308 vs 338 Federal for Elk <450 yds

SJB358

Ballistician
Dec 24, 2006
31,254
419
I don’t foresee you having too much trouble. It is a bit slow on twist but hopefully it works. If you can get 2800 out of the 168 TTSX you’d be doing great. Being as it is so long it seems to act more like a 180 class Bullet in some rifles.

Maybe try a little RL17 in your 06 with the TTSX and see where you get.

I’d not worry too much about either out to 400 yards. It’s going to matter more of where you hit them than a 100 FPS either way. I know you probably hear that till your ears bleed but with good Bullets like the AB, TTSX, etc you’re putting your best foot forward and they will dig plenty deep if you can hammer a 10” circle every time at 400. No elk is safe or would walk away too far. It won’t knock them off their feet, but then again, nothing does.
 

grifmXC

Beginner
Dec 6, 2019
20
0
I was actually thinking about trying RL17 for the 308, looking at burn rate charts it seems like it burns to slow but it’s have found quite a few people claiming to get good results with it. Also if I can find some, I want to try PP2000MR.


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grifmXC

Beginner
Dec 6, 2019
20
0
I was actually thinking about trying RL17 for the 308, looking at burn rate charts it seems like it burns to slow but it’s have found quite a few people claiming to get good results with it. Also if I can find some, I want to try PP2000MR.


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SJB358

Ballistician
Dec 24, 2006
31,254
419
grifmXC":17t91g6m said:
I was actually thinking about trying RL17 for the 308, looking at burn rate charts it seems like it burns to slow but it’s have found quite a few people claiming to get good results with it. Also if I can find some, I want to try PP2000MR.


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They are worth trying with the heavier Bullets I’d bet. A 165 AccuBond Impressed the heck out of me from a 30-06 on elk. Made me a believer.
 

PJGunner

Handloader
Dec 11, 2010
1,707
102
Looking in the latest Nosler manual they show 44.0 gr. W748 440g. as max for 2617 for the 180 gr. bullets. For Rl15 44.0 gr. max for 2617 FPS and for W760, 48.0 gr. for 2617 FPS. They used a 24" barrel with a 1 in 12" twist. FWIW, in their rifle/barrel the max RL15 was the most accurate as was the max with W748.

Latest Speer showed 2643 using Rl15 using a 24" barrel with 1 in 12" twist

Latest Hornady showed 45.7 gr. W748 for 2500 FPS and 48.9 gr. Rl17 for 2450 FPS using a 22" barrel with 1 in 12" twist. Hornady did not show any data for Rl15. and they were the only one showing anything using Rl17 which seem to agree with mine and thoughts of others that it's is most likely too slow.
I have three rifles in .308 Win., two have 1 in10" twists (Ruger M77 RSI and Remington M660) and a Winchester M70 Youth Ranger which has the 1 in 12" twist. (Won that last one in a raffle and put it in a Ramline stock. Quite accurate BTW) My go to bullet for the .308 has always been the 165 gr. Speer Hot Core which shoots quite well in all three. FWIW, I have run a few 180 gr. Sierra SPFBs though that M70 and most groups have run right around one inch if I do my part. The M77 RSI is at best a 1.25 to 1.50" rifle and the only load it would group well was a max load of W760 and the 165 gr. Speer Hot Core. It runs 2550 FPS from the 18.5" barrel of the RSI and I took a fair sized northern Arizona Mule deer with it at 250 yards. Bullet hit it in the chest just at the white spot at the throat and ended up in IIRC the left rear leg. Bullet retained 65% of its original weight. FWIW, that same load runs 2610 FPS from the 22" barrel of the M70. I've never shot it out of the Remington and couldn't tell you why. I just never did it. Maybe when I heal up and the doc gives me the OK I'll run some through the 660.
Paul B.
 

Gunner46

Handloader
Jan 12, 2015
483
0
Why has nobody mentioned Momentum ? Everyone seems caught up on energy.

For me? I have a 338 Fed, a 308 Win, and an inherited 30/06. They all shoot about the same accuracy wise.

When, If, I draw an elk tag, I'll be packing the 338.
 

