- Thread starter dustinoif3
- Start date
First, let me say I am certainly not the world's best, by any stretch of the imagination.
Having said that, if that were my target, I would be inclined to try some 3-shot groups going by smaller increments---say 0.1gr---starting at 46.9 and going up to 47.6, and again at 48.1-48.5 grains. What do you think the chances of #8 being so far right because of a wind gust or a shooter error??? It is very close vertically to #7 and #9, just a couple inches right. If you think there could be some other factor there, you might incorporate that into the finer shot group test run.
Was #10 reaching the pressure max for your rifle?
Now, I would like to see what others say to see if I am on the right track here. I wrote this, as it is what I'm thinking, would love to see if I interpreted the ladder correctly.
Having said that, if that were my target, I would be inclined to try some 3-shot groups going by smaller increments---say 0.1gr---starting at 46.9 and going up to 47.6, and again at 48.1-48.5 grains. What do you think the chances of #8 being so far right because of a wind gust or a shooter error??? It is very close vertically to #7 and #9, just a couple inches right. If you think there could be some other factor there, you might incorporate that into the finer shot group test run.
Was #10 reaching the pressure max for your rifle?
Now, I would like to see what others say to see if I am on the right track here. I wrote this, as it is what I'm thinking, would love to see if I interpreted the ladder correctly.
Can almost draw some conclusions but you only have a sample size of 1 for each powder charge. Do it again with 3 rounds per charge to see what is a result versus what is shooter induced.
Adding distance also helps spread things out. Don't worry about windage errors right now, just elevation groupings in successive charges.
Adding distance also helps spread things out. Don't worry about windage errors right now, just elevation groupings in successive charges.
Range?
POA?
least vertical 48-49
Once you ID load, tweak OAL
changing charge by .1gr wont tell you much, other than burn up more powder etc
A good load should be stable over a .6gr range, .3 above and below should all have same POI. So ckin loads at .1gr increments makes zero sense.
http://www.6mmbr.com/laddertest.html
The how to guide
known good 308 loads are plentiful, would it be safe to say you ck,d the reloading depot?
doing load work for 308 really not needed, every combo that works has been long found
168 loads generally dont make 1000yds, so if 1k was in your plan you need to rethink bullet selection
POA?
least vertical 48-49
Once you ID load, tweak OAL
changing charge by .1gr wont tell you much, other than burn up more powder etc
A good load should be stable over a .6gr range, .3 above and below should all have same POI. So ckin loads at .1gr increments makes zero sense.
http://www.6mmbr.com/laddertest.html
The how to guide
known good 308 loads are plentiful, would it be safe to say you ck,d the reloading depot?
doing load work for 308 really not needed, every combo that works has been long found
168 loads generally dont make 1000yds, so if 1k was in your plan you need to rethink bullet selection
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Thanks guys. I was thinking 2,3,4 was my max flex up then I saw 5 go high then back down with 6,7,8,9 I thought might be flex down. My #10 shot was .3gr higher than book max. No pressure signs I could tell. The range was 300y so the shot to the right might of been a small gust. My poa was the diamond shape on the bottom right of my shots. As far as reading the sticky from tresmon he mentioned picking the node at max flex up. Do you think my 6-9 shots are flex up or down?
6 and 8 are kind of hard to tell if that was shooter error or not. If not then go with 2,3,4 and 6,7,8.
Load up some rounds of #3(47.2) and #7(48.4), check your speed/spread and grouping with a couple of 5 shot groups for each charge. See which has the speed and accuracy you want then you can make seating depth changes if you want.
One question though. Did you by chance shoot these over a chronograph? If you did then you might already know which way to lean towards.
Load up some rounds of #3(47.2) and #7(48.4), check your speed/spread and grouping with a couple of 5 shot groups for each charge. See which has the speed and accuracy you want then you can make seating depth changes if you want.
One question though. Did you by chance shoot these over a chronograph? If you did then you might already know which way to lean towards.
Okay. Ill give that a go. I haven't shot over the chrono yet. Was going to do that after I pick the loads to develop further. Ill take it with me when I shoot #3 and 7
That is one heckuva pair of links; thank you so much for them.
Oddly, they're also making me hungry for chocolate ice cream now...
