Post by: engelwood on July 19, 2013, 06:44:17 AM
Just wanting to pick some brains here. Say that you have the bullet that you want to use and although you don't have a tool to measure distance to lands, you still want to know COAL of the load to get the desired distance off the lands that you are looking for. How do you determine what you want your length to be? Here is what I did... I found that I was getting some inconsistency at the range during barrel break in and figured that the bullet was "jumping" further than I wanted it to as I had only loaded up bullets at the "max" COAL stated in reloading manuals. After thinking about it I'm shooting a completely custom rifle that is throated for longer bullets such as the Berger VLD's. I attempted to measure the COAL of what my bullet would need to be to sit right on the lands by taking a spent cartridge, pinching down one small section of the neck so it would hold the bullet stiffly, but would allow the bullet to slide back in the cartridge as the bolt carried forward and the bullet pushed up against the lands. When I pulled the cartridge and bullet out, I measured the COAL to find that I was jumping the bullet way more than what would be considered reasonable. I did this method, starting over each time a total of 4 times. What I found was that each time I varied in measurement less than .010. I have determined that I think this is a reasonable way to measure what I need my COAL to be to sit say .010 or .020 off the lands. Thoughts on this process and anything that I may have overlooked?
Thanks
Post by: Jingles on July 19, 2013, 07:08:00 AM
Insert cleaning rod in muzzle mark on cleaning rod where end of barrel is once cleaning rod had come in contact with the bolt face
Pull out the cleaning rod 4 to 6 inches.
Insert JUST the bullet you want to load into the chamber.
GENTLY push cleaning rod back into barrel until it contacts the bullet
Mark on the cleaning rod the end of barrel.
Measure the distance between the 2 marks and you'll have your OAL.
Be sure to tap out the bullet before going hunting
Post by: fastdam on July 19, 2013, 07:42:44 AM
Post by: wsmnut on July 19, 2013, 07:44:36 AM
Hey guys,
Just wanting to pick some brains here. Say that you have the bullet that you want to use and although you don't have a tool to measure distance to lands, you still want to know COAL of the load to get the desired distance off the lands that you are looking for. How do you determine what you want your length to be? Here is what I did... I found that I was getting some inconsistency at the range during barrel break in and figured that the bullet was "jumping" further than I wanted it to as I had only loaded up bullets at the "max" COAL stated in reloading manuals. After thinking about it I'm shooting a completely custom rifle that is throated for longer bullets such as the Berger VLD's. I attempted to measure the COAL of what my bullet would need to be to sit right on the lands by taking a spent cartridge, pinching down one small section of the neck so it would hold the bullet stiffly, but would allow the bullet to slide back in the cartridge as the bolt carried forward and the bullet pushed up against the lands. When I pulled the cartridge and bullet out, I measured the COAL to find that I was jumping the bullet way more than what would be considered reasonable. I did this method, starting over each time a total of 4 times. What I found was that each time I varied in measurement less than .010. I have determined that I think this is a reasonable way to measure what I need my COAL to be to sit say .010 or .020 off the lands. Thoughts on this process and anything that I may have overlooked?
Thanks
Are you using a comparator to measure length? Lots of bullets vary in length, so measuring using the tip of the bullet is going to be inconsistent. I strongly suggest getting some type of bullet comparator, which will let you measure to the bullet ogive.
Wsmnut
Post by: Greenhorn on July 19, 2013, 08:22:53 AM
Post by: Fl0und3rz on July 19, 2013, 08:35:16 AM
This is another pretty good write-up using a cleaning rod, cleaning rod stops, and calipers.
http://wildernessmeans.com/articles/hand-loading/hand-loading-for-long-range/rilflings (http://wildernessmeans.com/articles/hand-loading/hand-loading-for-long-range/rilflings)
You can make a case for checking COAL by neck sizing a case shot in the rifle you wish to check.
Post by: andersonjk4 on July 19, 2013, 08:44:02 AM
As said above a comparator will go a long ways in telling you your COAL more accurately.
Another tip for when you are putting your bullet into the fired brass is to color the bullet with a sharpie or smoke it before you run it through the chamber. This will tell you if the lands are grabbing the bullet and pulling it back out a little. I have found that a lot of the time the bullets will be stuck in the lands and pull out a little when the bolt is opened. This will make your COAL measurement longer than it really is.
Post by: BULLBLASTER on July 19, 2013, 11:03:59 AM