A comparison of Saterlee's method and Optimal Charge Weight: With data/pictures

[frost1235]

So I was always looking to see if there was a direct link between Dan Newberry's OCW and Saterlee 10 shot method, and I have seen a few that put their two cents in. Being a data nut, I spent some time thinking of what controls could validate this information and came up with what I have here.
PREPARE FOR A LONG READ!
My second post will have the data, since I have to play with formatting for photos and such.
I am open to questions, but in regards to where I got the high speed tools/access to the range/what I do for work I will only say I have good friends that are just as passionate as I am about data and shooting.

Purpose
Which is the most efficient loading method between Optimal Charge Weight and a 10 round load test?
**10 round load test used at the reference name for Saterlee's development. I ended up using 30 rounds, 3 rounds per velocity reading
**OCW recommends a round robin type of shot, but I didn't want to deal with the pain of paying attention to which round I was shooting at which target so I did not do so

Equipment

• Magnetospeed
• Factory rifle, 1100 rounds down range before this test
• Custom rifle with a 26 in, 1 in 7.5 twist bartlein barrel, 300 rounds down range before this test
• Rifle shot on sturdy platform/rest
• Indoor range at 100 yards
• Peterson Brass, volumetrically sorted +/- 0.05 gr of H20
• Berger Hybrids 140gr sorted by base to ogive, base to overall length, then tipped for consistency
• New h4350 power
• New lot of BR2
• Redding T7
• Redding full length resizing die, no bushing
• Redding competition seating die
• 2 different brand Analytical Balance, with magnetic force restoration reading 0.01 grains (Not an autotrickler sadly)
• 21st Century large primer pocket plug
• 1000 microliter micropipette
• Both hornady and SAP comparators used to see which yielded consistent results
  • Values were different but accuracy/precision similar in both. SAP was easier to get consistent positions
• 2 mitutoyo 6 inch calipers
• Gordon's Reloading Tool

Method

• The majority of the time was spent brass prepping and sorting.
• 750 pieces of 3x fired brass was sorted to get 54 pieces of brass with internal volumes
  • Brass prep
    • Neck turned to 13.5
    • Hand deprimed with Frankford Arsenal
    • Wet tumbled for 30 minutes
    • Annealed
    • Chamfer and deburred case neck
    • Resized with full length sizing die without expander using imperial sizing die wax
    • Case neck ID lubed with one-shot
    • Expanded with 0.2615 gage pin for case neck tension of 0.0025
    • Dry tumbled to remove extraneous lube for 4 hours
    • Imperial dry neck lube for ID, extraneous lube on OD removed with cloth
    • Hand primed with RCBS hand primer
    • Powder weighed on two analytical balances using the same calibration weight, to confirm powder load +/- 0.02 grains from selected powder weight
      • Powder left to sit for approximately 5 seconds on a fully closed scale
    • Bullet seated via Redding T7 to the same length of 0.082in
    • Transported via plastic containers that hold rounds at case body with no slack to move
  • no less than 50.50 grains H20
  • no greater than 50.70 grains of H20

• Brass was of the same lot, using an AMP annealer with the setting of 149
  • Brass was originally shot through a different rifle to expand brass without using a newer barrel
  • Second firing was on custom rifle, at 158 shots already fired
  • Third firing get a better fit in custom rifle. Added trimming of case neck after expanding, rechamfer/deburred, and began generalized volumetric sorting
    • Case necks trimmed to be at 0.912in +/- 0.001
  • Fourth firing, used for this test, volumetric to stated values
    • 6 rounds of each charge weight were loaded during the same sitting, 3 for OCW and 3 for Velocity

• Volumetric data was gotten by use of deionized water at room temperatures between 62-68 degrees
  • Water was not reused to avoid contamination
  • Water poured in a glass be a erlenmeyer flask when ran out
  • All done in one sitting to avoid major temperature variances (It sucked, do not recommend)
  • Temperature gaged every 30 minutes in flask
  • Water was measured to the top of case necks, with a small yet consistent meniscus
  • Cases first had primer pocket plug inserted and placed on scale and left for 5-10 seconds to stabilize then tared to zero before adding water

