Does anyone know how the CTC claims are measured ?
How to measure the various internal diameters of a single barrel for choking ?
What is the cheapest (yet accurate) way to measure the weight of a single pellet ?
how to measure both muzzle velocity and velocity at 10 m cheaply ? Of course, having 2 chrono's will help but not very affordable.
How to measure pellet drop at say 10 m ?
Measuring things
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papaburger
- Posts: 371
- Joined: Fri Oct 28, 2005 4:38 pm
- Location: Richmond, BC, Canada
Hi Papaburger,
Does anyone know how the CTC claims are measured ?
The CTC of a group can be made by measuring between the extreme outside edges of the group hole and deducting one pellet diameter. This is how the benchrest shooters do the measurements.
If you are new to measuring I suggest shooting a couple of pellet holes beside your group so you can test how much grey ring you need to use to get the pellet diameter.
When measuring between widely spaced pellets (in a group) you can put the pointed ends of the vernier caliper in the center of each pellet hole. The human eye does a good job of centering things and your measurement will be very close, but maybe not perfect. It might be good enough for you needs.
How to measure the various internal diameters of a single barrel for choking ?
You can measure a barrel choke size by slugging the bore. Place a tight fitting pellet into the barrel and carefully push it through with a cleaning rod. Measure skirt size of pellet. To check size before the choke, you can push pellet in halfway and push back out breech end.
You can find tight spots in barrel by slowly pushing pellet through and feeling for constrictions. A tight fitting patch can also be used. You can then measure the distance from the breech to the tight spots and then use a pellet to get measurments. Hopefully you don't have tight spots. I hope this makes sense to you.
Powder burner shooters use a cast bullet and shoot it through barrel with a very light load of powder so it can be found in soft sand or padding. I watched one guy slug a .38/55 this way. He used less than one grain of bullseye powder and the bullet stuck at the muzzle. We pounded it out with a nylon coated metal cleaning rod. He was then able to use the measured slug to come up with a good size for his cast bullets.
What is the cheapest (yet accurate) way to measure the weight of a single pellet ?
Use a reloading scale. I prefer to weigh 10 pellets and divide by 10 to get an average for a specific pellet type.
how to measure both muzzle velocity and velocity at 10 m cheaply ? Of course, having 2 chrono's will help but not very affordable.
Do the measurements separately if you only have one chronograph. When testing at 10m you can cut a hole in a piece of thick wood/metal and place this "protector" in front of the chronograph so that it allows you to shoot over the sensors but not hurt the electronics if you miss.
How to measure pellet drop at say 10 m ?
Graph the pellet trajectory by testing drop at each distance (i.e 5m, 10m, 15m, 20m). The graphed results can be interesting.
Pellets start dropping as soon as they leave the barrel.
HTH,
Todd
Does anyone know how the CTC claims are measured ?
The CTC of a group can be made by measuring between the extreme outside edges of the group hole and deducting one pellet diameter. This is how the benchrest shooters do the measurements.
If you are new to measuring I suggest shooting a couple of pellet holes beside your group so you can test how much grey ring you need to use to get the pellet diameter.
When measuring between widely spaced pellets (in a group) you can put the pointed ends of the vernier caliper in the center of each pellet hole. The human eye does a good job of centering things and your measurement will be very close, but maybe not perfect. It might be good enough for you needs.
How to measure the various internal diameters of a single barrel for choking ?
You can measure a barrel choke size by slugging the bore. Place a tight fitting pellet into the barrel and carefully push it through with a cleaning rod. Measure skirt size of pellet. To check size before the choke, you can push pellet in halfway and push back out breech end.
You can find tight spots in barrel by slowly pushing pellet through and feeling for constrictions. A tight fitting patch can also be used. You can then measure the distance from the breech to the tight spots and then use a pellet to get measurments. Hopefully you don't have tight spots. I hope this makes sense to you.
Powder burner shooters use a cast bullet and shoot it through barrel with a very light load of powder so it can be found in soft sand or padding. I watched one guy slug a .38/55 this way. He used less than one grain of bullseye powder and the bullet stuck at the muzzle. We pounded it out with a nylon coated metal cleaning rod. He was then able to use the measured slug to come up with a good size for his cast bullets.
What is the cheapest (yet accurate) way to measure the weight of a single pellet ?
Use a reloading scale. I prefer to weigh 10 pellets and divide by 10 to get an average for a specific pellet type.
how to measure both muzzle velocity and velocity at 10 m cheaply ? Of course, having 2 chrono's will help but not very affordable.
Do the measurements separately if you only have one chronograph. When testing at 10m you can cut a hole in a piece of thick wood/metal and place this "protector" in front of the chronograph so that it allows you to shoot over the sensors but not hurt the electronics if you miss.
How to measure pellet drop at say 10 m ?
Graph the pellet trajectory by testing drop at each distance (i.e 5m, 10m, 15m, 20m). The graphed results can be interesting.
Pellets start dropping as soon as they leave the barrel.
HTH,
Todd
heres how i measure the drop in my bullets, make sure you use a benchrest so you are accurate. and make sure your scope/sights are set right
just measure the distance with a ruler to see how much your are dropping at 10m shoot all 5shots and divide it by 5 to find the average drop
edit-- if you need the actual size of this paper just pm me and i can give you the actual picture and then you can print it
just measure the distance with a ruler to see how much your are dropping at 10m shoot all 5shots and divide it by 5 to find the average drop
edit-- if you need the actual size of this paper just pm me and i can give you the actual picture and then you can print it
Last edited by gamerule9 on Wed Dec 07, 2005 12:13 am, edited 1 time in total.
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DoctorFrankengun
- Posts: 1657
- Joined: Thu Sep 08, 2005 1:58 pm
- Location: Cochrane, Ontario Canada
gamerule 9,
What is the scale of your very excellent target?
What is the scale of your very excellent target?
Come and visit ..Doctor Frankenguns Airgun Forum..
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papaburger
- Posts: 371
- Joined: Fri Oct 28, 2005 4:38 pm
- Location: Richmond, BC, Canada