Primer seating depth
- Thread starter Sniper King 2020
- Start date
Did you know about Erik Cortina's other YouTube Channel?
Here is a follow up test from the same guy. He confirmed the results on different tests. So in his video how is he measuring primer depth ?? Is he not using calipers ? So if calipers are not accurate then how is this video accurate ?? Just asking.
www.snipershide.com
Welcome to the forum. I've been watching some of your videos!
Thanks for the welcome! Looks like there has been some robust discussion in this topic. Good to see it and am always looking at the discussions to see if there is anything that can help me formulate my next test.
Heck yeah man. Check out that thread linked above. Tons of posts, some flame throwing, but overall lots of info including already linked to your tests. You should try out one of @orkan priming tools. Sounds like it's right up your alley.
I enjoy the videos a lot. If you are ever wanting ideas I am sure the brain trust around here can help.
Cool. Good to connect with another brain trust and learn from this group. My goal is to test, test, and test so that the shooting community can benefit.
Here is an idea... if you can show actual results I think it will be a big help (and a hot topic).
That would be to have your baseline load with all the bells and whistles shooting out of a good gun. Then load up several rounds .1 over (but all else the same) and .1 under (all else the same) and show what the groups actually are.
People fight like cats and dogs about getting perfect charge weights. That would be a useful tool to show people how much it matters (or doesn't matter).
To me it all matters but it's on a sliding scale depending on what I am doing. If I just want to shoot cans in the back yard if my ammo isn't perfect it doesn't matter. If I am trying to hit a 1,000+++ yard shot then it becomes more critical. Etc etc etc. You get the point.
Really enjoy your videos and how you go about your tests. Glad to have you here.
I'd just love to see a test on "nodes". Some very experienced and accomplished folks say that charge weight nodes don't exist. Many others say they do. The ones who say they don't exists, say that if you "find a node" then you just haven't shot enough to see that "node" isn't actually there. Such as someone loading a bunch of increasing weight charges and "finding 39.3gr-39.5gr have the same or within 5 fps of the same velocity...... "
This is how most shooters find their charge, then they play with seating depths to get the best group for that charge. It would be a big thing if you did a test in the complete way that you do them for this theory.
You may have already done this and I just haven't seen the video, if so, just point me to it pls. Thanks
I’m sure that people swear by the existence of “nodes” whether that be charge weight, velocity and/or standard deviation “nodes.” What I have found is that there are no such thing as “nodes” related to standard ballistic measures such as velocity and velocity standard deviation nor
charge weight. What I have found instead is that external atmospheric forces are the “node” (see my data on atmospherics in my videos). I can shoot in certain atmospheric conditions with the same powder charge but get massive variability in velocity (standard deviation) but still shoot with great precision. Once the atmospheric node shifts, I have to make major shifts in my load to make the load precise for that atmosphere. The major atmospherics variable that determines my “node” is barrometric pressure (if you are not at sea level, use station pressure). When the pressure drops below 29.7, the air is very turbulent and I have found that I have to go with mild to medium pressure loads to have great precision. In anything above 29.7, almost any high pressure load exhibits great precision. As for temperature in my typical atmosphere with N133 powder, anything above 65 degrees will cause an atmospheric “node:” Anyway, in short, atmospheric factors are the largest determinants of your “node.” My recommendation is to measure and track as many atmospheric variables you can while measuring precision in a well tuned barrel. I believe that this will inform you much more than anybody else’s assertions about “velocity nodes,” “standard deviation nodes,” or any other standard ballistic “node.”
Welcome to forum. Always great to have other data driven members.
For clarification, since the audience here is a bit different than say on Accurate Shooter…..
I’m making assumptions here, so I apologize if incorrect and please correct me accordingly. You are shooting disciplines which require the utmost precision and/or accuracy depending on the match format. You’re also using things like a Neo Max rest and Bigfoot or equivalent style of rear bag…..etc.