Yours,
David
Yeah man. I skimmed the first link. Definetly one you don't read while intoxicated
I have actually read the first one several times, and the second one once. I followed the advice in Chris Long's OBT Paper, and the first shooting was very promising. I also have emailed back and forth with Chris, and he gave me some pointers and helped me fine-tune the calculations, so my next round should have good results. If you really think about it, the OBT Theory does not in any way go against the OCW theory. It may however explain the results better than the "barrel whip" theory. I can't wait to get to range to test round two.
I've read dans stuff and I've read all the ladder stuff as well. I'm going incorporate the round robin firing this afternoon when I run my two 5 shot groups. Looking like I'm running a hybrid test. I sat down last night and looked at some targets from my first work up at 100. They were in .5gr increments at 100 and I noticed something between them and my ladder test. I had a tight group at 47 and a tight group at 48. Both had just about the same poi with the same poa. Today my 300y test is the 47.2 and the 48.4 extracted from my ladder. If things go well technically ill able to draw a conclusion that would tell me that both methods will yield just about the same results.
Okay. Ill pick some up on my way to the range. Ill update this afternoon. Thanks!
Went to the range yesterday. Took 3 5 shot groups with me. 47.2,48,48.4. I don't know what happened. I shot low to high each string. Maybe I should of alternated. Wind was gusts of 5 to 10 full value. I felt good behind it. Maybe 48.4 is a good load. Maybe there is some shooter error. Maybe I suck. I don't know.
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Also range is still 300y
dustin,
A few questions and observations
1. What direction were the winds relative to your POA direction?
2. If the winds were perendicular to POA, then you have at least 2 very good strings at 47.2 and 48 that warrant further loads.
3. I know tresmon doesn't belive wind is a major factor during inital ladder testing, I disagree. Wind affects vertical too, albeit less amounts. I prefer as light winds as possible during any load development. I know that is easier said than done because we work for a living and our time is tight, but take for example yesterday I was headed to the 600 yard range for final load testing for my 300 WM, after leaving work early and called my brother who lives near the range. He said the winds were gusting over 10 mph. That's too high for final load tests and I turned around and went back to work. Bullets, powder, etc. are too expensive to waste, so I'll wait it out.
A few questions and observations
1. What direction were the winds relative to your POA direction?
2. If the winds were perendicular to POA, then you have at least 2 very good strings at 47.2 and 48 that warrant further loads.
3. I know tresmon doesn't belive wind is a major factor during inital ladder testing, I disagree. Wind affects vertical too, albeit less amounts. I prefer as light winds as possible during any load development. I know that is easier said than done because we work for a living and our time is tight, but take for example yesterday I was headed to the 600 yard range for final load testing for my 300 WM, after leaving work early and called my brother who lives near the range. He said the winds were gusting over 10 mph. That's too high for final load tests and I turned around and went back to work. Bullets, powder, etc. are too expensive to waste, so I'll wait it out.
The wind was from left to right. What makes me wonder is why my first 9 rounds were close vertically and why last 6 were low. I ran 3 rounds then let cool. I'm kinda with you. Prolly just re do the damn thing. Just hate wasting components!
When talking group stage of the firing aren't I looking for group size? When I looked I saw 48.4 had 4 shots within a couple inches then the one that shot low. Or should I still be looking vertical moa in this stage?
Wind will cause issues at 300 and would try the test again in calmer conditions.
Reading the tea leaves my thoughts are 47.1 and 48.6 should be two pretty good loads judging from your original test.
Looking forward to your results when you try them again.
Reading the tea leaves my thoughts are 47.1 and 48.6 should be two pretty good loads judging from your original test.
Looking forward to your results when you try them again.
You fellas can keep your ladder test, that shit's confusing, here's my ladder test(168AMAX), just picked a load I thought would work judging by what 2000MR & CFE223 shot with the 178s(47.5grs), got the brain thinking and came up with 47grs, loaded up and went to the range, that 1 shot right with 2000MR might've been the wind or me, I took the 47grs CFE and shot a 4.7" group at 600yd the very next day. Oh, 2.5" vertical. Lapua brass, btw.
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Nice! This ladder was new to me. Sounded interesting. I'm in the frustration phase. I'm about to close my eyes and poke my finger through a bullet hole of my target and what ever charge is written next to it ill load 5 up. Maybe it'll work like your method.
