Load development and sighting-

[soumya sarkar]

My bolt rifle has been sighted using a certain brand of factory ammunition. Now I plan to develop a custom load using a different combination of bullets and powder, albeit same bullet weight. I know the ballistics of my new load are different from the one for which the rifle is currently sighted.

In a scenario like this where do I begin specifically knowing that my rifle has not been sighted for my new loads?

 

[CharlesT]

When developing a load, I am initially more concerned about group size than the Point Of Impact.

After shooting the first load group and recording the group size, I may roughly adjust windage and elevation to more closely align Point Of Aim to POI, just to keep things neat on the target.

I'll not adjust the sights or scope again until I have determined what will be my final working load. I don't think that there's much point in adjusting for the POA matching the POI until you have a "keeper" load.

Others will do things differently, this is just how I do it.

CT

 

[Rez Exelon]

If a load you create has a different Point of Impact but it's giving good groups it's easy enough to record the dope value to adjust between loads. I might have multiple loads for a rifle and a book indicating how to adjust between them.

 

[Ridge Runner]

My approach in load development sota falls in line with @CharlesT.

I start by running the ballistic data. Then do some load testing with the same bullet weight till my reloads are very close to the factory ammo I use. Then increase the powder charge by .5 gains till I'm 1.5 grains under max load. Or until my reloaded bullet velocity exceeds recommended max bullet manufacturer's bullet velocity. Drop down to the test load below the bullet manufacturer's max bullet velocity. Check My results For My rifle's most accurate reload. Do the ballistic calculations. Then start reloading.

When I change to a different bullet weight pretty much the same as forementioned process, but I may have to change powders, so there are a few more steps added to the forementioned process before I start reloading test cartridges.

Regardless my goal is to have the most accurate, most reliable, most efficient, cartridge that will quickly and humanely kill the animals I plan to hunt with that particular caliber.

 

[soumya sarkar]

When developing a load, I am initially more concerned about group size than the Point Of Impact.

After shooting the first load group and recording the group size, I may roughly adjust windage and elevation to more closely align Point Of Aim to POI, just to keep things neat on the target.

I'll not adjust the sights or scope again until I have determined what will be my final working load. I don't think that there's much point in adjusting for the POA matching the POI until you have a "keeper" load.

Others will do things differently, this is just how I do it.

CT

Thanks, what MOA do you aim for 100 yds, 1 that may be difficult when you are starting?

 

[CharlesT]

My goal is usually the tightest group. I always shoot all the test loads just to see what groups I'm getting. I load in half grain increments from recommend starting loads to maximum load.

When I find a node worth exploring, I'll load 0.3gn below that and work up at 0.2gn increments. For example, the best size group was at a load of 55.0gn. I'll load 54.7, 54.9 55.1 and 55.3. One of those will be the smallest group.

I once had a Parker Hale in 6.5x55 that gave a sub 1" group at 100, but it was near the bottom of the charge weight, and hence velocity. Further up the charge weight, it eventually shot a 1-1/4" group. For hunting purposes, that's more than adequate. If I recall, the velocity was about 2500fps which was more in the neighbourhood of what I was looking for.