What are the advantages and disadvaatage of each.
Do you get better volicity from flat bast because of better pushing area? Is acuracy beter with one or the other?

Boss - I think the standard answer is one usually gets a little accuracy and trajectory benefit from the boattail shape. The downside is felt to be that the boattail encourages throat erosion.

Boat tails seat easier (in my hands).

Benchresters generally prefer flat bases believing that propellant gases have less opportunity to upset the bullet as it exits for that extra margin of accuracy, but they only shoot 200 yards. Long range shooters generally prefer boat tails as they shed velocity less quickly than flat base bullets due to their streamlined shape.
I cannot tell any difference in accuracy in any of my guns, but I would add that you should pay particular attention to the barrel's crown. I have found many factory guns needed the crown lapped to smooth out imperfections.
Find the bullet your barrel likes the best and shoot it regardless of base configuration if you limit your target to less than 300 yards. Shoot boat tails at longer distances.

The boattail can seat a bit more smoothly, but that is of secondary consideration. A boattail will raise the ballistic coefficient by a very slight degree.

Although old wive's tales abound regarding them being rougher on the bore or more/less accurate, the many years worth of data don't support either theory.

Their main disadvantage in a hunting bullet is that they tend not to hold their cores bound to the jacket as well as a flat base (in a conventionally constructed bullet), because of the taper of the jacket/core juncture near the base of the bullet. This does not apply to the Nosler Solid Base, however, since the boattail involves only the solid rear portion of guilding metal and not the lead core (the Nosler may lose its core for other reasons, however.) I have found a significant difference in the structural integrity of Speer flat base bullets as compared to their boattails.

This tendency to come apart may be counted as an advantge in a varmint bullet (where a higher ballistic coefficient may also be important), thus they do tend to make excellent varmint bullets.

[ 12-21-2002, 02:39: Message edited by: Stonecreek ]

It's also easier to make a flatbase bullet more concentric than it is to make a boattail.

The most important thing is what your gun likes!!! My Browning A-bolt Stainless Stalker in 300Win Mag does not like any boatail bullet at all!!! Take the same powder and charge in a flat-base bullet and it touches holes every time @100yds.

I prefer boat tail when reloading, it's so easy to seat.
In danger of creating a new MK thread I will say that Sierra 168grs 30 cal MK is very accurate, and those are BT.

Dave, have you tried the comparison at longer distances, say 300 to 500 yards? Boat tails sometimes surprise you.

t_bob 38. When I go back to the farm in Penna. I shoot regulary up to 400+ yards at ground hogs with good success using my deer hunting round of IMR4350 and a SierraPro-hunter 180gr. At 300 yards I'll knock a 1/2 gallon jug all over the place on every shot. It just don't like boat-tails.