Interpret My Test Results! R700 .223 Rem Development *5x5 Groups!*

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thenerdboy

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Hi everyone!

I recently completed some longer range load testing to verify/improve a previous load derived from Dan Newberry's OCW method. The load was shooting fine (sub-MOA) but I'm not sure it was the optimum and had never done any seating depth testing with it, only OCW. Rifle is a Remington 700 SPS-V .223 in a properly bedded stock with free floating barrel (hoping to keep the discussion on the load testing, not equipment or components). Tests included two 300m charge ladders and one 200m seating depth test. I have attached photos of the test targets.

Wondering what your take(s) are on the optimum charge and best seating depth. I have already taken a stab at it and am not happy with the 100m results. I have my suspicions but am hoping for some confirmation here before I use up more components.

Thanks!

300m Ladder #1 - Ascending Charges

300m Ladder #2 - Descending Charges

200m Seating Depth Test - Round Robin - Labels Indicate Jump To Lands in Thousandths

*edit* Previous 100m Dan Newberry OCW Test

*edit 2* OCW Test w/Group Centers Located

*edit 3 - New OCW Tests w/Varget & V-Max + 55SPs*
Hornady 53gn V-Max OCW Test (measured w/OnTarget)
Hornady 55gn SP OCW Test (measured w/OnTarget)

*edit 4 - Vertical Dispersion Curves from recent tests*
55SP vs. V-Max Vertical Dispersion Curve
 
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I agree with MuthaFunk on possible node at 24.8 a 25 grains. On the seating depth, 3-round groups won't tell you much. Why not do OCW for seating depth as well?

Also, if your rifle isn't getting the results you want with this powder/bullet combination, it's possible that there is another combination that will serve you better. Had a 223 that used to love 75 grain Amax over Varget, rebarreled it wouldn't shoot the old load for beans and different loading could not improve the results. Switched to 80 grain Amax and the groups improved with almost no load tweaking.
 
3 shot groups at 300m introduce additional, potentially changing variables, so I would not put much stock in these results as measuring strictly load performance. I would run tests at 200m with 5 shot groups on seating depth only after rerunning an OCW (Optimal Charge Weight) approach to selecting charge range.

Also, do you have a chronograph to get veolocity data? Velocities also tend to go into a tight range at a node, and should correlate well with point of impact unless another variable is creeping in there.
 
Thank you both for your responses! Sounds like I was on track with identifying the node as I loaded the seating depth test at 25.0gns.

After the depth test, I loaded 25 rounds with 25.0gns at 0.005" off the lands to test at 100m for a final verification. Groups varied from 1.042MOA to 1.340MOA, which was a little disappointing as my old load was regularly shooting just under MOA. Is it possible that I may have inadvertently loaded some rounds into the lands? I realize now that I loaded my tester cartridge used for setting up my seating die after the last depth test (oops).

Pr589 - Would it be wise to load another 300m ladder for seating depth (or another 200m round robin test) while ensuring I save the setup components this time (lol)?

I actually just finished off the last of this powder but will have an unopened bottle that a friend just picked up for me out-of-town. Now that the charge weight has been confirmed, I don't mind talking components. Just didn't want the components to take away from the load development side. These were fired with IMR4320, CCI400 and Hornady 55gn SP projectiles as I had them on-hand and was hoping to squeeze as much out of them as possible. A couple of people have recommended a move to Win748 or H335 and I would imagine that the 53gn Hornady V-Max or 55gn SBK would probably shoot more in the accuracy range that I'm looking for. My goal with this rifle has been to complete the 3/4" Factory Varmint Barrel Challenge.

*edit* I do have a 100m OCW test that I can post that was fired with the same equipment and components at 100m. I do not have a chrony to verify muzzle velocity, unfortunately. Also, the seating depth test that is posted was completed at 200m, not 300m.

*edit 2* Just added the 100m OCW Test to the original post. I won't comment on it yet so as not to taint the discussion, except to say that 25.0gns has zero vertical dispersion - correlation between tests? Conditions were not ideal the day I shot this test - seating was poor but I did the best I could.
 
