Ok fellas, here it is:
I ran out of 140 grain Ballistic Tips and had to load up some 150 grain BT's.
I put one in a dummy round and loaded her long. Then I forced the bolt close on the round to see what the maximum seating depth would be. Forcing the bolt closed on the round produced a COL of 3.295". I then seated my live rounds 3.285", .010 off the lands (or so I thought). I chambered one and it still shows some slight rifling marks. It doesn't make sense to me that I went 10 thousandths deeper and still got some marks. I am going to shoot a few tomorrow and watch for pressure signs. When does it become dangerous? Would the gun blow up if you shot the bullet at the max of 3.295?
Any thoughts would be great.
By the way, any pet loads with the 140 grain BT's would be helpful. I love them with 58 grains of H4831. Produces 3,080 fps with great accuracy. Someone on this site said 4350 would be beeter powder so I will try that.
thanks

Having the bullet on the lands will generally raise the peak pressure about 10%. If the load was hot with the bullet off the lands and you then put the bullet into the lands it would be very hot.

Why don't you just seat them another .010 deeper? That should be easy unless they are crimped.

Don

[This message has been edited by Don G (edited 06-30-2001).]

if you used the rifling to seat the bullet into a case, you have what is sometimes referred to as a hard crush. A very hard crush. In other words, the bullet is pushed into the lands a good distance in the process. .01 is not anywhere close enough to get away from the lands. .1 might be closer to the right distance. FWIW, Dutch

What you need is a Stoney Point OAL gage. It will tell you exactly where the lands are. I start loading at 0.025" off the lands and then work up and down in 0.005" steps. The gage and modified case will cost about $40. You will also need a cleaning rod and a dial caliper. They have about 50 different mod. case for the most common cases and can make a modified case from once fired cases from any gun. I sent them a acouple 6TCU cases and they sent me back a mod case.

Primetime, I don't remember who said this but I read that when you seat the bullet by forcing it into the lands you are probaly about .020 past the point where the bullet first contacts the rifling. With this in mind, you would have to seat .040 deeper(into the case) just to have the bullet .020 OFF the lands. I know the BR shooters do it but I would not want to shoot a fullhouse hunting load jammed into the lands. I see your post was on June 30th so I hope you're still alive to give a follow up. I own 2 .280's myself and would like to hear from you to see how things worked out regarding preassure and seating depth. Best of luck. John <shakeout@excite.com>

I am still alive and well. I seated the bullet back about 25 thousandths (if I remeber correctly) and the bolt closes effortlessly. It has been a while since I posted this and that is why I cannot remember the exact OAL.
I know people that shoot loads right into the rifling but wouldn't want to try it myself.
By the way, the load is 58 grains of H4831SC with 140 Nosler BT. Shoots really well.