RepackboxInline FabricationRotoMetals2Bonett
ADvertise hereTitan ReloadingMidSouth Shooters SupplyLee Precision

Donate Now Goal amount for this year: 6000 USD, Received: 4330 USD (72%)
Our Annual server fund drive is going on now! This donation drive helps fund Cast Boolits for an entire year, and helps support our 2nd amendment rights! You can donate by Paypal by clicking the DONATE button. Or by Cash / Check / MO to the address below:

Willy Snyder
PO Box 2732
Pocatello, ID 83206
****Due to overwhelming e-mails, I will be very slow in updating this list. Please bear with me!****


Page 1 of 4 1234 LastLast
Results 1 to 20 of 61

Thread: Chronograph Challenge and chasing ES/SD

  1. #1
    Boolit Grand Master
    Join Date
    Oct 2009
    Location
    Northern Michigan
    Posts
    7,218

    Chronograph Challenge and chasing ES/SD

    I got into a bit of a controversy this week.

    I see a folks using chronographs and have never understood why a cast bullet shooter would need one. In fact, I cannot understand why most people would need one.

    I have whittled my main rifles down to a bunch of .223/5.56's and .308's. I did some back of the envelop calculations of the difference in POI if ES is 100 fps, and could not see much difference in making hits at 300 yards with .223 or 400 yards with the .308

    My assumption is that because I average about 1 MOA in the .223's and maybe a bit more in the .308's the loads I have are "good". ES doesn't matter...right?

    I understand that at long ranges (over 600 yards) ES will cause greater POI changes but I do not work out there. I assume most shooters do not either. So I wonder why would anyone worry about ES for pistols loads, cast loads and jacketed hunting loads.

    I have never been able to understand "ladder load development" either and that needs a chronograph. I am "old school" and use incremental load development to find a decent load then shoot a bunch of groups to confirm it was not a fluke. Once I get in the MOA area with a bolt gun I am done...good enough is good enough.

    For those still with me, I have a NIB chronograph. Back when I got it, I could only shoot at public ranges and it would have been a PITA to set up. Being as l like trigger time and components were cheap, I kept muddling along with shooting groups for years.

    So, here is the challenge. The chronograph (ProChrono) is "free" (you pay shipping). I will give it to the person who can best explain why someone with my needs could benefit from using one.

    My needs are simple:
    Varmints to 300 yards with .223's and 55 gr Hornady SP
    Deer to 400 yards with a .308 using 150 gr Hornady Interlocks or 165 gr Sierra GameKings
    Pistol calibers to 100 yards in carbines.

    If you make a good enough case, I will pay the shipping! Knowledge is not free and none of the stuff I have read has made a compelling case so far. But I am willing to learn.

    Mods, if this post is in the wrong forum please move. I put it here because the mantra is "You need a chronograph to develop loads" so it seems like a piece of reloading equipment.
    Don Verna


  2. #2
    Boolit Master elmacgyver0's Avatar
    Join Date
    Nov 2010
    Posts
    905
    I don't think you need one also, but they are a hoot to use if you are into air guns.

  3. #3
    Boolit Master Maven's Avatar
    Join Date
    Mar 2005
    Posts
    4,840
    I don't know whether anyone "needs" a chronograph, Don unless they're doing extensive load development and testing. I have a Shooting Chrony F-1 and haven't used it for years because, as you mentioned, I value my trigger time more than monkeying with that device. (They are especially sensitive to light intensity and direction, I've found.) Having said this, I will add, the most important reason for owning and using a chronograph is for load development with unknown or military surplus propellants, e.g., IMR 5010, IMR 7383, WC 860, WC 820, etc. You can get repeatable results and low SD's IF you chronograph your loads.

