- Location
- Prince Albert, Sk
I will try explain it, Jerry would be much better and will likely be along and help out my attempts.
You are looking for particular nodes(clusters) based on charge weight which will show patterns in barrel harmonics.Kind of have to decide what you also want for velocities for your application and look where those groups fall as well, short range plinking vs long range hunting for example.
73 - 77 grains in the first powder shows a tight cluster and 78 - 81 shows much more spread. This show that those particular charges "harmonate" in the barrels sweet spot.Easy to see with this IMR powder however less overall consistency.
Vertical stringing as well as horizontal will give a group so to say that shows what the barrel appears to like, the results are not always linear as barrels have more than one sweet spot I believe typically 2 or 3 is the norm when going from bottom to top charge.
The Retumbo results are much tighter and a bit tougher to choose where to work.However IMO the over all smaller group and more liner velocity increases tell me this powder is more suited for this barrel.
89, 91, 93 show very little vertical stringing and promising horizontal so that is why I decided to try 91,93 and 95 in group tests to see what I got as I was showing no pressure signs at 93 on my ladder test.
89, 91, 93 is about an 1.250" group @ 200 yards with different powder charges , I think that says something.
Definitely saves on components as opposed to group testing.
No flattened primers or difficult extraction yet to this point.
You are looking for particular nodes(clusters) based on charge weight which will show patterns in barrel harmonics.Kind of have to decide what you also want for velocities for your application and look where those groups fall as well, short range plinking vs long range hunting for example.
73 - 77 grains in the first powder shows a tight cluster and 78 - 81 shows much more spread. This show that those particular charges "harmonate" in the barrels sweet spot.Easy to see with this IMR powder however less overall consistency.
Vertical stringing as well as horizontal will give a group so to say that shows what the barrel appears to like, the results are not always linear as barrels have more than one sweet spot I believe typically 2 or 3 is the norm when going from bottom to top charge.
The Retumbo results are much tighter and a bit tougher to choose where to work.However IMO the over all smaller group and more liner velocity increases tell me this powder is more suited for this barrel.
89, 91, 93 show very little vertical stringing and promising horizontal so that is why I decided to try 91,93 and 95 in group tests to see what I got as I was showing no pressure signs at 93 on my ladder test.
89, 91, 93 is about an 1.250" group @ 200 yards with different powder charges , I think that says something.
Definitely saves on components as opposed to group testing.
No flattened primers or difficult extraction yet to this point.
Can someone please explain how to interpret your pics? how does shooting 1 round of each charge tell you anything when they seem to be all over the map? (by that I mean I dont see the pattern where a particular node of say 3 charges are grouped together any better than any other 3 shots?) Lets just say you didnt go past 92 as that was max..., how would you decide where to start shooting groups with a particular charge?
Last edited:






















































