Almost everything you do helps confirm my thoughts and findings. I try to let the data and real world results "do the talking " you are always up to something that is helping us. Thanks
This video is absolutely mind blowing!!!! Your accuracy and measurements are to national scientific standards for reference measurement!! I was taught "o" "give"....not "o" "jive"... Just saying
Good information. I generally begin bullet sorting by OAL vs CBTO to ensure that my "solution" still fits in my magazine. If you want your longest projectiles to work, this is the first step. Then weight and CBTO.
Thanks again for the time, effort & expense. I'm glad you covered this subject. I'm getting the same trend in velocity vs CBTO. When using the same powder charge of 36 grns of AR 2207 & altering seating depth by 0.003" from CBTO of 2.228" to 2.262", my 5 shot group velocity averages decrease with decreasing COAL. The kicker with my data is that, I'm testing 130 grain 0.308 projectiles which are in excess of 0.100" from the lands therefore, I think we can rule out your proximity to the lands as being a possible cause except when jammed or touching. The number of shots fired in both our testing gives very good statistical validity so, this is a real result & not noise. Your explanation as to the cause of the results may indeed be gas leakage however, I have papers on 2 studies, both undertaken at the Army Research Laboratory Aberdeen Proving Ground which tested the theory that the primer detonation is responsible for the initial bullet unseating & lodgement into the lands prior to the begging stages of the main charge ignition. The test results suggest very strongly that this is indeed the situation. The data obtained leaves me in no doubt of the appreciable differences in shot to shot consistency when comparing large differences in case neck tension which, must surely impact the result of initial primer unseating pressure. Regards Rotas.
Combine this research with your neck bushing/mandrel tension data and you are well ahead of many reloaders. I spent 20 yrs doing just this with many calibers/ cartridges to come to my conclusion of how to marry the two up.
I find COAL only relevant with regards to magazine fitment. In fact it can create problems as the tip of even the same bullets are never perfect and distance to lands can be different by a few thou from round to round. One of my rifles is a Ruger No.1 chambered in 6.5PRC; COAL isn't even a thought. Thanks for the video!
very thorough. every aspect covered. im not sure you made this point: if you mess with overall length you can no longer go with the powder recommendations in manuals. this is where it becomes unsafe for shooters because we are told to look for pressure signs, but as you showed even with powder increases in most cases overcharge cases are not evident. you can measure ".0001 growth of the rim which is recommended but no one has that tooling as a normal reloader. primer pockets and case separation dont always fail before the gun does (barrel explosion due to overpressure). I wish you could elaborate on your quickload assesment. you seemed to point out barrel pressure here but i didnt see it in the chart. moreover, quickload requires very specific parameters "H20" that can vary substantially. Several newer bullets and powders are still not withing the program POINT BEING: IF YOUR INTO RELOADING DUE TO THE AMMO SHORTAGE STICK WITH THE MANUALS BULLET SEATING DEPTH. IF YOUR TRYING TO SHRINK YOUR GROUPS A 1/4'' PREPARE YOURSELF FOR ALOT OF TIME, MONEY, AND THE REALIZATION THAT IT MAY HAVE JUST BEEN YOU NOT HOLDING THE BARREL ON TARGET DURING TRIGGER PULL.
Thanks for your video; I've been loving your content, and am very interested in the load development process that you mention in this video and your previous playlists. Have you only tested the process once? I would be interested in seeing the process used for multiple loads/rifles. While I'm interested in the process/data.... I'm more interested in group size results. Thanks-
I am sure that the groups are what most are interested in, but the question always comes up about the powder charge work being invalidated by changing the Coal. I wanted a video to point too.
Me and Dad love those ELDs, i shoot the 178gr M in .308win, he uses them 103gr in his 6mm I only have around 200 of the elds left, cant get anymore, so i bought some bergers to try out
@@BoltActionReloading Great. We've all seen where some of our best groups have the worst SDs, and where some of the best SDs have the worst groups. Begs the question: just how much can seating depth adjustments help those terrible groups with the great SDs.
@@BoltActionReloading appreciate the topic/video. You are well under a targeted time of .30 min. You can slow the speech down or go into further detail w/ no worries.
