I'm hoping to finally start loading for my Savage 12 BVSS in .243 Win this weekend. I bought this rifle new last July and haven't fired a shot through it yet. In an effort to improve accuracy and reduce throat erosion I would like to seat the bullets as close to the lands as possible. However, using a Stoney Point gauge and modified case I discovered the throat in this rifle is cut rather deep. Using a 105 grain Hornady A-max I get 3.000" OAL from the tip of the bullet to the case head, which leaves the base of the bullet contacting only about half of the neck. My Lyman manual suggests 2.710" OAL using this bullet. If I back it off about .020" off the lands I should be able to get most of the neck contacting the bullet. I found a similar situation using Remington 100 grain Core-Lokt where I ended up with 2.027 OAL and about half the case neck contacting the bullet.

I know moving the bullet closer to the lands can increase pressure. If I can seat them out far enough to still allow the full length of the neck to hold the bullet, should I be concerned with pressure spikes assuming I start with the minimum load suggestion? And what should I look for other than flattened primers? I've always played on the safe side and never pushed my loads very far past the minimum, but such an increase in length has me concerned. I don't care if they fit the magazine since I usually load them one at a time anyway.

I don't think you really need to worry about throat erosion at all if only loading..."never pushed my loads very far past the minimum." Although ball\spherical type powders are noted for having lower flame temps. That's why the military uses them in rapid fire arms.

And there is no law that says you must have any bullet seated for the total length of the case neck, where the base of the bullet is at the neck\shoulder junction. Load them longer if you wish, just as long as there is sufficient neck tension to keep a bullet from pulling out of the case, if you decide to eject it before firing, while being jambed into the leade.

I`ve heard one should seat their bullet one caliber deep in the case as minimum, but then there are cartridges like the 260 Rem with a neck shorter then the recommended one caliber.
I agree with onefunzr2. As long as the bullet isn`t so deep the bullet ogive is in the mouth of the case, or it is out to the point it jams in the leade or won`t fit the magazine you should be good.
Of course you need to drop back a couple grains from max and rework the load with the bullet at the COL you wish to use and don`t simply make seating adjustments with max charges.

Ok, here's what I ended up with today. I loaded 75 rounds using Remington 100 grain Core-Lokt bullets. I ended up seating them .080" off the lands in order to get enough of the bullet into the case neck. They chamber and fit the magazine fine. I'll do some more experimenting but I doubt I can go much longer and still have sufficient tension on the bullet.

I based my loads on info from Hodgdon's website, trying to stay about in the mid range of their min-max suggestions for 100 grain bullet loads. I ended up with 25 rounds each of the following:
40.5 grains H4831
38.5 grains H414
39 grains IMR 4350

Hopefully these will provide a good starting point, but its supposed to rain tomorrow so I may not get to test for another week. I'm also hoping H414 will work well in this rifle since it measures so much smoother and more accurately. Extruded powders are a pain in the ass with my powder measure.

Another factor with throat erosion could be selecting flat base projectiles rather than boat tail projectiles. The flat base projectiles do not have the gases swirling around the sides of the projectile like boat tail ones do.