what range to target to develop loads

[rstbkt69]

I am having a precision rifle built in 6XC. The bullets will all be boat tail of course. While I develop my loads what distance should I shoot. All my previous load development was shot at 100 yards for my hunting rounds but I didn't use boat tails. Since the bullet stabalizes at a further distance I am wondering if I should test my loads around 200 or 300 yards. My shooting will be mostly at 600 yards for a while because that is the limit of the local range, but I will eventually venture to longer ranges. I plan on taking baby steps. If 100 yards will work that would be sweet because target changes would be easier but I don't want to induce any error by not allowing the bullet to stabalize. Thanks

[joelogic]

IMHO, it is more about your data at long distances. The variables affect the round much more than your load being 1 or 1/2 MOA. However, I did notice that at 200 yards my 168SMK were much tighter than my 175SMK loads no matter the recipe.

[rstbkt69]

During the development I will use a Bench rest to stabalized the gun. That should take me out of the equation. I wont shoot on windy days while developing the load and trying different bullet Manufacturers. I'll use the bipod for normal shooting after I see what the rifle likes. So you think I should shoot 200?

[joelogic]

I am not a long range shooter but I would develop my load for the range I will zero it at. which happens to be 100yds for the .308 bolt gun.

[Whiterabbit]

I develop at ALL ranges. Multiple ranges tells me much more useful data.

So I develop a pistol round that shoots clovers at 25 yards, great. .5" at 25 yards, that means 1" at 50 and 2" at 100, right? Then I shoot at 50 and it's 4", and 100 it's 12" (let's say the gun and shooter are taken out of it for now). That tells me something useful about my load.

Same with rifle. Load shoots 1-holes at 50 and 4" at 100. Very interesting.

Or maybe I shoot pistol at 7 yards and get nice round holes but at 15 or 25 the bullets go through the paper sideways.

Or maybe it's my first load set, and I want 10 rounds each across a 20% powder charge spread. If goal is 200 yard groups, I'm pretty sure I will be nowhere near paper for 90% of such a wide charge spread. So I start at 50. The best load gets a tighter spread and I start over at 100. etc. When I redevelop, I make new rounds in the best performing old charge weights so I have a baseline to compare the new rounds to.

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Bottom line, I have a goal when I develop, but I don't start at my goal range (unless very short, but that hasn't been a need for me yet), I take it down to see if I'm linear or to help me get on paper if it's the very first load set.

[rstbkt69]

I have other rifles to shoot at shorter distances so I'm not sure how any data at 100 would help me. Thats why I'm asking. Ive never shot long range BR before. I have plans for more development later on for different distances as I start shooting this rifle more, but if a 100 yard ladder test would translate into the same relative size group at 600 then I'll shoot at 100 to keep it simple. I am thinking of a 300 yad zero but I like to add the data to the target after each string while the barrel cools and walking 300 yards when others are at the range will make for a long day. Plus I don't like to slow the other guys down as I stroll out to my targets. Trying to be considerate and lazy at the same time.

[Ahhnother8]

100 yards

[grant22]

I'm not suggesting, I'm asking, because I don't know:

Wouldn't the op want to develop the load for what he plans to do with that cartridge? If he primarily plans on using this cartridge for 300 yds, then wouldn't he develop for the bullets best characteristics at 300 yds? I would think if he develops at 100 yds, but this particular bullet stabilizes more at 200 then 300, and he's hunting white tail at 300 yds appx, it seems like it would be best to develop at 300.

Sorta like saying, 'break in your engine exactly how you plan on using it.'

[joelogic]

Just from empirical data, locally I only have a 100 yard range so I developed a load at 100 yards. When I took a 1000 yard class it was much more about the wind and your ballistic data. Consistency in the load seemed much more important. With the temperature, elevation, bc and fps I was able to make a cold bore hit in the black at 1k with someone else calling the wind of course and this was my first attempt at anything LR. I was shooting a 24" savage in .308 with once fired LC, a 175 SMK and surplus powder. Just my $.02 but a round shooting 1/2moa at 100yds is just the qualifier and your ability to call the wind and know your drop is what will get hits at distance. As a note my instructor did say shooting anything in the 6mm family is like cheating compared to the .308. He said with the 6mm you can be much sloppier with the wind since it just slices through.