@@justice1327 There isn't really a target time of 30 minutes, a lot of people don't like longer videos and some of these topic get more confusing more rapidly. I try to break up topics so that you can research one thing at a time and the subjects are searchable. If I put in the this in a COAL variation accuracy video no one would expect to have the velocity data.
For the better understanding of the diagrams, please put titles of them and put the parameters under or next the axles, to know immediately what are they. Thank you. Apart from this good representation as usual.
Thanks for doing this video. I’m tuning a load now by varying the seating depth. I see a variance in cartridge base to ogive of .002 from cartridge to cartridge when making ammo. This is frustrating when Eric says to vary cartridge depth by .003.
Try rotating the case during sizing and seating. That may help bring in your CBTO. Press it, give it a 1/3 turn press it again and another 1/3 turn and press it again. Also, you need consistent downforce when sizing. Are you camming over your press? You want the press to bottom out enough to take out the slop without inducing a lot of flex in the press frame.
@@br4713 Totally agree, I was just trying to give suggestions to make some improvents with what he already had. Although I'm not sure I'd see improvement on target beyond what comes out of my Co-Ax and Forster dies. They are dead repeatable when I do my job and work with properly prepped and annealed brass.
@@Not-the-only-one How consistent are you base to datum line after sizing and are you annealing or at least using brass with the same # of reload cycles? Differences in neck hardness/tension can easily cause .002 in seating length variance. The nice thing about Erik's method is that it will give you a measure of forgiveness for that error if you can't sort it out.
@@mab0852 I’m not using brass with the same number of reloads. That is probably where my problem lies. Not annealing either. Lapua brass. Redding dies. Thanks again.
Another case gauge is the LE Wilson case gauge with their micrometer, which allows for better precision for measuring cases for setting shoulder bump: th-cam.com/video/8P_UgrDv8k8/w-d-xo.html
In your video you said #3. We are going to perform the COAL test by shrinking the size by .003, could the same output be gained from shrinking/shortening the overall CBTO by .003" ? Just want to make sure I'm understanding. I'm not the sharpest tool in the shed.
Hi Matt, That is exactly what we are doing. I really only use the term COAL because is better understood. I would encourage you to track and control CBTO that way your not worrying about the variance in the projectile tips. Thanks for the question! BAR
Thanks for the info. Do you know about any interaction between any of these factors? Because if there is, you are very unlikely to find the peak of your inference space surface...
You hypothesize that the velocity loss is due to gas escaping around and to in front of the bullet which has me wondering if neck turning the brass (increasing the gap between bullet and brass) will exacerbate the velocity loss? For some reason I thought the velocity loss was due to the bullet getting a "running start" and reducing peak preasure
If one turns their brass using a mandrel first, you will have more even bullet coverage where the inside neck and bullet touch. This, along with proper neck tension will ensure no loss of gases around the bullet before it is fully released into the rifling.
What would you suggest for working inside magazine length ?? I've just loaded some with three different oal 30k difference and I'm doing it inside magazine length. Haven't gotten to shoot them yet hopefully in the next week
I really don't think there are hard and fast rules. I think that its going to depend on your application. I have a load that I have to single feed my 300 Win Mag that can hold under a 1/2 MOA but it can't hold that at magazine length. If it has to be mag length then figure out the range you can test and see what makes sense. Eric seems to change in .003" at a time and that may be the best way of doing it. if your moving in big steps you could be jumping right over some great options.
Great video as usual! My question is simple: when you seat bullet longer that reduces pressure therefore velocity. Gives you more volume to put more powder... do you use quickload to figure out how much more powder you can use safely or do you just increase .2 grains at a time and watch for pressure signs?
You may need to look at the charts again. What you state is the traditional belief, however when you look at the data, depending where you are starting in relation to the lands, seating deeper can lower the pressure / velocity. I only use QL for reference. You need to be able to look for pressure signs and know your in a safe area.
My question would be how repeatable are those SD numbers. Seems like some pretty large jumps in SD for very minor changes in COAL. Any thoughts on running a larger sample size?
Those are ES numbers not SD, yes when you see a jump to a ES of 20 not really small but when you see there are not large changes in average velocities and there are really no bad statistics in this chart the are where the projectile is just in or out of the lands is usually where you want to stay away from. I am pretty sure most would be happy if they never had a ES of higher than 20.