So, the “nodes” you notice atmospherically and such are a product of shooting so small and with equipment that allows for such shooting.
In something like PRS where you’re shooting 2moa steel off compromised positions, or using a regular bipod with rear squeeze bag or gamechanger equivalent……you’d like see much less or possibly none of those environmental effects…..at least not enough to show a decrease performance/scores. Would you agree with this statement?
This is a distinction many of us try to point out here and at times it’s misunderstood. A lot of things like “nodes” are being brought over from F class an BR disciplines into practical/prs/steel shooting disciplines. When either those things aren’t measurable with our equipment or able to be exploited in this discipline.
Again, love the videos and feel free to correct my assumptions. Also, if you don’t mind, we’d like to reach out to you about possibly trying out some of our products and providing feedback.
Thanks!
Yes but I have yet to update it with the data I collected when the temperature was at 65 degrees F and above. When it was 65 or above the tune changed dramatically much like it did when the barometric pressure was 29.7 or below. I found this across a few cartridges (ie, 6 Dasher and 6BR). I consider 29.7 and 65 degrees to be “cutoffs” in my atmosphere. I would bet my last shiny buckle that the atmospheric effects are different in different regions which is why I recommend testing in your specific environment.
Appreciate the welcome! Glad to be part of a forum like this because of the potential to learn from others.
I do shoot PRS style (although not this year because of back issues), prone, and bench. I have done testing on my PRS rig although I don’t publish those results because, like you said, the difference between an agg in the .1 range and .25 is so small that there is no major practical value when it comes to hitting large pieces of steel…on that, I can agree. However, I have observed major changes in tune that have negatively affected my ability to hit the steel at distance (600+ yards) if the atmospherics are not accounted for. For example, I tuned my PRS rifle to less than .25 at my main range at sea level and went to shoot a match at 2000 feet above sea level in a very different atmosphere. I input my sea level data into the Kestrel and went to the match. After my first stage, I missed several shots at around 500 yards. I was puzzled by this and was told by my spotter that I repeatedly shot over the target. I then quickly looked at atmospheric data on my weather app and found that the station pressure was much lower at the 2000 foot elevation. Given the data that I collected on atmospherics, I reasoned that I had underestimated the velocity by using sea level velocity. I estimated, based on previous testing that I was about 20 feet per second slower at sea level so I added 20 in my Kestrel. Basically, my aim point was spot on for sea level but not for the atmosphere I was currently in. After this correction, my Kestrel data was perfect and I began hitting steel. I learned a good lesson to bring my LabRadar to matches and verify my velocity before inputting it into the Kestrel. I also grabbed a tuner (Aaron Hipp’s tuner works great) so I can tune the load if I felt it was necessary (eg, if the groups opened up to .5+). Just be sure to input the velocity that you get after tuning because it seems like tuning itself can change the velocity slightly. This is why I emphasize that shooters pay close attention to atmospheric effects wherever they shoot regardless of discipline. One more quick story, I shot with a guy in a prone 600 yard F class match and he had high initial point of impact on a few of his sighter shots. He brought it down but essentially wasted three of the precious 5 sighter shots. He told me he used the same data from a month previous but the day we shot had a different barometric pressure than the month previous so we reasoned that his velocity on that day was higher because of the lower barometric pressure on that day versus last month. I knew this going into that match and adjusted accordingly so my 5 shots were spent getting me on the bull instead of simply adjusting for vertical. Take a guess who won that match.
Anyway, hope this response is helpful and I look forward to learning more on this topic.
I am always open to testing equipment so please feel free to contact me about that. I will let you know how realistic it will be for me to test the equipment given my constraints (I wish I can make a full time job out of this but that’s not in the cards unless I win the powerball
. Shoot small!