  4. #4
    Boolit Master AnthonyB's Avatar
    Join Date
    Mar 2005
    Posts
    1,293
    Load development with non-cannister powders is my excuse on the rare times I use the chrony.
    Tony

  5. #5
    Boolit Grand Master
    Join Date
    Oct 2009
    Location
    Northern Michigan
    Posts
    7,218
    I will let this run until midnight EST June 26th.
    Don Verna


  6. #6
    Boolit Master
    Mal Paso's Avatar
    Join Date
    Jun 2010
    Location
    Carmel, Ca
    Posts
    3,904
    I was able to work up a load for 350 Legend using 11FS powder and data for H110 as there is no data for 11FS and Cast.

    I also saw the spread was over 100 FPS and cut that in half with Magnum Primers. I'm now 39 FPS slower than the Maximum H110 load and still 2 grains Light of the calculated load.

    If you don't have pressure testing, how do you know without a speedometer?
    Mal

    Mal Paso means Bad Pass, just so you know.

  7. #7
    Boolit Buddy
    Join Date
    Jul 2011
    Location
    outskirts of Harrisburg,Pa.
    Posts
    176
    I may be the exception, but I use my chrono extensively. I am a competitive handgun shooter. I need to make certain power factors to qualify to shoot in certain divisions. I shoot ICORE and USPSA, for example. The major matches actually chrono your ammo and gun to ensure that you don't have a competitive advantage over others.

  8. #8
    Boolit Grand Master



    M-Tecs's Avatar
    Join Date
    Apr 2008
    Location
    Minnesota
    Posts
    7,860
    I find the chrono invaluable for post 600-yard load development.

    For the under 600-yard stuff once I find an accuracy load I record the velocity. When I switch lots of powder I vary the charge to equal the velocity of the old lot of powder. I find accuracy much more consistent compared to using the same charge weight. Even switching powder types it seems specific velocities tend to produce the peak accuracy.

    I also use a chrono as a ROUGH pressure indicator. If the velocity is high or low something is amiss with the load development.

    I am dealing mostly with target rifles or varmint rifles capable of sub 1/2 MOA ten shot groups.

    My cowboy rifles and pistols have never been fired over a chrono and most likely never will be.

    For handgun I need a chrono to ensure I make major.

    On the gunsmithing side I have used a chrono to determine inconsistent firing pin strikes were cause velocity variations that created accuracy issues. One was on an RPA 2000 action that the owner had lost a washer. Couple of others had burs that created issues.
    Last edited by M-Tecs; 06-23-2022 at 11:36 PM.
    2nd Amendment of the U.S. Constitution. - "A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed."

    "Before you argue with someone, ask yourself, is that person even mentally mature enough to grasp the concept of different perspectives? Because if not, there’s absolutely no point."
    – Amber Veal

    "The Highest form of ignorance is when your reject something you don't know anything about".
    - Wayne Dyer

  9. #9
    Boolit Master

    stubshaft's Avatar
    Join Date
    Apr 2009
    Location
    Southernmost State of the Union
    Posts
    4,852
    I use mine for load development and accuracy testing. I find it useful to find the velocity that a particular bullet shoots best at and be able to duplicate that velocity with another powder by shooting "ladder loads".

    Click image for larger version. 

Name:	338 target 11621a.jpg 
Views:	7 
Size:	95.8 KB 
ID:	301496

    I shoot a fair number of wildcat cartridges where there is no loading data or limited loading data. With a chronograph I can plot the velocity increase per grain of powder and determine when it runs out of juice and reaches a point of diminishing returns.
    Old enough to know better, young enough to do it anyway!

    When the only tool you have is a hammer, every problem is a nail.

  10. #10
    Boolit Buddy 414gates's Avatar
    Join Date
    Jan 2017
    Posts
    207
    The chrony is a tool that is only necessary to indicate the relative safety of a load, because velocity is an indication of pressure, and excessive velocity means excessive pressure.

    It's common practice to look for physical pressure signs on the brass or the primer, and not use a chrony, but I don't rely on that because in my testing I found that over pressure loads do not always show physical signs on the brass or the primer.

