Energy vs momentum.

kmarsh1966

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Frisco Texas
I built a 7SAUM with 24" 1:8 bbl. I have loaded up some 155 Absolute Hammers and can get the to 3200. I looked at going with heavier Hammers both the Hammer Hunter and Absolute Hunter. I bought some 177 HH's with hope to get them to 2900-3000. That is a tall order I realize. Doing the ballistic charts the 155's will always have more speed and kinetic energy from the muzzle to put further if using 2900 for the 177's.

My question is which will penetrate deeper. I'm planning on hunting Elk Lin 2023. I don't doubt either will kill, but does one out perform better than the other. So far I have not recovered a bullet in anything I shot with 6.5 123 AH or 6mm 101 HH.

I appreciate opinions or facts from folks in the know and even those speculating. 1000% Hammer Fan boy here.

Thanks
Kyle
 

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I think it all depends on distance you are wanting this performance at. What distance are you planning on shooting most of your game at and the speeds needed for proper expansion. I'm not sure if both of those bullets are designed to expand reliability at the same velocity.
I just shot a cow moose @80yRds with a 7mm rem mag 150gr TTSX @3250 at the muzzle and it went through both shoulders and the entrance hole was identical to the exit. No expansion at all due to how high the velocity was. Today I shot a mule doe at 250m with the same bullet and velocity through the ribs and exit hole was 3 times the size as the entrance so it expanded.

I feel if I was running a heavier bullet at slower velocities for the TTSX I would have had expansion on the moose kill.
 
I think it all depends on distance you are wanting this performance at. What distance are you planning on shooting most of your game at and the speeds needed for proper expansion. I'm not sure if both of those bullets are designed to expand reliability at the same velocity.
I just shot a cow moose @80yRds with a 7mm rem mag 150gr TTSX @3250 at the muzzle and it went through both shoulders and the entrance hole was identical to the exit. No expansion at all due to how high the velocity was. Today I shot a mule doe at 250m with the same bullet and velocity through the ribs and exit hole was 3 times the size as the entrance so it expanded.

I feel if I was running a heavier bullet at slower velocities for the TTSX I would have had expansion on the moose kill.
Thanks for the input. I had a similar experince running bergers. At 234 it was going too fast and didnt make it into the thorasic cavity. Then the same day shot another animal at 434 and typical berger bang flop. IE the moral of the story was there is an optimum speed where everything will perform. With the hammers being designed to shed the petals and leave the square edge of the remainder to rip its way through, I am not sure that they can be shot too fast.... Great info on the Cow Moose.

I generally think Im going to be between 50-600 yds, with most common in the 200 yard range
 
BC comes into play at extended ranges with a 155 @ 3200 VS a 177 @ 2900.

Let's just take yardage for where they drop below 1800fps.

@ 6500' AMSL and 30°F (typical late season elk conditions)

155 hits 1800fps @ 910 yds
177 hits 1800fps @ 930 yds
177 wins

If you want to take 1500ft/lbs of energy remaining:
155 hits 1500 @ 700 yds
177 hits 1500 @ 790 yds
177 wins

So if you keep shots below 700 yds, lets look at drops:
155 @ 79.7"
177 @ 100.6"
155 wins
 
Well you have the 172 AH in hand first step is to see if they run like you hope, otherwise it sorts itself out.

I'll swim against the tide a little and say heavier won't always penetrate better. The better question is will they both penetrate adequately for intended use, and I think yes is the answer.

The lighter bullet offers a bit better stability and would be my choice. I also wouldn't be afraid to drop into the 140 range, and be confident of enough penetration.
 
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