Bullet seating depth the easy way

[shilen30]

Never tried the split case method, but it aught to allign the bullet better and give you more repeatable accuracy. I agree completely about the stoney point OAL gauge. Don't think it is necessary, but the comparator on the other hand is a must IMO.

[dbhostler]

I've tried several methods over the years but now use the Sinclair Bullet Seating Depth Tool. Works best for me.
db

[Brent]

While checking the 210 JLK VLD design, it sometimes sticks in the lands just enough that the bullet will pull from the case as the bolt is withdrawn. When I check them now I will just push the case into the chamber fully with my index finger and push the bullet and case back out with a cleaning rod so it does not seat the bullet deeper of allow it to be pulled out farther. Pushing it out with a cleaning rod will not work if your fired case is sticky in the chamber, so select one that is not.

[kidcoltoutlaw]

i set up my redding dies the other day for seating the .338 sierra bthpm .then went to a different lot and its now .008 to .010 longer but still not touching the lands.im going to shoot them any way.have you seen it make a big difference.i myself have not.if your touching the lands and it then jams the lands i could see the difference im sure.right now im shooting 3 shot groups of .208 at 117 yards in a 338 RUM,thanks,keith

[kidcoltoutlaw]

i forgot to say im checking with a davis sds tool that measures off of the ojive {sp}got it from sinclair international,thanks,keith

Take the extractor out of the bolt. Seat a bullet long into a case to engage the lands. Seat the bullet with the bolt and then remove said bolt. Push the dummy round out of the chamber (from the muzzle) with a cleaning rod that has the brush/jag removed. This is the most repeatable and accurate method I have ever seen since it uses the bolt force to seat the round vice finger pressure. Remember we are only talking several thousanths of an inch between success and failure. [img]images/icons/wink.gif[/img]

James

[shilen30]

Kieth, yes, I was in a store that carried the stoney point comparator instead, but the one you mention is great too. Remember (those of you who don't do so already), finding oal to the lands is only a starting position! You have to vary seating depth after this. Personally, I find my OAL by the methods you mention. I then seat a bullet in a sized case to this OAL and chamber the round. If I see marks from the lands, I seat a tad deeper until I am barely off the lands, and I use this as my starting point. Then, find the best powder/charge/bullet combo FIRST before varying seating depth. When you have found the most accurate powder/charge/bullet combination, THEN vary seating depth to squeeze those groups down! To find the correct seating depth I load 6 shots with OAL to the lands (enough to get some real data (and remember plenty of cooling time between shots)), and then 6 more with an oal (again, measured with the bullet comparator) .005" less than this, and continue to do this until you have several sets of 6 rounds that span from just off the lands to around .03" off the lands. Once you found the best OAL out of these, you can vary seating depth .002" from this if you desire. After testing oal and finding the most accurate one, write down the "sweat spot" oal after finding it, and use it for the differnt bullets and lots of the same bullet you use. Very important: the bullet profile changes from lot to lot, and certainly from bullet to bullet, but use the same OAL MEASURED BY THE BULLET COMPARATOR for each. this means you will have to adjust your seating stem of your seater dieevery time you change lots or brand of bullets, but the oal measured by the bullet comparator stays the same.

[ 07-15-2004: Message edited by: shilen30 ]