    The chrony is very useful for precision rifle reloads. Precision being 1 MOA to 1000 yards. I want a load with a speed variation of single digits as the basis, and I need a chrony to find that.

  11. #11
    Boolit Buddy
    Join Date
    Apr 2021
    Location
    Australia
    Posts
    177
    Don -I don't need another chronograph, since I have had a perfectly good Oehler since about 1980. Today, I would feel lost without it. No doubt someone can benefit from yours however like I have benefited from mine.

    Fine tuning published loads to the peculiarities of my rifles has been an ongoing use - if pressure tested data says a combination is OK for pressure at say 2800 fps, and my workup looks like going to 2900, I'll believe the chronograph and stop at 2800. I have also used my chronograph to sort out useful cast bullet loads for some (free) 3031 lookalike powder.

    You mention ES and whether it matters. If a rifle is not too fussy about velocity, then maybe ES/SD does not matter as much. My Ruger 77V .308 is a case in point - a variety of bullet weights and loads will still pile up in a 100 meter group of no more than 3" or 4", and sometimes a lot better. Same bullet and same powder will likely produce 1.5" or so.

    A lever action Marlin or Winchester is another matter entirely, and I would not shoot a group from either without also chronographing the shots. These lever actions are velocity sensitive, as indicated when someone shoots a group with 150 gn ammo, and then another with 170 gn - vertical POI at 50 m may differ by 4" or more. This extends also to velocity differences between different loads with the same bullet, say another grain of powder, and even the variation within a single group.

    By plotting individual shots for POI and velocity I have determined to my own satisfaction that my Marlin 336A .30-30 shoots approximately 2" higher at 50 meters for every extra 100 fps velocity. This gives a very solid explanation for vertical stringing of some groups. Without the velocities we would be chasing around after bench technique, tightening screws, adjusting bedding etc, when the real fix is just to tighten up the SD - different powder, a bit more of it to get a good burn, same headstamp brass, maybe a softer primer etc.

    Bottom line - having the individual velocities helps me explain why one load shows vertical stringing and another does not. Sort out the velocity variation and I sort out the groups - but that needs the chronograph.
    Last edited by Wilderness; 06-24-2022 at 05:04 PM.
    It'll be handy if I never need it.

    Insomniac, agnostic, dyslectic - awake all night wondering if there is a Dog.

  12. #12
    Boolit Master

    Land Owner's Avatar
    Join Date
    Aug 2010
    Location
    Mims, FL
    Posts
    1,531
    I hunt meat and have enjoyed a lot of "trigger time" with feral hogs. I know my hunting land and the range finder distance to its landmarks from the stands.

    I want to believe, within a chronograph's measurable certainty, the average velocity of my reloads through my barrels, and not the Mfg's published velocities through their "test barrels". I create an individual Drop Table for each rifle, bullet, and powder charge with which I hunt. I also know the Point-Blank Range of my equipment from shooting 25-yd., 100-yd., and 200 yd. targets.

    Testing gives me great confidence in my equipment, my techniques, my components, and my capability to drop game, DRT, so I do not lose any to the thicket of the State's adjacent 'No Hunting' land.
    If it was easy, anybody could do it.

  13. #13
    Boolit Grand Master
    Join Date
    Oct 2009
    Location
    Northern Michigan
    Posts
    7,218
    Quote Originally Posted by Wilderness View Post

    A lever action Marlin or Winchester is another matter entirely, and I would not shoot a group from either without also chronographing the shots. These lever actions are velocity sensitive, as indicated when someone shoots a group with 150 gn ammo, and then another with 170 gn - vertical POI at 50 m may differ by 4" or more. This extends also to velocity differences between different loads with the same bullet, say another grain of powder, and even the variation within a single group.