• Live fire
  • Live firing was done in one day
  • Range was a 100 yard steel tube (This is not a public range at all.)
  • Muzzle would be inside the tube via a small opening
  • A metal steel bench was used, ensuring consistent placement
  • Rifle was supported on steel bench with specially formed sandbags to prevent movement and remain on target
  • Barrel of rifle sped up at round 195, so no deviation due to this variation occurred
  • Barrel/chamber/muzzle break cleaned before test using a jag, to near spotless patches
    • First 3 jag passes - Boretech Carbon Remover
      • 4th pass - Dry
      • 5th pass - CLP to wet bore
    • Muzzle break, Area 419 Hellfire 3 port, was left in a bottle with Boretech carbon remover for 1 day, cleaned and repeated one more time to bring muzzle break back to new condition
  • Rounds were first shot with OCW method, with one of OnTarget TDS's targets
    • 5 rounds not associated with the test were loaded at the median of the selected charge weights to be used as sighters/clean bore shots
    • 3 rounds would be shot consecutively, then a 5 minute rest would occur to let the barrel cool
    • Shot groups measured via Gordon's Reloading tool
  • Saterlee method shot afterwards
    • Magnetospeed attached after barrel cooled
    • 3 rounds loaded, then quickly fired with a similar 5 minute rest period

Possible reasoning for deviations
I'm not doing this test again without some corporate/sponsorship help as it took up about 2 months to do over all. I'm hoping this is a guideline that gets refined for future tests.

• During the Saterlee Test, I went ham and lost some data as noted in the satterlee chart.
• On the OCW part, on charge weight 39.8gr, I bumped the magazine off the table and it landed on the front of the mag. I did not want the data to be skewed, so I did not shoot the 38.9gr charge weight for OCW
• I did not move up charge weights by 0.1gr as Saterlee does, because I was getting frustrated sorting brass.
• I did not go beyond 41.2 grains because I did not want to load hot. I don't get pressure signs until 41.6 grains, but I didn't want to burn out another 6.5 barrel at 2300 rounds because I thought faster is better.
• I used Gordon's reloading tool to mark my shots by mouse, so target data could be off for OCW by minute amounts
• Rate of fire was not controlled
• I did not sort primers
• I did not, and do not chase lands until need be
• The barrel temperature should have been measured at certain points to ensure a constant firing temperature each time
• Though I did have an UPS battery on the closed analytical balances, there may have been electrical variations
• I did not have a measured line to measure the meniscus, so case neck length variation may lead to greater standard deviations in volume weight at the 0.01 place, hence I chose the 0.1 place to sort brass
• Primer pockets, once fired, are pushed upwards. This leads to a space between primer pocket plug and primer pocket where there is an extra drop of water. Considering how an extra drop of water could be 0.3 grains added, I used a micropipette to inject water to help with consistency but this could be a point of variation
• Once the brass was sorted, I loaded charge weights 39.6 to 40.4 with brass that was within 50.50gr to 50.60gr of water, but then realized I should have mixed it up. I did this at 40.6gr to 41.2gr. In my opinion, this may invalidate ranges in this part of the test
• I don't doubt my shooting abilities; between 2018-2019 I have a tracked amount 500,000 rounds tested, not added my personal range time or unaccounted firings. Pulling a trigger isn't the issue, but variances in breathing, parallax, cheek weld/etc could lead to variations in the last few groups on the OCW test as well
• I want to add in because this may be a factor, I took most of 2020 off most marksmanship due to burnout/pain. It sounds cool slinging this much lead down range, but the human body is NOT meant to handle with this many rounds down range.

 

[frost1235]

Data
This was the first time I realized I could make a template on google sheets instead of just writing things down, so I apologize for the basic layout of said data.
- It is fairly straightforward, as intended, but I must add that the data at the bottom of both charts was the change from the column/charge weight the value was sitting in to the next column/charge weight.
- The green box denotes what Saterlee's test would consider as a node
- The blue box is what OCW would consider a node


Saterlee modified

OCW modified

I will add in from what I found/questions that arose:

• The innate accuracy/precision of 6mm benchrest rounds could be because there is not as much needed to draw the brass out. I found in my quick sort of 10 pieces of brass that the volume was incredibly consistent between lapua and peterson's BR round.
• Considering how I shoot with a usual SD of 8 +/- 2fps and still consistently get good hits if I call wind well, this amount of work is really rendered moot by ability to call wind.
• I had tried the satterlee test when I first started reloading, but I didn't have the skill and attention to detail to make it work. From how much pressure to put into your press to the accuracy of your tools as well as knowledge in how your barrel wears, I still believe the Saterlee test requires a good foundation in reloading practices before you attempt it. However, if all the boxes are checked, I think it's a good method of data gathering at 3 rounds per firing, versus just 1 round.
• I'm curious as to how tuners or the company that makes "dead" barrels would affect this.
• I currently think seating depth acts like a micro-adjustment of pressure and would like to test out shooting new brass and testing seating depth. (Someday, when I have time and money.)
• I did this with the manners stock while I had it; I am curious if doing this with a metal chassis would do anything different?

