Chronograph

Bianchi · November 2, 1999, 08:20 PM

I've been reloading for a few years ( by the Books). I just started using a chrony to check my loads. I don't get anywhere near the velocities published in the books with their loads. i.e 5.2gr bullseye with a 230 gr hardball produced 765 ft/sec avg. from a 5" 1911. published results are around 835-845. I'd like to increase powder but am wary of pressure. There is no signs of high presure on the 5.2 load. Should I keep increasing load until I get the desired velocity?

John Lawson · November 2, 1999, 09:27 PM

Don't increase your loads over book until you determine some things: How much taper crimp are you putting on? If you use an accurate micrometer, you should mike a case, run it into the t. c. die and be able to read .002" reduction in mouth diameter. This is average. Some reloaders go a thousandth more on lead bullets.
Find somebody who has a well proven out load (one that has been chronographed) or buy a box or fmj rounds that will give you a place to start checking your chrony. If it is reading right on the 835 or whatever the velocity has proved out on another chrono or factory velocity on a lot of ammo, you know where to begin. A very small variation in screen distance makes a big difference.
It is best to check your chrony against another chronograph of proven accuracy, if you can persuade some kind handloader to set up on the next bench.
Once you know what the problem is, you can begin experimenting to solve it.

HankL · November 3, 1999, 08:37 PM

Bianchi, Good advise is posted above but first and foremost your chrono is not their chrono! Your chrono can be a very useful tool for you if you understand a few things.
Given the short screen placements and non repeatability of this setting on hobby chronos you will have some variations. Most of the test data you see has been fired from test barrels that may be longer and tighter than yours.
Do this. Purchase a round with a published velocity that you find in a reloading manual or article and fire it over your rig. Make notes. Make detents, drill holes, take measuring tapes etc. to insure that you set up your chrono exactly the same way and the same distance each and every time and Make notes. Evaluate your loads as to accuracy given the muzzel velocity as shown by your setup and don't worry about what West Simpelton says he did with his 398 Bouywhacker at 1400 yds.
It's a useful tool for me. Your velocities will be your's. Simple enough huh?
Best regards and good and safe shooting
Hank

Others here can explain scientific notation and Occam's Razor "?" etc. just be careful and enjoy

Bianchi · November 3, 1999, 08:47 PM

Thanks Guy's, I did chrono PMC 230 FMJ target load and it measured 835 ft/sec. so I thought I had the chrono set up right. I'll keep trying with the same load before I increase anything.

November 2, 1999, 08:20 PM	#1
Bianchi Member Join Date: November 2, 1999 Location: Randolph, MA USA Posts: 38	I've been reloading for a few years ( by the Books). I just started using a chrony to check my loads. I don't get anywhere near the velocities published in the books with their loads. i.e 5.2gr bullseye with a 230 gr hardball produced 765 ft/sec avg. from a 5" 1911. published results are around 835-845. I'd like to increase powder but am wary of pressure. There is no signs of high presure on the 5.2 load. Should I keep increasing load until I get the desired velocity?

November 2, 1999, 09:27 PM	#2
John Lawson Senior Member Join Date: August 28, 1999 Posts: 281	Don't increase your loads over book until you determine some things: How much taper crimp are you putting on? If you use an accurate micrometer, you should mike a case, run it into the t. c. die and be able to read .002" reduction in mouth diameter. This is average. Some reloaders go a thousandth more on lead bullets. Find somebody who has a well proven out load (one that has been chronographed) or buy a box or fmj rounds that will give you a place to start checking your chrony. If it is reading right on the 835 or whatever the velocity has proved out on another chrono or factory velocity on a lot of ammo, you know where to begin. A very small variation in screen distance makes a big difference. It is best to check your chrony against another chronograph of proven accuracy, if you can persuade some kind handloader to set up on the next bench. Once you know what the problem is, you can begin experimenting to solve it.

November 3, 1999, 08:37 PM	#3
HankL Senior Member Join Date: March 11, 1999 Location: The Sunny South Posts: 2,174	Bianchi, Good advise is posted above but first and foremost your chrono is not their chrono! Your chrono can be a very useful tool for you if you understand a few things. Given the short screen placements and non repeatability of this setting on hobby chronos you will have some variations. Most of the test data you see has been fired from test barrels that may be longer and tighter than yours. Do this. Purchase a round with a published velocity that you find in a reloading manual or article and fire it over your rig. Make notes. Make detents, drill holes, take measuring tapes etc. to insure that you set up your chrono exactly the same way and the same distance each and every time and Make notes. Evaluate your loads as to accuracy given the muzzel velocity as shown by your setup and don't worry about what West Simpelton says he did with his 398 Bouywhacker at 1400 yds. It's a useful tool for me. Your velocities will be your's. Simple enough huh? Best regards and good and safe shooting Hank Others here can explain scientific notation and Occam's Razor "?" etc. just be careful and enjoy

November 3, 1999, 08:47 PM	#4
Bianchi Member Join Date: November 2, 1999 Location: Randolph, MA USA Posts: 38	Thanks Guy's, I did chrono PMC 230 FMJ target load and it measured 835 ft/sec. so I thought I had the chrono set up right. I'll keep trying with the same load before I increase anything.