1000yd Benchrest Load Development

[Curious]

Ive been shooting 1000yd benchrest for one season now with some reasonable results. I have won 3 matches outright but I am far from settled on my load development so thought I would ask you guys your opinions on my method and what improvements I can make.

So far I have used the OCW method for selecting a charge weight and tuned accuracy with a separate seating depth test, all of this is done at 100yds, I try to pick still days and use wind flags at 50yds and 100yds.

Typically I end up with my gun shooting 5 shot groups mainly in the 0.2s with the occasional group in the mid to high 0.1s and the odd one in the low 0.3s, they agg around 0.250" over 4x5 shot strings. Velocity is measured with a LabRadar and ES is usually around 10fps.

I dont test at longer ranges before going out to 1000 because Im not convinced that I can separate good loads from the effects of the wind and I dont do ladder tests. Im a novice to 1000yd benchrest reloading but make sure my brass prep is very good, I neck turn, AMP anneal and everything is as near to the same size as most can achieve, neck tension is 0.001"

Im also curious what you guys consider an accurate enough rifle to be competitive at 1000yd benchrest.

Many thanks

 

[dkhunt14]

Many times a load with low ES and accurate at 100 will fall apart at 1000. I am looking for the load that shoots through the conditions. To do that you need to shoot at 1000. Also it is easier to see what changes take place at 1000 and find that node. Matt

 

[Mozella]

..... snip........
I dont test at longer ranges before going out to 1000 because Im not convinced that I can separate good loads from the effects of the wind ........ snip........

I can't answer your question about how good you have to be, but I will agree you on the problem of testing in winds. Think about it. Nearly everyone can find a nearby 100 yard range where he/she can get out there at the crack of dawn and test in zero or near zero wind conditions. It's MUCH harder to find a 1000 yard range and it usually takes more than one person to test at 1000.

At the moment you're shooting better than 1/4 MOA at 100 yards. If you were able to do that at 1000 yards, we'd know you as a World Record Holder or darn close to it. Of course what you want to do is to shoot 1/8 MOA if you can, but as you already know, that is a goal we all dream of but don't really expect to reach. But we all keep trying anyway.

To get better than you already are, you will be looking for TINY incremental improvements in performance. These improvements are considerably smaller than the typical deviation you expect caused by wind when shooting at 1000 yards. So it makes sense to me that testing at long ranges in wind is quite likely to mask the tiny changes you're trying to observe and quantify unless you can always read the wind perfectly. In that case, you would already be the World Champion in several divisions, right?

If you aren't measuring your targets using computer software, consider doing so. I use On Target software. You can either scan or photograph your targets, mark the bullet holes VERY accurately, and let the software analyze the results. You can then save an image of the marked and measured target. But more importantly, you can transfer the data to a spread sheet where you can add some other parameters such as powder type, charge weight, MV etc. Then you can study it and compare it to other load recipes. Once you have the ability to sort a batch of data by various parameters, you are better able to detect what improves performance and what doesn't.

Measuring your groups by using a coin or carpenters tape and logging the results in a tatty dog-eared notebook isn't nearly as good.

I shoot mainly 600 yd F class and BR but I occasionally shoot 1000 yd Br. I do all my serious testing at 100 yards in zero or near zero winds. I've tried testing at longer ranges and/or in wind and the results are invariably less definitive because the effects of wind always tend to mask the incremental changes in performance.

Every gun and every load recipe I have that works well at 100 yards also works well at 600 yards; well enough to win my fair share of matches at least. Most of my fellow competitors follow the same routine; i.e. test at 100 and compete at 600 or 1000 yards.

There are quite a few different opinions on this subject, so it's up to you to sort the fly poop out of the pepper while the rest of us make a fresh batch of popcorn, sit back, and watch. Remember, this is the internet.

 

[dkhunt14]

Now is a poor time to ask because everybody that's good is prepping for Nationals. They are Sept 2 and 3 and they are measuring bullets and prepping brass. That is a full weeks work for the 6 sets of ammo (3 light and 3 Heavy) plus a back up set for each.

I can almost guarantee the guys that are setting records and winning the aggregates are almost all testing at 1000. You are looking for that load that drifts less, shoots less vertical and Maybe shoots about 1 inch smaller. Maybe Alex Wheeler or Tom Mousel will chime in, he is better at explaining it. I had a gun that would shoot in the 0's and had extreme spreads of 2 to 3 and the smallest group it shot at 1000 was 13 inches, all vertical. The load fell apart, which can be common. The gun with a load that shot extreme spreads of 8 to 9 and groups at 100 that were close to 1/2 inch would shoot 4 to 5 inch groups at 1000. Also these are 10 shot groups because we shoot 10 in both light and heavy. Matt

 

[Alex Wheeler]

There are many ways to find a load. The only one I consider to be a sure thing every time is a 1000 yd ladder. It will get you there fast and put you in the middle of the node. Ladders are very easy to read, so long as you can shoot. Your tuning with positive compensation, all other methods will require you to verify your load at distance, because you may be one the wrong side of the node and your small groups with tiny es may end up 14" tall at 1k. Ladder testing is well know, things we do in 1k Br that are slightly different is load 3 shots per charge and look for what we call overlap. Overlap is where 2 consecutive powder charges will print on top of each other at 1k. Thats the point where PC is working. Different speeds converging at 1k.

