Longer Range Load development - How useful is shorter range testing ?

[Thatcher]

I have a question on load development - On my usual range days I get to shoot 300 and 600 yards - each shot is marked individually and theres no real opportunity to shoot and keep a specific target, so measuring group size isn't really very practical. I can use the spotting scope to see where the spotting disk is on the target but its not a very precise method for measuring incremental improvements in a load.

I want to work up some reloads and I have the chance to use a 100 meter range where I will get to shoot and keep my own targets. How useful an indicator is group size at 100 meters to how well a load will perform at 300 and 600 yards ?

 

[Zak Smith]

I've only had one load in 260, 6.5, 308, and 338 that worked OK at 100 yards but fell apart at 1000 (338/250LAP/H1000/215M).

 

[D&T]

Full bullet stabilization is not achieved until you get to or exceed the 200 yard range with high powered rifles...

Most guns will actually shoot tighter groups at 200 yards than what they will at 100 yards. I have shot several rifles that would should no better than 3/8" to 1/2" groups at 100 yards but when the target was moved out to 200 yards, group size was dropped to 1/4" or less at 200 yards. I have seen this so many times that now, when I do a load development it is always done at 200 yards. With the "beanfield" rifles that I build, all load development with them is done at 600 yards because most of the time, that is the minimum distance at which they are shot....

 

[peterotte]

"Most guns will actually shoot tighter groups at 200 yards...."

I knew this to be true of 303 SMLE's with MK7 ammo and the earlier loadings of 375 H&H but of most rifles is interesting. (It is not true of my 1902 LMLE with a new No.4 barrel and hunting bullets - not at 200m anyway).

 

[Stinger]

1/4" or less at 200 yards

Of course you do, everybody on the internet shoots at least that good

 

[Slamfire]

I do all my load development at 100 yards. I have access to a 100/200 yard range. I can see my groups and don't have to walk 400 yards to change targets.

I shoot mostly .223, 308, 30-06 with a smattering of odd ball calibers, but only the first three get taken to a military range and shot at 600 yards, or 1000.

You can commit a lot of reloading sins and still have wonderful accuracy at 300 yards. Beyond that, to have decent accuracy it is a test of the load, the barrel, and you. With you being the largest error source.

So, if the human is the largest error source, that is the part that needs the most work. Only after you have that down pat will you be able to see that your barrel (or load) will barely hold the 10 ring at 600 yards.

I do believe that at 100 yards you might not be able to discriminate the difference between good loads, but at 300 yards you might see one load do a little better than another. But it is all time related. You can develop match winning ammunition at 100 yards, lots of people do it, but of course, the final test is the match.

 

[wanderinwalker]

Thatcher,

Sounds like you're shooting in Highpower or similar situations. Anyway...

Yes and no on the developing a good long range load at short range. Out to 300 yards, as stated, it doesn't take too much to get a good group. I don't weigh cases and charges on my "short range" .223 loads, and the combo will still easily slip every round inside of a 2.33-MOA circle at 300. I know, not impressive by benchrest standards, but it's about the best I can do laying on my belly with a sling and iron sights. Have yet to clean a 300 rapid this season, but I've been shooting lots of 97-99s.

My 600 yard ammo doesn't look too good at 100 yards, but it shoots well "out there". So if I see a 1.5-MOA group from an 80gr .223 load at 100 yards, I can live with it until I try it at 600. But I wouldn't waste time at 600 with a load that couldn't go under 2-MOA at 100.

If any of that helps, I'll be surprised, but take it for what you paid for it.

 

[fineredmist]

For what it's worth, do your load developement at 100 yds (meters) to find the accoracy potential of your loads. You want the best groups you can get and when you get out to longer ranges your ability becomes more important. I have done extensive load developement for my varmint rifles over the past 8 or 9 years and if they hit tight and CONSISTENT at 100 they will not let you down as the range increases.

 

[Clark]

I like </= 3mph wind for 50 yards and 0 mph wind for 100 yard testing of rifles and loads.

Right now I am waiting for a 3 mph day when the range is open.

 

[snuffy]

Full bullet stabilization is not achieved until you get to or exceed the 200 yard range with high powered rifles...

I disagree. Or should I say not in all cases. Heavy for caliber bullets in a slow twist do not "go to sleep", meaning fully stabilize, until at or beyond 100 yds. Normal for caliber weights are fully stabilized much sooner in a proper twist rate barrel.

Another thing to watch for is extreme spreads in velocity, while at the same time a vertical stringing showing up on the target. That vertical stringing will be vastly magnified at long range. Nice round groups of at LEAST 5 shots will be nice round groups at 3 - 6 - or 1000 yds. Generally, the group size @ 100 yds. will be a factor of increase parallel to the range, IE 3/4 at 100 = 1.5 at 200, 3" at 400 and so forth. I've never seen a group get smaller at further ranges! One good group proves almost nothing. 10 or 20 shots WILL tell you if you have a load to depend on. Another thing, waiting for your barrel to cool while testing loads may save throat erosion a bit, but when it comes time to shoot in a match, there's no time to let it cool. Shoot like you compete, or you might get a surprise as the barrel heats up.