Thread: 6.5mm questions....

Originally Posted by Moa Hunter

Nathan Foster explains this in his 'Game killing Fundamentals' In short the instant kills we see are often not actually kills ( unless brain or CNS ) but instant paralysis from hydrostatic shock. The animal bleeds out whilst paralysed before we get to it. The bigger the diameter the projectile the lower the velocity required to still cause hydrostatic shock. I was surprised how quickly some rounds loose the ability to cause HS

Interesting, does he have much evidence on this? Or is it theory based?

Originally Posted by outdoorlad

Always an interesting subject, this roar I used my Sako 260 (20”) with a box of factory ammo as I didn’t have time to sort out a load, I used Hornady superformnace 129SST, I shot 5 deer with it (3 stags, 2 yearlings) and it smacked them all down emphatically, none needed a follow up shot, I chrony it recently at a slow 2650fps!

What distances?

Originally Posted by outdoorlad

Always an interesting subject, this roar I used my Sako 260 (20”) with a box of factory ammo as I didn’t have time to sort out a load, I used Hornady superformnace 129SST, I shot 5 deer with it (3 stags, 2 yearlings) and it smacked them all down emphatically, none needed a follow up shot, I chrony it recently at a slow 2650fps!

That is slow and interesting. The 6.5 pill is a long, penetration piece of machinery and penetration is where it’s at.

Originally Posted by Flyblown

I'd point out that the 143gr ELD-X is a stone cold killer out to pretty decent ranges even when driven at modest velocity. Mine is doing 2760fps out of a 24" barrel with 42.4gr AR2209 and it flattens goats in the 500s, 600s with ease. Was whacking them just past 700m a couple of weeks ago. A 100-150fps difference in MV won't make a huge difference in range I wouldn't have thought, would have to check the energy numbers. A very accurate and low recoiling 6.5 makes for a highly effective 500-600m+ pest goat controller, doesn't need to be fast.

I believe it's the combinations of bullet-length,plus rpm's (8-twist), and BC/SD, that make the 6.5's so efficient at the lower FPS. It appears to be one of the few calibers that gets everything right. With the 6.5x55, it was second only to 9mm parabellum, in having the highest no. of ballistics-experts, involved in its development.

Originally Posted by Gibo

Interesting, does he have much evidence on this? Or is it theory based?

Not sure, but isn't that the whole point with Hydrostatic shock? Nothing dies instantly unless you smack it in the head, even then it's brain dead but the heart is still pumping for a little while? I guess making a mess inside and still having the animal move would increase bleed out?

The instant knockdown is preferable anyway and most animals that get hit that hard in the boiler room and get up don't make it far from my experience so I'm not sure if he's saying it's a good thing or bad?

Originally Posted by SlimySquirrel

Not sure, but isn't that the whole point with Hydrostatic shock? Nothing dies instantly unless you smack it in the head, even then it's brain dead but the heart is still pumping for a little while? I guess making a mess inside and still having the animal move would increase bleed out?

The instant knockdown is preferable anyway and most animals that get hit that hard in the boiler room and get up don't make it far from my experience so I'm not sure if he's saying it's a good thing or bad?

Wasn't questioning hydrostatic shock per say, more the reference to projectile diameter/velocity and its effect on HS. Just looking for evidence not opinion is all.

Same! I know you weren't questioning, I'm intrigued by the idea too.

It's often seen on Rabbits with the little 17's. First time I shot one with an Hm2 it looked like it was being electrocuted. I have a video of a large billy shot with 7mm08 at 220 yds 129 sst and it did the same. Literally just stiffened up and died. Wonder what sized/speed calibre would be required for Reds in comparison.

Banged a quick video together for an example.
You can see them stiffen up then start to move a few seconds later as the shock passes through.

https://www.youtube.com/watch?v=6Qs7RbKbuZ0

Originally Posted by Gibo

What distances?

@Gibo Varied between 10m to 150m, only one that didn’t exit was a big stag at 150m.

@outdoorlad, how would you characterise the shot replacement on your five deer with the 6.5 mm SST? Where they roughly the same?

Was there a common point of impact and angle of pass through? Can you describe it like "front line of foreleg" or "in the crease" or "behind the shoulder", that kind of thing?

For normal hunting ranges, I'm 100% convinced that where you hit them in the boiler room, and with what, has more influence on whether or not they go down fast, than calibre and speed. Take an old school .30-30 and a slow flat point, and a .243 and a fast soft-point spitzer, and you can do exactly the same thing to a deer with a certain type of boiler room shot.
@Mooseman's large sambar the other day was a perfect example of the Swede doing the bizzo yet in some countries these days it seems the Swede is regarded as "not enough gun" for their poxy tiddler deer!

