Thread: 6.5mm questions....

Originally Posted by Cigar

Checked chrony data, 20 inch barrel.
120BT doing 2833 with 45.5gr of 2209, best group 0.7moa at 100m with 44gr.
143 ELD-X doing 2593 with 42.5gr, 2634 fps with 43gr ( Best group 0.38moa at 100m with 42.5gr.
129sst does 2606 and 2637 with same powder charges. Best group 0.7moa but didn't write down what powder charge.

At this stage I'm going with the 120BT and 143 ELD-X, but will check out how the 140 Gamekings go.

2209 generally gives very good accuracy in a 260, but its as slow as a wet week. If you can live with dialing a bit more elevation and reducing your terminal range then its a good powder.

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.

Was working up a load using some SMK150gns. I dont have perminant access to a decent labradar or anything but using rwd i've figured im getting 2760fts with them. Almost same terminal speed at 500y as eldm 147's and i know they kick off at 2810fts in my rifle.
Yep they stabilise in my 1/8 twist barrel. Better precision than i've experienced with Eldm, x, berger etc. Seems to like more neck tension than less (funny enough).

But i wanted to add that during load development i did notice a tapering off of mv gain at 46.6gn of 2213sc. Chose 45.9 as it had the same velocity but seemed to node right there.

The max useable COAL in my sako 85 7mm08 is limited by the longest live round it can eject. This is about 2.800". Longer rounds can feed and fit into the magazine but in my opinion are not satisfactory for all round hunting.

Note that the 6.5 PRC is a short magnum class cartridge with max COAL 2.955" compared to 7mmWSM at 2.880" and 6.5 Creed at 2.825. So the PRC could substitute in some 7mmWSM actions if you limit its length but not in 308 (Sako S) actions. It's meant for people rebarreling their 6.5-284 or WSM.

Originally Posted by Cigar

Checked chrony data, 20 inch barrel.
120BT doing 2833 with 45.5gr of 2209, best group 0.7moa at 100m with 44gr.
143 ELD-X doing 2593 with 42.5gr, 2634 fps with 43gr ( Best group 0.38moa at 100m with 42.5gr.
129sst does 2606 and 2637 with same powder charges. Best group 0.7moa but didn't write down what powder charge.

At this stage I'm going with the 120BT and 143 ELD-X, but will check out how the 140 Gamekings go.

I would try 2208 for the 120's you should get better speed. I run 2208 for the 120's and 2209 for the 140's

Originally Posted by johnd

I would try 2208 for the 120's you should get better speed. I run 2208 for the 120's and 2209 for the 140's

I'll give that a try, I have some 2208. Most load data I've seen online shows better speed with 2209 but that's normally with 24 inch barrels

Shy of starting a new thread, have procured a Sako in 260 with 1:8 twist. Now the real question, to AI or not to AI...

Originally Posted by HuntGatherRepeat

Shy of starting a new thread, have procured a Sako in 260 with 1:8 twist. Now the real question, to AI or not to AI...

Been there done that would I do it again.
NO there was no real advantage other than not having to trim your brass.
Just use it as is what is the barrel length

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I really like the 6.5 caliber and have had a couple of 6.5x55. Current one is deadly (Schultz & Larsen).

My only reservation is that they are not magic. My experience is that once the distance gets out to 350 yards odd they can be slow killers. I have experienced this with Sierra, Amax and SST 140grn projectiles at circa 2.8K. They have always died, but not in an emphatic manner.

I know that it won't be other people's experience, but it is mine, that both the 7/08 and 308 seem to kill better at all ranges - I often wonder if its something to do with the smaller expanded frontal area of the 6.5? Dunno really.

Originally Posted by Tahr

I really like the 6.5 caliber and have had a couple of 6.5x55. Current one is deadly (Schultz & Larsen).

My only reservation is that they are not magic. My experience is that once the distance gets out to 350 yards odd they can be slow killers. I have experienced this with Sierra, Amax and SST 140grn projectiles at circa 2.8K. They have always died, but not in an emphatic manner.

I know that it won't be other people's experience, but it is mine, that both the 7/08 and 308 seem to kill better at all ranges - I often wonder if its something to do with the smaller expanded frontal area of the 6.5? Dunno really.

Switch to 130 Bergers, put it in the boiler room, the bergers come apart better. It's working for me in my 6.5 CM. Agree about .308, reckon it's the lower SD and bigger hole, big heavy soft pill does them in every time, and doesn't have to be travelling at silly speed to do it.

Not sure why you got those results @Tahr as the bullets you listed there are generally quick opening bullets, maybe it's more to do with the speed as they have modest velocity in the heavier weight bullets. In saying that the 7mm/08 and 308 aren't what I would call fast either.
It could be something to do with the good penetrating qualities of the 6.5 projectile. Haven't shot anything past 80 odd yards with mine yet so can't really comment on that one.

Tahr,

I agree with you on this topic. I believe impact velocity has a lot to do with it and 2800 fps at the target with cup and cores is a sweet spot.


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Originally Posted by HuntGatherRepeat

Shy of starting a new thread, have procured a Sako in 260 with 1:8 twist. Now the real question, to AI or not to AI...

If it's got the original barrel, you may have trouble getting a smith to ream it cleanly. Plenty of info about on Sako & Tikka barrel hardness and poor results in chamber change. As mentioned an improved case requires less maintenance and it's a better case shape for powder burn.

Originally Posted by Tahr

I really like the 6.5 caliber and have had a couple of 6.5x55. Current one is deadly (Schultz & Larsen).

My only reservation is that they are not magic. My experience is that once the distance gets out to 350 yards odd they can be slow killers. I have experienced this with Sierra, Amax and SST 140grn projectiles at circa 2.8K. They have always died, but not in an emphatic manner.

I know that it won't be other people's experience, but it is mine, that both the 7/08 and 308 seem to kill better at all ranges - I often wonder if its something to do with the smaller expanded frontal area of the 6.5? Dunno really.

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

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!