6.5x47 compared to 6.5x284

[lutheran]

When comparing these two rounds loaded with 130 bullets from a 24" barrel, what is the actual difference in velocities they will produce?

thanks
lutheran

 

[Laurie]

6.5-284 has a 37.5% greater case capacity than 6.5X47L. The rule of thumb is to divide the case capacity % change by four to get the % MV change assuming both cartridges are loaded to equal pressures. On that basis, you'll get ~9% more MV from the bigger cartridge. In reality, probably a bit less given a 24-inch barrel that favours the smaller number and use of 130gn bullets which are below the maximum they'll both handle, especially the 6.5-284.

And that's pretty well how it works out. 6.5X47L will give a 130 2,800 fps plus or minus 50 fps depending on powder and maximum charge adopted. Add 9% and you get 3,052 fps, but in all likelihood you'd struggle to better 3,000 fps with all bar a few ideally suited double-base powders from 24-inches. Depending on the powder, bullet, and charge weight that actually suits your barrel, the improvement would be at best 300 fps, at worst 100 and most likely somewhere in the middle.

 

[TheSnake]

Not to hijack the thread, but what is the cost in barrel life for the additional velocity of the 284?

 

[Laurie]

Not to hijack the thread, but what is the cost in barrel life for the additional velocity of the 284?

A lot is the short answer Robert. Depending on the pressures being run and the shooting style (ie slow v rapid), people are saying they're getting 2,000 rounds + from 6.5X47L, many saying they're still shooting well at the 2,500 rounds mark. BUT .... an Australian or Kiwi F-Classer said on this forum recently that accuracy dropped off after ~1,500 rounds of hot loads in high ambient temperatures and competition string-shooting.

6.5-284 competition use with 139-142s is 800-1,200 rounds generally.

However, it depends what use lutheran has in mind. A 1,000-1,500 round barrel life might be fine if he's thinking of using it in a long-range hunting rifle with a low annual round count and mostly used with a single shot from a cold barrel.

 

[mshelton]

If you're asking because you are on the fence trying to decide between the 2.

Take a look at the .260, .260AI and the 6.5x55 Improved (few varieties) you can come close to the 6.5x284 velocities with a bit better barrel life and less powder.

An important thing to keep in mind too is that with VLD bullets, faster isn't always better.

 

[TheSnake]

Thanks guys. I was asking to add a little color to the overall picture. I have a 6.5x47L and I really love it. I don't run hot loads because mine will do all I ask of it with the milder loads and the 130 VLD's. I also considered the 284 before getting mine.

 

[lutheran]

Thanks for the informative responses. I currently have a 6.5x47 and yes it is a
hunting application rifle.

In the fall I'll practice "field" type shooting and may run 500-600 rounds through a rifle prior to a trip. Most of the time 20 shots per evening so no rapid strings and hot barrels. I'm able to shoot at my house to 600 yards at a life size target I made from AR500 with a kill zone ringer plate. Shoot a lot of sparrows from the barn with it for fun. Also have harvested 4 deer and about 35 coyotes with it. Dang thing shoots 85 sierras really well.

I like the 6.5x47 because I can let it beat on me a lot without becoming afraid of the recoil. Bullet placement is key so practice is paramount. Hence, a cartridge I can shoot a lot and improve my skill as I do.

I've used hotter cartridges and it's a pain keeping up with them.

lutheran

 

[Nomad47]

lutheran,
Not to change the subject but you mentioned a "ringer" plate. I have three 8" diameter AR500 steel plates that I hang from iron pipe. The steel does not "ring". Could you explain the difference?

 

[TheSnake]

lutheran,
Not to change the subject but you mentioned a "ringer" plate. I have three 8" diameter AR500 steel plates that I hang from iron pipe. The steel does not "ring". Could you explain the difference?

That's odd. My 12" round plate rings very loud and could probably hear a mile away. I suspend it with steel cable so it swings. Is yours round?

 

[Nomad47]

here is what I have. I replaced the U-bolts with steel straps and the straps hang from rebar which is inserted in the ends of the horizontal pipe. I can easily hear hits at 1000 yards, but the sound is more of a "whack" than a "ping" or "clang".

 

[TheSnake]

I think it being round or not would make a difference with the type of sound. I thought you were saying you could not hear it at all. Your hanger is just about like mine but mine hangs in the middle of the forward pipe square and my front legs are shorter than the back legs. I wrapped my cable ends in a figure 8 around the top corners and clamped them off.

 

[lutheran]

The life size elk target a I referred to has a 10" square cut out with fairly large radius corners..."kill zone". A plate just larger than the cut out hangs on the back side from a "D" causing the ringer to lay flush against the back side. Hence, when a bullet hits the "kill zone" the ringer plate jumps away from the target and "claps" steel to steel when it returns. This produces pretty good visual effect and sound that can be heard through ear plugs. It helps to be entertained when practicing.
If you miss the "kill zone" and hit the main target body you only hear a "whack". I also have a life size solid coyote target mounted on springs but it just "whacks" also.

lutheran

 

[alf]

I replaced the U-bolts with steel straps and the straps hang from rebar which is inserted in the ends of the horizontal pipe. I can easily hear hits at 1000 yards, but the sound is more of a "whack" than a "ping" or "clang".

I think you're not getting the "ring" because you're not letting the steel "vibrate" as when it's hung from chain, bungee cords, or fire hose.

 

[Raptor]

I use railroad cross plates welded togeather to shoot at and they are harder than woodpecker lips. They are hung from chain and all I get is a "Wack" or thud sound when I hit them. A lot of times I can't even hear my hits at 1000yds.

 

[coreydelong]

I replaced the U-bolts with steel straps and the straps hang from rebar which is inserted in the ends of the horizontal pipe. I can easily hear hits at 1000 yards, but the sound is more of a "whack" than a "ping" or "clang".

I think you're not getting the "ring" because you're not letting the steel "vibrate" as when it's hung from chain, bungee cords, or fire hose.

x2

 

[Nomad47]

I replaced the U-bolts with steel straps and the straps hang from rebar which is inserted in the ends of the horizontal pipe. I can easily hear hits at 1000 yards, but the sound is more of a "whack" than a "ping" or "clang".

I think you're not getting the "ring" because you're not letting the steel "vibrate" as when it's hung from chain, bungee cords, or fire hose.

Thanks, but I think my method of hanging will allow as much vibrating as hanging from chain. The straps are 1/8"x1"x5" bent in a U shape. And the grade 5 bolt attaching the strap to the steel is a 3/8" bolt going thru a 1/2" hole in the steel. So there is plenty of free play in my set up. I'll post a couple pics later today.

 

[Nomad47]

And here are pics of my non-ringing setup.

 

[stacy]

Less powder less recoil less ware and tare 6.5x47L is my choice love mine it shoots bugholes 99.9% of the time w/130gr VLD bergers and H4350 CCI 450s