Bullet seating depth question

[pastorbuck]

I just checked a case and bullet in my 7mm-08 TC Encore rifle for COAL where the bullet just engages the lands.  The measurement was 2.813"  .  I'm using barnes TSX BT, 140 Grain.  My question is, how far back from the measurement that engages the rifle lands should I set the bullet depth.  Barnes data calls for a 2.735" COAL.  My groups with the Barnes data are 1" at 100 yards.  Being new to reloading, where could I expect to find an increase in accuracy between the  2.813" and the 2.735" (I think I need to decrease the 2.813 measurement by .06250" to start, but which way do I go to experiment safely (less or more) and how can I avoid dangerous pressure while still trying to find the sweet and accurate COAL for this cartridge?

Thanks guys,

Scott B.

[Kurt L]

Iwould go back to about 2.793
If you worked your loads @2.735 you would be better to start low and work up
on the powder.
I most always set mine at close to lands to start when I work up a load then I can pull the bullet back in
or shorten oal and try differant settings without getting into trouble.
But if you work up aload with a short oal then extend the bullet out more for a longer oal you  can run into high pressure troubles.hope this helps

[Glanceblamm]

I would not be able to tell you on the 7mm-08 but would lean towards what kurt L said.
It seems that if you are under a .30 cal, the best accuracy can be found .010-.015 from the lands.
If you are at .30 cal or over, the best accuracy may be right at the lands. The thing to do if you choose the latter would be to soot up a bullet (kitchen match) and seat it to where you see the lands take the soot off the bullet but yet have absolutely no mark or indentation on the bullet by the said lands.

[Catfish]

Every barrel is different, but here are some thing I have found that are true more times than not. The longer the bullet the closer it needs to be to the lands. Very rear is the gun that will shoot it best with the bullets more than .035 off the lands. Some will shoot just as well at .050 off the lands as they do at .035, but not better. Changes of less than .005 in oal are not measureable in the group size. Now, just go burn some powder and find out what works best.

[LaOtto222]

I took this straight off of Barnes site for bullet seating with the TSX bullets.

3. Where do I seat the Triple-Shock, Tipped TSX and MRX bullets?

Answer. We recommend seating these bullets .050″ off the lands {rifling} of your rifle. This length can be determined by using a “Stoney Point Gauge” or other methods. You do not have to seat the bullet at, or on one of the annular rings.

Here is some other pertinent information regarding the TSX bullet.

1. What load data do I use for the Tipped Triple-Shock and Maximum Range X Bullets?

Answer. We recommend using Triple-Shock X Bullet data from Barnes Reloading Manual Number 4 or the Technical Section of Barnes Bullets website.


2. How accurate is the Triple Shock?

Answer. In testing we have found the Triple Shock bullet to be very accurate. For another test on the accuracy of the new Triple Shock- check out the July, 2003 issue of Shooting Times and Rick Jamison’s article on ” New Loads for an Old Favorite - The .270 Winchester .

The TSX bullet is completely different than copper jacketed lead bullets. I would not go any closer than 2.763" for COAL Good Luck and Good Shooting

[pastorbuck]

Thanks again to all you reloaders for the great information.  I'll be sure to post the results.

Scott B.