    By plotting individual shots for POI and velocity I have determined to my own satisfaction that my Marlin 336A .30-30 shoots approximately 2" higher at 50 meters for every extra 100 fps velocity. This gives a very solid explanation for vertical stringing of some groups. Without the velocities we would be chasing round after bench technique, tightening screws, adjusting bedding etc, when the real fix is just to tighten up the SD - different powder, a bit more of it to get a good burn, same headstamp brass, maybe a softer primer etc.

    Bottom line - having the individual velocities helps me explain why one load shows vertical stringing and another does not. Sort out the velocity variation and I sort out the groups - but that needs the chronograph.
    This is most interesting as it is unexpected. Ballistically, a 100 fps variation cannot effect POI by 2" at 50 meters. Trying to determine why this is happening is making me scratch my head. BTW, I am not doubting your information...only attempting to understand. You have done enough testing to confirm the phenomenon in this particular rifle, and this determination would not have been possible without chronograph data. BTW, this is the first time I have seen a chronograph make a significant contribution to developing a load for practical purposes.

    Do you think barrel/action harmonics in a lever action (or at least your 336) have a greater effect than with other platforms? Thus a 100 fps difference has a more pronounced affect than a simple math calculation of POI change due to velocity change?

    But your post is why I made the challenge here....to learn. What I read about using chronographs is always about "precision rifle shooting" at ranges most ethical hunters would pass on.

    Also, I want to thank the others who are responding. Your information tends to confirm my understanding and opinions.

    I should have added in the first post that I do not go "off the reservation". I use powders that are published for the caliber and bullet weight (or close to it). My goal is to find the most accurate load at close to peak performance. If max charge is 45 gr and my accurate load is at 43 gr. I stop working on the load. "Losing" 100-125 fps by being under maximum is not important to me.
    Don Verna


  14. #14
    Boolit Buddy
    Join Date
    Jun 2013
    Location
    SW ND
    Posts
    278
    Hi Don. I can’t tell you why you need one right now. Sounds like you use common components and follow manuals data. The best reason I could give you for keeping it around is if you start using surplus powders or developing your own load data. Or if you wanted to play with bullet weights that are uncommonly used in the calibers you have. For instance very light or heavy for caliber. It’s interesting to me how much just a primer change or lot number change in powder can make

  15. #15
    Boolit Buddy 414gates's Avatar
    Join Date
    Jan 2017
    Posts
    207
    Quote Originally Posted by dverna View Post
    This is most interesting as it is unexpected. Ballistically, a 100 fps variation cannot effect POI by 2" at 50 meters. Trying to determine why this is happening is making me scratch my head.
    Lever actions are known for shallow rifling.

    If that is the case here, it may lead to an explanation of why the trajectory is so finnicky.

  16. #16
    Boolit Buddy Cast10's Avatar
    Join Date
    May 2020
    Location
    TX
    Posts
    312
    I’ve got an older Pact model and love it. Had it since the 80’s.

    Everything about load development, shooting, casting, LIFE is all about CONSISTENCY.

    With the assistance of a Chrony, a shot group will provide you with variables all designed to point to the most CONSISTENT group, regardless of on target grouping, as this may vary due to shooter. In the event you find several shot groups close in NUMBERS, the chrony can provide further insight by giving you standard deviation, extreme spread, shot per shot velocity, average velocity, energy, ballistics, and more. All these values provide you a scientific insight into the CONSISTENCY of the load you fired/developed. It may also indicate a load that varies in different firearms, that without a chrony, you could lose lots of ammo trying to provide inaccuracies. If you have one, use it as needed. Mine is used during load development.

    BTW, I ‘m not looking for another, pass on the offer. Best of luck.

  17. #17
    Vendor Sponsor


    DougGuy's Avatar
    Join Date
    Apr 2013
    Location
    just above Raleigh North Carolina
    Posts
    6,740
    Quote Originally Posted by Cast10 View Post
    Everything about load development, shooting, casting, LIFE is all about CONSISTENCY.

