6.5 Cartridge's Speed

[long40shot]

Hello all,

I was just in a conversation with a couple friends whom are gun nuts like us. There was a debate on which 6.5 cartridge was the fastest. We did not mention any of the magnum calibers, what was talked about was the 6.5x284, 6.5 Creedmoore, 6.5x47, 260 Remington and the 6.5 BRM, all with a 140 bullet. I thought that the 6.5x284 was the king of the hill on speed, there in laid the argument. They where all sure that the 6.5 Creedmoore was top dog. I was looking for some more informed input.

Thanks,
Matt

 

[camac]

You will find as much debate on this site as elsewhere but there are 2 threads running on this topic on the main board. 6.5 Creedmore vs 6.5 x 284. And to a lesser extent but still related the one on 284 based cartridges.
Whilst I think it is pretty clear that for the same pressure a 6.5*284 eats the creedmore, the discrepency may come from the fact that you can push the pressures in the creedmore more easily. The 284 based cartridges seem to show pressure signs at the case head earlier (I believe this is a good safety feature though) Whether the Creedmore pushed at those velocities or pressures is safe, or will save on barrel life or is as accurate I think is where the real debate will come.

 

[GaryD]

I have a 6.5 creedmore with a 30 inch barrel. 5 shot average through chrono with hornady factory ammo 140 grain Amax is 2710 fps. This was shots 21-25 and may speed up a little after the barrel is broken in. This is simular to the publish data on the box. I think the 6.5 x 284 is faster but here is my results to compaire with someone elses data.

Gary

 

[camac]

The 6.5*284 comfortably does 2950 fps with 28-30 inch barrel. It can go to 3100 but the brass shows significant signs of case head distortion at these speeds (see other thread on main page). Most 6.5*284 shooters have learnt to settle on lower velocity to save brass and barrel and maintain accuracy rather than push the higher node.

 

[boltman13]

My 6.5 Creedmore will give me 2,880 fps over my crono with a load of H4350 just below Hornady's listed factory load with Berger 140 gr VLD's. Brass has no problem with the preassure. I am at 4,700 feet above sea level, however. The 6.5-284 will surpass that velocity easily at this altitude.

 

[15Tango]

With whatever you do to hot rod either the 6.5 Creedmoor or 6.5-284 the 6.5-284 will yield just a bit more velocity. From my experience the Hornady brass can't withstand the hard loads very long as the primer pockets will open up. With the proper brass you can really beat on the 6.5 Creedmoor and it holds up better to going past the limits than the 6.5-284 does as Camac suggested. With my 28" barrel with the Creedmoor 43.0 grains of R17 in Lapua .22-250 brass gave me 3030 FPS with a 140 VLD and 42.5 of R17 gave me 3040 FPS with a 140 A-Max. I only brought it up that fast and hard in load testing, I've since stopped using R17 in that cartridge, ES/SD wasn't good enough; I'm using H4350 again with the 140s at 2920 FPS. When both cartridges are brought to their limits it gets very close but the 6.5-284 will still beat it by 50-100FPS.

If I had to guess what the fastest 6.5 would be I'd go with a 6.5-WSM.

Wayne

 

[2644ever]

Wayne, with all due respect, I would consider the 6.5 Hoyer aka 6.5-300 Wby to be the fastest of all... Since we talk about non magnums here, I think the fastest ever, according to PS Shooting's Bob Jourdan, is the 6.5-06 Ack Imp that actually outperforms the .264 Win Mag with less powder (!), the law of diminishing returns at work, here...

 

[15Tango]

2644,

I'm sure you're right, I was just throwing out there what I thought may be it. 6.5-300Wby would certainly have a lot of powder behind it. Diminishing returns is right for sure.

 

[Obtunded]

The one bastard child that always gets left out of these debates is the venerable old 6.5X55 Swedish Mauser. This case easily pushes 139-142 grain bullets to 3000 fps without adverse pressure. Lapua makes brass for it (HUGE plus) and it is incredibly versatile as both an excellent North American big game hunting cartridge and a capable 1000 yard F-Class cartridge.

The 260 Rem in its standard livery and with a 28" barrel also easily hits 2900 with the same bullets; One of the top Western Canadian F-Class shooters is campaigning a 260 with incredible success. The 260AI has all the benefits of a 6.5-284 with significantly better barrel life.

 

[boltman13]

In my very limited experience at long range shooting I find a load that stays supersonic at 1K yds with a small ES and low SD that doesn't eat brass and/throats is what everyone wants. A little more velocity, all other things remaining the same, is a good thing, but not at the expense of the others. Some can afford rebarreling more often than others but I can't.