As a gunsmith with about 1/2 half a century of experience I never understood the fad that is the 6.5-284. Good shell, and dose all the 6.5-06 dose in the hunting fields.............for more money.

See, the 284 Winchester was introduced by Winchester in their M88 lever action for the expressed purpose to duplicate the 270 Winchester's performance in a lever action. It did that just about perfectly.
The 270 is just a necked down 30-06 in effect.
So the case capacity of the 284 was about the same as the 06.

Now we've have had the 30-06 since 1906. The 256 Newton was basically a 6.5-06. The 6.5-06 has existed for a very long tome. Since the 20s at least.
So here comes a new fad shell trying to convince everyone that it's somehow worlds ahead of all the "competition", and it's not. In fact, it's the same formula. Pressure for pressure and barrel length for barrel length, the 6.5-06 is the same or slightly ahead. The 6.5-284 is a tie at the the best, and a very close second in most cases. On deer and antelope I can't see any difference between the 6.5-284, the 6.5-06 and the 270 Winchester. One elk I can see a bit of difference with the 270 beating them both. (For less money and fuss)

So the next argument is that the short actions are "better". But in my 49 years of building I have yet to see any evidence that they are. I read that they are all the time. I know most target shooters go to short actions because they embrace the idea that may be stiffer and they can't hurt. I agree.
But "better...................... No I can't say they are, in any way. I have not see in in 49 years of gunsmithing. No worse mind you, but no better. Especially in hunting rifles. I think most of that is a rehash of the Emperors New Cloths.

And then I see the demand to make 6.5-284s most often are from those that want to put the cartridge into a long action anyway. As a man who dose the work, I can assure those reading this it's true.

I have made more 6.5X284s for customers on Mausers and Remington long actions and a handful of Ruger 77s, and so far I have not had anyone bring me a short action to make their custom 6.5X284 on.

On Mausers I have made a LOT of 6.5-06s and about 25 6.5-284s. I shoot them, I zero them, I do load work for them, and I own a chronograph. They are equal in accuracy and the 6.5-06 will out-run the 6.5-284 by a small margin in every bullet weight.

When I made the first 6.5-284 back about 30 years ago the customer brought me a Steyr M98 long action already re-barreled in 270. He was going to make a 270 but then read some magazine article that made him want a 6.5X284. I have to pull the barrel and make one in 6.5 bore and install that.

No problem.

The action on the other hand had to be modified to feed the 284 shells which took a bit of work. The 284 brass was hard to get and it's not much easier now. It was expensive then and it's far more now. The reamer cost me about 2X more then the 6.5-06 reamer. The dies cost 3X more.

And so the build was far more expensive than it would have been for a 6.5-06 and the customer was delighted, so I was happy too, but I did see the truth of it. I told him all this BEFORE I went to work. He didn't care, so I did as I was bidden. He wanted to have a 6.5-284 because it was so "modern" and showed he was an expert in rifles.

He got 98% of a 6.5-06 for about $400. $400 more 30 years ago. That $400 was worth a LOT more 30 years ago than it would be today.

Now I expect since Norma brought out the shell as a factory standard, it may have come down some, but the brass has not. Necking up a 25-06 or necking down a 270 to make a 6.5-06 is much cheaper.

But I don't have a dog in the fight.

I do what the customers tell me to do, as long as it's safe, and as long as I tell them all the options and lay out the facts. I feel no obligation to try to sway them. I only make these points to them so if they come back later saying that it's not as fast as they hoped it would be I can say "well I told you". Facts don't often move passion. They will move intelligent inquiry, but not passion. We see that in politics every day. Truth means nothing to those that want something other then truth to be right.

Heck, if speed is the key, I might just suggest a 264 Win Mag. Dies and brass are not high at all. (264 is a bit hard to buy, but 7MM Rem Mag necks down in one pass perfectly)

The 26 Nosler is super fast too, if you don't mind the super expensive brass, high price for the dies lots of action work and short barrel life.