Max COAL.

[abhunter8]

I was about to work up a new load for my Custom .280 Rem, trying the 150 gr Accubond LR. I used an empty fired brass case and pushed the bullet in to try to establish the Max. OACL. I have done this before with other rifles and worked great. I put the bullet in the case and cycle to close the bolt, then take it out and measure, 3 times to get a consistent MCOAL. I have repeated several times and For some reason each time I am getting different measurements and I am getting frustrated? Any suggestions for easy method. I also tried marking the bullet and measuring, same thing different lengths each time.

[elkhunter11]

The bullet is grabbing in the rifling, and pulling out slightly as you remoe the dummy cartridgev. Try setting the dummy cartridge at the shortest measurement you have obtained, and then increase in .002" increments.

[abhunter8]

Thanks, that was what I figured was happening. The more I tried, the more I was getting frustrated.

[Dmay]

Also can try splitting the neck on the brass.....will have less tension and won't jam into the lands so hard...

[abhunter8]

Thanks, I tried a case with less tension to start and I thought I had the Max COAL but then thought I would double check and tried a case that had a little more tension. I think I will start over and try both your methods and come up with a number I can settle with.

[marky_mark]

https://youtu.be/TWmIwPwLyyg

The best way to do it
I never use my hornady gauge anymore

[abhunter8]

Thanks, That is great but I would rather not remove the ejector and firing pin.

[Mikey198]

Take a pair of side cutters and snip either side of the case neck. Put the case in your sizing die or neck sizing die and re size, works for me consistent measurements every time.

[Long Ranger]

A simple but modified way to get the MCOAL without any machine work as shown and made for me by Henry Remple. Take a gun cleaning rod, plastic coated preferred to protect the muzzle and ease it down the muzzle on your gun with the action closed and cocked. Uncocked and the rod will be indexing on the firing pin and give a wrong reading. Henry made a sliding lockable index ring that slides up and down the rod for me. Instead, you can use a ruler and with a fine tip permanent marker, mark the rod flush with the muzzle. Take the rod out of the barrel, remove the bolt and drop the bullet you are using down the chamber end of the barrel. Use the rod to push the bullet into the lands tight enough so it will stay logged in the barrel. Without jarring the gun so as to not drop out the bullet, reinsert the rod into the muzzle using the same end of the rod as before going in first. Gently run the rod in until you feel it touching the bullet. Carefully mark the rod with a fine tip marker flush with the barrel. Measuring the difference between the two gives you the MCOAL for that gun/bullet combination. You can use the rod to bump the bullet back off the lands after your reading is taken. Different bullets of the same brand/grain/type can have variations of up to +/- .004 or more depending on the manufacture's quality control. Plastic tip and lead tips if they have been dinged will show the most variation. Repeat 4 to 5 times with an undinged bullet tip will give a good start. Using a bullet comparator when using other brands or types of bullets will give the MCAOL for those bullets used. Regards.
Long Ranger

[abhunter8]

Thanks for all your replies. I got it, just had to use a case with less neck pressure so I could get a consistant reading.

[YYC338]

Originally Posted by abhunter8

Thanks for all your replies. I got it, just had to use a case with less neck pressure so I could get a consistant reading.

Yup, that's the way I used to do it. Just touch the case slightly with the FL resize die. In other words just resize a small fraction of the neck length enough to hold the bullet but not grip it too tight.