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I did a quick graph of your two ladder tests. First, I think the POI's are a little erratic to come to any firm conclusions. Have you ever done chronograph tests of your loads? I suspect that while you are loading to the same charge, you are not getting the same velocity for the same charge. This graph is of the POI vs charge weight. If you get a chance to use a chronograph, I would suggest recording the velocity for every single shot separately, and then do a similar graph. You can lump them into one trend line instead of two. My best guess of a flat spot would be from 24.8 to 25.4. So perhaps do a seating depth test at 25.1 and once you have that as good as you can get it, then circle back and do the ladder test again, using the same overall range and the optimized seating depth. But again, if you can get a chronograph it would be very helpful. The other benefit is seeing what loads and seating depths are giving you the lowest velocity extreme spread and standard deviation. Currently I think velocities must not be that uniform to get those wide variations in POI. Hope that helps some...

223%20Ladder.JPG
 
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thenerdboy said:
I actually just finished off the last of this powder but will have an unopened bottle that a friend just picked up for me out-of-town. Now that the charge weight has been confirmed, I don't mind talking components. Just didn't want the components to take away from the load development side. These were fired with IMR4320, CCI400 and Hornady 55gn SP projectiles as I had them on-hand and was hoping to squeeze as much out of them as possible. A couple of people have recommended a move to Win748 or H335 and I would imagine that the 53gn Hornady V-Max or 55gn SBK would probably shoot more in the accuracy range that I'm looking for. My goal with this rifle has been to complete the 3/4" Factory Varmint Barrel Challenge.
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No, I would not recommend IMR 4320, nor Win748, nor H335. Why? IMR is more temperature sensitive than Hodgdon extruded powder and the other two are ball powders and sensitive to temperature changes. The temperature change can be ambient, but also from the time they sit in the warm/hot chamber waiting for you to fire, temperature from shot to shot can vary. My suggestion for the 55 grain would be Varget. Also did you know you are over the maximum recommended load from Hodgdon on your IMR 4320? If you go back down in bullet weight to 50 grains, you could go a little faster than Varget and try Benchmark or H4895. These are all Hodgdon Extreme powders that are not temperature sensitive. For small rifle primers I like CCI BR4. You may also want to try the Berger 52 and 55 grain target bullets for better accuracy.
 
From your previous post, I assume when 5 thou off the lands, there is still plenty of bullet bearing surface in the case neck?

You are using fireformed brass from the same manf and lot... properly sized and bullet seated with minimal runout? What dies are you using?

What scale are you using?

What is the ambient temp you are shooting in?

Are you willing to consider other components?

Do you have access to a chronograph?

What type of scope, base and rings are you using?

What type of rests and supports?

Jerry
 
Wow, great feedback everyone. Thanks! Some clarification:

Ron - I dropped my elevation 2 clicks for ladder #2 to get the grouping closer to the bull (unnecessary for the purpose of testing). So there will be some variation between the two tests. I see what you mean that there are no nice flat spots on the lines. I may be able to borrow a chrony to check my velocities. I'm open to trying different components as all the 4320 is gone.

Jerry - Lots of bearing surface in the neck. These are FL sized with the standard RCBS die set. I have the Lee collet die as well and could try more necksizing. Scale is an Ohaus 10-10. I have not made a concentrated effort to shoot in consistent temperatures. Tests fired over the last couple of weeks, 3 to 10 degrees. Would consider different components, may be able to borrow a chrony. Bushnell 6-24x50, Weaver one piece rail, weaver 6-hole rings and Caldwell Rock rest. All mounts torqued to spec. with torque wrench.

Thanks again!
 
