162 AMAX (.284) Min Expansion Velocity

[hmbleservant]

Can you enlighten me on the SXR's please...I've havent heard of them yet. Thanks

 

[hmbleservant]

Elkaholic why didn't you vote! I noticed you didn't actually influence the poll by voting.
Anyways thanks for sharing.

 

[elkaholic]

Elkaholic why didn't you vote! I noticed you didn't actually influence the poll by voting.
Anyways thanks for sharing.

Sorry, I'll vote now. The SXR's are my own that I make for my 30's......Rich

 

[Michael Courtney]

We've done reduced velocity terminal performance testing of many bullet designs. If the bullet remains point forward until expansion, and if performance depends on expansion rather than tumbling, then the spin rate is not relevant to the expansion threshold. The expansion threshold depends only on the velocity and the test medium (as long as it remains point forward until expansion).

10% ballistic gelatin will most accurately predict the expected expansion on game. If gelatin is not available, then a row of water jugs or ziplock bags filled with water would be my second choice. In most cases, water will overestimate the expansion threshold, because water offers less resistance than gelatin. Wet phonebooks will tend to underestimate the expansion threshold because it offers more resistance than gelatin or tissue.

It is also notable that many bullet manufacturers underestimate the minimum expansion threshold. If you read the fine print, most do a pretty good job of measuring the threshold in ballistic gelatin, but then only require a 10% increase in bullet diameter to call the expansion a success. I think a 50% increase in diameter is a more reasonable minimum to categorize an event as the kind of expansion that would be desirable.

Even though we have not measured the expansion threshold in the AMAX, we expect it to be lower than most other bullets. My preferred AMAX load is doing 1730 fps at 1000 yards under hunting conditions, so I'm not really worried about exactly where the minimum is.

 

[elkaholic]

We've done reduced velocity terminal performance testing of many bullet designs. If the bullet remains point forward until expansion, and if performance depends on expansion rather than tumbling, then the spin rate is not relevant to the expansion threshold. The expansion threshold depends only on the velocity and the test medium (as long as it remains point forward until expansion).

10% ballistic gelatin will most accurately predict the expected expansion on game. If gelatin is not available, then a row of water jugs or ziplock bags filled with water would be my second choice. In most cases, water will overestimate the expansion threshold, because water offers less resistance than gelatin. Wet phonebooks will tend to underestimate the expansion threshold because it offers more resistance than gelatin or tissue.

It is also notable that many bullet manufacturers underestimate the minimum expansion threshold. If you read the fine print, most do a pretty good job of measuring the threshold in ballistic gelatin, but then only require a 10% increase in bullet diameter to call the expansion a success. A think a 50% increase in diameter is a more reasonable minimum to categorize an event as the kind of expansion that would be desirable.

Even though we have not measured the expansion threshold in the AMAX, we expect it to be lower than most other bullets. My preferred AMAX load is doing 1730 fps at 1000 yards under hunting conditions, so I'm not really worried about exactly where the minimum is.

Michael.....I can tell that you have done some testing as your expansion media results duplicate what I have found. It is refreshing to me to hear someone respond without just winging it! (not that everyone on this forum does that)........Rich

 

[barnesuser28]

I shot the A-Max at the water jugs the other day and recovered one out of three. The one I recovered had an impact velocity was about 1200 fps and there was no expansion, only the tip broke off. I shot a load that had an impact velocity of 1350 fps and I didn't recover it but I did notice some fragments in the bottom of the jugs so I am assuming that it expanded some. If you want to see pics search 280 grain Barnes LRX low end expansion velocity results

 

[sportmuaythai]

Apology for an ignorant question. Will the 162Amax stabilize well in 1:9.5 twist Rem.mag.?

 

[barnesuser28]

They stabalize in my 9.25 twist 7mm-08 so i think you should be able to with a 9.5 7mm Rem.

 

[sportmuaythai]

They stabalize in my 9.25 twist 7mm-08 so i think you should be able to with a 9.5 7mm Rem.

Thanks for your very prompt reply.

 

[Shoot 708]

Trying to vote on this one. Following the rule of thumb, wanting 800-900 ft. Lbs energy for deer. A 162 gr bullet drops to 800 ft. Lbs at 1500 fps. I have recently loaded 162 Hornady interlocks to 2800 fps using 2000 MR, Winchester brass, WLR primer. No excess pressure signs. Remington 700 varmint, 7 mm 08. 26" barrel through a CED M2 chronograph. This gives the interlock 1488 fps and 796 Ft. Lb at 1000 yards. (4700 ft elevation). The higher BC of the Amax retains 1016 Ft. Lb with a velocity of 1681 fps at 1000 yards. And some try to say 7 mm 08 isn't enough for elk.

 

[Michael Courtney]

Back in 2012, we measured the expansion threshold of the 208 AMAX in to be 1700 ft/s in ballistic gelatin. Slower impacts reliably tumble and demonstrate excellent wounding via tumbling, but they do not expand or fragment. Our experience in deer is that hitting bone can initiate expansion or fragmenting at lower velocities than bare gelatin, but bare gelatin is representative of hitting softer locations.

Usually different caliber bullets of the same basic design and construction have comparable expansion thresholds, so 1700 ft/s is likely a good estimate for the 162 AMAX. 1800 fps gives some margin for error.

Tumbling in one caliber does not indicate a likelihood to tumble in other calibers. I also don't feel as good about the wounding potential of the shorter, thinner, lighter 162 AMAX as I feel about the 208 AMAX. High speed video shows excellent wounding potential of the 208 AMAX when it tumbles, even without expansion or fragmentation.

Bottom line is the 162 AMAX might be iffy below 1800 ft/s. If it hits something harder to initiate expansion or tumbling, you might do OK down to 1400 ft/s.

 

[gohring3006]

I think the bullet should be super sonic to give good results or right at super sonic so I say 1200 to 1400fps

 

[remingtonman_25_06]

Ive killed deer and elk with them, furthest out to 1125 yards from a 7 RM loaded at a slow but very accurate 2900fps and theyve had no problems expanding/penetrating like any other cup and core bullet.

Average impact velocity at 1125 yards with above combo give or take etc, would be around 1450fps along with 750 ft lbs of energy.

I know its plenty and gets the job done with that bullet put in the chest cavity.