    With the assistance of a Chrony, a shot group will provide you with variables all designed to point to the most CONSISTENT group, regardless of on target grouping, as this may vary due to shooter. In the event you find several shot groups close in NUMBERS, the chrony can provide further insight by giving you standard deviation, extreme spread, shot per shot velocity, average velocity, energy, ballistics, and more. All these values provide you a scientific insight into the CONSISTENCY of the load you fired/developed. It may also indicate a load that varies in different firearms, that without a chrony, you could lose lots of ammo trying to provide inaccuracies. If you have one, use it as needed. Mine is used during load development.
    ^^^^THIS^^^^

    CONSISTENCY is *THE* goal! When I worked on figuring out the mod I use for Lee's collet crimp handgun caliber dies, I found that my SD was under 20fps, which the modded crimp gave a good account of itself in this area of reloading. Ruger 7.5" SBH throats sized .4325" Lee C430-310-RF boolits .432" cast 50/50+2% over 17.0gr H2400, WLP primers (each case individually weighed and trickled). Loads run 1180-1200fps, and accuracy at tree stand distances is exceptionally good.

    Many years ago before I knew diddly squat about nothing, I worked over a Ruger M77 in 308. Lapped locking lugs, pillar bedded screws, bedded the entire action with a 100rd box of 45 Colt ammo tied to the front sling swivel which gave upward pressure against the barrel when removed. Loaded only fire formed brass, bullets seated .025" from the leade ins of the rifling.

    The cat's meow came with the crimp die! Weighed charges of H4895 under 180gr soft point plain base j words. When seating bullets, I culled any that seated easier at the press, same with the stiff ones, set them aside. Then I ran the good ones under the collet crimp. Rounds that had the crimp right on the case mouth were culled, ones that had more than about .030" of case mouth ahead of the crimp band were culled, so out of 100 pieces of LC brass I wound up with maybe 15-18 rounds that would go 3 into a guitar pick @ 200yds from a prone position. I shot a turkey with this rifle and load as mentioned, distance was a walked off 340yds, hit within 1/2" of POA.

    dverna you may want to investigate the collet crimp if you aren't already, as it may bring your SD down noticeably, which would cut your MOA at distance IF you had chrony data to verify with.
    Last edited by DougGuy; 06-24-2022 at 10:01 AM.
    Got a .22 .30 .32 .357 .38 .40 .41 .44 .45 .480 or .500 S&W cylinder that needs throats honed? 9mm, 10mm/40S&W, 45 ACP pistol barrel that won't "plunk" your handloads? 480 Ruger or 475 Linebaugh cylinder that needs 6° 30min chamfer reamed? Click here to send me a PM You can also find me on Facebook Click Here.

  18. #18
    Boolit Grand Master


    Larry Gibson's Avatar
    Join Date
    Jul 2005
    Location
    Lake Havasu City, Arizona
    Posts
    19,888
    dverna

    "This is most interesting as it is unexpected. Ballistically, a 100 fps variation cannot effect POI by 2" at 50 meters."

    Your argument is overly simplistic. It does not take into account several other things such as; the drop figures are of the center of the cone of fire and not taking into account linear dispersion of the group caused by the velocity variation, the variation in the location of barrel nodes is greater with large ES, the variation in angle of departure between rounds of different velocities, etc.

    Variation of group size/accuracy with cartridge giving large ES can easily become apparent at 50 yards with handguns and even at 100 yards with rifles. Yes, you can have some, what appears to be, usable accuracy with some very inconsistent loads a t shorter ranges but for the best loads you'll want an ES with a proportionate SD that is conducive to best accuracy. That is not saying to chase the lowest ES or SD or combination of both to the lowest nth degree. Factually, most rifle and handgun cartridge loads that can give a consistent ES 50 fps or under with a proportionate SD for a 10 shot test are going to be good loads given quality bullets that are appropriate for the barrel twist. Chasing a lower ES or SD can be frustrating because once you get that low of ES/SD then the simple variation of test to test results can be misleading. A balance of a less than 50 fps ES/SD combination AND on target results at the longest range you will shoot is what most of us seek for consistent accuracy.