If it were me, i would match the bullets to your rifle's twist - and as mentioned above, Varget or R15 if you can find.
You will know when you get your dream load - that rifle should be getting 1-1.5" groups at 300.
I have done a lot of load testing - way more than i care to mention - i like your attention to detail with all the tests - very good! However, Brass prep may help you (it did me), use good prepped brass - took me a while to figure that out despite me reading about it time and time again...also, if I may suggest, if you have a 10 twist or faster, try 69 SMK's - most rifles will shoot those into wee bitty groups around 24'ish grns of Varget/R15. I started using 55gr, then 60, then 69, then 80. The heavier the bullets, the better my rifle shot, but it has a fast twist.
Good luck and keep us posted
 
thenerdboy said:
Ron - I dropped my elevation 2 clicks for ladder #2 to get the grouping closer to the bull (unnecessary for the purpose of testing). So there will be some variation between the two tests. I see what you mean that there are no nice flat spots on the lines. I may be able to borrow a chrony to check my velocities. I'm open to trying different components as all the 4320 is gone.

Jerry - Lots of bearing surface in the neck. These are FL sized with the standard RCBS die set. I have the Lee collet die as well and could try more necksizing. Scale is an Ohaus 10-10. I have not made a concentrated effort to shoot in consistent temperatures. Tests fired over the last couple of weeks, 3 to 10 degrees. Would consider different components, may be able to borrow a chrony. Bushnell 6-24x50, Weaver one piece rail, weaver 6-hole rings and Caldwell Rock rest. All mounts torqued to spec. with torque wrench.
Click to expand...

I suspected that the scope was changed from one to the other after I saw the graph. It will not change the shape of the average line, but if you imagine it displaced up a bit that would be the result. It does make your velocity variations look better though. The real way is to actually measure velocity, and I would recommend it. I suspect your data graph would smooth out quite a bit and be much more revealing if the x-axis was velocity not just grains of powder.

If you have a collet die, I would use that in preference to a full length resize. Not sure how adjustable a collet die is, but if it is, then you could try resizing about 2/3 of the neck rather than the whole neck, providing the cartridge has been fired in your gun. That will give you a tighter fitting cartridge which should be better centered in your chamber. Same trick can be done with a FL die. Just make sure the neck sized cartridges will chamber in your gun before you load them.

Varying temperatures would affect your powder, and I would still recommend Varget with the 55 grain bullets.
 
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chrismc said:
If it were me, i would match the bullets to your rifle's twist - and as mentioned above, Varget or R15 if you can find.
You will know when you get your dream load - that rifle should be getting 1-1.5" groups at 300.
I have done a lot of load testing - way more than i care to mention - i like your attention to detail with all the tests - very good! However, Brass prep may help you (it did me), use good prepped brass - took me a while to figure that out despite me reading about it time and time again...also, if I may suggest, if you have a 10 twist or faster, try 69 SMK's - most rifles will shoot those into wee bitty groups around 24'ish grns of Varget/R15. I started using 55gr, then 60, then 69, then 80. The heavier the bullets, the better my rifle shot, but it has a fast twist.
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His first target indicates he has a 26" 1 in 12 twist. That probably limits him to 65 grain flat base as a max. So he can shoot all the Berger FB Varmint bullets, but only the first two lightest Match bullets. SMK's tend to be very long, and I suspect a 12 twist would be too slow for a 69 grain boat tail MatchKing... Unfortunately Sierra does not provide twist data or even dimensions so you can calculate required twist. Too bad they would not put it on the box like Berger does.
 
thenerdboy said:
Wow, great feedback everyone. Thanks! Some clarification:

.....
Jerry - Lots of bearing surface in the neck. These are FL sized with the standard RCBS die set. I have the Lee collet die as well and could try more necksizing. Scale is an Ohaus 10-10. I have not made a concentrated effort to shoot in consistent temperatures. Tests fired over the last couple of weeks, 3 to 10 degrees. Would consider different components, may be able to borrow a chrony. Bushnell 6-24x50, Weaver one piece rail, weaver 6-hole rings and Caldwell Rock rest. All mounts torqued to spec. with torque wrench.

Thanks again!
Click to expand...

just because I have been burnt with this before... check the bedding and all the screws and bolts for proper tightness and function.