Conclusion
You can draw from this yourself. I'm probably going to get slammed for some reason as is, but I just wanted to test these processes out with as much controlled variables as possible so others can draw and learn from it. I really do hope it helped someone out, but if not, I am look forward to the constructive (brutal or not) criticism that'd go a long ways to help myself and others!

 

[Sheldon N]

Thanks for the test and the write up. I'm in the camp that does load development the same way, though I don't think it needs to be quite so meticulous for the average shooter.

Shoot three shot groups over a chrono that doesn't attach to the barrel (floating mount magnetospeed or labradar). You get both velocity data and POI data at the same time. I usually do around 5-6 groups/15-18 rounds since I know the general charge weight window I'm looking for.

Looking at your results it looks like the Satterlee method and the OCW method agree with each other pretty well in this particular gun. Good velocity flat spot around 2730fps between 39.8 and 40.1ish, then wants to jump up to the 2760 range between 40.4 and 40.7gr. POI on the target jumps up when the velocity jumps up, but holds fairly well within each of those charge weight windows. The gun certainly shoots better in the lower charge weight range, so I'd probably pick 39.9-40gr and call it a day.

 

[TX_Diver]

I have an extremely stupid question (maybe 2). Based on lack of experience so hopefully easy answers.

You loaded 6 rounds per charge weight? It looks like the pics only show 3 rds per charge weight though?

Groups 3 & 4 (40 & 40.2 gr) appear to show the smallest groups as well as the smallest change in velocity/.2gr powder. But you mentioned 40.4 & 40.6 were the OCW "Node"? Can you explain that?

Been curious to do both at the same time but w/out a labradar it may be a bit harder.

 

[ShtrRdy]

This is awesome!! You've definitely put some WORK into this. Looking over the two data sets I would go for 40.1 grain for a load. I thought the OCW group results were more telling but 'Satterlee' results look really good around there. To confirm this it would be nice if you could load a few rounds with this recipe and see if it repeats.

Is there a reason you used 'mean' instead of 'average'?

 

[frost1235]

@Sheldon N
I'll definitely agree there is NO need to do this for even a top tier PRS shooter. You could maybe justify this for high level benchrest for a rail gun, but this was beyond needed. I may add more data for 41.3grs to my max pressure for curiosity's sake, but there was too much time spent on the bench for me to ever do this again.

But with the BC of the berger 140's, I definitely plan on running them at at 41 grains with the velocity of 2730. It's a 0.2 less calculated recoil that makes shots easier to spot, less powder/wear on a great barrel and a rather huge 0.2gr node I can be sloppy with, with my transonic out to 1400 yards still and a minute near negligible increase in wind holds.

@TX_Diver
6 rounds total, with 3 rounds used for OCW, and 3 rounds used for Velocity

My bad! I confused the colors, it's been changed!
If you look on the OCW chart/images, the "average" row on the chart is the horizontal and vertical location of the shots in respective to the point of aim. OCW's method focuses solely on consistent point of impact as the deciding factor for a node, not group size.

I chose 40.4 to 40.6 as the node simply because the delta for my my POA/POI, 40.4gr to 40.6gr had a smaller change in the vertical axis, which is what I focused on vertical spread as my priority.

• Vertical delta for 40.0gr to 40.2gr was 0.127, which 40.4gr to 40.6gr was 0.077.

I should update the chart to have that data, but realistically the delta for the group targets could be affected by me moving the mouse/cursor by a minute amount, so you could tell I was really trying to disprove a link and show superiority over one another only to find it came to the same answer.

@ShtrRdy
That was just how Gordon's Reloading tool put it haha.
It wasn't a variable I cared about because I wasn't shooting multiple 3 round groups with the same load, so I didn't even notice.

 

[918v]

Do a 10 round velocity test with 40.1grs

 

[frost1235]

Do a 10 round velocity test with 40.1grs

I'll just load 40.1grs from now on and shoot it, and adjust if anything happens later on down the road. I do 6-12 rounds for zero/velocity whenever I shoot anyways, so I'll have more than enough time to confirm it.

 

[TX_Diver]

@frost1235 So the images only show the OCW results. 10-4.

Also your explanation makes more sense to me now as to what you did. Again showing my lack of knowledge here, but you're looking for the minimum change in vertical deviation between the two POIs as powder charge changes regardless of group size?

If group size doesn't factor into this portion of the OCW test then is there another step in the process after this to fully develop the load and shrink groups?

 

[frost1235]

@frost1235 So the images only show the OCW results. 10-4.

Also your explanation makes more sense to me now as to what you did. Again showing my lack of knowledge here, but you're looking for the minimum change in vertical deviation between the two POIs as powder charge changes regardless of group size?

