Chronographing a Shotgun
-
Topic author - Senior Member
- Posts in topic: 1
- Posts: 306
- Joined: Fri Dec 24, 2004 6:02 pm
- Location: Texas
Chronographing a Shotgun
How does one go about chrongraphing a shotgun. I see some ammo manufactures state velocities on the box, but how do you keep the wadding from screwing up the velocity reading.
There will be no peace until they love their children more than they hate us - Golda Meir
-
- Senior Member
- Posts in topic: 2
- Posts: 26796
- Joined: Wed Jan 16, 2008 12:59 pm
- Location: North Richland Hills, Texas
- Contact:
Re: Chronographing a Shotgun
This is just a guess...... the wadding follows the shot charge out the barrel, and it has very little mass. So the shot charge is what the chrono picks up, and it just doesn't even see the wad...except as part of the larger mass of the shot charge. The chrono is most likely set up 10' or less in front of the muzzle, and at that distance the shot column and the wad are still one amorphous mass.TEX wrote:How does one go about chrongraphing a shotgun. I see some ammo manufactures state velocities on the box, but how do you keep the wadding from screwing up the velocity reading.
“Hard times create strong men. Strong men create good times. Good times create weak men. And, weak men create hard times.”
― G. Michael Hopf, "Those Who Remain"
#TINVOWOOT
― G. Michael Hopf, "Those Who Remain"
#TINVOWOOT
-
- Senior Member
- Posts in topic: 1
- Posts: 2973
- Joined: Sat Mar 31, 2007 9:39 pm
- Location: Western Texas
Re: Chronographing a Shotgun
I have never gotten a good chrono reading with lead shot, stainless shot has worked well for me. The chrono works by sensing the change in lighting as the projectile crosses the windows, with that in mind I think it will measure the front of the shot column more than anything else. As for why lead shot has never given me good results I do not know, I do know that I have gotten good results with the PDX plated stuff as well.
How do you explain a dog named Sauer without first telling the story of a Puppy named Sig?
R.I.P. Sig, 08/21/2019 - 11/18/2019
R.I.P. Sig, 08/21/2019 - 11/18/2019
-
- Senior Member
- Posts in topic: 2
- Posts: 17350
- Joined: Tue Jul 03, 2007 12:53 pm
- Location: Houston
Re: Chronographing a Shotgun
TAM - that is a good guess. I am sure that SAAMI has a standard test method for measuring the muzzle velocity of shot shells.The Annoyed Man wrote:This is just a guess...... the wadding follows the shot charge out the barrel, and it has very little mass. So the shot charge is what the chrono picks up, and it just doesn't even see the wad...except as part of the larger mass of the shot charge. The chrono is most likely set up 10' or less in front of the muzzle, and at that distance the shot column and the wad are still one amorphous mass.TEX wrote:How does one go about chrongraphing a shotgun. I see some ammo manufactures state velocities on the box, but how do you keep the wadding from screwing up the velocity reading.
NRA Endowment Member
Re: Chronographing a Shotgun
I too wondered about that and there is a YouTube video
" onclick="window.open(this.href);return false;
to condense, they fire with the choke that they plan to use in the field at a distance of 3-4 feet and are always prepared to buy a new sensor. In this video they did not use the sun shield.
" onclick="window.open(this.href);return false;
to condense, they fire with the choke that they plan to use in the field at a distance of 3-4 feet and are always prepared to buy a new sensor. In this video they did not use the sun shield.
-
- Senior Member
- Posts in topic: 1
- Posts: 10371
- Joined: Tue Feb 03, 2009 6:51 am
- Location: Ellis County
Re: Chronographing a Shotgun
Fixed it for you.rotor wrote:I too wondered about that and there is a YouTube video
[youtube][/youtube]
to condense, they fire with the choke that they plan to use in the field at a distance of 3-4 feet and are always prepared to buy a new sensor. In this video they did not use the sun shield.
Life is tough, but it's tougher when you're stupid.
John Wayne
NRA Lifetime member
John Wayne
NRA Lifetime member
-
- Senior Member
- Posts in topic: 2
- Posts: 26796
- Joined: Wed Jan 16, 2008 12:59 pm
- Location: North Richland Hills, Texas
- Contact:
Re: Chronographing a Shotgun
I never knew that. I always assumed that it sensed the mass of the object passing through the screens. Don't know why I thought that.......I just did.G.A. Heath wrote:I have never gotten a good chrono reading with lead shot, stainless shot has worked well for me. The chrono works by sensing the change in lighting as the projectile crosses the windows, with that in mind I think it will measure the front of the shot column more than anything else. As for why lead shot has never given me good results I do not know, I do know that I have gotten good results with the PDX plated stuff as well.
“Hard times create strong men. Strong men create good times. Good times create weak men. And, weak men create hard times.”
― G. Michael Hopf, "Those Who Remain"
#TINVOWOOT
― G. Michael Hopf, "Those Who Remain"
#TINVOWOOT
-
- Senior Member
- Posts in topic: 2
- Posts: 17350
- Joined: Tue Jul 03, 2007 12:53 pm
- Location: Houston
Re: Chronographing a Shotgun
Some of the earlier chronographs worked by the bullet breaking the continuity of an electrical current. When the projectile broke the first [metal] screen the timer started and when the bullet went through the second screen the next circuit broke and the timer stopped. If you knew the distance between the screens you can calculate the velocity. I haven't kept up with the current technology.The Annoyed Man wrote:I never knew that. I always assumed that it sensed the mass of the object passing through the screens. Don't know why I thought that.......I just did.G.A. Heath wrote:I have never gotten a good chrono reading with lead shot, stainless shot has worked well for me. The chrono works by sensing the change in lighting as the projectile crosses the windows, with that in mind I think it will measure the front of the shot column more than anything else. As for why lead shot has never given me good results I do not know, I do know that I have gotten good results with the PDX plated stuff as well.
NRA Endowment Member