These are the steps I would do if this were my rifle.

Do not FL size the cases anymore... Use the Lee collet neck die with fireformed brass. If the cases get a bit stiff to chamber (and they will), I use a Redding body die to bump the shoulder just enough for proper chambering. For precision work, I want a very close fit between the formed case and my chamber.

The Hrn 55gr SP's can do very nice work BUT other bullets tend to offer more consistency. 55gr Vmax, Berger or Sierra of similar weight should be on the menu to try.

Seat 5 to 10 thou OFF the lands and leave it alone.

Use CCI450 primers.. too cold for 400's and precision work

Benchmark, IMR8208XR, H4895 would be the powders I would use.

Work up in 0.2gr increments, staying within the printed charge limits and velocity. If you are near max charge and 100 to 150fps slower, then slowly increase and watch for pressure signs. Make sure the Chronie battery is warm. If you have access to a good quality digi milligram scale, compare your beam to this digi to ensure you get what you are expecting.

If the barrel will shoot, you will see very good results right away and you can fine tune after that. Charge weights variance will be far more critical then seating depths. If you cannot keep charges to the same 0.1gr, you will see inconsistencies in your load tuning.

I have more info on my website in the Tech sections.

Enjoy and good luck.

Jerry
 
thenerdboy said:
Thank you both for your responses! Sounds like I was on track with identifying the node as I loaded the seating depth test at 25.0gns.

After the depth test, I loaded 25 rounds with 25.0gns at 0.005" off the lands to test at 100m for a final verification. Groups varied from 1.042MOA to 1.340MOA, which was a little disappointing as my old load was regularly shooting just under MOA. Is it possible that I may have inadvertently loaded some rounds into the lands? I realize now that I loaded my tester cartridge used for setting up my seating die after the last depth test (oops).

Pr589 - Would it be wise to load another 300m ladder for seating depth (or another 200m round robin test) while ensuring I save the setup components this time (lol)?
Click to expand...

After a more diligent re-reading of your original post and a look at the previous OCW results. I would suggest some exploration of a 24.8 grain load with the same bullet (55 Hornady SP?). I also gather that you were already doing an OCW test for seating depth since you referred to doing a "round-robin" - missed this on the first read.

If you believe the "shock wave theory", seating depth tuning won't have significant results and the theory would suggest that exploration of this parameter may be a waste of components. I have to admit that I have found any benefits of OAL tuning to have been relatively minor in comparison to finding an optimal powder load. i.e. Don't waste your time and components on doing more tests on OAL unless you love this stuff like many of us geeks.

As Jerry suggests, you may have already maxed out the results you can get from the Hornady SP - it isn't a match bullet after-all.

The timing of this thread is great since I'm just working up a load for an 82 grain Berger - a new bullet to me. I've been getting less enthusiastic about ladder testing due to some recent 2nd hand experiences. One example - a few weeks ago, an excellent young shooter at my club with a superb new benchrest 6BR shot what is the most ideal ladder that I've ever seen. Shot at 300 yards, the ladder showed a vertical rise in POI elevation with rising charge weights (with less than 1" in lateral deviation) with one almost clover-leaf (~0.7") followed a short vertical string of holes followed by another almost clover-leaf, classic stability nodes. However it turns out that when loads were developed at these nodes they didn't shoot well at all. A load finally discovered using alternate means resulted in groups in the 0.2 MOA range - but this load showed nothing on the ladder test.

Shot 3 ladders today to try to use this load development cycle to decide whether to shake the ladder-test out of my methodology for good. The rifle shot well with little horizontal dispersion on 2 of the ladders but results are inconclusive. Will try OCW next weekend.
 
Pr589 said:
One example - a few weeks ago, an excellent young shooter at my club with a superb new benchrest 6BR shot what is the most ideal ladder that I've ever seen. Shot at 300 yards, the ladder showed a vertical rise in POI elevation with rising charge weights (with less than 1" in lateral deviation) with one almost clover-leaf (~0.7") followed a short vertical string of holes followed by another almost clover-leaf, classic stability nodes. However it turns out that when loads were developed at these nodes they didn't shoot well at all. A load finally discovered using alternate means resulted in groups in the 0.2 MOA range - but this load showed nothing on the ladder test.