What about brass trim length? Staying within factory spec but shortest vs longest. Say 308 trimmed to 2.005 vs 2.015 or say you accidentally over trimmed some by 5 thou... I'm sure someone has done that, not me of course. Thx 4 ur wrk
Sorry if im late to the party, but just getting started at reloading. And a matter of fact just getting back into the shooting sports after a 25yr absence. But my first question is, is it sensible to start this whole process with new brass? Or should it wait until i get some once fire brass from factory ammo or reloads straight from a manual? Thanks in advance
Lmao,, ya know what sucks?? My headspace guage got dented real bad in a “cat accident”. So I had to buy a replacement,, Therefore my load book that iv been keeping was no good anymore , because even with the same brand of tool replacement,, everyone is different,,
They call the comparators for a reason, they are not gauges. Measurements will vary even if using 2 or 3 or more of the same brand headspace comparators .
Any correlation with POI or group sizes in the stable area of your SD chart between 2.21" and 2.198"? Mind just be a fluke in the data, but they look pretty erratic other than that window.
@@mattchilders3123 lol , BAR makes some very informative videos that we all benefit from by watching. The great man would have made a great horse 🐎 race caller .
Check out more examples of developing low SD / ES loads with the ILD process: th-cam.com/video/paUMACbJxTs/w-d-xo.html
Can I know I you get a COAL that is consistent. I was tell that only CBTO give a constant mesure
Almost everything you do helps confirm my thoughts and findings. I try to let the data and real world results "do the talking " you are always up to something that is helping us. Thanks
Glad you enjoy the content!
Your video quality has surged, this is a very well made and informative video. Great job!
Thanks Mike!
This video is absolutely mind blowing!!!! Your accuracy and measurements are to national scientific standards for reference measurement!! I was taught "o" "give"....not "o" "jive"... Just saying
Good information. I generally begin bullet sorting by OAL vs CBTO to ensure that my "solution" still fits in my magazine. If you want your longest projectiles to work, this is the first step. Then weight and CBTO.
Outstanding work brother thank you and keep it coming looking forward to seeing some groups
Thanks again for the time, effort & expense.
I'm glad you covered this subject. I'm getting the same trend in velocity vs CBTO.
When using the same powder charge of 36 grns of AR 2207 & altering seating depth by 0.003" from CBTO of 2.228" to 2.262", my 5 shot group velocity averages decrease with decreasing COAL.
The kicker with my data is that, I'm testing 130 grain 0.308 projectiles which are in excess of 0.100" from the lands therefore, I think we can rule out your proximity to the lands as being a possible cause except when jammed or touching. The number of shots fired in both our testing gives very good statistical validity so, this is a real result & not noise.
Your explanation as to the cause of the results may indeed be gas leakage however, I have papers on 2 studies, both undertaken at the Army Research Laboratory
Aberdeen Proving Ground which tested the theory that the primer detonation is responsible for the initial bullet unseating & lodgement into the lands prior to the begging stages of the main charge ignition.
The test results suggest very strongly that this is indeed the situation. The data obtained leaves me in no doubt of the appreciable differences in shot to shot consistency when comparing large differences in case neck tension which, must surely impact the result of initial primer unseating pressure.
Regards Rotas.
Combine this research with your neck bushing/mandrel tension data and you are well ahead of many reloaders. I spent 20 yrs doing just this with many calibers/ cartridges to come to my conclusion of how to marry the two up.
I find COAL only relevant with regards to magazine fitment. In fact it can create problems as the tip of even the same bullets are never perfect and distance to lands can be different by a few thou from round to round. One of my rifles is a Ruger No.1 chambered in 6.5PRC; COAL isn't even a thought. Thanks for the video!
