Confused About Bullet Performance


Well-Known Member
May 11, 2009
Honolulu, Hawaii
First of all, great forum with lots of info!!!!!!! Please forgive my ignorance but I'm a little confused. I sent the following question to Sierra Bullets.

I am currently shooting Sierra Game Kings in .308 pushed by 39.2 grains of
IMR 4064 at 2500 fps. According to ballistic calculations, at 500 yds. the bullet would be down to about 1600 fps. Is that fast enough to perform as
designed on deer sized game? I really want to stay with this load as I
can cover three shots with a dime at 100 yds. all day long.

I recieved the following response from Sierra:

Robert Treece <[email protected]> wrote:
> No, it wont expand at that velocity unless it hits something hard--out past
250 yards; would sure aim for heavy shoulder bones to try getting bullet to
> Good hunting and thanks for using our products!
> robert
> Ok now I'm confused!!!!! The MAX load in the Sierra manual for 165 g. Game Kings is traveling at 2800 fps at the muzzle. This equates to about 1800 fps at 500 yds. (Used the ballistic calculator from If it won't expand at 1600 fps. will it perform much better at 1800 fps.?
Does this mean Sierra bullets aren't good for hunting beyond 250yds????

I checked the Barnes manual with the 165g. TSX and got a similar fps. at 500yds. Does this also mean Barnes won't perform?????

Need guidance before my head EXPLODES!!!!!!
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IMO, most big game bullet manufacturers want 1800 fps for RELIABLE expansion. It does NOT mean that they won't expand at all, but that you may not get your traditional mushroom.

Like the tech wrote, hit the shoulder on the way in and it will expand. If you only hit ribs going in then you most likely won't get a bang flop! As a hunter you should know what to expect when you pull the trigger and plan accordingly for either a followup shot, an extended wait, or a trailing job :)

Hey 308,

I am no expert but I think 300fps is a pretty large amount in a 308 cartridge. You have very good accuracy at 2500 ,so the question is how much acc. do you lose if you go up to 2700 fps? The dime size groups are sure great to see and show that you and your weapon are very capable. Now if you increase velocity and you groups go to ,say, nickel size that is still darn good, and your bullets should perform better.

As a reloader also I know testing can be pricey, stinks to buy a full box of bullets only to find out they don't work in your gun.
Found this guy and he is a life saver ,Tom Reddin at
Check out the site and if you see something you wish to try write down the info on a piece of paper go to the order form and fill it out ,don't forget your phone # and e-mail. The first time I ordered from him it was a little different because after you submit your order Tom will call you on the phone usually that day to review your order then take cc info. I got some Bergers from him and thats what I use now in my 300wsm. Also he ships your order out fast ,sometimes that day if you catch him early..

Good luck..
ps Lots of long range hunters use sierra matchkings with good results in the bigger cartridges.
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All bullets are designed to perform under a specific set of conditions. velocity,type of animal
or a target,maximum distance,Ballistic coefficient, ETC: .

Some examples are=

Varmint bullets - very light, normally very fast,thin jackets for easier
engraving in the rifling and explosive expansion with no consideration
for tissue loss.

Target bullets- Thin jackets, High ballistic coefficients for consistant long range
performance, with no provisions for anything but shooting holes in paper.

Big game hunting bullets (Deer size and up)- Heavier jackets for better control
of expansion (Some are bonded to the core) and some are mono metal (Solid)
They also have a range of velocities that they are designed to perform at there
best (1800 to 2800 normally) And this is there impact velocity performance design
and above or below that they do not perform as well as designed. They are designed
with tissue damage and energy transfer as the prime objective.

Dangerous game bullets- These are the heavy weights (Normally 300 grains and up)
They have the heaviest jackets,and are bonded,have a partition or are solid mono
metal with engraving rings because the mono metal is hard. They are designed to stay
together and may expand slightly but retain all of there weight and penetrate deep
in big tough animals.

So you can see that all bullets are not created equal and must be picked according to
there intended use.

If you like the bullet your now using you should look at the maximum distance that it will
fall into the 1800 to 2800 range and limit your distance to what that is in order to get
the most from it.

If you want to extend the distance you will/should change bullets or bullet types.(A hollow
point or polymer tipped bullet will expand better/easier than a spitzer at the same velocity).

The reason that they set the bottom velocity @ 1800 is that they consider a pure meat shot
and no bone to get the expansion started and reasonable performance.

If you have to make a shot that will be below this design velocity then shot placement will
dictate bullet performance.

I use to use a lot of these bullets in my 308 but know that there are so many new bullets to
choose from I recomend a Bonded and tipped (a hollow point with a inserted tip for better
BCs and controled expansion) For use on game.

Sierra still makes fine bullets but there are other good bullets that may out perform them for
certen typs of hunting

I hope this helps.

Well said J.E. I have been making several posts on this subject and still maintain that when shooting at the ranges we talk about on this forum MOST factory bullets will not perform well and quite often it's the most expensive that are the worst! That is exactly why I make my own......Rich:D
Thanks for the quick and informative responses. I'll work on the load to get at least the 1800 fps. at 500 yds. I don't think my I'm capable of ethically hunting beyond that distance......YET! Again thanks for the help.
308ltr......Don't be too surprised if they don't open at 500 yds. either. I think there is better than even odds it will take MORE than 1800 fps......Rich
can't speech of the gamekings but while looking for a hunting bullet for my 308. I settled on the 178 a-max because of how many good reviews I read on here about it. So far this year this bullet has done awesome on everything shot with it. My wife shot a large bodied 3x5 bull elk at 185 yards bullet entered midbody tight to the shoulder and excited through the muscle on the opposite side leg leaving about a 1'' hole and lots of messed up muscle and bone it hit a rib going in and performed great,she also shot a 4x4 whitetail at 415 yards downhill the bullet entered midbody tight to the shoulder and left a 1'' exit hole not very much bloodshot, the deer humped up at the shot and tipped over 15 seconds later he never took a step, the elk made it about 30 feet before going down. I have shot three coyotes at 100,250,575 and all three were drt with huge exit wounds. I am not sure if its just the bullet or what but I have never heard a smack so loud when it hits an animal the buck sounded like she shot a rock it was so loud. My gun is throwing the 178s at 2740 out of a 26 inch tube and shoots 1/2 inch at a 100 and gets better the farther out you go.
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