If you’re above sea level, then you would want a measure of station pressure and a Kestrel would provide you with that and more atmospheric data. A LabRadar would measure the velocity data. And, of course, a good target that is good for your eye sight, reticle, etc. is needed. After that, it’s putting rounds at the target and measuring everything. Group data can be measured with center-to-center with calipers but you can get more sophisticate and get fancy caliper add one to get real precise group data. Then, inputting the data into Excel or similar software can help you graph the data and even run some statistical tests of significance. It’s a lot but it all matters if you want to get very precise and shoot the best you can.
Appreciate the welcome! Glad to be part of a forum like this because of the potential to learn from others.
I do shoot PRS style (although not this year because of back issues), prone, and bench. I have done testing on my PRS rig although I don’t publish those results because, like you said, the difference between an agg in the .1 range and .25 is so small that there is no major practical value when it comes to hitting large pieces of steel…on that, I can agree. However, I have observed major changes in tune that have negatively affected my ability to hit the steel at distance (600+ yards) if the atmospherics are not accounted for. For example, I tuned my PRS rifle to less than .25 at my main range at sea level and went to shoot a match at 2000 feet above sea level in a very different atmosphere. I input my sea level data into the Kestrel and went to the match. After my first stage, I missed several shots at around 500 yards. I was puzzled by this and was told by my spotter that I repeatedly shot over the target. I then quickly looked at atmospheric data on my weather app and found that the station pressure was much lower at the 2000 foot elevation. Given the data that I collected on atmospherics, I reasoned that I had underestimated the velocity by using sea level velocity. I estimated, based on previous testing that I was about 20 feet per second slower at sea level so I added 20 in my Kestrel. Basically, my aim point was spot on for sea level but not for the atmosphere I was currently in. After this correction, my Kestrel data was perfect and I began hitting steel. I learned a good lesson to bring my LabRadar to matches and verify my velocity before inputting it into the Kestrel. I also grabbed a tuner (Aaron Hipp’s tuner works great) so I can tune the load if I felt it was necessary (eg, if the groups opened up to .5+). Just be sure to input the velocity that you get after tuning because it seems like tuning itself can change the velocity slightly. This is why I emphasize that shooters pay close attention to atmospheric effects wherever they shoot regardless of discipline. One more quick story, I shot with a guy in a prone 600 yard F class match and he had high initial point of impact on a few of his sighter shots. He brought it down but essentially wasted three of the precious 5 sighter shots. He told me he used the same data from a month previous but the day we shot had a different barometric pressure than the month previous so we reasoned that his velocity on that day was higher because of the lower barometric pressure on that day versus last month. I knew this going into that match and adjusted accordingly so my 5 shots were spent getting me on the bull instead of simply adjusting for vertical. Take a guess who won that match.
Anyway, hope this response is helpful and I look forward to learning more on this topic.
I am always open to testing equipment so please feel free to contact me about that. I will let you know how realistic it will be for me to test the equipment given my constraints (I wish I can make a full time job out of this but that’s not in the cards unless I win the powerball
How small of a piece of steel were you shooting at 500yds that 20fps created a miss scenario?
@Bryan Zolnikov welcome to the hide. Great videos. I had typed out a long reply and it disappeared on me. I am not going to retype it. Would be interested in having some discussions down the road. I test a lot and use quick load with barrel time calculator. I have found most of my rifles run best on barrel time somewhere around 1.5 grains back from max. And yes, atmosphere has a big effect. We have to watch temp and air density as day goes. Can be .2 to .3 mil elevation difference from first string to last. Thanks for the videos.
Appreciate the welcome! Glad to be part of a forum like this because of the potential to learn from others.