very thorough. every aspect covered. im not sure you made this point: if you mess with overall length you can no longer go with the powder recommendations in manuals. this is where it becomes unsafe for shooters because we are told to look for pressure signs, but as you showed even with powder increases in most cases overcharge cases are not evident. you can measure ".0001 growth of the rim which is recommended but no one has that tooling as a normal reloader. primer pockets and case separation dont always fail before the gun does (barrel explosion due to overpressure). I wish you could elaborate on your quickload assesment. you seemed to point out barrel pressure here but i didnt see it in the chart. moreover, quickload requires very specific parameters "H20" that can vary substantially. Several newer bullets and powders are still not withing the program POINT BEING: IF YOUR INTO RELOADING DUE TO THE AMMO SHORTAGE STICK WITH THE MANUALS BULLET SEATING DEPTH. IF YOUR TRYING TO SHRINK YOUR GROUPS A 1/4'' PREPARE YOURSELF FOR ALOT OF TIME, MONEY, AND THE REALIZATION THAT IT MAY HAVE JUST BEEN YOU NOT HOLDING THE BARREL ON TARGET DURING TRIGGER PULL.
Thanks for your video; I've been loving your content, and am very interested in the load development process that you mention in this video and your previous playlists. Have you only tested the process once? I would be interested in seeing the process used for multiple loads/rifles. While I'm interested in the process/data.... I'm more interested in group size results. Thanks-
I am sure that the groups are what most are interested in, but the question always comes up about the powder charge work being invalidated by changing the Coal. I wanted a video to point too.
Me and Dad love those ELDs, i shoot the 178gr M in .308win, he uses them 103gr in his 6mm
I only have around 200 of the elds left, cant get anymore, so i bought some bergers to try out
Would love to see a graph of the group size vs CBTO.
Its coming, trying to keep the video on topic and not 30 minutes long.
@@BoltActionReloading Great. We've all seen where some of our best groups have the worst SDs, and where some of the best SDs have the worst groups. Begs the question: just how much can seating depth adjustments help those terrible groups with the great SDs.
@@BoltActionReloading appreciate the topic/video. You are well under a targeted time of .30 min. You can slow the speech down or go into further detail w/ no worries.
@@justice1327 There isn't really a target time of 30 minutes, a lot of people don't like longer videos and some of these topic get more confusing more rapidly. I try to break up topics so that you can research one thing at a time and the subjects are searchable. If I put in the this in a COAL variation accuracy video no one would expect to have the velocity data.
@@BoltActionReloading Copy on the longer videos. However, your videos are done well and 30 min would go easy.
For the better understanding of the diagrams, please put titles of them and put the parameters under or next the axles, to know immediately what are they. Thank you. Apart from this good representation as usual.
Thanks for doing this video. I’m tuning a load now by varying the seating depth. I see a variance in cartridge base to ogive of .002 from cartridge to cartridge when making ammo. This is frustrating when Eric says to vary cartridge depth by .003.
Try rotating the case during sizing and seating. That may help bring in your CBTO. Press it, give it a 1/3 turn press it again and another 1/3 turn and press it again. Also, you need consistent downforce when sizing. Are you camming over your press? You want the press to bottom out enough to take out the slop without inducing a lot of flex in the press frame.
@@mab0852 thanks for the advice. I rotate the case 2 times while seating a bullet. Yes, the Lee press I use does cam over to the stop.
@@br4713 Totally agree, I was just trying to give suggestions to make some improvents with what he already had. Although I'm not sure I'd see improvement on target beyond what comes out of my Co-Ax and Forster dies. They are dead repeatable when I do my job and work with properly prepped and annealed brass.
@@Not-the-only-one How consistent are you base to datum line after sizing and are you annealing or at least using brass with the same # of reload cycles? Differences in neck hardness/tension can easily cause .002 in seating length variance. The nice thing about Erik's method is that it will give you a measure of forgiveness for that error if you can't sort it out.
@@mab0852 I’m not using brass with the same number of reloads. That is probably where my problem lies. Not annealing either. Lapua brass. Redding dies. Thanks again.
The ONLY cartridge I don’t mess with COAL in is my 300 wby, Weatherby builds a lot of freebore in, same with RUM rounds
Great video.
I guess I'm first to commit and find this very interesting
Glad you find it interesting. I was surprised that after the initial transition away from the lands how consistent the velocity is.
Another case gauge is the LE Wilson case gauge with their micrometer, which allows for better precision for measuring cases for setting shoulder bump: th-cam.com/video/8P_UgrDv8k8/w-d-xo.html
When the velocity was at its highest was the ES at its lowest and what did the group size look like
In your video you said #3. We are going to perform the COAL test by shrinking the size by .003, could the same output be gained from shrinking/shortening the overall CBTO by .003" ? Just want to make sure I'm understanding. I'm not the sharpest tool in the shed.
