How to set up my gameseeker scope yardage lines for a 243.i shoot a100 grain bullet

no
there is a small lip that pulls the shell out of the breach as the bolt moves back
take it in to a firearm repair shop and have it properly fixed

You can buy a laser bore sight that looks like a bullet that shoots a laser out. You just load it like a bullet and then sightyour scope to match it at the proper yardage. If you can remove the action(like with a bolt action) then you could just sight down the barrel(with the rifle in a gun vise) and then adjust your scope to point at the same thing you see through the barrel.

Even in my reloading book if you load over max with an H4350 on a 85 gr. bullet you only get 3235. If you drop to a 70 gr. bullet you can get 3457.

its all ways best to test fire the rifle/bullet to fine out what your drop is going to be,, then lurn to hold over or hold under,,,i never rely on compisaters

It sounds good to me, don't forget, the 25-06 is a flat shooting round, you have your scope pointing up, the bullet crosses the line of sight twice, One at 100 yrds, your zero and the other on it's way down at about 500 yards. You can check the ballistic coefficient of that bullet and see where you need to be zeroing it in at. I would think about 250 yards, will be 1 1/2 low at 100 yards, 3/4 inches low at 200 yards, dead on at 250, then it will start coming down, say 8 inches low at 400 and 18 inches low at 500. Something like that. So your BDC will not be needed till you reach out past 300 yards, which is varmint country stuff. I have my .22 marlin sighted in at 100 yards, and it will put the lights out on anything at that range. You can probably find the charts on line someplace, if you don't have a reloading manual. Check it out.

Here is an excellent article on zeroing scopes:

http://www.outdoorpros.com/How-To-Guides/How-To-Zero-A-Rifle-Scope/5

Most BDC scopes have you line up a small set of wires on a target and then compensate for that range, some will be a holdover, some will have you raise the stadia to the zero. Basically a mildot, except the mildot is already set for an 18 inch target, you just raise the dots up. That is if you know your range. It can be confusing, A little practice and a bunch of ammo should have yo shooting ducks on the wing in no time. The range increments are usually 100 yards, maybe 4 dots, I don't think they would go much more than that.

Here is some good reading for you.

This happens will all firearms. what happens when the bullet leaves the bullet is a decieving "rise" of the bullet. The reason for this is the Line of Sight (Scope View), angles down and away from the Line of Departure (Barrel). The bullet actually never rises and is in fact continally falling away from your rifles Line of Departure but because this is higher than the Line of Sight the bullet seems to Rise than fall to the set distance in the scope (i mention set distance and not zero because you can change your Minutes of Angle on your scope to increase and decrease range)

http://www.rifleshootermag.com/shooting_tips/ballistics_0303/

this is a chart that illustrates what i just said.

now that you understand that you should take a good read into Exterior Ballistics. this is the Mathematics of your fireamrs trajectory ( I say your firearms because your bullet's flight depends on the length of the barel which will vary from gun to gun) this science of shooting will teach you how to understand bullet Grain and Volume relations. understanding the Feet per second of your rounds and how the affects you. teach you about shooting in high pressure and low pressure environments and extremly windy environment.

now there is alot of math to all of this and its hard to find it all on the net and if your not that great at math you can do what i do bc im lazy and im not a sniper im just a hobby kinda guy. '

Sierra Infinity V 6 Ballistics Software. I dl'd mine off the net you might have to buy it depending on how resourceful you are. it is well worth the buy. You can punch in the daily variables (Barometric Pressure, Temp, Humidity, and Altitude) (of couse with your bullet as well) and it will give you a "Cheat Sheet" for those conditions stating Windage and Elevation adjustments per decided incriment (50 yrds is standard) then you take that to the range and (bring a laptop if you got it and arent embarrased (som1 might even help you tune in the variables) hope this helps if not ill check back in a bit to see how you did