Originally Posted by Flyblown

@outdoorlad, how would you characterise the shot replacement on your five deer with the 6.5 mm SST? Where they roughly the same?

Was there a common point of impact and angle of pass through? Can you describe it like "front line of foreleg" or "in the crease" or "behind the shoulder", that kind of thing?

For normal hunting ranges, I'm 100% convinced that where you hit them in the boiler room, and with what, has more influence on whether or not they go down fast, than calibre and speed. Take an old school .30-30 and a slow flat point, and a .243 and a fast soft-point spitzer, and you can do exactly the same thing to a deer with a certain type of boiler room shot.
@Mooseman's large sambar the other day was a perfect example of the Swede doing the bizzo yet in some countries these days it seems the Swede is regarded as "not enough gun" for their poxy tiddler deer!

In Scandinavia they use 6.5 swede on moose but Victoria state won't allow anything less than 270 for sambar.

Originally Posted by Gibo

Interesting, does he have much evidence on this? Or is it theory based?

To answer your question @Gibo here is the link https://www.ballisticstudies.com/Kno...e+Killing.html

There is quite a lot to humane game killing, I have shot Roe deer in Saxony with a 30 06 and 180 grn pills and they all ran. Big hole plenty of damage but no instant collapse. Wonder what would have happened if I was using a 2250 or 243 with light high velocity bullets that can better shed energy.

Originally Posted by Flyblown

@outdoorlad, how would you characterise the shot replacement on your five deer with the 6.5 mm SST? Where they roughly the same?

Was there a common point of impact and angle of pass through? Can you describe it like "front line of foreleg" or "in the crease" or "behind the shoulder", that kind of thing?

For normal hunting ranges, I'm 100% convinced that where you hit them in the boiler room, and with what, has more influence on whether or not they go down fast, than calibre and speed. Take an old school .30-30 and a slow flat point, and a .243 and a fast soft-point spitzer, and you can do exactly the same thing to a deer with a certain type of boiler room shot.
@Mooseman's large sambar the other day was a perfect example of the Swede doing the bizzo yet in some countries these days it seems the Swede is regarded as "not enough gun" for their poxy tiddler deer!

All bar one were in the shoulder region and normally I go for the foreleg area to break bone, two however were angled, one stag facing me on an angle in the bush, hit thru the shoulder and exited mid ribs. The other was a yearling angling slightly away, behind the shoulder and out thru the offside shoulder.

I guess the point I was trying to make was that the 129SST seems to preform very well at a slow to moderate speed, a friend tried the 130gn sst in his 270 years ago and hated them as they expanded to quickly and didn’t penetrate at the high speed they were going.

And its a point I agree with 100% @outdoorlad. Often we see or hear about guys unhappy with bullet performance, and a frequent common denominator is a fast cartridge with a soft-ish bullet.

Seems to me that a lot of the common cup-and-core hunting bullets are at their performance limits around 2500-2600fps impact velocity, so say 2700-2800fps muzzle velocity. Poor penetration and excessive fragmentation are complaints about the SST all over the world. But how many of these complaints are from 7mm Rem Mags, 270s, 6.5-284s, etc etc?

Who knows, just seems to me that the complaints about Hornady SST, Sierra GameKing, Nosler Ballistic Tips etc often concern close range impacts from 3000fps+ cartridges. That additional 10% MV seems to make a lot of difference. We had a similar concern on here recently with ELD-X out of 7mm Rem Mags.

My one cuz used a new CZ 6.5 Grendel last season with (I think) the same weight SST in factory ammo, and loved it. Mule deer. In the front of the fuse box, all over rover.

Originally Posted by Flyblown

And its a point I agree with 100% @outdoorlad. Often we see or hear about guys unhappy with bullet performance, and a frequent common denominator is a fast cartridge with a soft-ish bullet.

Seems to me that a lot of the common cup-and-core hunting bullets are at their performance limits around 2500-2600fps impact velocity, so say 2700-2800fps muzzle velocity. Poor penetration and excessive fragmentation are complaints about the SST all over the world. But how many of these complaints are from 7mm Rem Mags, 270s, 6.5-284s, etc etc?

Who knows, just seems to me that the complaints about Hornady SST, Sierra GameKing, Nosler Ballistic Tips etc often concern close range impacts from 3000fps+ cartridges. That additional 10% MV seems to make a lot of difference. We had a similar concern on here recently with ELD-X out of 7mm Rem Mags.

My one cuz used a new CZ 6.5 Grendel last season with (I think) the same weight SST in factory ammo, and loved it. Mule deer. In the front of the fuse box, all over rover.

I use the 6.5G with 123gr SST MV 2430ish and it's truly devastating when I shot a couple of big billies at about 80m side on square shoulder, exit wound was large. I'm not changing from them as I think they work well in this cartridges speed (I think the 123gr may have been developed for the 6.5G)