Shot 3 ladders today to try to use this load development cycle to decide whether to shake the ladder-test out of my methodology for good. The rifle shot well with little horizontal dispersion on 2 of the ladders but results are inconclusive. Will try OCW next weekend.
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When you do a ladder you need the velocity for every bullet. Ignore any horizontal deviation from the aim point. Plot the POI, vertical only, vs the velocity, not the load. This will give you a clearer picture of the impact velocity has on POI. You want to find a velocity tolerant range where changing velocity has no impact on the vertical. Here is an example of three different bullets which basically give the same sweet spot velocity of 3400-3420.

LadderVel.jpg


And here is what three consecutive targets looked like for the 68 grain Berger when I used this target velocity.

68BergerS14-10C.jpg


In my opinion the ladder works if you chrongraph results. OCW strikes me as just organized trial and error. I do not believe in the shock wave theory. Ladder is simple. All you are doing is finding a velocity where the bullet exits on the barrel upward movement cycle. Fast bullets exit sooner with the barrel pointed lower. Slow bullets exit later when the barrel is higher. The elevation of the barrel self corrects for velocity variation. No more complicated than that. That said to make it work you need an accurate gun. If the gun is spraying bullets you are probably wasting your time. A ladder test will not make a silk purse out of a sow's ear.
 
RonAKA - I may try a chrono to eliminate other factors (neck tension, etc. that may affect velocity) however I see these things as being secondary factors to powder load. All other things being equal, velocity, pressure and powder load should be closely correlated - pressure and velocity will rise with increasing load as will the POI of rounds at a given distance. So it seems to me that vertical impact point is representative of velocity and clusters of impact points are representative of velocity stability ranges. Isn't this the whole point after-all in doing a load ladder?

As to OCW being trial and error - you do realize that OCW is just an evolution of a ladder test that seeks to reduce the spurious signal that might result from factors other than powder load, right? By doing a round-robin of different loads across multiple targets, one randomizes the effect of shooter error, barrel condition, wind, etc. so that only the "signal" from velocity/powder load is apparent. One is still looking for stability node/ranges - it is just that one has to look for the nodes by comparing POIs across a number of targets. It is a valid method of dealing with experimental error.

I mention horizontal dispersion since this provides a suggestion of the overall accuracy potential of the barrel/rifle and the capability of the shooter to hold POA - not because it is significant in evaluating load. An accurate rifle does make it easier to see ladder test patterns, at least in my experience.

Seems to me that the point of doing load development is to find the optimal load for a given rifle/bullet/powder combination and as such it should help any rifle to see its potential (with a given powder and bullet) wherever that might lie from an accuracy perspective. While I would agree that a rifle that has lots of noise due to bad bedding, loose screws, defective barrel, etc. will have difficulty finding a consistent load (due to this "noise" overwhelming and signal from velocity/powder-load), I can't agree that "to make it work you need an accurate gun". I and others have had great success dramatically improving the groups of M1A-type rifles for example, that aren't known for being accurate (at least compared to bolt-guns).

Congrats on finding a load that your rifle likes. You should show the folks on Underthegun's 0.5 MOA at 300 yard Challenge how it's done.
http://www.canadiangunnutz.com/foru...at-300-yards-meters-All-Day!-Really-Prove-It!
 
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Pr589 said:
RonAKA - I may try a chrono to eliminate other factors (neck tension, etc. that may affect velocity) however I see these things as being secondary factors to powder load. All other things being equal, velocity, pressure and powder load should be closely correlated - pressure and velocity will rise with increasing load as will the POI of rounds at a given distance. So it seems to me that vertical impact point is representative of velocity and clusters of impact points are representative of velocity stability ranges. Isn't this the whole point after-all in doing a load ladder?
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No. I think you are missing the whole point of doing a ladder test. Vertical impact point is not representative of velocity. The whole purpose of a ladder test is to find bands where velocity increases but POI does not elevate. You are looking for flat spots, not clusters or small groups.

