I was reloading some Flat Base bullets in my 270 Win last night and was thinking I sure prefer to load Boat Tail bullets as they start down the neck easier and they have a higher BC. So why do they even make FB bullets? What are the pros and cons of the FB and BT bullets? Would you ever choose one over the other for a particular application? Why do mfg. offer both style bullet bases? Any good reason or just preferance?

By the way the FB bullet I was loading (Speer GS 150gr) shoots .5" groups @ 100 yds. using 54 gr of IMR4831 & WLR primers, COL of 3.240".

Flat bases are frequently more accurate. They have a longer bearing surface to support the bullet concentrically in the case neck and bore. The boattails have a greater and longer exposure to any asymmetrical gas push on the bullet base at exit due to bullet or barrel crown asymmetries. Flat bases have a reputation for holding together better on impact, again because of more "gripping" surface between the jacket and core. Within typical hunting ranges, there's little ballistic difference in either velocity or trajectory. Boattails' aerodynamic advantages mainly show up beyond about 600 yards.

[ 10-28-2003, 18:56: Message edited by: NotRicochet ]

The main advantage I see to flatbase bullets is that the jackets do not separate from the cores as often. Better terminal performance. The slight ballistic advantage a boat tail offers is meaningless at the ranges I hunt. On varmint bullets, I don't worry about the above.

The boat tail advantages are smoother seating and a slight increase in B.C. The disadvantage is that in conventionally constructed bullets the core is more likely to separate from the jacket.

The Nosler Solid Base design gives you the best of both in that there is no internal taper in the jacket where it bonds with the core, so there is no ADDITIONAL tendency for the core to seperate (as with any un-bonded core, they can and will separate.) The solid guilding metal base also provides some additional penetration that you do not find with conventional bullets.

There is no practical difference in the accuracy of boattails and flat base bullets. Either can be made with the base canted in relation to the axis of the bullet, which will spoil accuracy. Conversely, either, when manufactured competently, can be made with the base perfectly square with the axis.

A hunter will never be able to tell the difference in trajectory or retained velocity with one as opposed to the other.

I shy away from conventional boattails for game hunting, simply because they MAY loose their structural integrity more quickly than is optimum. For varmints, use whatever shoots best in your particular rifle.

There's an old myth that boattails cause more rapid bore wear. And that's exactly what it is -- a myth.

Stonecreek.....when you say "conventional bullets" are you talking about Boat tails or lead core copper jacketed bullets?

A lot of old generalizations are no longer true with the new bullet designs.Bonded bullets such as the scirocco,interbond and accubond use bonded cores that do not shed their cores and retain just as much and in many cases more weight than most flat based bullets including some the partitioned bullets.As well the barnes x boatails have no core to shed.Each bullet must now be evaluated as an individual.Trajectory is not the only advantage of boattailed bullets.At distances of 300 yards or more they are noticeably less effected by wind drift than flat based bullets.As far as accuracy is concerned the most accurate bullet in all of my hunting rifles is the ballistic tip which is a boattail.

[ 10-29-2003, 07:19: Message edited by: stubblejumper ]

And when I said that flat base bullets are "frequently more accurate than boattails" I meant exactly that. Lots of folks have found that to be the case in their rifles, whereas others haven't. It's not a generalization; you'll have to try it for yourself to see if it's the case for your combination.

The benchrest crowd would agree with NotRicochet. Their take is that flat-base bullets ARE more accurate than an equal-quality boattail bullet... By AT LEAST a few hundreths of an inch! >>>>>>>>>>>>>>>>>>Bug.

Boattails have little to offer in a hunting bullet least of which is accuracy and terminal performance on game....and yes they are handy to load, but thats their only redemming quality in a hunting bullet IMO...

The 100 and 200 yard bench rest shooters seem to prefer the flat base and the 1000 yard bench rest shooters seem to prefer the boat tail design. They are all looking for every bit of accuracy they can find.

Using solid copper, such as Groove Bullets, I see no advantage or disadvantage with using either on game.

Don

FB's For Hunting
BT's For Paper

I like Flat bases, Flat noses & Round Noses generally for hunting they kill better IMHO.

I prefer FB/BT/CB as the circumstances dictate, am aware of their benefits and limitations.