 

[jdh47]

Eric Cortina has some good ideas on 1000 yard load development at 100 yards. Here's the thread:

http://forum.accurateshooter.com/threads/long-range-load-development-at-100-yards.3814361/

Joe

 

[Curious]

There are many ways to find a load. The only one I consider to be a sure thing every time is a 1000 yd ladder. It will get you there fast and put you in the middle of the node. Ladders are very easy to read, so long as you can shoot. Your tuning with positive compensation, all other methods will require you to verify your load at distance, because you may be one the wrong side of the node and your small groups with tiny es may end up 14" tall at 1k. Ladder testing is well know, things we do in 1k Br that are slightly different is load 3 shots per charge and look for what we call overlap. Overlap is where 2 consecutive powder charges will print on top of each other at 1k. Thats the point where PC is working. Different speeds converging at 1k.

I can see your reasoning here Alex but at what stage in load development do you get to the 1000yd ladder test?

Could you point me in the direction of a more comprehensive description of this method please?

 

[Alex Wheeler]

I can see your reasoning here Alex but at what stage in load development do you get to the 1000yd ladder test?

Could you point me in the direction of a more comprehensive description of this method please?

The very first thing I do is go to 1k and shoot a ladder test. I have posted about it quite a bit, so have others on this site. Basically I will do a coarse ladder test. 3 cases per charge, .2-.3 apart. 12-15 shots. Color bullets with markers so you know the different loads. That ladder will give you and idea of where to go, load another ladder .1 grain apart in that area bracketing the expected best charge. You are now looking for an area the 2 consecutive charges overlap each other on the target to form a group. That would be the powder charge where compensation is happening. Seating depth would be next, if the groups looked good in the powder ladder m0ve the bullet .002" or .001". If they didnt look great do larger jumps in seating depth, more like .003" at a time. You may not see overlap here, just look for the best grouping that is not bracketed by huge ones. Always look for the sine, where the tune comes in and out and load in the middle. Theres a lot more to reading ladders and many tricks to evaluating whats going one, but thats the basic idea. With a hunting rifle or other rifle that needs to shoot many ranges I will do something similar but will also employ a chrony. I will look for a spot in the ladder where grouping is good AND the velocity stabilizes or has a flat spot. If you need any help along the way PM me.

 

[BenPerfected]

When practicing at 500-1000 yds, are you reading the mirage or using wind flags?.....using a camera system?
Ben

 

[Northridge]

When practicing at 500-1000 yds, are you reading the mirage or using wind flags?.....using a camera system?
Ben

all though I have done Ladders at all times of day I prefer first thing in the morning at first light to reduce point of aim movements in regard to mirage. mid day is doable just the information within the ladder will likely be bigger but the same info just the same. at this point I don't try to manipulate shots based off wind as I have found when you find that spot or tune it will defy what we know about wind drift to a point so don't be detoured if mid day is your only option especially if your tuning with score shooting in mind do it. just shoot your ladder as efficiently as possible with out giving up precision or point of aim. just shoot a shot then get back to battery settle on dot as centered as possible then send another shot and so on. at this time a strong coming & going head wind would be my only concern.

Shawn Williams

when practicing yes I would watch mirage and wind shooting in multiple conditions as to record how dramatic each condition affects my platform for score shooting. if it is !000 yard bench rest I'm just graphing start up and what condition I've been shooting to stay centered up.

 

[Raythemanroe]

I don't know the post to link it, but Tom posted his ladder testing early this year..

I think Alex made a good point about ladder testing vs the Cortina 100.. You can be on the edge of a node shooting low ES's and small groups at 100y, but get on the range at 1k and have huge vertical.. This because you were on the edge of a node or a scatter node.. He calls it Positive compensation and it is but is usually referred to as the high node.. Group will flatten with different charges, I usually load to the center and try seating depth testing.. I sometimes revisit powder when I get seating depth working to varify..

Lots of things look good at 100 that won't shoot @ 1k.. I had some free 80g flat base bullets to fire form with me that shot nice at 100y, low ES and small groups.. I shot them after the Vapor Trails to form a couple and see how they shot.. Well they looked great at 100y..lol

Ray

 

[hogpatrol]

Best advice I've ever heard and taken, test at the distance you are going to shoot.

 

[savagedasher]

I don't know the post to link it, but Tom posted his ladder testing early this year..

