Does this target make sense?

[Tikka223]

Last range outing I decided to play with my .308 load after my Magnetospeed showed me the load was not as consistent as I thought. This has been my go-to for over a year now has been 44.0gr of Varget and 178gr ELD-X. I’ve used this in a T3 CTR for PRS. I decided to try 43.8 and 43.6 to see what would happen. As it turned out, with a data set of 5, the 43.6 had an ES of 20 and an SD of 7 vs 44.0 with an ES of 38 and SD of 13. I tried again with 43.6 and this time got an ES of 33 and SD of 10.

Are these not fairly decent numbers for a handload? This is a 10 shot group at 300m with a very slight (maybe 3mph) wind at my 6 o’clock. What’s with the vertical size of the group??? Could that be the ES? Tail wind? Shooter?



I trust the Magnetospeed more than my shooting but I guess at the end of the day I’m chasing statistical ghosts in small data sets. 44.0, 43.8 and 43.6 averaged 2600, 2601 and 2608 respectively. Clearly I’m in a pretty stable node. Maybe I’ll just load 43.8 from now on.

Thoughts?

 

[Tikka223]

Not sure why the picture isn’t oriented property. The date is the top of the target.

 

[Mystic Precision]

Tune your load based on what your target tells you. As you have just demonstrated, ES/SD don't always tell you how the groups are going to form.

Assume by your comment, the 43.8gr load has the lowest vertical dispersion of the 3 loads?

Jerry

 

[Tikka223]

I figured 43.8 was the safest best for a wide range of condition and powder temp variation (although Varget is quite stable)

Here is a pic of 3 groups at 300m. I had to use a marker because I was shooting at a plastic board.

 

[Mystic Precision]

Keep dropping your powder charge... 43.0 to 43.4gr might be where you need to be

See what happens



If the barrel and loads are up to the task, kind of what we are looking for at 300m. Team mate working up a load for his 22 Creedmoor ... distance 300m, 4rds group.

Jerry

 

[Lead hammer]

I figured 43.8 was the safest best for a wide range of condition and powder temp variation (although Varget is quite stable)

Here is a pic of 3 groups at 300m. I had to use a marker because I was shooting at a plastic board.

View attachment 407266

I agree with Jerry, try 43.0,43.4 Also, if your target was level, the average impact of the 43.8, 43.6 is on the same level. If the lower powder charges don't tighten up you could try seating depth changes to get it there.

 

[IAFS]

Radius between 43.6 & 43.8 groups are very similar (if you draw a circle from the center of the groups). I've often found seating depth to matter more in barrels than a couple tenths of a grain.
Secondly, how accurate is your powder drop? The lymans I use (when scaled on on a separate unit) can be +/- 0.2gr out even after calibration.

 

[Maple57]

Tune your load based on what your target tells you. As you have just demonstrated, ES/SD don't always tell you how the groups are going to form.

Jerry

I could not possibly disagree with this statement more.

I know there are lots of guys who think the target at long range provides the ultimate answer, but that is from people who do not understand proper analysis.

The farther you shoot, the more environmental factors will influence the end result. Not to mention the accuracy of the rifle and ammo.

If you are testing for one thing, then test for that one thing.

Dont look for an answer to one thing based on results that were acquired based on 20 other possible variables.

Yes... In the end, the load that groups best at long range is the best but you will never find a better aggregate group at long range with a 50 FPS ES than the same bullet at similar velocity with 10 FPS ES.

 

[Tikka223]

I was following the 10 shot load development concept as seen on some 6.5 Creedmoor videos. I really don’t know if I’m a good enough shooter to say I’m not a big variable influencing the pattern on the target. For all I know, inconsistent recoil could explain the vertical stringing. I’d like to know if the ES is sufficient or maybe ES + wind. I was hoping to see a much flatter group given the ES.

 

[joehunt]

Keep dropping your powder charge... 43.0 to 43.4gr might be where you need to be

See what happens

View attachment 407335

If the barrel and loads are up to the task, kind of what we are looking for at 300m. Team mate working up a load for his 22 Creedmoor ... distance 300m, 4rds group.

Jerry

That’s a nice group

 

[Camoman1]

5 shots is quite low to determine an accurate SD/ES, try 10 for a minimum, this should give you more consistent results. 0.2g increments are quite close, like you said you are playing in the same node, i would branch out farther and try to find where the high and low charges are for this particular node and pick a charge in the middle, this should give you the best chance to help any variations in your ammunition to stay in the node (high/low temps, case variations, over/under charge etc.) That much vertical dispersion at 300 yards would not be cause by an ES of 30 ish, could be negative compensation, but most likely shooter or just not a good node. Could also be parallax not set properly or mirage throwing you off. I have a hard time interpreting issues at 300y, i do my initial load development at 100y to find node and test ES/SD, then move out to 600y, much easier to interpret groups.

