Thread: Testing a conventional approach to load development

I have non-hunting and non conventional needs for load development for several rifles. But the level of testing I need to do often isn't associated with the load itself but cleaning and shooting regimes. The below target is with black powder 38-55. I was testing how long I can shoot reasonably quickly while blow tubing before shots went outside the group. 40m, as that's the longest range I had at the pistol club, will do some slower group testing at 100 and 200m later. I had 20 shots out of 21 fall inside the group, shots 22-25 went out. So 20 shots is my upper limit before I have to clean when target shooting, assuming consecutive shots. If there is a pause in shooting fouling may harden so the regime shortens (but I also have time to clean so no issue). Shot 14 was well outside of the group this I consider a genuine flier of unknown cause, most likely a deformed cast projectile base, but I don't know.
The long and the short of this is load testing should fit intended use.

My smokeless load testing consists of a load ladder to find pressure or velocity I want, often only 1 our 2 shots per charge weight, not shooting for groups, but I shoot to the same point of aim, generally even several grains of powder difference are not detectable in terms of point of impact with any reliability at 100m. If this mixed charge weight group is massive - I'll change powder or projectile or both. Then I sight in with the charge weight that gets me the velocity I want. I actually don't believe powder weight nor seating depth influence group size to the extent I can detect so if a load doesn't shoot it's either the rifle, powder, or projectile that'll be changed. People doing a lot more testing than I can bother to do, in applying appropriate statistical tests would appear to align with my belief.
Post script note: the 1 or 2 shot velocity check often results in one powder weight apparently shooting slower than or the same as another, this is just statistical noise, I'm just looking for the velocity, or thereabouts. With sufficient numbers of shots the relationship between charge weight and velocity is directly proportional, no such thing as velocity nodes.

Note: before anyone mentions size of group = size of aim point. I'm using open sights, with a circle front sight element. Aiming at a black dot ensuring an even amount of white ring shows around the aim point is incredibly precise if the front sight element fits the aim point dot well (just a ring of white showing). This day the front sight element was slightly too small but good enough for the level of accuracy I needed to test so I didn't swap it out, I would suggest quite a bit of the group variation is shooter/sight alignment error because of this.