Seating depth for tc pro hunter

[Fscott1520]

I am fixing to start working up a load for a new 300 win mag tc pro hunter with 178 gr eld bullets. My hornady oal guage says I contact the lands at 3.53 coal. Since it is a single shot and I can seat long what would be a good starting point and about how many different depths should I try to determine my ultimate depth? 3 shot groups each .01 or .02 deeper than the other. This will be a hunting rifle but I would like to get it dialed in close. Also does it matter if the brass is new or fire formed already in this first step. Also does powder choice matter during the depth seating step? Btw barrell is 28" stainless fluted. Thanks.

 

[J E Custom]

I would start .020 to .030 off the lands and go from there. Work up the loads and once you have a good load adjust the seating depth in .005 thousandths increments. Load 3 to 5 of each and shoot a group of each.

The reason for starting off the lands is to prevent/control pressure while doing load work up.

J E CUSTOM

 

[Alibiiv]

I have a TC, Pro Hunter, 28 inch blued barrel in 7mm RemMag that I was thinking of selling. Presently with nothing other than full-length resizing the barrel is shooting bugholes with 139gr Hornady bullets and Remington brass. I never thought about the possibilities of developing a load for this barrel. Planned on selling the barrel to scratch up some money to build a 6.5-06.

If I were going to work up a load for the rifle I would get a measurement after firing for COAL, then full length resize and bump the shoulder back .002 thousandths. I would then purchase a Hornady (or similar) comparator tool to determine where the bullet meets the lands and go from there. My 7mm RemMag barrel likes H4831.

 

[RT2506]

With a hunting rifle I learned to NEVER seat bullet close to the lands the hard way. Had a Rem 700 7mm Rem mag. Seated bullets just to kiss the lands. Shot bug holes. Went deer hunting one morning and did not see anything and needed to take a bladder dump and went to unload my rifle to climb out of the stand and only the case came out and it dumped most of the powder down into the rifle and the bullet stuck in the bore. I did not have a cleaning rod and tools with me and I was 28 miles away from my camper. On my way back to my truck, yes you guessed it, old big boy walks out into the logging path not 60 yards away and stands there looking at me and I have a fouled rifle. I have always been able to find a seating depth at least 10 thousands off the lands since that would shoot. There was just a little difference in that one bullet that made it stick because I cycled all the other rounds I had loaded up and no others would stick. Oh! Never did see old big boy again either, somebody else must have taken him home with them.

 

[Alibiiv]

With a hunting rifle I learned to NEVER seat bullet close to the lands the hard way. Had a Rem 700 7mm Rem mag. Seated bullets just to kiss the lands. Shot bug holes. Went deer hunting one morning and did not see anything and needed to take a bladder dump and went to unload my rifle to climb out of the stand and only the case came out and it dumped most of the powder down into the rifle and the bullet stuck in the bore. I did not have a cleaning rod and tools with me and I was 28 miles away from my camper. On my way back to my truck, yes you guessed it, old big boy walks out into the logging path not 60 yards away and stands there looking at me and I have a fouled rifle. I have always been able to find a seating depth at least 10 thousands off the lands since that would shoot. There was just a little difference in that one bullet that made it stick because I cycled all the other rounds I had loaded up and no others would stick. Oh! Never did see old big boy again either, somebody else must have taken him home with them.

Ever since my daughter buried a Ruger 77 in .243 in a creek bottom, muzzle first and up to the forend, I always have one of these kits in my pack; Otis Copact Gun Cleaning Kit:

www.brownells.com/gun-cleaning-chemicals/cleaning-kits/rifle-cleaning-kits/compact-gun-cleaning-system-prod25052.aspx

And...yes it's one more thing to weigh the pack down, however have found it to be worth having. It was used this past deer season on another hunter's snow filled barrel.

 

[Mikecr]

Do full seating testing per Berger's recommended procedure.