    Having said that I'm not going to try to convince you to keep and use your chronograph. What you have been doing and are doing certainly fits your needs. Thus you, apparently, feel no "need" for a chronograph. However, your needs are not mine nor others. There are indeed benefits to using a chronograph. Whether one "needs" or can use those benefits is a matter of individual preferences.
    Larry Gibson

    “Deficient observation is merely a form of ignorance and responsible for the many morbid notions and foolish ideas prevailing.”
    ― Nikola Tesla

  19. #19
    Boolit Grand Master
    Join Date
    Oct 2009
    Location
    Northern Michigan
    Posts
    7,218
    Quote Originally Posted by Messy bear View Post
    Hi Don. I can’t tell you why you need one right now. Sounds like you use common components and follow manuals data. The best reason I could give you for keeping it around is if you start using surplus powders or developing your own load data. Or if you wanted to play with bullet weights that are uncommonly used in the calibers you have. For instance very light or heavy for caliber. It’s interesting to me how much just a primer change or lot number change in powder can make
    I looked at buying surplus powders years ago, but would never trust a chronograph to tell me a load is safe. Muzzle velocity is not a measure of pressure when "going off the reservation". Even with known powders, I have seen data that shows little to no increase in MV with some powders as pressures exceed max. I suppose when you reach the point that adding more powder has little or no increase in MV it indicates the load is past max. pressure. Would that be correct? But what is the max pressure that happens at? It might depend on the type of powder, case capacity, length of barrel, other things? And say it happens at 60k psi. Well that is high for a .30/30 lever action. Just too many variables for me to juggle and have confidence in.

    If someone would post how they use a chronograph to determine a safe load that would be worth examining. My way archaic. I start about 10% below max and work up to max. If I see flattened primers on the way up, I stop. I know that is "wrong" but I have not blown up a gun....yet.

    It would an interesting discussion.
    Don Verna


  20. #20
    Boolit Grand Master


    Larry Gibson's Avatar
    Join Date
    Jul 2005
    Location
    Lake Havasu City, Arizona
    Posts
    19,888
    "Flattened primers are not always an indication of excessive pressure. I have actually pressure tested others loads where they though there was excessive pressure even though the load was below "max" in various cartridges. I've found excessive headspace caused by oversizing the case and/or setting the shoulder back to much is most often the cause. Even if that is not the case with many primers by the time you get really flattened primers [the primers are flattened all the way to the edge of the primer pocket with no rounding at the edge] the load is usually into proof load pressure range.

    When using a chronograph if you know the burn rate of the surplus powder and compare velocities of max loads of similar burn rate powders then when the velocity of the test loads approaches those comparison velocities you know you are getting close. No, it is not for sure, but it is a lot better than depending on primers flatness, case head expansion, bolt lift/extraction or other such methods. That is based on the use of chronographs since '74 and pressure testing since '07 to test thousands of loads.
    Larry Gibson

    “Deficient observation is merely a form of ignorance and responsible for the many morbid notions and foolish ideas prevailing.”
    ― Nikola Tesla

Page 1 of 4 1234 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Abbreviations used in Reloading

BP Bronze Point IMR Improved Military Rifle PTD Pointed
BR Bench Rest M Magnum RN Round Nose
BT Boat Tail PL Power-Lokt SP Soft Point
C Compressed Charge PR Primer SPCL Soft Point "Core-Lokt"
HP Hollow Point PSPCL Pointed Soft Point "Core Lokt" C.O.L. Cartridge Overall Length
PSP Pointed Soft Point Spz Spitzer Point SBT Spitzer Boat Tail
LRN Lead Round Nose LWC Lead Wad Cutter LSWC Lead Semi Wad Cutter
GC Gas Check