Effectiveness of Flat base vs Boattail on game animals

Cool, learned something new.
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So have I Freedom.

I know more about projectiles than I did before,but I still can't find anything to support or deny my observations.

All things being equal a properly constructed bullet of either shape will kill critters equally dead
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Yes maybe it does just come down to construction and once you place a good shot in the kill zone FB or BT there's no predicting how the animal will react or how far it will goes before it dies but die it will.

Altough I just came upon some information about BT shedding their jackets more readily than the FB I'm looking into it.
 
JohnKSa, thanks that cleared some things up.

Altough I just came upon some information about BT shedding their jackets more readily than the FB I'm looking into it.
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I've heard this as well, I've never seen it though. I've never had a boat tail bullet fail to the job yet as long as I'm on top of my game.
 
nate45, here's an out of context comment in regards to bullets tumbling. An example could be that as the bullet impacts, it deforms and mushrooms. Now it acts just like an 18 wheeller with front brakes only on wet streets. The back end wants to pass the front end and starts swapping ends or tumble. The BT bullets will shed the core quicker as there is not much a manufacturer can do to get the core to bond to a cone (the boat tail) that has forces on it that are trying to eject the core. Here's the commentary:

In the 1960s we all thought bullet tumbling on impact was a unique and wonderful effect of 1:14 rifling and there was much controversy when the Army adopted the "inferior" 1:12 rifling.

Since that time Army medical research in 1988, confirmed by later ballistic research, has confirmed that (1) all bullets longer then their diameter will tumble in animal tissue, (2) tumbling bullets cause only small additional wounds, much like hollow points, and (3) the massive wounds caused by M193 and M855 Ball are caused by bullet fragmentation tearing the walls of the temporary cavity resulting in 150mm wounds. Temporary cavity requires rifle velocity target strikes (pistol bullets have very minor temporary cavities if at all) and the fragmentation of these rounds does not occur below 2500fps, or about 150 meters.

Hope this has value for you.
 
I've never seen any DRT difference between flat-based and boat-tails. I've used both for some forty+ years. ,243 and .30-'06.

I've never seen any notable difference in group sizes, either. That's with hunting rifles which mostly shoot somewhere between 1/2 and 7/8 MOA. I used to have an old Ruger 77 heavy-barrel .220 Swift. I used exclusively the Sierra 52-grain HPBTs. Five-shot groups of 3/8 MOA, darned near every time I checked. Dangfino.

Art
 
I've never seen any notable difference in group sizes, either.
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I have not either.

I'm not much of a target shooter and didn't even know benchrest shooters primarily used FB bullets till I started this thread.

Years ago my Dad used to shoot 1/2 in groups with his Douglas barreled custom 1909 Mauser .25-06 and he used exclusively BT back then.

Maybe there is nothing to it and it's all circumstantial.

Perhaps if there really is something to it the secret might lie in the structural diffrences of BT and FB.

As far as DRT goes last year my Dad dropped one in it's tracks with his Tenpoint crossbow so maybe you never can tell.
 
Nate, what kind of bullets are you using? Are using a flat bottomed brand x with 40% weight retention and trying to compare it to a boat tailed brand y with 65% weight retention? (I shouldn't use brand as a variable here as within brands there are often styles with a wide variety of expansion rate and weight retention. But it illustrates the question.)
 
MeekAndMild

Nate, what kind of bullets are you using?
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I put this in post # 9 it's the most I have on one brand and I have know idea what their respective weight retaining properties are.

Here's a good actually example: my Dad's favorite rifle cartridge is .25-06 he for years he used the 117gr Serria SBT Gameking he shot 100+ deer with it all ran an average of 40 to 50 yds before falling.

When I told him about my switch to the flat base after hearing of their increased effect and noting it myself.

He switched to a 117gr Serria spitzer Prohunter since then he has shot 30+ deer with that combo all have either dropped or ran less than 25yds.
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I myself have noticed the most difference in effect with two different brands the .308 150gr Nosler Ballistic tip and the 150gr Speer spizer flat base.

Like I've said before there's nothing scientific about this it just seems to me and some others I've spoken with that the FB has a greater effect.