I think Alex made a good point about ladder testing vs the Cortina 100.. You can be on the edge of a node shooting low ES's and small groups at 100y, but get on the range at 1k and have huge vertical.. This because you were on the edge of a node or a scatter node.. He calls it Positive compensation and it is but is usually referred to as the high node.. Group will flatten with different charges, I usually load to the center and try seating depth testing.. I sometimes revisit powder when I get seating depth working to varify..

Lots of things look good at 100 that won't shoot @ 1k.. I had some free 80g flat base bullets to fire form with me that shot nice at 100y, low ES and small groups.. I shot them after the Vapor Trails to form a couple and see how they shot.. Well they looked great at 100y..lol

Ray

That's the way I see it I never have had a flat base bullet shoot at 1000 . Larry

 

[Northridge]

I don't know the post to link it, but Tom posted his ladder testing early this year..

I think Alex made a good point about ladder testing vs the Cortina 100.. You can be on the edge of a node shooting low ES's and small groups at 100y, but get on the range at 1k and have huge vertical.. This because you were on the edge of a node or a scatter node.. He calls it Positive compensation and it is but is usually referred to as the high node.. Group will flatten with different charges, I usually load to the center and try seating depth testing.. I sometimes revisit powder when I get seating depth working to varify..

Lots of things look good at 100 that won't shoot @ 1k.. I had some free 80g flat base bullets to fire form with me that shot nice at 100y, low ES and small groups.. I shot them after the Vapor Trails to form a couple and see how they shot.. Well they looked great at 100y..lol

Ray

what do you mean by higher node ray? higher velocity node? upward impact on page vs trending down impact? In my experience there will be several spots that you will witness or benefit from BC not just higher velocity node. more often then not I'm in the lower BC velocity range these days but on the saddle of up swing in BC.

Shawn Williams

 

[Raythemanroe]

what do you mean by higher node ray? higher velocity node? upward impact on page vs trending down impact? In my experience there will be several spots that you will witness or benefit from BC not just higher velocity node. more often then not I'm in the lower BC velocity range these days but on the saddle of up swing in BC.

Shawn Williams

Well, I guess we differ here because I haven't heard of PC or the higher node as a saddle..

Ray

 

[Northridge]

Well, I guess we differ here because I haven't heard of PC or the higher node as a saddle..

Ray

I really wasn't attempting to disagree Ray, but was trying to clarify if you felt you had to run a rifle hard in regard to velocity to witness BC. as far as "saddle" go's? pick one "top of frequency" "peak of frequency" "crest of frequency" "Flat"
"BRA" vs "BRAI" get my meaning BC or barrel compensation has a bottom middle & a "top" usually then it will start all over again, in a couple spots not just running things hard that's all I was trying to add. I will use the term "saddle" more often as to help you know it when you see Lol!! good shooting...

Shawn Williams

 

[Alex Wheeler]

For positive compensation to occur the load needs to be tuned so that the fast bullets leave at a lower trajectory than the slow ones. The barrel needs to be going up. This will happen just before the stop at the top of a sine wave or just after the bottom of a sine wave. When you load on the other side of the sine, you get negative compensation. This is why that tiny group with tiny ES is 14" tall at 1k, wrong side of the sine wave, barrel traveling down.

 

[Raythemanroe]

I really wasn't attempting to disagree Ray, but was trying to clarify if you felt you had to run a rifle hard in regard to velocity to witness BC. as far as "saddle" go's? pick one "top of frequency" "peak of frequency" "crest of frequency" "Flat"
"BRA" vs "BRAI" get my meaning BC or barrel compensation has a bottom middle & a "top" usually then it will start all over again, in a couple spots not just running things hard that's all I was trying to add. I will use the term "saddle" more often as to help you know it when you see Lol!! good shooting...

Shawn Williams

Top for me, bottom not so good..I think we are arguing over the same thing..


Ray

 

[Raythemanroe]

For positive compensation to occur the load needs to be tuned so that the fast bullets leave at a lower trajectory than the slow ones. The barrel needs to be going up. This will happen just before the stop at the top of a sine wave or just after the bottom of a sine wave. When you load on the other side of the sine, you get negative compensation. This is why that tiny group with tiny ES is 14" tall at 1k, wrong side of the sine wave, barrel traveling down.

Could negative comp Shoot at 100?

Ray

 

[Northridge]

For positive compensation to occur the load needs to be tuned so that the fast bullets leave at a lower trajectory than the slow ones. The barrel needs to be going up. This will happen just before the stop at the top of a sine wave or just after the bottom of a sine wave. When you load on the other side of the sine, you get negative compensation. This is why that tiny group with tiny ES is 14" tall at 1k, wrong side of the sine wave, barrel traveling down.

Could negative comp Shoot at 100?

Ray

yes & at 1000 but has a smaller +- to hold a tune