A bit of historyI've had two 25-06s that shot most any flat base bullets far better then any boat tails at most any range. OK, tonight's question. I'm loading 150 grain FMJ BTs with IMR 4895 and came across 500 flat base FMJs. Is there any thing I should be aware of when loading the flat base bullets? The 150 grain FMJBT would extend deeper in the powder space, maybe increasing pressures VS the flat base? Any help should be appreciated

I'm curious as I shoot a 257 Roberts . What brand and style of 150 grain bullet are you shooting?

I’m confused.

25 cal 150s who makes those ?

Nobody

"150 grain FMJ BTs with IMR 4895" Sounds like a 30-06 and not a 25-06 to me.

Gentlemen My mistake. My reference to the 25-06s was to explain my curiosity about the superior accuracy of the flat based bullet vs the boat tail. I'm testing 150 grain bullets in a 308. I've used factory ammo ever since I bought this rifle. Sorry for my befuddlement.

My only aversion to flat based bullets is that they are a little trickier to start into the case when seating. For hunting any supposed advantage in accuracy of a flat base is offset by superior downrange ballistics of boattails but it really comes down to what works in YOUR rifle.

Thanks for your reply, after my snafu at the beginning of this thread. Many years ago I took up shooting ground hogs why out yonder and found that I needed a heavier bullet at high velocity for long range groundhogs in highland County Virginia. I tried all the Sierra boat tails and was never impressed with the accuracy. A friend gave me a box od Speer 100 grain flat base hollow points And never went back. What I'm looking for is very accurate 150 grain 30 caliber for off hand shooting from 100 yards to 300 yards. Again thanks for you response.

Offhand shooting out to just 300 yards does not require high BC bullets, so whatever design shoots best in your rifle is what matters. For example, using Hornady bullets at 2700 fps, there is less than one inch difference in drop between the two types at 300 yards - not even noticeable in the field.

With the same bullet ogive and loa, either style will take up about the same volume in the case. It is the volume of the bullet in the case which matters, not how far the bullet base extends into the case. But in my experience, most FMJ bullets seldom give the accuracy of soft or hollowpoint bullets give. But that depends on the particular bullet.





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I had a 270 that only liked flat based bullets.

Correct. Using the OP’s 25.06 as example a 117 pro hunter(flat base) vs 117 Game King(BT) when launched at the same speed there is .1 inch difference @ 200 and .3 inch difference @ 300. The BT doesn’t offer any real advantage until past 300.

Ehank you all. Another question is there any pressure difference, using the same weight with the same powder powder, same bullet weight.
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I have a Remington 700 in 30-06 that has a very long throat and only likes flat base bullets. It especially likes Speer 180 Spitzers.

Yes. The NRA tested this decades ago in the .30-06 and 150-grain bullets, all with the same charge and seating depth. Their testing found pressure differences in excess of 7000 cup between different bullet brands and styles, and velocity differences of nearly 100 fps. The data showed no easy way to predict which bullets gave higher or lower pressures, like comparing bullet length, core hardness or bearing surface.



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Just curious, what is the purpose of a FMJ bullet? Other than war, I have no clue why anyone would want a FMJ bullet???

FMJ bullets are less expensive to manufacture than expanding bullets and thus are sold cheaper.

Folks shooting M1 Garands, M14/M14, M1 Carbines generally are not hunting and the guns were designed for smooth feeding FMJ bullets anyway.

Some folks use FMJ bullets so as to not the damage the pelts of fur bearers.

The bearing surface would change somewhat, but if the only difference between two bullets was the BT, I wouldn't worry about pressure differences too much.

I have a 25.06 that's the same, it absolutely loves flat base bullets.

I'm plan to shoot at steel gongs / plates off hand out to 300 yards. The FMJs are cheaper then the cup and core.

I highly doubt you’ll see much difference what gun are you shooting and bullets a 308 tends to be a pussy cat that eats everything

Went out to the range on Sunday. Got the rifle sighted in for 100, 200 300 yards with the 150 FMJ boat tails, shot acceptable groups at all three ranges. Cleaned the barrel and shot the flat base with the same powder charge and primer. The flat base bullets did rather well at 300 relative to the the boat tails. Using either bullet would would work for shooting the steel plate at 300 off hand once I get up to snuff. Now I need to start practicing..
thank you for the info and advice..

Always flatbase first........

Not if you chamfer necks.. I prefer flat based bullets, I think they penetrate better...

of course that can be an opinion instead of an observation..

Necks are chamfered. Boattails are easier.

Some .308's shoot 150 grain flat base bullets better than 150 boat-tails because they have a long throat e.g. Remington 700's, and the only way you can get anywhere close to the lands with 150's is with flat base bullets.

Boat tails are definitely easier. However, it depends on what flat base we are talking about. Some are far easier than others. I just loaded some 150gr Nosler partitions, but those are actually chamfered to allow for easier seating. Some flat based bullets are not like that at all and are a biotch.. Now, as for accuracy. This has been brought up a 100 times here. Generally flat based bullets are more precise at moderate ranges. Say out to 400 yards. But after that, the boat tails are generally better. They are more streamlined, so it only makes sense..

Boat tail vs flat base bullets are an enigma in the dozen or so 7x57's I have owned. The longer throated barrels don't care much for boat tails, but with only a couple exceptions they all liked Nosler Partitions even though there is a light chamfer at the base.

My std. bullets for the .270 Win and 6.5x55mm are flat-base Speer GS, 150 and 140 gr. respectively.

For decades, it was the Speer Hot-Cor and then Nosler Partitions swapped in for hunting. Both flat-base as well.

Only boat-tails are the Barnes TXS bullets, but they shoot very good as well.




GR

Most every rifle I have tested flat base bullets shoot better at 100 meters. I suspect it would be different at 500 meters.
Example: my 300 savage shoots 150 grain Interlock flat base under 1 1/2 MOA, it shoots boat-tail 150 grain Interlocks around 4 1/2 MOA.
I have rifles that shoot boat tail bullets well. But flat base bullets almost always beat bt’s in accuracy in my testing.
I still test both.