Bullet Seating - Determining depth?

Originally Posted By: zillaI use an OAL length gauge and a bullet comparator.. i used to the smoked bullet deal, the mark a cleaning rod deal, and the split a case mouth/insert a bullet & chamber method.. The length guage and comparator are the most accurate i have found.. I have a Stony Point [now Hornaday] length gauge and comparator.. The trick is to insert a flat topped jag on a cleaning rod so you can feel the bullet hit the lands..

Zilla.
I am right there with you, I have done it the other way for years but took the plunge for the proper tools and it takes all the guess work out of it and gives the most precise measurements for determining C.O.A.L. to the Ogive.

The other ways will work but not as accurate.

DAB
 
Hornady makes the tool to determine the coal to the lands. You will need to buy their modified case/ caliber. Not a big investment, you are able to determine the coal for each bullet you load for that cartridge.
Jim
 
Originally Posted By: Don FischerOriginally Posted By: ANGCorsairHow do you guys stop the plastic tip tingy from melting when you use heat to soot your bullet? I ruined 5 or 6 and can't figure it out.

Unless you have a bullet comparitor won't you need the tip to measure to? I tried that bullet in the case deal years ago and never could make it work, sure it does though. Now I simply run a cleaning rod down the barrel to the bolt face and mark the rod, at the muzzle, with a vary fine magic marker, pencil does work also. Then remove the bolt and drop a bullet into the chamber and hold it there, new pencil will work and so will a wood dowel. Run the cleaning rod back to the tip of the bullet and mark the rod again. Distance between the two lines is the seating depth. Someone above mentioned a similar method. Now that you have the measurement, use THAT bullet to set the seating die. Use a different bullet with different ogive position and you'll only be close. Save that case to tweek the distance off the lands. Similar to a method I used but instead of taking the cleaning rod to the bolt I used a loaded round, then did the math.
 
If you take max case length + min bullet length of like type (bullet lengths do definitely vary sometimes), then subtract diameter of the bullet since you will want to keep at least this much bearing surface within the case neck at all times, you should get what the "optimal" length for that particular bullet would be. But then you really need to compare that against a good throat measurement, and magazine max length, and take the shorter of the three. Don't exceed your gun's true maximum. For example, I just measured some 39gr Sierra BK's for a 204 ruger. I found that the bullet could have gone as far as 2.377, keeping .204 still within the case neck - but this gun I was working with at the time could only support about 2.323. Then they tell you to back off .020 to .040 as the amount of 'free bore' for bullet travel to the lands (start of rifling). So I'll probably go about 2.280 in this case for starters. (I had one throat reading that was way down at like 2.316, so playing it a little conservative.)

Like others, I too have tried dow rods and smoked bullets and all of that. But I finally broke down and just ordered the Hornady OAL guage. It's a fine little tool and like others have said, not a real big investment when you consider how important it is to get this measurement right!

Best of luck to you.
 
Originally Posted By: RottyI take an empty (unprimed) case of the cartridge I want to load, and cut 3 slots from the case mouth down to just into the shoulder with the finest cutting wheel I can find on my dremel. I then full length resize the case, then take the bullet I want to use and insert it into the case mouth, then chamber it. When I take it out that is my maximum cartridge length. I usually back off from this dimension about .030 then do .010 increments out until i reach the max to find my best OAL. This way it is easy to check different bullets, and is quick easy and reusable.


I use this, and it works well for me.
 
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Originally Posted By: RottyI take an empty (unprimed) case of the cartridge I want to load, and cut 3 slots from the case mouth down to just into the shoulder with the finest cutting wheel I can find on my dremel. I then full length resize the case, then take the bullet I want to use and insert it into the case mouth, then chamber it. When I take it out that is my maximum cartridge length. I usually back off from this dimension about .030 then do .010 increments out until i reach the max to find my best OAL. This way it is easy to check different bullets, and is quick easy and reusable.

I use a variation of this method as well. Works great, Grizz.
 
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