I do shoot PRS style (although not this year because of back issues), prone, and bench. I have done testing on my PRS rig although I don’t publish those results because, like you said, the difference between an agg in the .1 range and .25 is so small that there is no major practical value when it comes to hitting large pieces of steel…on that, I can agree. However, I have observed major changes in tune that have negatively affected my ability to hit the steel at distance (600+ yards) if the atmospherics are not accounted for. For example, I tuned my PRS rifle to less than .25 at my main range at sea level and went to shoot a match at 2000 feet above sea level in a very different atmosphere. I input my sea level data into the Kestrel and went to the match. After my first stage, I missed several shots at around 500 yards. I was puzzled by this and was told by my spotter that I repeatedly shot over the target. I then quickly looked at atmospheric data on my weather app and found that the station pressure was much lower at the 2000 foot elevation. Given the data that I collected on atmospherics, I reasoned that I had underestimated the velocity by using sea level velocity. I estimated, based on previous testing that I was about 20 feet per second slower at sea level so I added 20 in my Kestrel. Basically, my aim point was spot on for sea level but not for the atmosphere I was currently in. After this correction, my Kestrel data was perfect and I began hitting steel. I learned a good lesson to bring my LabRadar to matches and verify my velocity before inputting it into the Kestrel. I also grabbed a tuner (Aaron Hipp’s tuner works great) so I can tune the load if I felt it was necessary (eg, if the groups opened up to .5+). Just be sure to input the velocity that you get after tuning because it seems like tuning itself can change the velocity slightly. This is why I emphasize that shooters pay close attention to atmospheric effects wherever they shoot regardless of discipline. One more quick story, I shot with a guy in a prone 600 yard F class match and he had high initial point of impact on a few of his sighter shots. He brought it down but essentially wasted three of the precious 5 sighter shots. He told me he used the same data from a month previous but the day we shot had a different barometric pressure than the month previous so we reasoned that his velocity on that day was higher because of the lower barometric pressure on that day versus last month. I knew this going into that match and adjusted accordingly so my 5 shots were spent getting me on the bull instead of simply adjusting for vertical. Take a guess who won that match.
Anyway, hope this response is helpful and I look forward to learning more on this topic.
I am always open to testing equipment so please feel free to contact me about that. I will let you know how realistic it will be for me to test the equipment given my constraints (I wish I can make a full time job out of this but that’s not in the cards unless I win the powerball
But I agree. Generally what I advise for PRS is to chrono in a new location. Which should keep everything in line for practical shooting.
Yes, a slight variation in the powder charge doesn’t matter at short range. This is why I use a manual powder thrower at short range matches. I tested the thrower (the best out there - a Mike Bryant thrower) and 85% of the time the manual thrower had the same weight to .1. The other 15% of the time, it is off .1 in either too high or too low. With that variation in a well tuned BR rifle at short range 100-200 yards, you cannot see a difference. I am doing a test right now of the difference between a high quality manual thrower versus an electronic thrower. Stay tuned for the results of that test.
To clarify, what I mean by well tuned is that the rifle shoots in the same hole with variances in charge of .2 either too high or too low and seating .006-.008. A great barrel will have this large of a “tune window” and shoot in the same hole even with these variances. What I do when I’m tuning is find this window and load to the middle of it. So, if the bullet flies into the same hole with, for example, 29.6-30, I will set the charge at 29.8. Same with seating, if for example they shoot in the same hole at .003-.009 off lands, I will seat to .005. Each barrel is different with how wide the window will be. A “hummer” barrel will have the widest windows and you can just about shoot anything and it will shoot a small hole.
For long range applications, Brian Litz has great data to show how you need to have a very precise and reliable charge…basically to the kernel…in order to shrink your groups. This is why I use my Matchmaster for long range matches because it will load Varget and some other powders to the kernel.
Oh boy, not sure but they looked to be 8x8 inch. PRS and NRL matches nowadays seem to have smaller targets relative to 5-6 years ago. 20fp/s can be a huge issue at that distance with that small of a target. Also, I had no way of getting a stable platform and assessing actual impact area so my estimate “got me on target” but I may have still had some error (could have been 25-30 fp/s for all I know). This is why I take my LabRadar with me and take some time before the match to get the right velocity and set my zero at center punch. Not making that mistake again!
