Page 1 of 2 12 LastLast
Results 1 to 10 of 17

Thread: The Joys of a Chronograph: No hiding from the truth.

  1. #1

    The Joys of a Chronograph: No hiding from the truth.

    I have been loading some US Military surplus powder in my 308 called WC852F. It is a pull down powder taken from tracer rounds. The distributor lists "IMR 4895 Data" as a starting place so I have been loading some 165 and 168 grian bullets at 40.0 grains. The powder is very dirty but accurate. In my Model 70 sporter I shot some .5 and .6 inch, three shot groups after mounting a new Leupold eye glass. I was down to about 12 rounds left when I realized I had driven my 'fair weather' car to the range which had my chronograph and related gear in the back. (It is beautiful out side today: warm and sunny with almost no wind.) I quickly set up and fired 10 shots.

    I had expected these loads to be in the 2550 fps range but the chronograph doesn't lie: my average was 2370 fps from my 22 inch barrel. I had reduced the starting load because of using Lake City military brass (thicker) but I see there was no need. It was a little disappointing but we're talking surplus powder and surplus brass. The bullets were PPU 165 grain BTSP cannelured hunting bullets. (which have always shot well for me in the past)

    What did not disappoint me however, was the extreme spread of 46 fps and the standard deviation of 21 fps. I was really pleased when that tape rolled out of the machine! The charges were not weighed, loaded on Lee Dies, the necks flared before bullet seating, and crimped at the last. The bullets seated to the base of the neck.

    I need to go back to the drawing board but it's a start.~Muir

  2. #2
    I need to go back to the drawing board but it's a start.~Muir
    Do I detect a note of sarcasm ?

  3. #3
    Quote Originally Posted by Muir View Post
    The charges were not weighed, loaded on Lee Dies, the necks flared before bullet seating, and crimped at the last. The bullets seated to the base of the neck.

    I need to go back to the drawing board but it's a start.~Muir
    It makes you wonder ehh Britt?

  4. #4
    Well.... yes. And no. It is just a little ironic that without a lot of fuss and gadgetry, I found a load that is both well balanced (ballistically speaking) and accurate, and totally short of my expectations and needs. It's like finding a sweet deal on a two seat sports car when you are looking for a mini van. You're pleased to find it but need to keep searching.

    This powder is an unknown quantity for this application. I have seen data on the internet but one source erroneously listed it's burn rate in the H380 class, and another mimicked this bad info. I have no real indication of how this powder acts under (increasing) pressure. I was looking for 2500 fps from a 168 grain bullet so that I could plug these bullets my long range plinker and match the drop charts I'm building. I thought I had it nailed but like I said, the chronograph don't lie. (drat!)~Muir
    Last edited by Muir; 17-03-2013 at 14:42.

  5. #5
    Twenty or so years ago I got my first Chrony !

    Used it for everything back then . Rifles , shotguns , pistols , muzzleloaders and even my bow !

    It was great , then one day I set the muzzle loader to close and the extra stuff that blows forth from a ML fried the LED on the front .

    Since I bought it used and only had $50 in it I never bothered to get it fixed .

    We got another at the shop about a year ago and it stays in my possesion all the time .

    I'm back again doing some chronographng .

    And I gotta be truthfull . Sometimes I like the thing when it gives me numbers I like and other times I don't when it doesn't give me the numbers I was hoping for . But you are 100% correct , it doesn't lie .

  6. #6
    I like the Chrony units: I keep a couple of them for calculating ballistic coeffecients. I was testing some "problem" ammo for a manufacturer a couple of years back and a squib round clipped my Chrony right above the LED. The company sent me the "master" version with the math/stat computer and all the bells and whistles. To that damaged Chrony's credit, it still gave me a velocity and when I bent the mangled metal away from the screen, it continued to work! I still have it.

    My first chrongraph was a Tipico Time Meter that required a station wagon to haul around and you needed to manually convert nano seconds to fps. I got it third hand back in 1980. These new chrony's are a godsend by comparison.~Muir

  7. #7
    Quote Originally Posted by Muir View Post
    I like the Chrony units: I keep a couple of them for calculating ballistic coeffecients. I was testing some "problem" ammo for a manufacturer a couple of years back and a squib round clipped my Chrony right above the LED. The company sent me the "master" version with the math/stat computer and all the bells and whistles. To that damaged Chrony's credit, it still gave me a velocity and when I bent the mangled metal away from the screen, it continued to work! I still have it.

    My first chrongraph was a Tipico Time Meter that required a station wagon to haul around and you needed to manually convert nano seconds to fps. I got it third hand back in 1980. These new chrony's are a godsend by comparison.~Muir

    What you mean it was not the drop rod and knife blade type?

  8. #8
    Quote Originally Posted by Muir View Post
    I like the Chrony units: I keep a couple of them for calculating ballistic coeffecients. I was testing some "problem" ammo for a manufacturer a couple of years back and a squib round clipped my Chrony right above the LED. The company sent me the "master" version with the math/stat computer and all the bells and whistles. To that damaged Chrony's credit, it still gave me a velocity and when I bent the mangled metal away from the screen, it continued to work! I still have it.

    My first chrongraph was a Tipico Time Meter that required a station wagon to haul around and you needed to manually convert nano seconds to fps. I got it third hand back in 1980. These new chrony's are a godsend by comparison.~Muir
    When I first started doing this stuff the older guys around here always claimed anything but an Ohler was junk . I never was willing to lay out the cabbage for one . For what I do the Chrony seems to give one a good enough idea of whats going on .

    The one we've got now has the LED on the front again . I do wish we'd gotten the one with the LED you can sit on the bench , older eyes and all don't you know LOL's !

  9. #9
    I've got a friend down in Texas that does a good bit of work with cast bullets in lever actions like myself . As a matter of fact several of my molds came from him . Anyway he had a Ohler setup that hooked up to a laptop and also would plot where the bullets were hitting at 100 yards as it had another screen at that distance as well . He also had his PC hooked up with some stuff he could put on the barrels and check pressure .

    I expect he had over a grand tied up in that setup maybe more I dunno . Woulda been cool to have but I don't really think for what I do i could justify a need for that much equipment .

  10. #10
    Quote Originally Posted by Brithunter View Post
    What you mean it was not the drop rod and knife blade type?
    Just a step up from a ballistic pendulum, actually. ~Muir

Similar Threads

  1. Joys of taking Novice stalker and thansk to JayB
    By Heym SR20 in forum Articles & Write Ups
    Replies: 14
    Last Post: 17-09-2012, 10:53
  2. C,mon tell the truth
    By Brough in forum Deer Stalking General
    Replies: 11
    Last Post: 01-02-2009, 23:58
  3. THE TRUTH ABOUT THE SITE
    By sikamalc in forum Deer Stalking General
    Replies: 22
    Last Post: 09-07-2008, 17:37
  4. Hiding from the mother in law
    By Rob Mac in forum Jokes & Funnies
    Replies: 0
    Last Post: 11-12-2007, 09:14
  5. Too close to the truth
    By Rob Mac in forum Videos
    Replies: 2
    Last Post: 06-11-2007, 17:48

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •