Group size at distance

[milo-2]

Mathematically, the 1" at 500 becoming 14-15" at 1000 doesn't make sense. I haven't experienced this. I do ladders at 500 then seating depth at 300 or 500. Maybe that helps. I'll play with this more with the chrono this week. Have some finalized loads at 300 and 500 that I'll take out to 1200. Thanks for taking the time to explain, guys.

You are right, it did not make sense. I also gave advice to group at advancing distances to get a feel for the load, in my case, it was irrelevant to know where it fell apart, getting that good of grouping at 500 should suffice.
This past summer, I had a 6x47 Lapua chambered after a 2 yr absence from shooting one. A mix up between the smith and I resulted in him throating it for dtacs, I was not happy. First it took close to 200 rds for the barrel to quit speeding up, but I was close with a load, or so I thought. So one morning I load around 20 test loads to be shot at 500, can't recall the split number wise, but did have 9 charges of the one that had been doing the best and was producing the best numbers, win win. Did not go as planned, as it seemed my seat depth was not good, what I did end up with from this charge was those 9 rds producing a vertical spread at 500 of maybe half an inch.
Ok, this should be simple, I run back to town, load 40 rds of same charge, seated long, throw the coax in portable mount, take die and caliper-comparator to find the seat depth.
This is where the rodeo started, testing at 100 yards, at .006" off the lands, shooting project board with 1/4" dots made with a sharpie, it matches up good with a Kahles dot. Making minute adjustments, the seat depth changes literally clocked themselves around my dots as I tested, I think my first set was just high right of the dot, and subsequent groupings just rounded the dots, and nothing improved as far as group size. Figure that one out.
Thank God on the way home I realized another amateur smith was just getting off work, I stopped by and had him spin the barrel off, I was done with it, it did get a 2nd chance at life as a Dasher barrel for a friend, working well this go with 110 sierra's. And I got a new Krieger to replace it, happy happy

 

[TBell]

I have never built a rifle that groups well at 200 (that is where I initially test) that didn't shoot well at 500 or 1000. I still don't see mathematically how you can get good groups at one range and not the other. I'd have to see pictures

well there is a phenomenon my dad used to talk about when standing behind a 50 caliber shooting tracers at night. He said that you could watch the tracer spiral outward then back inward toward center several times in it's flight. Just theory but would suspect possible impurities in the actual bullet that might effect the centricity of the actual bullet when spinning

 

[emp1953]

Not a new shooter, but still learn something new everyday, usually from this forum.....So , my question is....why do some guns shoot 1/2" at 100 yds and 2" @ 500 yds, and another that shoots 1/2" @100 won't hold 5" @ 500 yds ? I know in my case it's probably the loose nut behind the trigger, but curious if it's possible or for that to be a mechanical thing with barrel or load or?. Thanks for any info....rsbhunter

Draw on a piece of paper a starting point, your rifle, and an end point your 100 yd target. Draw a straight line from one to the other, or what you think is a straight line. Tape a couple of pieces of paper to the one you've drawn on and put an end mark your 500 yd target lined up as best you can behind the first "target". Extend the original line that you drew. More than likely that line will not be in the center of the 500 yd target. What ever error you have closer, in this case 1/2" is magnified over distance or 5x. I probably tried to simplify this too much to the point where it doesn't make sense. Read up on MOA and how 100yd MOA equates to 500yd MOA and 1000yd MOA.

 

[skipglo]

Not a new shooter, but still learn something new everyday, usually from this forum.....So , my question is....why do some guns shoot 1/2" at 100 yds and 2" @ 500 yds, and another that shoots 1/2" @100 won't hold 5" @ 500 yds ? I know in my case it's probably the loose nut behind the trigger, but curious if it's possible or for that to be a mechanical thing with barrel or load or?. Thanks for any info....rsbhunter

There is a plethora of variables at play. But often it's fine scope adjustment or miss adjustment at 100 yrds. You think your shooting is great at 100 but keep in mind...1/2" out at 100 Is 2.5 " out at 500. That's mostly the start of what you see. Zero your guns at greater distance. 200, 250 or 300. Shoot 1/2 at 300...you should be shooting 1/2 to 3/4 at 500...or at least have a better chance of it.

 

[rsbhunter]

I tend to agree with the error magnified at distance....some mechanical, some psychological....we all "KNOW" it's harder to hit at distance.....or so we convince ourselves....rsbhunter

 

[Alex Wheeler]

It has to do with the direction the muzzle is traveling when the bullet exits and where it is in relation to its dwell point. If the muzzle is traveling up you can achieve positive compensation which will negate ES for the most part. The opposite is true if you tune on the wrong side of the dwell point. Hard to know for sure how a short range tune will work at long range until you try it, on paper.

 

[SilverbulletMAG]

I didn't take the time to read all the comments but, if not already stated, beyond obvious high ES causing problems at longer distances, another big variable is the scope you're running. Specifically, if you have enough clear magnification to shoot/aim as consistently as you do at 100-200 yards when you get out to 500 yards+.

 

[rsbhunter]

Yes, using a 10-50 Sightron , not having problems now, just in case with the new 6mm Dasher...just received my Berger 109 hybrids.....we'll see....rsbhunter

 

[kennyg]

It has to do with the direction the muzzle is traveling when the bullet exits and where it is in relation to its dwell point. If the muzzle is traveling up you can achieve positive compensation which will negate ES for the most part. The opposite is true if you tune on the wrong side of the dwell point. Hard to know for sure how a short range tune will work at long range until you try it, on paper.

Hey, I have learned a lot from your posts over the years, and always appreciate your input. Could you explain-or point me to some information-on how to get this tune correct when doing load development?

 

[Alex Wheeler]

The fool proof way is to tune at the longest distance you will shoot. If you do not have access to long distance you will need to tune for a very small group with very small es, even then theres no guarantee it will shoot at 1k. No matter how you tune, you can't be 100% of a long range tune until you put it on paper at long range. I will be honest, I have not had luck tuning at short range and having it work at long range. On occasion its worked but not every time. Some do make it work. But most will tell you they still verify it at distance.

 

[Bob Wright]

Tagging in

 

[Stgraves260]

Good

Not a new shooter, but still learn something new everyday, usually from this forum.....So , my question is....why do some guns shoot 1/2" at 100 yds and 2" @ 500 yds, and another that shoots 1/2" @100 won't hold 5" @ 500 yds ? I know in my case it's probably the loose nut behind the trigger, but curious if it's possible or for that to be a mechanical thing with barrel or load or?. Thanks for any info....rsbhunter

question. It can be a number of thangs. The list would be long. It could just be the weather// wind conditions outside. Maybe a none temp stable powder. The powder charge.

 

[kennyg]

The fool proof way is to tune at the longest distance you will shoot. If you do not have access to long distance you will need to tune for a very small group with very small es, even then theres no guarantee it will shoot at 1k. No matter how you tune, you can't be 100% of a long range tune until you put it on paper at long range. I will be honest, I have not had luck tuning at short range and having it work at long range. On occasion its worked but not every time. Some do make it work. But most will tell you they still verify it at distance.

Thanks!

 

[emp1953]

It has to do with the direction the muzzle is traveling when the bullet exits and where it is in relation to its dwell point. If the muzzle is traveling up you can achieve positive compensation which will negate ES for the most part. The opposite is true if you tune on the wrong side of the dwell point. Hard to know for sure how a short range tune will work at long range until you try it, on paper.

The proof is in the pudding. Got to try it for real on paper.