Is a Boat Tail worth its Salt?

[royinidaho]

Just how much advantage is a boat tail over a flat base on two bullets that are exactly the same except for the boat tail.

I'm talking to 1200 yards.

On exceptionally long bullets is the longer bearing surface of the flat base have a major effect.

I'm talking 170gr 277 cal bullets.

I have some 170 grain double jacketed bronze tip flat base bullets coming one of these days for testing.

The inner jacket is a lead core "wadcutter" design. the outer jacket is high bc design w/bronze point.

Any hintz?

[Derek M.]

I spoke with Sierra and Speer about this many years ago. They both gave the same answer:

"Inside of 300 yards, take your pick. In fact, the flat base spitzer will likely be more accurate because there is little to no deformation of the bullet base, so when the gas pushes the bullet out the muzzle, it is more even. That is the trick with a boat tail bullet and seating. The less concentric a boat tail is seated, the higher the risk of uneven gas blow by. However, long range accuracy ultimately means using Boat tails with high BCs."

[royinidaho]

Derek,

Thanks for the response.

To be more specific, lets consider the Sierra 300 SMK.

How much lower for BC if it were a flat base?

[Mikecr]

It would be a big difference in a 300smk(~.1 in BC). And anyone shooting 1200yds for some reason, should consider the increase in wind drift(especially your error) from this.

Nothing is free

[royinidaho]

Mikecr,

That much eh? Wouldn't hat tho't it.

my problem is I'm shooting 140gr 277 bullets w/a .496 BC @3600 FPS.

A 170 class bullet w/a bc of 0.74 @ 3250 will out do the faster 140 class bullet at any distance all the way around.

However the 170 class bullets are no longer available.

But I've found a maker producing very similar bullets to the aforementioned 170 class bullet. Its better up front in that it has a bronze point vs a hollow point. On the back end it is flat based vs RBBT.

I'm not looking for a free lunch, just somewhat of a feeling for what's going on before I jump in.

Found this link:Flat Base versus Boat tail

[Derek M.]

Which 170 bullet is no longer available?

[James Jones]

it all boils down to BC , if you could get a flat base bullet to have a well enough desgine at 170grs to match the BC of the old 170gr bullet that it should shoot pretty close but in order to gain that BS without the sleek boat tail the ogive is gonna be Loong so it may be hard to get to shoot well.

If you look at the short range BR guys the vast majority of them shoot flat base bullets but any of them shooting to 600 or more generaly always shoot the boat tails.

That sounds like a very expensive bullet to produce your looking at , you may want to try out some of the Lathe turned bullets out their though your barrel may not like them