For my hunting loads I use the 3 shot method, shoot 2 shots, let the barrel cool for 2 mins(if its warmish out) then shoot the 3rd, I then take the most accurate load and load up 9 shells and shoot 3, 3 shot groups, 5 shot groups for varmint rigs or target rifles. heavy rifles get shot at 300yds, 100-200 and sometimes 300 for shits and giggles for hunting rigs. Whoever came up with that ladder method had way too much time on his hands. This photo shows testing with 4 different loads, much less confusing than the ladder test.
<a href="http://s1113.photobucket.com/user/JGorski80/media/2011-06-25-83129-1.jpg.html" target="_blank"><img src="http://i1113.photobucket.com/albums/k513/JGorski80/2011-06-25-83129-1.jpg" border="0" alt="2011-06-25-83129 photo 2011-06-25-83129-1.jpg"/></a>
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J I found this on my phone. It's a pic of a 100y 5 shot group with 48gr. 4 good ones and one pull because I got excited. This was shot a awhile back before I decided to try the ladder test. Posting it here because I can't figure out how to attach to PM.
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That pulled shot mightve been wind or you, after all, you're shooting a 2.5lbs trigger, my Jewell is set around 7oz, so its easy to shoot groups like Im getting. Take it out to 300yds if you can, if its a calm day that is.
For sure. When that pic was taken that was with my factory x mark at 3.5lbs. I'm about to shoot it now at 100y with some buddies. If it does better ill throw another pic on this
I took the X-mark trigger off my SPSS as soon as the Jewell came in, then gave it away to some fellow in PA. For precision shooting you cant beat a light trigger. What do you have for a stock on your rifle?
Do either of you have access to or own Quick Load? If you do, you may be able to short-circuit the "ladder" test and get the info you want without shooting all the ammo. Chris Long did a very informative paper on Optimal Barrel Time, and his theory seems very sound. He backs it up with experiential data too. I have studied his work, and done a preliminary test, which showed good results. I have corresponded with him several times since, and he has helped me tweak my method. I will go to the range with some loads that I believe will do very well, and I will report back my findings, but, as I said, the first round test was some of the best I've done with hand-loads in development yet, and I didn't have to do the "ladder" to get them.
I've got a McMillan a5 stock, ptg bottom metal, alpha type 1 mag, millet 4-16x50 trs-1, badger base and rings.
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I sure don't. Is it a software? I've heard people talk on here a little bit about it. I keep reading that obt paper but I don't understand fully. The man uses terms and theory's I can't comprehend I guess. Would you break it down big bird and Barney style for me? Little crash course if you would. Thanks!!!!
Nice rifle Dustin, course the barrel is too short for me, haha
About the 180s in the 308, I dont see any data for the 180 on Alliants site, but since Im shooting the 178s, 2 grains away from 180, duh, I could drop the charge a few tenths, if that, and give the 180s a try, but thats with 2000MR, 47grs even sounds good to me. Yeah, of course Ill work up, wink. Ill be shootin for just under 2700 with this rig.
About the 180s in the 308, I dont see any data for the 180 on Alliants site, but since Im shooting the 178s, 2 grains away from 180, duh, I could drop the charge a few tenths, if that, and give the 180s a try, but thats with 2000MR, 47grs even sounds good to me. Yeah, of course Ill work up, wink. Ill be shootin for just under 2700 with this rig.
That's a nice rifle as well. Hey was this rifle pictured next to another one on the for sale thread? Stock and camo looks familiar.Nice rifle Dustin, course the barrel is too short for me, haha
About the 180s in the 308, I dont see any data for the 180 on Alliants site, but since Im shooting the 178s, 2 grains away from 180, duh, I could drop the charge a few tenths, if that, and give the 180s a try, but thats with 2000MR, 47grs even sounds good to me. Yeah, of course Ill work up, wink. Ill be shootin for just under 2700 with this rig.
How long is that barrel?