If group size doesn't factor into this portion of the OCW test then is there another step in the process after this to fully develop the load and shrink groups?

Yes, I tried to limit my focus on as few variables as possible, since this can be one deep hole to get lost in.

I forget the name of the gentleman that put the steps in for OCW, but I recall he made mention of seating depth the adjust group size. I do also recall someone else (maybe Emil from one of the podcasts) mentioning that seating depth is good for shrinking horizontal spread.

Since the cases are already separated, if I can get back to that range, I could definitely do more tests. If someone wants to spend time sorting and tipping my bullets for me, that'd be a TON of help!

 

[Buzzinga]

Out of respect for Dan Newberry, the gentleman who put the steps in for ocw, who asks on his website to be referenced when people are discussing OCW, here is a link.

Dan Newberry's OCW Load Development System

Dan Newberry OCW or Optimal Charge Weight Load Development method or system for handloading, reloading, bullets, brass, powder, primers, accurate handloads.

optimalchargeweight.embarqspace.com

1. Decide on the bullet you want to use.



2. Choose a powder. This is probably the most important step in the whole process. As a rule, you should choose the slowest burning powder practical. There seem to be plenty of exceptions here, so if you have it on good authority that a slightly faster powder works well with the bullet/cartridge combo you're using, feel free to choose that powder. A couple of examples would be IMR 4350 in the 30-06 and IMR 3031 in the .243 Winchester. An aside: When in doubt, consult the Nosler manual for their "most accurate powder tested." That powder nearly always gives good results in the application listed.



3. Consult at least three load data sources for maximum charge weight for the powder you've selected. Powder manufacturers are the most reliable source. You must then decide on what your maximum charge will be.



4. Back away from the maximum charge by 7 to 10 percent, and load one test round with this charge. Add 2% to the charge weight, and load another cartridge with that charge. Load a third test cartridge with the next 2% graduation. You will use these three cartridges for sighters, and more importantly to determine pressure tolerance in your individual rifle.



5. Add another 2% or so to the charge level used in cartridge #3 of step 4, and load three rounds with this charge weight. Add .7% to 1% to this charge, and load three more. Add that same graduation again, and load three more. Continue adding the chosen graduation until you have moved ONE increment above your chosen maximum powder charge.



6. The seating depth for all test loads should of course be the same. I normally seat the bullet a caliber's depth into the case, or to magazine length--whichever is shorter. I don't believe loading to approach the lands is necessary, or even desirable in most situations. So long as the bullets are seated straight, with as little runout as possible, the advantages of loading close to the lands are largely over-stated. This said, be certain that the seating depth you choose does not cram the bullet into the lands. Stay at least .020" or so off the lands for these excercises.



7. The primer brand you choose is entirely up to you. Use magnum primers only with magnum chamberings, as their added pressure may distort the OCW conclusions on standard chamberings. One exeption here would be with low density loads, as I believe that magnum primers improve ignition consistency in loads where the powder only fills 85 percent or less of the case.



8. At the range, you should set up 5 to 7 targets at 100 yards. The number of targets you use will depend on how many "sets" of cartridges you loaded. Be sure the targets are identical, and level. I like to use a simple black square, drawn on a white background with a large felt tip marker. I draw the square about 3/4" (interior dimension) for my 9 power scope setting. This allows a "tight fit" of the crosshairs in the square, and thus a repeatable sight picture. For higher power scopes, draw the square smaller, and vice versa.



9. You can also put up one "sighter" target, and use the initial reduced rounds to get the POI on paper, as close to the bullseye as possible.



10. Your barrel should of course be clean before starting. Depending on the number of rounds you will fire, you may decide that it is necessary to clean half way through the string, fire a couple foulers, and allow a couple of minutes to cool before continuing. With custom barrels, you may be able to fire 25 shots or more before fouling begins spoiling group sizes. With factory barrels, I wouldn't fire more than 15 to 18 shots before cleaning... This is all relative, of course.



11. After you have fired the sighters and confirmed that there are no pressure signs (hard bolt lift, flattened primers, etc.) you allow the barrel to cool for an adequate amount of time (use common sense--the hotter it is outside, the longer it will need to cool) you will then fire your first shot from the first group of the graduated charges. You fire this shot at target number 1.



12. Allow the barrel to cool, then fire a shot from the second graduation at target number 2. Wait for cooling of the barrel, then fire a shot from the third graduation at target number 3. Continue this "round robin" sequence until you have been through all of the targets three times. At this point you will have a three shot group on each of the targets.