Perhaps it does come from increased fragmentation and certain brands of FB expand and fragment more violently than some BT and thus make a more severe wound.

I have no idea if this is true of FB and BT hunting bullets in general.
 
I'm with Art on this one. There is no difference you or I will ever see. I have hunted and killed animals all over the West over the past 30 years. I have participated in shooting matches for a number of years. I have never noticed a difference between the terminal effects of BT or FB bullets of the same design and weight. You poke a hole in an animal and they react differently depending on what they are doing at the time. You poke a hole in paper and the only thing that establishes group size is where the barrel was pointed when the round went off. Looking for an answer anywhere else is looking for exceptions and anecdotes to prove a claim.
 
This holds only--repeat, only--for Sierra .30 bullets:

I had a 150-grain SPBT blow up in a mule deer's neck. No exit. It was at about 30 yards. 26" on the '06, loaded max. My estimated muzzle velocity, based on my experiences with holdover and Sierra's external ballistic tables for trajectory, was around 3,100 ft/sec.

A Sierra fellow got into the discussion here at TFL. He stated that I had driven the bullet too fast for the range at which I hit the deer. The jacket on the boat-tail is a tad thinner than on the flat-base. Had the velocity at impact been down around 2,700, it probably would not have blown apart. He further stated that a 150-grain flat-base would probably have held together.

Velocity at time of impact is thus a factor.

All other kills, at longer ranges, have had the boat-tail to be very effective; generally with exit wounds.

In the mule deer incident, the blowup didn't matter. A neck shot is a neck shot, and the deer didn't go anywhere from where he was lying as I walked up on him.

Art
 
I was gonna say, that's exactly what you WANT with a neck shot - a blow up. Good reason to drive them fast and try for neck shots. But then you limit yourself if only a vitals shot makes its appearance (say, at a range too long to try for a neck shot).
 
Bonded matters

Always,these issues are more complex.
Ross Seifred has far mor experience than I.His contention was that the cylindrical portion of the jacket contributed greatly to jacket-core integrity.
He said boattails were far more prone to separate (fail)
He also said at reasonable (300 yd or less) hunting ranges,the effects of the better BC on velocity/trajectory are not significant.

All good info.

I use my rifle for fun (not just big game hunting) at long ranges and I dial in one load,sightin and scope .I use HiBC heavy boat tails.
I have been using Accu-Bonds when I think they are a good idea(200 gr in a 30-338).It works.While I would not shoot Game at 700 yds,at my 5000 ft altitude 2900 fps at the muzzle is still breaking 2000 at 700 yds,kind of like a 30-40 Krag at 100 yds.Those work
 
Here's a good actually example: my Dad's favorite rifle cartridge is .25-06 he for years he used the 117gr Serria SBT Gameking he shot 100+ deer with it all ran an average of 40 to 50 yds before falling.

When I told him about my switch to the flat base after hearing of their increased effect and noting it myself.

He switched to a 117gr Serria spitzer Prohunter since then he has shot 30+ deer with that combo all have either dropped or ran less than 25yds.
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Are we discussing an "average drop dead distance" difference of 15 to 25 yards? Not enough difference, even if 100% accurate, to make me change anything I am doing...
 
The boattail , as noted is pretty much on par with the flat base inside 300 yards or so .. It maintains downrange velocity better due to less drag ..
It is pretty well noted that a flat base is more accurate ( tinier groups ) , my WAG on this is the flat base is bore diameter , and there fore has less chance of being off kilter leaving the muzzle ..
Accurate means different things to different people .. Even tho a long range shooter has the skills to put a flat or boattail , probably anywhere they want it , a long range shooter wants all the advantages he can get , therefore , the boattail , with less drag = more downrange velocity and less drop ..
In 99.5 % of hunting situations , I think it is a moot point as to which is better ..
Also remember that BC is directly affected by MV .. Your .540 BC bullet maybe .540 with a MV of say 3000 fps , go over or under and the BC changes up or down ..
I dont hunt beyond 250 yards or so , and I prefer the other BC bullets , ballistically challenged .. Gimme a round nose or a flat point any day ..
 
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