 

[Mystic Precision]

I was following the 10 shot load development concept as seen on some 6.5 Creedmoor videos. I really don’t know if I’m a good enough shooter to say I’m not a big variable influencing the pattern on the target. For all I know, inconsistent recoil could explain the vertical stringing. I’d like to know if the ES is sufficient or maybe ES + wind. I was hoping to see a much flatter group given the ES.

Follow my load advice and you will see real quick whether it helps... or not.

Shooting is such a simple sport... have an idea, go out and prove it on paper. If it works, it will work and it will repeat... for you and for others.

If it doesn't, figure out where the error is and correct.

Good luck.

Jerry

 

[Mystic Precision]

That’s a nice group

Thanks.. the combo is working well.

Jerry

 

[Clocked92]

Did you shoot the groups with the Magnetospeed on the barrel? If so, that's likely affecting your grouping. Also, what are you using to weigh your powder?

 

[Mystic Precision]

I could not possibly disagree with this statement more.

I know there are lots of guys who think the target at long range provides the ultimate answer, but that is from people who do not understand proper analysis.

The farther you shoot, the more environmental factors will influence the end result. Not to mention the accuracy of the rifle and ammo.

If you are testing for one thing, then test for that one thing.

Dont look for an answer to one thing based on results that were acquired based on 20 other possible variables.

Yes... In the end, the load that groups best at long range is the best but you will never find a better aggregate group at long range with a 50 FPS ES than the same bullet at similar velocity with 10 FPS ES.

Well apparently, the OP is having issues as can be seen in his groups. His 'numbers' sound reasonable but his grouping doesn't match up. Is there are correlation of ES/SD vs his groups and loads? What are your thoughts?

As we have debated many times, if a process works, it works... it repeats and is repeatable.... for you, for me, for anyone anywhere.

If a process is flawed, it might work sometimes or under some situations... but apparently, not everyone is seeing the results.

That is not a process I choose to use. The process I choose, and my team mates choose lead to the type of results I have posted. It is a process that has worked for 2 decades and one that many of my customers have used with success

pick the process that works for you... It's all good.

Jerry

 

[buji88]

I trust the Magnetospeed more than my shooting but I guess at the end of the day I’m chasing statistical ghosts in small data sets. 44.0, 43.8 and 43.6 averaged 2600, 2601 and 2608 respectively. Clearly I’m in a pretty stable node. Maybe I’ll just load 43.8 from now on.

Thoughts?

If you shot this with your Magneto on I would try it again without it. I get vertical dispersion with my Magneto on it in a very similar manner. Once I take it off it clears right up. I love the Magneto, but this is one area I will admit the Labradar is a great tool.

 

[kthomas]

Use the powder charge that gives you the best ES/SD, and use bullet jump to tune in precision.

Since you are a PRS shooter, and shoot at all sorts of distances from 30 yards to 1200+ yards, having a good ES/SD will be more beneficial then a positive compensated charge optimized for one set distance.

Using this method, I've never found any issues getting a ~1/3 MOA or better load with 15 ES or less. Works great from 0 yards to well over 1,000 yards.

 

[kthomas]

Also, the 10 shot load development method, AKA the "Satterlee method", is not a good way to develop a load, IMO. There's not enough sample size to make it statistically relevant. I used to do the ladder test, until I one day decided to load up two identical ladders - the so-called "nodes" never lined up between the two ladders. I've since gone away from that method, and have had much better results. Looking back, none of the "nodes" I found in a ladder was a real so-called node.

Use a ladder to find velocities per charge, and to find any pressure. From there, load up 5 shot rounds of a few charges that are comfortably below pressure. Shoot those 5 round groups over a chrono to find the best ES/SD. Use bullet jump to tune in precision - this can be done when you are breaking in the barrel, the barrel will take ~100-200 rounds before speed stabilizes, perfect time to test bullet seating depth.

It takes a little bit of work on your first barrel and cartridge, but once you get an idea of what speed your projectile likes, you can carry forward that same target velocity in future barrels. For example, I've found that 6.5mm 140 Berger Hybrids like the speed ~2830 fps out of a 24" barrel. Next barrel I just find the powder charge that gets me that speed. Using a projectile that you are comfortable with and is easy to tune/very predictable makes the process easy as well - for me, that happens to be Berger Hybrids. If I jump them 5 to 20 thou from the lands, I know they will shoot. This has held true from 6mm to .30 cal projectiles.

 

[Tikka223]

Did you shoot the groups with the Magnetospeed on the barrel? If so, that's likely affecting your grouping. Also, what are you using to weigh your powder?

Correct, the Magnetospeed was on the barrel. At 300m I get a 1mil POI shift upwards.

I used an RCBS 5-0-5 to weigh my charges. I’ll compare it every once and a while to Gempro 250. Although after some testing, I’ve discovered the Gempro to be more accurate in powder throws. I recently did a similar load development test for my 6.5 Creedmoor and was quite surprised to see some very low ES and SDs.

 

[Tikka223]

Just for fun, here is where I’m at with my 6.5 Creedmoor. I tried to read the target at 200m but the group was too small. Moved to 300m and the group size didn’t really grow. I’m going to try and up the velocity and try to find a higher velocity node.