168gr vs 178gr In a Shorter Barrel

[RedRanger328]

Specifically, 168 ELD-M vs 178 ELD-M in a 20" barrel 1/11" twist rate.

Which is going to be the better long range killer? I can't find much of anything on the 168 ELD-M, but plenty of people using the 178 ELD-M.

1) Is there enough of a difference to even warrant the discussion?

2) The problem I have is I can't find too many people discussing it that are also using a 20" barrel. Which weight is more efficient?

If I sound ignorant, it's because I am.

 

[Matt Tatum]

I'm in the middle of a discussion about lighter weight stuff for kids, but I have shot 168 and 175 extensively in a 16" 308. I'm able to push the 175's just as fast as the 168's and the bc is better on the 175's so it maintains its velocity farther out. It hits like a hammer too.

 

[RedRanger328]

That's what I would like to hear. A couple of my friends say hands down the 168gr is the way to go with the simple reasoning:

"The lighter bullet can be pushed faster, and hence, will impact with more energy, making it more effective at killing. And with a shorter barrel, I need a lighter bullet since I'll have less barrel to burn powder."

I highly doubt it's that simple. Like you mentioned, the BC is higher with the heavier bullet. I guess it depends how fast I am able to push either bullet. If there's a 200 fps difference, the 168gr would beat out the 178gr all the way to 1000. Would you happen to know about what velocity I should be aiming for at the muzzle?

 

[Matt Tatum]

In my 16" both the 168 and 175 are about 2550 give or take a couple fps. It's a very stout load of varget in Lapua brass. I also shoot 155's, they run about 2700.

 

[Idaho Lefty]

My son's, 7mm-08, shooting 168 HVLD Bergers, launched at, 2,750 - 2,760 FPS with, StaBall, out of, his 22.4" bbl'd, Tikka is still going, OVER, 2,000 FPS at, 800 Yards ! This load, Freakin', "catches up" to my 140 Classic Hunter's, from my .270 WSM going, 3,185 FPS at, the Muzzle and the EXTRA, 28 grain, HIGH BC, Bullet, will most probably, Hit,.. HARDER !!
Since we've both agreed that about, 650 yd's is our Max range on Elk we have,.. NO "problem" !
The little 7mm-08 will Surprise you,.. IF, Hand loaded properly with, high BC Bullets !

 

[Idaho Lefty]

To the OP,..
I would ALWAYS USE, the Fastest Burning Powder, "possible" with, accuracy of course IN, a short barreled, Rifle.
And I'd stay with, the 168's,.. personally.

 

[RedRanger328]

So how I'd want to go about this, is test shots over a Chrono, get an average speed, and check to see if I've got the velocity on the bullet at whatever range using a ballistic calculator under various conditions, is that about right?

I've currently got IMR 4064 stockpiled, and with what I'm reading, I actually want a faster burning powder, but that's gonna be a bit difficult. I've got 178 gr ELD-Ms on hand, but not the 168s.

 

[Idaho Lefty]

Yup,. Finding "everything" we WANT, is a bit "difficult", Today !
Just do your best and,.. don't worry !
Those 178's will, "work" fine, on Elk!
What Cartridge, are you loading for ??

 

[RedRanger328]

I'm loading for .308

 

[Idaho Lefty]

When, i used to Hunt with, a .30-06, I loved the 165 Partitions ( Always thought that, the 165- 168 gr bullet was, Perfect ! ).
What speed are you getting for, the 178's ?

 

[RedRanger328]

I haven't loaded any up yet, I'll be loading and testing this weekend

 

[Idaho Lefty]

Good luck, be SAFE and keep us, posted !
Remember that, ALL, Bullet, "Bearing surfaces" are DIFFERENT lengths and, the composition of the Copper Jackets are different from, Mfg to Mfg !
The Hornady Book would be, BEST to look at,.. IF the ELD-X or ELD-M 178 grain Bullet, is shown,..
use that, STARTING, Data and "work up", carefully !
I start with, 3 shot groups with, one or, two, to get me near, the Bullseye and Foul, the Clean Barrel.
( that's 5 at, the lowest Charge ) then shoot 3, every 1/2 grain apart,.. after, that !
Watch for pressure signs, Velocity and look for,.. "good" Group's !
Then you can "Fine tune" after finding, the best , 3 shot group !

 

[cabelasken]

When using a shorter barrel, a heavier bullet will allow more of the powder to burn more completely before the bullet exits the barrel. For one, it has more bearing surface and has a little more resistance as it travels down the barrel. Also, the weight of the bullet provides a little more resistance against the pressure build as the powder ignites and forces the bullet down the barrel. Therefore a heavier bullet is a little more "efficient" in s short barrel for caliber cartridge.

 

[Bud LaRoche]

155 Scenars are a well known killer