The rifle is a Sako A-7.

Your thoughts and suggestions are appreciated.
Loaded up some rounds

66 grains Shot 2625

68 grains. Shot 2725

70 grains Shot 2850

All shot ok , around an inch , but haven't found a node , I'm going to load a few with 71 , and 72 , and see what shows , Berger book shows 68.5 as max load Nosler book shows 74 as max load

Everything I shot showed no signs of pressure , but I did notice , it would shoot the first two shot side by side then as barrel heats shoots third either up or down , plus barrel fowls quickly , so I'm sure as things slick up will shoot cleaner , and we saw from the S S T that it shoots them good hot , that superformance powder is hot stuff !


Thanks,
Ski+3

That is a fairly wide spread on max powder charges. Double check the components listed in the loading data.

If you had a bullet go down range, you had pressure signs. Good thing to chronograph your loads as you go.

You will need to develop a load which shoots well from a cold barrel if you are to hunt with the rifle. Your first shot at a game animal won't be with a hot barrel.

If your range goes to 300yards, you can try a ladder test. It is pretty easy to set up and I find it to be a faster way to get a node worked out. Do it on a calmer day.

There are instructions on the web for this test. I usually load in 1/2 grain increments for ten rounds up to the book max. So the first is say 60gr, the second is at 60.5gr, etc. Each of the ten cartridges will have a different charge in it.

I set the target at 300 yards. It is a piece of cardboard 30" long with an orange dot on it 8" down from the top. Aim at the dot every shot. You are just using the dot as an aiming point, not actually trying to hit it.

Shoot the lowest charge first. It will hit well below the aiming point. Make a chart on a notepad at your bench and mark where it hit with the velocity. Shoot the next, it should print a little higher, mark it on your chart. Keep track of where each shot hits vertically. Take your time, and let the barrel cool between shots.

As you go, you should see some shots group together, and then the next will be higher. Each grouping is a node. You should also notice that the velocities at the node charges are pretty close.

I then take the middle charge at the highest velocity node and try it for 3 or 5 shot groups. Then I can dial it in from there.

Jeremy

I am going to disagree with farbedo. The ladder method is meant to identify those loads where a small difference in powder weight does not materially affect the group size. if you have a target quality rifle, then 300 yards is a good distance. The reason is that the groups are small enough that the POI is not masked by the group size. If you do not have a target quality rifle then the 3 inch groups that you are shooting will mask the impact change that is occurring. Bullet choice and weight is the most significant determinant in group size (after the barrel (not easily changed!)). So I would suggest trying different bullet types, focussing on the bullets appropriate for the application in mind. My choice would be to start with target quality bullets. Use a chrono at 100 yards, and keep track of velocity SD and extreme spread. IF you have a decent scope then use one of the multi target small bore rifle targets. They have about a 2" black, and give you about 8 targets on one sheet of paper. Shoot 3 shot groups and confirm the better ones with 5 shot groups, and then confirm again! MY 300 WM's (plural) shoot very well with 168 gr. SMK's. I have not tried the 190's (too expensive!). They also shoot 180 gr. Nosler Partitions very well. What powder?
Just my 2 cents,
Peter

Peter, I am not sure I understand your post.

You don't shoot groups in a ladder test. You shoot single shots at different powder charges, keeping all other things equal.

The result is a string of shots generally in a vertical line below your aiming point. At 300 yards there is usually enough drop to get a string.

When you are near a node, two or usually three shots will be closer together. The next one will be higher and so on.

I don't worry so much about horizontal position as long as it isn't way off.

There is a lot of discussion on using this method on other LR forums.

At any rate, it is a method that I like to use as it takes a lot less ammo to get what I want.

Jeremy

Jeremy, let me try to explain my post as I may not have been clear. You have a 1" rifle at 100 yards. That is roughly a 3" rifle at 300 yards. That means that any given round will go somewhere in a 3' circle. So I fire 1 round, and let's say it goes at the top of it's 3" circle. The next round (.5 grains heavier) goes at the bottom of it's 3" circle. These rounds could be touching, or very close to each other. Now, what conclusion do you draw from this? The point is that the dispersion can hide any variations in impact point.
I do not frequent LR forums, other than this one, and, I am not an expert, but I have read, and have a copy somewhere, of MacPherson's article on Audette's ladder method printed in Precision Shooting many years ago. But, to each his own.
Peter.

Ok, that makes sense. I can see the reasoning.

I have not seen that article, but would be interested in it.

This method has helped me work out loads for several rifles, but a better understanding of the limitations is a good thing. That said, these rifles also ended up sub-1/2MOA shooters, so maybe it is dependent on the rifle used.

Thank you for the explanation.

Jeremy

Jeremy I think we were only disagreeing about the distance. I still think there are some other issues with the OP. The velocities seem low for a 300WM shooting reasonable bullet weights, and still no mention about the powder used. As I have already stated, my 2 300WM's are very accurate (sub MOA) out to 300 yards, the furthest I have tested them, and this is with Nosler Partitions, a hunting bullet. As I recollect I achieved best results with Re 22.
Peter.

Thanks guys,

Found 72 grains of IMR4831 pushes the 180 grain Nosler AB's at 2850. Great groups.

Now to the field.

Ski+3

Rob,
It seems to me that you are giving up too much speed. I've got a 30-06 that produces 2850 with 180s, and an arm-full of .300s that top 3100 quite handily.

quote:

As I have already stated, my 2 300WM's are very accurate (sub MOA) out to 300 yards, the furthest I have tested them, and this is with Nosler Partitions, a hunting bullet.

After quite a few years down playing the accuracy potential of the Partitions I'm on a hot streak where they are shooting extremely well in everything I try them in. I don't know if the scales are just now balancing out or if the quality level went up over the years.