lower than 40.5gr. you just don't necessarily know until you shoot it, and results don't always follow like you think they will (physics is funny that way).

but what doesn't seem right to me is that a .5gr (41 to 41.5) change in charge weight has 3" of vertical dispersion. i would go back to my loading procedures if it were me. and i'd do it again. if it comes out the same (and you were sure of your scope and shooting), chalk up another one for physics being hard to understand!

 

[micahb]

Re: Need ladder test help

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mattlewis</div><div class="ubbcode-body">don't mean to be rude here, i'm just trying to help. no offense meant...

are you weighing your powder or throwing it? looks to me like you may have some reloading inconsistencies.

or you have a scope/mounts that won't hold zero.

or you have a faulty shooting technique.

and after all that, it's still a 5" group at 400 yards with a factory rifle. i'm not sure i'd care! LOL

anyway, the ladder test is about barrel harmonics and powder charges, right? it may be accurate that 44gr is 5" lower than 40.5gr. you just don't necessarily know until you shoot it, and results don't always follow like you think they will (physics is funny that way).

but what doesn't seem right to me is that a .5gr (41 to 41.5) change in charge weight has 3" of vertical dispersion. i would go back to my loading procedures if it were me. and i'd do it again. if it comes out the same (and you were sure of your scope and shooting), chalk up another one for physics being hard to understand!

</div></div>

No offense taken whatsoever

Scope is a new Konus m30 8.5x32x52
New weaver tactical 6 hole rings
New EGW 20moa base
Shooting from a Caldwell rest
Using a rcbs range master 750 for powder measure not .1 or .9 it's exact on the number when I loaded it

A guy was teaching how to reload a couple weeks ago and we loaded some rounds just to show me the basics and I shot this so I don't think it's me

 

[micahb]

Re: Need ladder test help

41.5-43.5 are kinda close so I'm going to do them in .2 increments
What condition should the barrel be in if I start the day with a clean cold bore ?
How many foulling shots?
How long between shots?

 

[targaflorio]

Re: Need ladder test help

I'm amazed that you could keep track of the bullet holes at 400 yds. You had a spotter with a really nice spotting scope?

 

[targaflorio]

Re: Need ladder test help

Did you shoot any groups at the same powder charge? I don't know how anyone can get valuable feedback off that target. Other than you do well putting all kinds of different loads into a good group at 400. Maybe try OCW instead?

 

[micahb]

Re: Need ladder test help

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: targaflorio</div><div class="ubbcode-body">I'm amazed that you could keep track of the bullet holes at 400 yds. You had a spotter with a really nice spotting scope?</div></div>

lol
It was just me and my Kubota rtv back and forth back and forth it sucked

 

[micahb]

Re: Need ladder test help

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: targaflorio</div><div class="ubbcode-body">Did you shoot any groups at the same powder charge? I don't know how anyone can get valuable feedback off that target. Other than you do well putting all kinds of different loads into a good group at 400. Maybe try OCW instead?</div></div>

Well it supposed to look like a ladder with a small group somewhere in it
Not like mine It's all wrong lol

Ocw?

 

[Dog Doc]

Re: Need ladder test help

So a question regarding ladder testing as I have seen this multiple times with my tests:
As the charge weight is increasing, most of the time the elevation of impact is increasing. Occasionally you will have a charge drop down lower than the last impact and then start climing again. This always seems to be where I get the least amount of vertical spread. I am only talking .5 MOA or so but I notice this alot with my ladder tests. These are at 300yds by the way.
I guess I am describing what happened in the OP's pic above.

Would this be a node or is this a mistake on my part?

 

[targaflorio]

Re: Need ladder test help

http://optimalchargeweight.embarqspace.com/

There are two major schools of thought around finding a charge weight that allows the bullet to exit the muzzle at the optimum inflection/harmonic. Ladder and OCW.
I use the chronograph and group sizes to pick a good charge weight, but would lean toward OCW for the reasons Dan Newberry espouses.