Hi Matt, That is exactly what we are doing. I really only use the term COAL because is better understood. I would encourage you to track and control CBTO that way your not worrying about the variance in the projectile tips. Thanks for the question!
BAR
Thanks for the info. Do you know about any interaction between any of these factors? Because if there is, you are very unlikely to find the peak of your inference space surface...
I am not sure what you are asking here.
You hypothesize that the velocity loss is due to gas escaping around and to in front of the bullet which has me wondering if neck turning the brass (increasing the gap between bullet and brass) will exacerbate the velocity loss?
For some reason I thought the velocity loss was due to the bullet getting a "running start" and reducing peak preasure
If one turns their brass using a mandrel first, you will have more even bullet coverage where the inside neck and bullet touch. This, along with proper neck tension will ensure no loss of gases around the bullet before it is fully released into the rifling.
What would you suggest for working inside magazine length ??
I've just loaded some with three different oal 30k difference and I'm doing it inside magazine length. Haven't gotten to shoot them yet hopefully in the next week
I really don't think there are hard and fast rules. I think that its going to depend on your application. I have a load that I have to single feed my 300 Win Mag that can hold under a 1/2 MOA but it can't hold that at magazine length. If it has to be mag length then figure out the range you can test and see what makes sense. Eric seems to change in .003" at a time and that may be the best way of doing it. if your moving in big steps you could be jumping right over some great options.
I was going to ask the same question. Thanks for the information
Please explain your table at 5:01, what is the expander column and why do you have it?
Watch this video and it will explain how that chart was generated. th-cam.com/video/tQS338G4nZ0/w-d-xo.html
Great video as usual! My question is simple: when you seat bullet longer that reduces pressure therefore velocity. Gives you more volume to put more powder... do you use quickload to figure out how much more powder you can use safely or do you just increase .2 grains at a time and watch for pressure signs?
You may need to look at the charts again. What you state is the traditional belief, however when you look at the data, depending where you are starting in relation to the lands, seating deeper can lower the pressure / velocity. I only use QL for reference. You need to be able to look for pressure signs and know your in a safe area.
My question would be how repeatable are those SD numbers. Seems like some pretty large jumps in SD for very minor changes in COAL. Any thoughts on running a larger sample size?
Those are ES numbers not SD, yes when you see a jump to a ES of 20 not really small but when you see there are not large changes in average velocities and there are really no bad statistics in this chart the are where the projectile is just in or out of the lands is usually where you want to stay away from. I am pretty sure most would be happy if they never had a ES of higher than 20.
What about brass trim length? Staying within factory spec but shortest vs longest.
Say 308 trimmed to 2.005 vs 2.015 or say you accidentally over trimmed some by 5 thou... I'm sure someone has done that, not me of course.
Thx 4 ur wrk
Sorry if im late to the party, but just getting started at reloading. And a matter of fact just getting back into the shooting sports after a 25yr absence. But my first question is, is it sensible to start this whole process with new brass? Or should it wait until i get some once fire brass from factory ammo or reloads straight from a manual? Thanks in advance
It is perfectly sensible to get brand new brass.
Lmao,, ya know what sucks?? My headspace guage got dented real bad in a “cat accident”. So I had to buy a replacement,, Therefore my load book that iv been keeping was no good anymore , because even with the same brand of tool replacement,, everyone is different,,
They call the comparators for a reason, they are not gauges. Measurements will vary even if
using 2 or 3 or more of the same brand headspace comparators .
Any correlation with POI or group sizes in the stable area of your SD chart between 2.21" and 2.198"? Mind just be a fluke in the data, but they look pretty erratic other than that window.
That is ES not SD
I like your channel but dude you go to fast. Thx
Hi Ronnie, I do try and slow down. You might try changing the speed in you settings you can literally slow the speed down to 25%, see if that helps.
You can always watch it again if you miss something lol 😆
@@conservativesniperhunter7439 Heck I have to watch it up to 3 times. Great info but wow, he does go fast.
@@mattchilders3123 lol , BAR makes some very informative videos that we all benefit from by watching. The great man would have made a great horse 🐎 race caller .