Short range tuning for 1000yd BR?

[Curious]

Ok, I accept that the ultimate is to ladder test at the range you are competing so in this case 1000yds and tune to find positive compensation. I dont doubt this one bit but my problem is I can't get out to 1000yds.

I have easy access to 100-300yds with a concrete bench and flags.

In the past I have tuned at 100yds using an OCW type method (0.2gr first then 0.1gr charges) looking for a stable POI then a seating depth tune, this has consistently given me a tune that will produce 5 shot aggs for a LG around 0.250" or a little less at 100yds. In competition at 1000yds these type of loads have given me mixed results ranging from aggs of 5.5""-10" depending on conditions, Ive shot a few in the 3s, 4s and 5s and even one in the 2s but I feel its more luck than method.

Is there a better method than the one Im using, if so will you share it with me?

I would very much like to know what a well tuned 1000yd load looks like at 100, 200 & 300yds, surely it must have vertical stacking?

I wonder what can we glean from looking at long range tunes at shorter distances in the positive compensation aspect?

If not positive compensation then what other methods up to 300yd testing has yielded you good results?

 

[retired]

do a search..it is an on going thread

 

[ttfreestyle]

Here is the thread that may answer your question. Hope this helps. Troy

 

[Dusty Stevens]

You can start at 100 to eliminate more of the wind variable then go out as far as you can go and fine tune it. If it doesnt shoot at 100 i can guarantee you it wont get smaller

 

[Curious]

do a search..it is an on going thread

Forgive me if this appears selfish but I dont want to trawl through 103 pages of discussion.

I started a new thread to hopefully keep it relevant to my own interests.

 

[CoyoteTan]

Like you I don't have easy access to 1000 yards, so I do all my load development at 100 yards for my 1000 yards match loads. I use a chronograph to find the "flat spot" and fine tune from there.

 

[Curious]

Like you I don't have easy access to 1000 yards, so I do all my load development at 100 yards for my 1000 yards match loads. I use a chronograph to find the "flat spot" and fine tune from there.

I just dont see many flat spots?

I chrono all my load development and I could look back over literally dozens of charge weight test targets and there are times a flat spot will show up but I would say its very much in the minority, as such I can't buy into this method. Typically I see ES in the low double figures or high singles but usually each 0.2gr shows a 10-20fps increase in my BRA case over 3 shot averages.

My most recent charge weight test yielded the following

6BRA 107 SMK N140 CCI 450

30.4 - 2826 fps
30.6 - 2834 fps
30.8 - 2853 fps
31.0 - 2870 fps
31.2 - 2876 fps
31.4 - 2887 fps
31.6 - 2900 fps
31.8 - 2919 fps (heavy bolt lift)
32.0 - 2939 fps (to heavy)

This is fairly typical of what I see, what would that tell you that I could be missing?

 

[Curious]

You can start at 100 to eliminate more of the wind variable then go out as far as you can go and fine tune it. If it doesnt shoot at 100 i can guarantee you it wont get smaller

Ive had lots of good loads at 100yds, the problem is they all haven't shot as well as each other at long range and Im struggling to identify the better ones at short range.

I guess 300yds will start to show up the differences and might be more telling.

I started this new thread to see what people thoughts were on the different ways to tune at 300yds, we have touched on velocity flat spots for example. Im unsure as to whether ladder tests for example would reveal anything more than my OCW method would?

I appreciate my own testing would reveal this but like most of us Im limited by time and suitable conditions hence the open question to all.

 

[CoyoteTan]

I think between 31.0 - 31.2 is the flat spot, only 6 fps difference compare to others have 10~20 fps when powder charge increased. I'd load 31.10gr. and fine tune from there.

 

[Curious]

I think between 31.0 - 31.2 is the flat spot, only 6 fps difference compare to others have 10~20 fps when powder charge increased. I'd load 31.10gr. and fine tune from there.

Thats really interesting because looking at the holes in the paper its the most obvious place I would avoid. From 31.0 to 31.2 there was clear shift in the POI which then stabilised for the rest of the charge weights.