Blkram

Handloader
Nov 25, 2013
1,823
154
Gunner46":13mjx0gd said:
Why has nobody mentioned Momentum ? Everyone seems caught up on energy.

For me? I have a 338 Fed, a 308 Win, and an inherited 30/06. They all shoot about the same accuracy wise.

When, If, I draw an elk tag, I'll be packing the 338.

Good point!
Momentum is part of that on-game performance I was referring to...just didn't put a name to it.
Frontal area is another factor of that on-game bullet performance that I like about the 338 over the 308.
 

grifmXC

Beginner
Dec 6, 2019
20
0
Not caught up with it but it is information that is readily available (given automatically in most trajectory calculators available). To me, comparing momentum between bullet/caliber choices is not an apples to apples comparison without further analysis/estimation. I may be wrong but here is my rational.

I look at kinetic energy as simply a point of reference of available energy at a given point in space and time. So if that point is the impact with the animal, then that is the energy available to “do work”. What is done or how that energy is transferred is all depended on bullet choice.

I associate momentum with penetration. I don’t think it is valuable or accurate to simply take the bullet weight and velocity at impact. So when comparing momentum you need to estimate how much weight retention your bullet will have a that point. When you’re comparing mono bullets, that maintain near 100% of weight its east mass*velocity. Cup and core bullets, shed mass on/shortly after impact. How much is shed is depending on both bullet construction and velocity. In my mind, when comparing momentum, you should only be considering the momentum of the maintained weight. A 120gr mono bullet and a 120gr frangible bullet, traveling at the same velocity are going to impact with the exact same momentum but have extremely different outcomes.

Applying to more what has been discussed in this thread, becomes much harder to get an apples to apples comparison because you have to either calculate(harder) additional information or make assumptions(less accuracy).

168gr TTSX vs 180gr AccuBond or Partition. And let’s say, the 168gr TTSX leaves the muzzle at 2750 and the 180gr bullet at 2600. If the 180gr bullet sheds more than 7% of it’s weight then it will the weigh less then the TTSX and it’s traveling at a lower velocity. There would also have to be an assumption or calculation of when the weight is lost. If you assume it’s lost on impact, This will result in less penetration. Now the energy of the weight lost by the 180gr bullet didn’t disappear, it was transferred into the animal.

But how much is all dependent on how and when the weight was shed (much harder to figure out).




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Guy Miner

Master Loader
Apr 6, 2006
16,458
705
Well, you've heard from some very experienced elk hunters, even right after your initial post on this in December. I think you've got some excellent advice, and am looking forward to your range results and hopefully photos of a successful elk hunt this fall.

(y)
 

Teknys

Handloader
Jan 14, 2008
707
7
I agree with the process grifmXC has described. Hence the engineering we benefited from with bullets the last few decades to control expansion and shedding weight. This so that we maintain penetration with out just simply adding weight up front from the start. Some components of the physics can be a challenge to substitute for such as frontal area.
Me... I like my 338F for timber / brush elk. I use my 300WSM but when I'm in the brush all day I have the 338F. It has taken a few elk at the close range and with the BC reticle I had on it, I could bang the gongs out 400yds any day of the week. A stiff cross wind beyond 300 yds becomes a real challenge.
 

super-7

Handloader
Jun 27, 2009
838
1
Sometimes I believe the more we reload and shoot we start to over think and over analyze things. Admittedly that is some appeal to buying new rifles in different calibers. Guys like my grandfather would grab his model 88 in 308 win grab a box of off the shelf 180gr cupncore bullets and head out a fill the freezer. Moose, Elk, Deer,Bear. Never worried about his ballistics, sd’s, weight retention, .

While it’s fun to ponder & discuss different bullets and calibers I don’t believe there is an elk anywhere that could tell the difference between a 308 win or the 338fed or a 30-06.
I’d say grab whichever rifle feels most comfortable and go enjoy a hunt .


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Blkram

Handloader
Nov 25, 2013
1,823
154
There's a lot of truth in your grandfather's reckoning!
My grandfather did it too with his ol' 30-30 and 22!
And the meat on the table was proof enough!
 

grifmXC

Beginner
Dec 6, 2019
20
0
So I’ve made a couple trips to the range to do some pressure tests.

