doubleA Posted January 24, 2009 Report Share Posted January 24, 2009 I decided do a incremental/ladder load test this past week. The rifle is a Cooper 6.5x284 with sammi spec chamber. The load was using Norma brass, Federal 210M,Reloder 22 and a Sierra 142gr SMK. OAL was 3.121. Evereything was kept the same other than powder weights. Three rounds were loaded with each powder charge and I used 10 different increments for a total of 30 rounds. I started with the lowest and fired a round at a bull, then went to the next higher increment and fired at another bull untill each bull has one round fired at it. I repeated this 3 times until all rounds were firedat the respective bullesye. I started with a clean barrel but did foul it with 3 shots before the test started. Between chrongraphing, taking notes and keeping the barrel cool this is a time consuming process. My intention was to shoot at 200 yards but due to the high winds and later mirage these were shot at 120 yards. The idea behind this is to be able to see where sweet spots are within a series of using different powder charges. You would try to find a charge where the point of impact doesnt vary much using different charges.This supposedly allows room for variences in your load and shouldnt affect accuracy. In my case it's hard to tell due to to range they were fired. Although the POI shifted between loads, there isnt any combination that sticks out to me. All shots were accounted for and no shots/flyers were thrown out. The smallest group fired was .260" while the largest went 1.120". .546" was the average group size with all 10 groups. The average velocity for all 30 shots was 2660 fps. Extreme spread was 161 fps. between all loads fired. The 46.5 gr load has the least E.S at only 7fps. The 46.2 gr load hd the highest E.S. at 30 fps The 48.3 gr load had a heavy bolt lift and showed pressure signs. I feel that I am not getting the velocity that I should and will try this with another powder. Has anyone here used a ladder test , if so can you share any findings? The set up.......... Here's the target..... Quote Link to comment Share on other sites More sharing options...
EricF Posted January 25, 2009 Report Share Posted January 25, 2009 I don't load my own....but your post and the pics are very impressive, and equally intriguing. Quote Link to comment Share on other sites More sharing options...
Ravin R10 man Posted January 25, 2009 Report Share Posted January 25, 2009 the only "ladder" test Im familar with is with the Fire Dept. but yours is very impressive, your gun likes 46.8 gr. Quote Link to comment Share on other sites More sharing options...
PotashRLS Posted January 25, 2009 Report Share Posted January 25, 2009 To be honest with you, most guys would have quit pretty early on with the groups you're putting on paper there. Your worst groups are better than most will ever shoot. Quote Link to comment Share on other sites More sharing options...
doubleA Posted January 25, 2009 Author Report Share Posted January 25, 2009 Well thank all of you for the kind words, but I want to stress that doing this type of testing isnt about the group size but rather the POI shifts due to the different powder charge weights. These ladder test work better at longer ranges as the groups most likely wont be that clustered on account of velocity loss will have affected them. Quote Link to comment Share on other sites More sharing options...
HUNTINGMAN Posted January 25, 2009 Report Share Posted January 25, 2009 Wow,that looks like alot of thinking.It is giveing me a headache looking at the pics. Quote Link to comment Share on other sites More sharing options...
Doc Posted January 25, 2009 Report Share Posted January 25, 2009 Judging from most of the replies, and my own understanding as well, I would say that the term "Ladder Testing" is a bit foriegn to most of us. Could you explain the term and process and the mission of the test? Doc Quote Link to comment Share on other sites More sharing options...
Strut10 Posted January 25, 2009 Report Share Posted January 25, 2009 Never did any testing in such a sequence as that. I can see that it's a good method to find the data you are looking for. I can also see that I'd be loading 46.8 or 47.7 grains if I continued on with the R22. Most all of my range testing is for velocity/group size only. It surely is a time consuming process to go through several 5-shot batches of ammo loaded at 1/2 or 1 grain increments or different primers, etc. The iron I'm generally toting are a bunch of barrel-warmers. I usually will take 3 rifles to work with so 2 can be cooling while I work with the other. Quote Link to comment Share on other sites More sharing options...
PotashRLS Posted January 25, 2009 Report Share Posted January 25, 2009 Never did any testing in such a sequence as that. I can see that it's a good method to find the data you are looking for. I can also see that I'd be loading 46.8 or 47.7 grains if I continued on with the R22. Most all of my range testing is for velocity/group size only. It surely is a time consuming process to go through several 5-shot batches of ammo loaded at 1/2 or 1 grain increments or different primers, etc. The iron I'm generally toting are a bunch of barrel-warmers. I usually will take 3 rifles to work with so 2 can be cooling while I work with the other. This is exactly what my buddy and I are in the process of doing with my Browning 223 wssm. Its been so darn cold that we haven't gone out to the range since before our gun-deer season. Right now its still -6 with a high expected to be +5. Not exactly the best time to figure out a good load. Quote Link to comment Share on other sites More sharing options...
Strut10 Posted January 25, 2009 Report Share Posted January 25, 2009 Right now its still -6 with a high expected to be +5. Not exactly the best time to figure out a good load. Don't have to worry so much about your barrels staying hot. :D:D Quote Link to comment Share on other sites More sharing options...
toddyboman Posted January 26, 2009 Report Share Posted January 26, 2009 As stated above most guys are happy with hitting a paper plate size target at 100 yards........when you get into the fine precision shooting is when things like this come about....... Generally we(dad and I) don't worry about this as much. As we do velocity and grouping. We do often load several different rounds with various powder weights to see what load shoots the BEST out of what gun. Best part is we can do all this off dads front porch....so its easy to run inside and up to the gun room to try a new load Quote Link to comment Share on other sites More sharing options...
Rinky Posted January 27, 2009 Report Share Posted January 27, 2009 Very interesting and still complex but flawless setup there, most impressive. As for me Potash, depending on what time of year you will mostly use your .223 wssm sighting it in in the cold could be what you need, my new .22-250 is sighted in for dead on at 200 yards at 10 degrees above zero. It is a coyote gun after all and theyre only worth something in the cold times of the year. Quote Link to comment Share on other sites More sharing options...
PotashRLS Posted January 27, 2009 Report Share Posted January 27, 2009 Very interesting and still complex but flawless setup there, most impressive. As for me Potash, depending on what time of year you will mostly use your .223 wssm sighting it in in the cold could be what you need, my new .22-250 is sighted in for dead on at 200 yards at 10 degrees above zero. It is a coyote gun after all and theyre only worth something in the cold times of the year. Very good point you make. I do plan on using it in the spring for yotes during fawning season too. If we could just get some normal winter temps I'd be out there bangin. Yesterday morning was -17 and this morning its -9. Windchills are way down there since its quite breezy. Shooting is supposed to be fun too, and the weather kinda takes that out of it. Appreciate the input. Quote Link to comment Share on other sites More sharing options...
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