Im not saying I am right and you are wrong but I hate the idea of tuning near a node shift as I feel the barrel doesn't know which of the two it wants to be at and in the past this has always lead to an unsuccessful seating depth test.

Looking at the target it is stable from 30.4 to 30.8 and then 31.0 is the transition, 31.2 to 32.0 is again stable. Based on what your saying then there is also 6fps between the first two charges but it was just too slow down there.

 

[CoyoteTan]

Give it try, if the group is good and sd/es in single digit, I don't see why not using this load?

 

[270WinDude]

I'm purely educated speculating here and have minimal experience... But based off what you have now, why not work up 2 test batches around your 2 favorite spots (probably 30.4 to 30.8 and 31-32) and shoot it at 300? It's general consensus from what I can tell that 300 is a great measure for 1k loads. I'd take the data you have now and work up in .2grs (or whatever) with 4 rounds per increments and in 2 batches and shoot for groups at 300. That'd give you 18-40 more rounds to figure it out and you can use that info for better ES data also.

 

[Terry]

I just dont see many flat spots?

I chrono all my load development and I could look back over literally dozens of charge weight test targets and there are times a flat spot will show up but I would say its very much in the minority, as such I can't buy into this method. Typically I see ES in the low double figures or high singles but usually each 0.2gr shows a 10-20fps increase in my BRA case over 3 shot averages.

My most recent charge weight test yielded the following

6BRA 107 SMK N140 CCI 450

30.4 - 2826 fps
30.6 - 2834 fps
30.8 - 2853 fps
31.0 - 2870 fps
31.2 - 2876 fps
31.4 - 2887 fps
31.6 - 2900 fps
31.8 - 2919 fps (heavy bolt lift)
32.0 - 2939 fps (to heavy)

This is fairly typical of what I see, what would that tell you that I could be missing?

I find shooting two shots tells me much more. First some loads will produce one hole groups. Even those that don't tell a story. They move from horizontal to vertical and back. Two shots gives me two velocity readings. Some have large spreads some are identical. The best ones I try at distance.

Best Wishes!

 

[ShootDots]

If you are shooting F-Open, you only have a couple of choices. .1) Build and tune a rifle for dedicated 1000 and build another for Mid-Range 2.) Build a rifle for Mid / Long Range and use it for both, which is what most F-Open shooters do. Obviously you can have multiple rifles for shooting very specific conditions I.E. using a .300WSM with 230gr pills for 1000 yard in HEAVY wind conditions...etc... Or like a friend of mine who has built a rifle specifically to attempt to beat the current 300 yard F-Open record of 200-30xs! Whether he can pull that off remains to be seen. But simply because you have excellent groups at 100 yards is NO GUARANTEE the groups will hold together further out. REAL LIFE EXAMPLE: About 4 years ago I embarked on a project for an excellent 600 / 1000 yard rifle under even terrible conditions. I chose a 30-06A.I. to shoot 210gr JLKs, which would not shoot and 200 Hybrids. With the 200 Hybrids I shot a 100 yard 0.016 (as best I could measure) 5 shot group. However, at 300 it would open up to 1.5-1.75 inches! How? Why? Example#2: I currently have a 6 x 47 that shoots BOTH the 105 Scenar and the 107SMK very well. However, the 105 Scenars fell apart at 500 pretty bad, where the 107s stayed the course! I develop loads at 300 and shoot a match at either 500 or 1000 to see how they hold. Most of the time, NOT ALL the time, they hold all the way out. However, in my opinion the BEST way is to develop a load at the distance you intend to shoot. However, in F-Open, unless you have dedicated rifles for each distance, you must choose a load that will shoot excellently from 300 yards on out!

 

[JFrank]

Ok, I accept that the ultimate is to ladder test at the range you are competing so in this case 1000yds and tune to find positive compensation. I dont doubt this one bit but my problem is I can't get out to 1000yds.

I have easy access to 100-300yds with a concrete bench and flags.

In the past I have tuned at 100yds using an OCW type method (0.2gr first then 0.1gr charges) looking for a stable POI then a seating depth tune, this has consistently given me a tune that will produce 5 shot aggs for a LG around 0.250" or a little less at 100yds. In competition at 1000yds these type of loads have given me mixed results ranging from aggs of 5.5""-10" depending on conditions, Ive shot a few in the 3s, 4s and 5s and even one in the 2s but I feel its more luck than method.