[damndave]

200-300 yrds would be preferred. I have loads that shot lights out at 100 yrds, but opened up to 3-4" groups at 200.

[sonnyt650]

but opened up to 3-4" groups at 200.

I think the question is whether some other load that did relatively poorly at 100 did better at 200 on that particular day. The whole notion of needing even a hundred yards before stabilizing seems far fetched to me since I have no idea why a bullet that's "happy" the moment it leaves the muzzle blast would ever shoot more poorly than one that is moving all over the place due to disturbing its own airflow. How can it be that the unstable part of bullet flight is more than made up for by the stable part of the bullet flight?

BTW: not trying to be a jerk about it, so if the answer is it just does that's fine by me. Maybe the high BC bullets have a narrow velocity range or something where they get that BC, and it turns to crap otherwise. That's one reason to pick another bullet too where I'd prefer performance over a wider range of temperatures over stellar performance on one day.

[CSACANNONEER]

100 yards

I was going to say that loads should be developed at the range you plan on shooting them. But, I'll have to listen to those who know better and go with 100 yards.

During the development I will use a Bench rest to stabalized the gun. That should take me out of the equation. I wont shoot on windy days while developing the load and trying different bullet Manufacturers. I'll use the bipod for normal shooting after I see what the rifle likes. So you think I should shoot 200?

BTW, using a bench rest system does not take the shooter out of the equation. There are many different variables to consider when using a rest system and changing any one of them, including way the shooter is holding the rifle in the rest, the way the trigger is pulled, the way the rifle is balanced between the front and rear rests, the way the shooter is able to read conditions (wind is only one of many conditions that affects bullet travel), etc. will all affect the results of any test or group being shot.

A friend of mine, Randy Dierks, once told me about a test that he, Skip Talbot and a couple other well respected LR shooters did. They set up targets in a straight line and set at the correct elevations to catch the arch of the bullet. Then, they shot groups that went through all the targets. The results were what should be expected. The group size was dirrectly related to the distance and the seconds or angle did not vary from one distance to the next. Of course, this would not take into acount any conditions that could arrise at a specific distance and affect all shots past that distance. So, working up loads at any distance will work as long as your loads don't go subsonic between your testing distance and the actual distance you end up shooting them at.

[damndave]

Never said that a load shot poorly at 100 and then shot good at 200. I have many loads that shoot excellent at 100, but not at 200 or 300. Load development past 100 yrds is critical if you want loads to go out past 700+

[rstbkt69]

So Is it safe to say that if I were to have 10 incremental powder charges and three different bullets, That shooting at a 100 yard target could help narrow down the loads to say 3 or 4 Charges for each bullet. Then I could take those loads that were determined to have the better velocities and tighter groups out to 200 or 300 and from there pick a few to start shooting at my 300 td zero and start working up different neck tensions and OAL's at that point?
Great input! thanks Never had to worry about this while only shooting at 100 yard zero's on my hunting rounds.

[Ahhnother8]

You are shooting the 6xc out to 600 yards. Barrel brand and twist is critical information not given. The cartridge has plenty of capacity to push any bullet far beyond 1000 yards, but not all barrels and bullets are designed for that job. Choose wisely!!

Testing beyond 100 yards introduces environmental conditions out of your control. Even at 100 yards, the bullets will get moved around by these conditions. So in calm or consistent conditions, shoot groups for comparison. Once a bullet leaves the barrel on a given trajectory, when it gets past 100 yards, it does not magically change directions. And that could mean either away from the center or towards the center. Bullets that leave the muzzle in the "wrong" direction continue on that path until they hit the ground. And as previously mentioned, shooting off a rest is not as easy as it looks. That is a learning experience in itself.

With that said, this can be really easy - buy good dies, brass, primers, jugs of H4350, and Berger 105 hybrids. Test at 100 yards and look for nice round groups. ANY type of stringing is BAD. Out to 600 yards, chrono numbers simply don't matter. It's ALL about the group size and shape. Beyond 800 yards, then good chrono numbers must be combined with great groups.

Or you can test a variety of powders and bullets, and waste components, barrel life and time...