The stock is for sale, the stock on my 6mmREM will go on this rifle once I get my 6mmREM built(rebarrel), thats a 26"
Yes, sir. QuickLoad is a software, costs in the $150 range, it is a tool, does not replace the manuals---I have 5 manuals so far myself, and I frequently go to the manufacturer websites also. It does however give some data to cross-reference against the manuals and do developments off of. What it does do, is feature some calculations that are built in with fields of data that are standard, but you can manipulate some , as you can change them to match user measured data. For instance, when you choose a bullet and a case, it will tell you what the COAL should be, and you can change that number if you seat the bullets lower, say, or possibly higher. By doing this, you change the case capacity with that bullet at that depth, and change the pressure curve in the chamber/barrel when fired. You can use this to show effects of seating depth----provided you know where that bullet will hit the lands in your rifle---(the software does not know this, so you must know it and know if you can safely do that with a given powder charge. You do need to do a chamber pressure versus powder charge string (similar to the ladder test, but not necessarily the same, as all you are really trying to get is your specific rifle chamber pressure max---or where you see what you consider unwanted pressure signs. From there, you back off to what you want as your max safe pressure with that rifle and that powder/bullet...combo.) Having done this, you can then use QuickLoad to explore different options with bullet seating depths and other changes, to know generally where you are headed with a round.
Enter the OBT Paper. Simply put, Chris Long is educated in engineering. He says, "Let's find a way to short circuit burning powder and primers and slinging projectiles, and find 'Accuracy Nodes' with calculations instead of the old ladder test." So, he studied into it, and some people point to barrel harmonics---the vibration pattern within the barrel set off by ignition of the primer and powder charge and it's subsequent shock wave on the base of the bullet---some figure this is a whipping action and that the barrel may be at a different point in the whip action at different bullet velocities due to powder charges. They search for patterns on the target, and do "ladder tests" to find those patterns. Chris theorized that it was actually the fact that the barrel expands and contracts with this shock wave moving down it's length and back, so if you can time the bullet to the muzzle being at it's smallest diameter, you would have a tighter group----to a point, this is proved by the fact that a good tight bore can improve accuracy(too tight would not be good either).
So, on the basis of the above theory, Chris set out with some powerful engineering software and known "harmonic data" on vibration wave travel in steel, and made some predictions to test. When he tested these predicted results, his actual collected data matched the predictions closely enough for him to do further tests. After more testing, he developed some formulas to predict the behavior of the harmonics in a given barrel and find your "Accuracy Nodes" on paper before going to the range. Then you can load up only a few three shot groups bracketing your predicted node and take those to the range for test shots, instead of the entire ladder. One failing of the single shot ladder is that you don't have any real check on whether the shooter affected the shots or not. You have to rely on your thoughts, which may or may not have been 100% accurate on your own performance---hence you "should" really do a more extensive ladder test to get "good" results.
Any way, Chris also sent me a Microsoft X-cell based tool which you can enter a barrel length into, and it spits out the OBT's for that barrel length and I think up to 7 Nodes. I have a 34" barrel on my 338LM, and I have only seen the need to check up to the 6th Node, so it will probably suffice for most people. He also told me how measure your "effective" barrel length for a particular rifle---in my case, it is about 1" shorter than the nominal barrel length---23" on my 24" 30.06 barrel, and 33" on my 34" 338LM. Armed with these numbers, I have run some scenarios in QuickLoad, which does have "barrel time" as an automatically calculated field, and determined some good test charges to match "Nodes" based on "barrel time" as calculated by QL. I have only done three tests, before communicating with Chris, and they were based on my original understanding of his paper. The results were "good", but hampered by the fact that the wind was starting to rise, and I started to see mirage, neither of which am I good at reading consistently yet. Anyway, at 300 yards, the groups were string like, about 2.75" wide (wind) and 3/4" high. Also, they were based on a full value 34" barrel. I have since changed it to 33" effective barrel length, and the powder charge varied a slight amount---I can't tell you just how much without going back to the data book.
I did choose to work with Reloader 50 on these tests, and that is working out very well. This decision was based on the fact that my original calculations using Chris's formula showed four powder choices--H870, Reloader 33, Reloader 50, and VVN570 to be the only four choices with my barrel length that approached 2800FPS with 300gr Bergers. All the other "suitable powders" were down around the 2730 mark and lower to match the "nodes." Any higher, and I couldn't reach the next lower Barrel Time Node or OBT without serious over-pressures. Reloader 50 was available, and had the added bonus of being the highest velocity---2820 FPS---with pressures in the 57K range. Further testing will fine tune the loads, but the direction looks very promising.
If you email Chris, (his email in the paper works), I'm sure he will send you the X-cell tool, or I can email it to you. He is most helpful with explaining and clarifying his paper, and he has more data now than in 2004 when he wrote it. Very nice guy to deal with.
