New 6.5 Idea

[sj-pratt]

Just thought I would post a preview of a round I and 7mmRHB have been working on. We were looking for a true short action round that would fit standard magazine boxes but get 140 Bergers up and running and still have mild recoil without jumping to the extreme of a 6.5 WSM.
We started with Lapua 6.5-284 brass and went from there, we ended up with a perfect powder charge easily pushing 140 Bergers 3000-3100 with low pressures. The bearing surface of the bullets stays above the neck and shoulder junction, and with a nice long neck you could push the bullets out futher say a Wyatts Extended Box but we think its not necessary. We have just started testng so I'm jumping the gun a little bit, but I had a little time to kill so heres a preview.
More pictures and information to follow.
Left to Right 6.5-284, our Wildcat, 6.5x47 Lapua, 6.5 Creedmore, 260 Remington.

 

[Win.308Stealth]

You have my attention..........

 

[Rocky Mountain]

How many grains of ??? are you using? with the 140s at 3000-3100fps

 

[C.O. Shooter]

Did you come up with a name yet? 6.5.........?

 

[Shooter264]

Fancy. I'm in the process of a 6.5 SAUM so this peaks my interest as well.

 

[marioq]

I'm looking at building a 6.5x284 now.... Maybe I should wait??

 

[benchracer]

So you REDUCED case capacity, REDUCED pressures, and INCREASED velocity? Pardon my cynicism, but I am waving my BS flag. There is no way that all three of those things can be true.

 

[MachV]

 

[Greyfox]

The concept of 6.5x284 performance with a 140 Berger from a short action is appealing, but sounds like a tall order as described. Superb accuracy, and very low ES at 2950-3050 FPS is the primary attribute, and many would maintain, so far, the uncontested domain of the 6.5x284 when it comes to the 6.5's. I will be very interested in the unveiling of your cartridge.

 

[sj-pratt]

The case will hold 50+ grains of powder and we pushed the shoulder back to the area that a 6.5-284 would lose in a short action because the bullet was taking that area up any way. The long neck allows the bullet to be left out of the case area. Its been a fun project and we are not trying to market it just thought it would be fun to show what we were playing with. You must take in to consideration that 6.5-284'S work much better in a long action or single shot in a short and the 260 remington loses case capacity to the bullet being seated to far into the case also.
Have not came up with a catchy name yet, it's been 15 degrees or snowing and we haven't done much testing but it will be wrung out over a chronograph and I will let you know how it works out. I have some cut away pictures of the brass showing what we are trying to achieve and I'll get somemore pictures posted. Quickloads shows with safe pressure we should get 3075 FPS when the weather breaks a little we will see. BS or not.

 

[benchracer]

I think it was David Viizzard who said something to the effect that he doesn't have opinions he has dyno test results. Ultimately, the hard data you develop will trump anyone's opinion.

It will be interesting to see how your project comes along and how close the real world results are to the modeling data provided by Quickload. If it proves out, I can certainly see the appeal of your cartridge design for folks who prefer short actions.

 

[7mmRHB]

Since I'm the guy that dreamed this cartridge up, I guess a little more info about the cartridge and why I think this will be a great little round. First of all I have done this before with an RUM case to make a very potent 7mm. The case was shortened from 2.850 to 2.555 with less taper and a 35* shoulder and a bit longer neck so that a 200 gr Wildcat bullet could be seated where I wanted it yet not need a Wyatts box to be a repeater. It worked very well with performance a bit better than the parent 7mm RUM case performs in a factory Remington, using 10 to 12 grs less powder.

That was 12 years ago and has proven to be a very accurate and efficient cartridge so I decided I would give it another shot with the 6.5- 284 case. I shortened the case to 1.970 with .320 neck length with enough taper removed so it could not be accidentally loaded into a 6.5 - 284. I kept the 35* shoulder because 35* shoulders work very well. The case holds 54 gr to the base of the neck compared to 50 gr in a 260 Rem. case, 47 gr in a Creedmore case and 44gr in a 6.5 x 47 case. The 6.5 284 case is about a 62 or 63 gr case. All these capacities are water to the neck shoulder junction which is the best comparison of these rounds. I believe the reason that this round will perform as well as the 284 case is because it gets you to a better burn rate in powders (H 4350?) that will fill the case closer to 100% I hope I'm right.

Steve and I worked together to design the step down dies and Steve did the machine work on the dies and rifle and is painting it as I'm writing this. ( Steve has a bunch of sweet shooting guns to his credit by the way.)

The brass is super hard to make so this isn't for the faint of heart to try to do this. We're going to do three guns total since I have made 500 pcs of brass and will not be doing any more if I can help it.

These are fun projects and hopefully this 6.5 will work well !! We will try to get more pictures up soon. -------- 7mm RHB

 

[liltank]

Just tagging in.

 

[MontanaRifleman]

Since I'm the guy that dreamed this cartridge up, I guess a little more info about the cartridge and why I think this will be a great little round. First of all I have done this before with an RUM case to make a very potent 7mm. The case was shortened from 2.850 to 2.555 with less taper and a 35* shoulder and a bit longer neck

First, good work on you're new 6.5 offering. Next, if I'm reading you right, you reinvented the 7 Dakota with a 35* shoulder and long neck? I'm actually thinking of doing a similar Imp Dakota in 7mm, 270 and 6.5. they are quite efficient rounds. The Dakota fits nicely into mag boxes with long, high BC bullets.

so that a 200 gr Wildcat bullet could be seated where I wanted it yet not need a Wyatts box to be a repeater. It worked very well with performance a bit better than the parent 7mm RUM case performs in a factory Remington, using 10 to 12 grs less powder.

Are you actually saying That your 7 wildcat (Dakota Imp) performed better than a 7 RUM? By performance, I'm assuming you mean velocity. I think I could get very close to 300 RUM performance with a 300 Dakota using RL17 in the Dakota which is too fast burning in the RUM, but I don't think I could surpass it.

That was 12 years ago and has proven to be a very accurate and efficient cartridge so I decided I would give it another shot with the 6.5- 284 case. I shortened the case to 1.970 with .320 neck length with enough taper removed so it could not be accidentally loaded into a 6.5 - 284. I kept the 35* shoulder because 35* shoulders work very well. The case holds 54 gr to the base of the neck compared to 50 gr in a 260 Rem. case, 47 gr in a Creedmore case and 44gr in a 6.5 x 47 case. The 6.5 284 case is about a 62 or 63 gr case. All these capacities are water to the neck shoulder junction which is the best comparison of these rounds. I believe the reason that this round will perform as well as the 284 case is because it gets you to a better burn rate in powders (H 4350?) that will fill the case closer to 100% I hope I'm right.

How about shortening the SAUM case (which is already shorter than the 284) vs the 284 case and get some extra capacity?

Steve and I worked together to design the step down dies and Steve did the machine work on the dies and rifle and is painting it as I'm writing this. ( Steve has a bunch of sweet shooting guns to his credit by the way.)

The brass is super hard to make so this isn't for the faint of heart to try to do this. We're going to do three guns total since I have made 500 pcs of brass and will not be doing any more if I can help it.

These are fun projects and hopefully this 6.5 will work well !! We will try to get more pictures up soon. -------- 7mm RHB

Good job fellas! I know how hard it is to "shrink" brass. sounds like a niffty little cartridge.