Pr589 said:
As to OCW being trial and error - you do realize that OCW is just an evolution of a ladder test that seeks to reduce the spurious signal that might result from factors other than powder load, right? By doing a round-robin of different loads across multiple targets, one randomizes the effect of shooter error, barrel condition, wind, etc. so that only the "signal" from velocity/powder load is apparent. One is still looking for stability node/ranges - it is just that one has to look for the nodes by comparing POIs across a number of targets. It is a valid method of dealing with experimental error.
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No OCW is not an evolution of the ladder test in my opinion. The OCW method averages results and really is just an organized way to find small groups. I call that trial and error. A ladder test is designed to find a velocity when the barrel is vibrating upward when the bullet exits. You ignore horizontal dispersion when you are doing a ladder test. I would agree that the OCW method may be more suitable for a less accurate gun. Remember that the ladder test is only designed to find a good velocity, not the best group. Once you find the best velocity then you focus on seating depth, primer, powder type. neck tension, etc. Those variables will typically show up as your velocity extreme spread and standard deviation. When you minimize those, then your group size should come down.
 
Ron AKA said:
Vertical impact point is not representative of velocity.
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Ron - If this is true then you are going to have a hard time explaining to Issac Newton and generations of ballisticians why higher velocity has nothing to do with time-in-flight, the force of gravity and bullet drop :p. Won’t the scope makers be surprised when you convince them that those pesky elevation turrets are wasted effort.

Trolling aside, I think most would agree that velocity will, in general, affect vertical POI – even your own graphs show this. If you read the original article on Audette (the originator of the ladder method) in the 1998 Precision Shooting reloading guide, you will see that Audette showed that stability bands existed where powder load (and chamber pressure) did not increase velocity as would normally be demonstrated. See the link below.
http://2poqx8tjzgi65olp24je4x4n.wpe...audettes-20-round-string-load-development.pdf

These stable velocity bands are what lead to a lack of vertical POI shift (i.e. a cluster of shots) when shooting a string of ladder loads. I think history and other loaders would agree with my interpretation of a ladder test (i.e. Incremental Load Development Method). Here are more links that explain the methodology.
http://www.6mmbr.com/laddertest.html
From the link:
“What is a ladder test? A ladder test is, fundamentally, a method of testing a load combination using continuous increments while looking for a cluster of consecutive shots showing similar points of impact (POI).”
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http://precisionrifleblog.com/2012/07/13/creighton-audette-ladder-testing/

You have a different take on a ladder test and it may work for you better than what is commonly understood as a ladder test - but it isn’t the same. Your insistence that one not look for the “best group” in a ladder test is a red-herring since you are confusing shooting groups with looking for "a cluster of consecutive shots showing similar points of impact (POI)" i.e. where there is little vertical dispersion due to varying velocity.

Ron AKA said:
No OCW is not an evolution of the ladder test in my opinion.
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Well I think that we’re discussing if your opinion is well grounded. If you read Dan Newberry’s website, when he was developing the OCW method he saw it as an improvement of the ladder test (the one most others understand to be a ladder test – not your own unique take). So maybe the guy who was developing OCW was wrong about his own thinking – I’ll leave that others to decide. Link below:
http://optimalchargeweight.embarqspace.com/

All that being said, I have yet to find a good theory as to why these well documented velocity bands would occur in a load ladder. Everything that I have seen on chamber pressure variances with powder load show that pressures rise smoothly with increasing charge in the range of “acceptable” pressures. Why either pressure increases would plateau even with increasing charge weight (in these narrow bands), or increasing pressure would fail to translate into increased velocity (again only in these anomalous bands) is mysterious. I hope Ganderite pops into this this thread since he used to work for a powder manufacturer.
 
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