First trip I loaded up 2 -15 round (1 varget and 1 CFE223) strings with 168gr TTSXs sitting .05 off the lands and a COAL of 2.995. I saw no pressure with the varget string and it topped out at 2743 and the CFE223 showed pressure (slightly stiff bold and a lite mark on the case where the notch in the bolt face was) about halfway through the string. Max velocity was 2795.

Went back this morning with 4 strings.

String 1: I stepped up the varget did the last 10 shots of the last string and added 5 more at .2gr per shot so that I increased by 1 gr. Max velocity was 2789

String 2: CFE223 with 168 seated .1 off lands and the same steps as last time. I only loaded 12 because I didn’t expect to get all the way through but wanted to check/confirm what people have shared on here as well as other forms that letting the barns bullets jump about .1 reduces some initial pressure. Well I had no pressure signs all the way up and maxed out at 2820.

String 3: Varget and 150gr TTSX@.1 off lands(had to seat that deep to get .308 of bullet in case. No pressure signs all the way up and max velocity was 2874.

String 4: CFE223 and 150 TTSX@.1 off lands. No pressure signs all the way up and max velocity was 2925.

Next things to try are RL17, PP2000MR, and the 165 accubonds (when SPS gets them back in stock) may also try the 180 partitions just to see if the extra case capacity I gain from being able to have a longer COAL will gain me anything.




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grifmXC

Beginner
Dec 6, 2019
20
0
So I’ve made a couple trips to the range to do some pressure tests.

First trip I loaded up 2 -15 round (1 varget and 1 CFE223) strings with 168gr TTSXs sitting .05 off the lands and a COAL of 2.995. I saw no pressure with the varget string and it topped out at 2743 and the CFE223 showed pressure (slightly stiff bold and a lite mark on the case where the notch in the bolt face was) about halfway through the string. Max velocity was 2795.

Went back this morning with 4 strings.

String 1: I stepped up the varget did the last 10 shots of the last string and added 5 more at .2gr per shot so that I increased by 1 gr. Max velocity was 2789

String 2: CFE223 with 168 seated .1 off lands and the same steps as last time. I only loaded 12 because I didn’t expect to get all the way through but wanted to check/confirm what people have shared on here as well as other forms that letting the barns bullets jump about .1 reduces some initial pressure. Well I had no pressure signs all the way up and maxed out at 2820.

String 3: Varget and 150gr TTSX@.1 off lands(had to seat that deep to get .308 of bullet in case. No pressure signs all the way up and max velocity was 2874.

String 4: CFE223 and 150 TTSX@.1 off lands. No pressure signs all the way up and max velocity was 2925.

Next things to try are RL17, PP2000MR, and the 165 accubonds (when SPS gets them back in stock) may also try the 180 partitions just to see if the extra case capacity I gain from being able to have a longer COAL will gain me anything.




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RMiller

Beginner
Sep 29, 2004
89
0
Pick one and practice then go hunting.

My last two Elk I shot with my 308 win and 165 Sierras. The one before that was with a 30-06 and 175 Barnes LRX.

I have also shot moose, black bear and Dalls sheep with a 308. The moose was with the 165 XBT at 2660 fps muzzle velocity.
 

Guy Miner

Master Loader
Apr 6, 2006
16,458
705
RMiller":taa911w1 said:
Pick one and practice then go hunting.

My last two Elk I shot with my 308 win and 165 Sierras. The one before that was with a 30-06 and 175 Barnes LRX.

I have also shot moose, black bear and Dalls sheep with a 308. The moose was with the 165 XBT at 2660 fps muzzle velocity.

Way too simple... (y)
 

grifmXC

Beginner
Dec 6, 2019
20
0
That is basically my plan. COVID-19 has put a major damper on my range time. But once everything calms down and we settle into whatever the new normal is I plan on testing the 168s to see if they are stable in my 1in12 twist. If they are, I am going to try pp2000mr. What I have read is that it is produces similar velocities to CFE223 but what little I have been able to find on temperature sensitivity suggests that pp2000mr is more stable. I plan to test and see what results I find.

If the 168s won’t stabilize I will try the same with the 150s.


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