Is there a better method than the one Im using, if so will you share it with me?

I would very much like to know what a well tuned 1000yd load looks like at 100, 200 & 300yds, surely it must have vertical stacking?

I wonder what can we glean from looking at long range tunes at shorter distances in the positive compensation aspect?

If not positive compensation then what other methods up to 300yd testing has yielded you good results?

I'll probably get torched for this but here goes-
Why would you guess there would be vertical stacking?
Would you believe me if I said that a well tuned 1k load was just a really tight group at 600?
Eric Cortina tunes at 100 and claims that it's good to 1k
That may work for him however (I ) do not see anyone else succeed using those methods.
The people I know that compete at long range and succeed shoot very small groups at 600 and do not spend a lot of time on short range rather arrive at matches early load on site and test for the conditions .
they have great equipment outstanding knowledge accompanied by excellent table manners! And these people work very hard at their craft earning every little inch.
That's what I'm seeing first hand, to coin a phrase ( it's not rocket surgery) nor magic just hard work and long range testing.
Best regards
Jim

 

[savageshooter86]

All in how you go about it. And your shooting skills. I’ve taken load straight to 600. But have also started at 100 yards when I had no idea where to start with a particular combo. Both did well and held at 1000 yards

 

[DHuffman]

30.4-30.6 & 31.0-30.2 are your flat spots.

This is what mine did at 600 the other night at the 30.4 and 30.6 loads

When I started tuning this 6 BRA I decided I was not going to chrono it. I was going to test it at 600 and see what it wanted to shoot not pick a fps "flat spot" and try to make it shoot there.

 

[JFrank]

You can start at 100 to eliminate more of the wind variable then go out as far as you can go and fine tune it. If it doesnt shoot at 100 i can guarantee you it wont get smaller

Interesting you should say that and it brings to mind a couple of years ago I was working on a 308 175 gr load that grouped about an inch or so at 200 yards but was about the same at 300 I asked a buddy about it he said they were
( lazy ) ..
what's up with that?
J

 

[Dusty Stevens]

Interesting you should say that and it brings to mind a couple of years ago I was working on a 308 175 gr load that grouped about an inch or so at 200 yards but was about the same at 300 I asked a buddy about it he said they were
( lazy ) ..
what's up with that?
J

Bullets going to sleep has long been a myth often repeated when a longer range group luckily shoots better than the closer one.

 

[Curious]

I'll probably get torched for this but here goes-
Why would you guess there would be vertical stacking?
Would you believe me if I said that a well tuned 1k load was just a really tight group at 600?
Eric Cortina tunes at 100 and claims that it's good to 1k
That may work for him however (I ) do not see anyone else succeed using those methods.
The people I know that compete at long range and succeed shoot very small groups at 600 and do not spend a lot of time on short range rather arrive at matches early load on site and test for the conditions .
they have great equipment outstanding knowledge accompanied by excellent table manners! And these people work very hard at their craft earning every little inch.
That's what I'm seeing first hand, to coin a phrase ( it's not rocket surgery) nor magic just hard work and long range testing.
Best regards
Jim

Positive compensation works at only one distance when rounds of varying velocities converge with minimal vertical at the distance the specific rifle was tuned for. At all other distances the trajectory of the variable MVs differ and so I would expect them to show this at the target in a vertical manner.

I think you are confusing what you consider a regular 1000yd tune where positive compensation is not occurring, In that case I would agree a good load should then probably show itself at all distances.

Im not a positive compensation zealot but I understand the science and respect the fact those using it regularly shoot smaller groups than their ES should allow, this tells me its real and Ive also dont it at shorter ranges myself and seen it for that specific distance.

The point of this thread is I can't tune for PC over the range distance I have as its not the distance I compete at at the moment which is 1000yds.

Because I realistically have only 300yds on a daily basis and the occasional 850yd option I need to find a way of tuning that doesn't work with the intention of finding PC. I am told there are some good methods used by some competitive shooters, Im just trying to find out what they are.