Good advice! I also advise .25 to .4MOA is sufficient so don’t waste barrel life getting in the 1s or low 2s. It’s nice if you get 1s or low 2s during load development but with the size of the targets, you don’t really need that. With how many rounds you shoot at each match, that barrel is gonna burn out fast anyway! What’s more important is getting yourself into a stable platform with your technique and then wind reading. Also, I do far less with case prep because I’m not trying to shoot in the 1s like I would with BR.
Ah. Makes sense. Stacking errors.
20fps (obviously larger with ES above and below the average) is about about a 2” difference at 500yds with a 6mm in the 109 Berger area. But if your wobble adds to it, makes things a bit different.
Indeed a Priceless gem.
This post should be a sticky.
For practical/prs/steel…..sure. Or just make sure it’s flush/below and seated well. You won’t be able to exploit the difference shooting off props.
For F class and BR, I wouldn’t worry until you’re at the top of the pack and looking for every advantage possible.
Devil's advocate, but if the concept is that primer seating depth influences powder ignition, then testing one load with multiple primer seating depths is just going to tell you how those changes influence that load, and it isn't going to tell you much more. It may not even tell you that, other than that load, seating depth is influential, but certainly I don't think it can establish an optimal seating range with h4350 by only testing on n133 given different ignition properties of different powders. It is definitely an interesting test, but it's too easy for people to read too much into a narrow set of results. Just mho, but I am really grateful for the work you put into it and the willingness to share.
Agreed. Definitely needs more testing.
I can see it being a powder and/or charge specific and I could also see it being a primer doing generally better.
Either way, the amount of testing needed to verify either is substantial.
As well as likely only possible with a rail gun or F/br rest setups. I wouldn’t expect a bipod and squeeze back to cut down on “noise” enough to properly test it.
It's an interesting concept especially if you look at something like pistol powders where each powder is either a magnum primer or regular primer powder. What this tells me is that you may be able to tune your ignition somewhat in the gap between. What it does not tell me is whether it is particularly worth doing so for most disciplines.
I've always argued that the best primer tools, and the CPS is great, allows you to get in the correct range easily, consistently and to do it quickly. The ability to tune or not from there is secondary to me.
Like Einstein said, "not everything important is measurable, and not everything measurable is important." I think that we get a ton of that in the reloading world, and as we get better measuring tools we continue to preference what we can easily measure. What we cannot easily measure, we discard. I keep trying to figure out which aspects of reloading belong in which column, and hopefully why.
I agree with the above posts.
But, I think that the other side of the coin is to look at how many people have almost the same loads for 6 Dasher or 6.5 Creed.
Even if people don’t know why something works, they can know if it works.
So, buying a tool like this and measuring distance below flush from case head from primer seating depth, I do think you’d eventually start seeing trends for the common loads that people use.
Precision Primer Gauge
The Precision Primer Gauge takes precision measurements of primer pocket depth and the depth of seated primers in relationship to the face of the case head.bullettipping.com
The good news is, this is one of those things that “can’t hurt” even if it’s not really helping.
And if it puts you in a better mindset, then it “works” regardless. I personally make much better ammo for PRS than I need to. But I find that I take each shot much more seriously since I have substantial time and work invested. So, I still see a performance increase even though it’s mental.
But something like trimming and tipping bullets, you can completely fuck up.
So, I’m always more accepting when people do things that can’t hurt even if it doesn’t matter. Than something that may not matter and can completely screw things up.
F class john had done a video on traveling with ammo and the effect that it had on OAL. Now that we are looking at the other side of the case, some people push their brass past when it can hold a primer or even just seating into looser pocket. Is there any chance of the anvil having a certain level of spring back either on its own or with the aid of traveling? I really don't even know if the anvil has more plastic or elastic characteristics.
May be a stupid thought but if .001" movement will screw you, I feel like it's worth thinking about.
May be a stupid thought but if .001" movement will screw you, I feel like it's worth thinking about.
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