After you have done testing at the range, and collect chronograph results, etc, you can tweak QL with some of your collected data, and fine tune the loads even more for OBT. I have yet to get to the range for round two, and I'd be happy to share results when I do get there. It may be a while, as my job is very unpredictable.
Hope this sheds some light for you,
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That would great! I read the article again. It actually started sticking to my brain. Interesting. So it's showing how you can already know what charge will perform well before going to the range?
Yes, it is possible. Whether you or I will be able to fine tune it perfectly on paper, probably not, but much of the work can be done before hand, so that you can have a lot less testing to perfect it. i do suggest that you consider buying the QuickLoad software---somewhat pricey, but armed with this new information, I think it is well worth it.
QuickLoad will save you alot of time and $$ in long run
You can run various powder/bullet combos and see results for PSI and barrel time etc
Using Quickload n OBT tables you can very quickly id the powder that will most likely perform best with bullet selected
QL is a very powerful tool and and take some time to fully realize its potential, it is without doubt a must have for serious reloaders
OCW/OBT, ladder, round robin etc etc
Use what ever gets you the results you seek, everyone has their own method of madness
You can run various powder/bullet combos and see results for PSI and barrel time etc
Using Quickload n OBT tables you can very quickly id the powder that will most likely perform best with bullet selected
QL is a very powerful tool and and take some time to fully realize its potential, it is without doubt a must have for serious reloaders
OCW/OBT, ladder, round robin etc etc
Use what ever gets you the results you seek, everyone has their own method of madness
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1000% agreement, Jedi. I have had QL for about a year now, and just in the last month started to realize what I really had in terms of an all-purpose tool that would help to figure things out. I cross-reference the data with the manuals regularly, but QL is what I use many times first to decide which direction to go in terms of powders and intended results. I am in the process of planning my next build---or rather, rebuild---and QL and the OBT tables are figuring quite prominently in this planning. I am working to figure out, given several powders and their applications, and the intended bullet weights for distances I plan to shoot, what is the best barrel length to maximize the OBT's and the velocities with those powders. It will take some time to plan, but I think the end result will give me the desired performances.
When i put the 308 to the curb back in 07, i used QL to ID the cal and bullet powder combo that would meet my performance goals
tweaking the various data fields yields very accurate info, i spent several weeks crunching data before deciding what best met my performance goal
So planning a build based on QL data means you can pert mush be assured build will meet your performance goals
Nothing worse than regretting cal selection after you spent $$ on a custom build, QL can for sure give ya a warm n fuzzy your making right choice before laying out $$
tweaking the various data fields yields very accurate info, i spent several weeks crunching data before deciding what best met my performance goal
So planning a build based on QL data means you can pert mush be assured build will meet your performance goals
Nothing worse than regretting cal selection after you spent $$ on a custom build, QL can for sure give ya a warm n fuzzy your making right choice before laying out $$
You guys are going to mess around and make me buy it! Hahaha. I've already decided to dump the ladder. Taking my pet load and loading some up 1% above and below to see if its good according to OCW
So I've been reading more into the OCW method and have a question. It talks about being tolerant to temp changes and even different brass. I assume that it's tolerant to full length sized brass and fire formed? Stinkin bolt was getting sticky so I've been moving shoulders with my fl die.
Well of course you're going to size your brass so it fits the chamber almost perfect, use the best primers, CCIBRs work great for me, hint hint. I got some Hornady "Custom" bushing dies as to reduce stress on my brass, hope that would help. And shooting in temps below 90 may or may not help, too. It isnt that hot in Joplin yet, is it, Justin?
Oh, "We dont need no stinkin QL"
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Hahaha well I know that. I had neck sized the last two firings when I noticed mister sticky bolt. Haven't splurged for a bushing die. I think if the wife see one more package arrive with gun stuff she may shoot me. Need to let the water calm down for a week. Lol. Man you know what the Midwest is like! Sunday it was 70 and Monday was 39! If we don't like it we wait 5min right!?
I know, sunday it was 37 today its 27.brrrrrr
Hornady bushing die is only 42 bucks. Ive got both NS & FL dies, plus the New dimension set.
Hornady bushing die is only 42 bucks. Ive got both NS & FL dies, plus the New dimension set.
Heck that's not bad. Ill take a look at them. Yeah I'm sorry. Not a huge fan of Wisconsin. Spent a month at fort McCoy during January for a mob and it ruined it for me. It was damn cold
Oh yeah, it gets pretty cold here in Jan.