13. It is assumed that you are an experienced reloader, and that you know to watch for pressure signs on each of the increasing charges. Fire the subsequent charge only if there are no pressure signs on the previous charge. You can safely fire the heaviest charge you loaded so long as the next charge under it showed no pressure signs. This "heaviest charge" should be about 1% over your selected maximum charge, but will be safe so long as the next lowest graduation showed no pressure signs.



14. Triangulate the groups. This means to connect all three shots in a triangular form, and determine the center of the group, and plot that point on the target. Measure this point's distance and direction from the bullseye, and record the information somewhere on the target. Do this for all of the targets. If you have a called flyer, you should discount that shot, or replace it in the group if you have an additional round loaded with that charge.



15. You will now look for the three groups which come the closest to hitting the same POI (point of impact) on the targets. The trend of the groups should be obvious, normally going from low and favoring one side, to high and favoring the other side. But along the progression, there should be a string of at least three groups that all hit the target in the same relative point.



16. After you have carefully measured group sizes and distances and directions from the bullseye, you will know which three groups come the closest to hitting the target in the same POI. You now choose the powder charge which represents the center of this string. For example, if 34.7, 35.0, and 35.3 grains all grouped about 1.5 inches high, and about 3/4 of an inch right of the bullseye, you would choose the 35.0 grain charge as your OCW (optimal charge weight). This charge will allow 34.7 and 35.3 grain charges to group right with it. This will be a very "pressure tolerant" or "resilient" load.



17. Remember, don't get "bowled over" by a tiny group which falls outside the OCW zone. You can tune any of the groups to be tiny with bullet seating depth changes. After you have determined the OCW, you may want to try seating the bullets deeper or longer in .010" increments to see where your particular rifle does its best. I have often found that OCW recipes are so reliable that seating depth alterations--especially for hunting cartridges--often don't seem necessary.



18. Your next step would be to confirm your load recipe at the maximum range you will expect to use it. Load one round about 1% below, and another round about 1% above the OCW charge, and fire a three shot group with these two charges plus the standard charge at the maximum range you will require the load to be accurate at. You should note MOA, or very close to MOA grouping...



19. The OCW load development plan works best with rifles and shooters that are actually capable of MOA accuracy. If your rifle has not shown a propensity for reasonable accuracy, you may want to have it corrected before wasting time and material with additional load developement. If you are not confident that you are at a level where you can shoot consistent MOA groups, you may want to hold off on intricate load development until your skills are better honed. Lots of practice with a scoped .22 LR is invaluable...



20. I would sincerely recommend using shooting glasses during the firing sequences of ANY load testing. You can never be too careful here... And please know that anytime you embark on load development, you're basically on your own. Just like any provider of load data or development instructions, I must mention that I accept no responsibility whatsoever for any occurrences which are outside the realm of your expectations...

 

[Cascade Hemi]

Isn't the "Satterlee Method" a single 10 shot string in .2gr increments?

 

[calshipbuilder]

Shoot three shot groups over a chrono that doesn't attach to the barrel (floating mount magnetospeed or labradar). You get both velocity data and POI data at the same time. I usually do around 5-6 groups/15-18 rounds since I know the general charge weight window I'm looking for.

I've found a floating magnetospeed changes my POI

 

[Sheldon N]

I've found a floating magnetospeed changes my POI

Interesting. I've not seen that in my results, usually it's about 0.4 mils off with it strapped on and dead zero'd when floating.

 

[Steel head]

I've found a floating magnetospeed changes my POI

I don’t get any change.
I turn sensitivity to max and run a pretty big gap.

 

[Hawk in WY]

I don't use either of these methods having found Optimal Barrel Time and QuickLOAD gets me where I need to be.

I have seen myself the POI shift with the OCW method and believe it probably has merit.

My problem with the data you present as the Saterlee method is they do not show statistically significant differences based on the standard deviations where you think you can see differences. The same problem exists with the shoot increasing charges at distance and look for different charges which shoot to the same POI method.

If the sample size was ten or more and the differences were greater than around three times the standard deviation, I would understand.

I suppose if it works, I shouldn't argue but it smells like vodoo to me.

 

[Doom]

I’m a proponent of Dan’s OCW method because it works for me. That said, it seems that Scott’s method and even Audette’s seem to come to about the same nodes/loads. At least for the 223 and 308 loads I work with.

 

[calshipbuilder]

I don’t get any change.
I turn sensitivity to max and run a pretty big gap.

I'll see how this works, running a big gap with high sensitivity looks to be the way to go with a magnetospeed

 

[Steel head]

I'll see how this works, running a big gap with high sensitivity looks to be the way to go with a magnetospeed

David is the one I learned it from.