6.5x47 & 6x47 lapua Question.......

ultramagmed

ultramagmed

JKM
Is there any advantage or disadvantage to the Ackley improved versions of these fine cartridges? I have read quite a lot about the standard versions, but not much about the improved versions. I would like to know if anyone has experience with the improved cartridges and if anything worthwhile is gained, (other than velocity) or more importantly, anything lost.

Thanks In Advance,
Med.
 
Thanks Al I was hoping you would chime in! Kind of a loaded question for you. The reason I ask is PT&G has a 6.5x47 reamer on special that is ackley improved, and was wondering if I should buy it or just have one made to my specs. Take a look at it on the specials page and see what you think. I would also be interested in seeing your 6x47L print if you don't mind. I have been religiously following all of your posts on the 6x47L, and would welcome any info one the 6.5x47L, if you have any to offer. Feel free to PM anything you don't want to share with everyone.

Thanks for the reply,
Med.
 
Yo Med,

Gimme a fax number and I'll send over all three generations of reamers with my scribbles all over them........

I hear you, a half price reamer shore looks tempting BUT!!!!! It's money poorly spent IMO.


Here's the deal....

so you save 60-70bucks on a reamer, now what? You've got a chamber for 60-70 bucks cheaper.... but what do you DO with it? Having a chamber is only a small part of the equation (bear with me here, this is not so trite as it seems... :D )

Brass is spendy stuff. Brass prep'd the way I prep it is stinkin' GOLD, I wouldn't do it for 5 bucks a case. I wouldn't do it for TEN bucks a case. My loaded rounds are perfect. Perfectly straight, perfectly fit to MY (saved 70 bucks!) chamber after about three firings.

Life is good.

So, you've got three firings on your cases and they're PERFECT and they're shooting dots.

(In your "saved 70 bucks" chamber)

But they're starting to tighten up, You've gotta' resize them.

HOW???

(In your "saved 70 bucks" chamber)

NOW you're at a crossroads. You saved 70 bucks back when you chambered the gun but NOW WHAT?

You wanna' start shooting now....right? So you need a fitted full length die.

So it's off to Neil Jones with 5 cases and you get back a persnickety FL die...... but for some mysterious reason it just doesn't size so very-very good......


--------------------------------------------------------------------

Now here let me digress a little. I've NEVER TRIED a 6.5X47L Ackley Improved case.... I may be off in la la land. IT MIGHT WORK, but I doubt it. In my guesstimation you'll find that the 40degree shoulder "bounces" funky. For a sizing die to work perfectly it must push the shoulder straight back while keeping the tapered shoulder section (40 degree section) parallel to the surface against which it abuts, the front or headspacing portion of the chamber. What I've found with 40degree shoulders is that they DO NOT like to be pushed back cleanly. In My Opinion this is a function of the LENGTH of the shoulder surface. For instance, a 30-06 AI works ok, the stepped or shouldered portion is so SHORT due to the 30cal neck that it's fairly amenable to resizing. I LIKE the 30-06 Ackley Improved case even though I haven't spent a lot of time with it. But I flailed my head against the frickin' WALL trying to get the .243AI to resize properly. I tried everything I could think of except having Neil make my shoulder bushings in incrementally different angles, like 41*, 42* etc in an attempt to massage the shoulders into shape. About the time I'd decided to go this route I started playing with the 6BR (this would be about '94-'95ish) and I found satisfaction.... In fact that's where I switched all my efforts until the 6.5X47L case showed up.

I'm still a big fan of the plain-jane 6BR.


But then the word came trickling down the pike about a NEW case, a stretched 6BR case only in 6.5 neck. I grabbed up the first 500 that came off the boat.

HALLE-flippin'-LUIAHHHHH Ferdinand!!!!

HERE was GOLD!

I figgered,

and it WAS

and it IS

IMO the 6.5X47L case makes the ultimate 6MM 1000yd case AND the ultimate legal HBR 30cal case. And I'm sure it's a wicked-frickin'-winner in it's own right. Dunno personally, I don't have any 6.5 bullets.

My first "6X47L" chamber was cut with a 6BR reamer, my third and "perfectest" 6BR reamer by my definition. And even though the neck cuts too long for the 6X47L brass it steenkin' shoots. It holds its own, in competition with real shooters. And I haven't had any problems with "the carbon ring" as a result of the short neck.

In fact, my own "6X47L" reamer is still designated a 6BR Matson spec down at PPG. I ordered it as a 6BR reamer because I'm kinda' K.I.S.S. simple bordering on stupid..... I KNEW what I wanted but could only describe it in "6BR terms" so I ordered a weirdly spec'd 6BR reamer and a "6X47L" Go Gauge only I ordered the gauge a few thou undersized (short) because It's not been standardized and one of my "fireforming secrets" is to chamber such that I can always achieve a crush fit on my fireform cases.

Basically I just copied PPC techniques that had been pioneered by others.

And it works.

End digression.

------------------------------------------------------------


whewwww,

So now, my experience with the 40* shoulder has been mainly in 6MM...... maybe the 6.5 shoulder is short enough that it WOULD resize well. (And let me state here that these are MY OPINIONS, many others shoot 40* shoulders with perfect happyness.)

It is for this reason that I myself would skip the reamer in question. I think it will prove to be frustrating and unsatisfactory in the long term.

And I DO so find the 40 degree shoulders to be cute, or as a certain varminting scribe is wont to describe it, "jaunty."


hth


al
 
Odd that you post this to the gunsmith forum -- though given the recent discussions on the long-range forum, I guess I see why.

I'm going to take a completely different tack than Al. Al is one guy, with a home range, who has a background in gunsmithing and devotes much of his time and considerable talent towards the accuracy goal. Buried in all that praise is "one guy." Sample size real small. I'm more of a journalist. Sample size larger. Of course, the larger sample size comes with a lot less control over variables, which has its own problems.

And I'm no special fan of the 40-degree shoulder, but for a different reason. I have a number of such cases. There is a theoretical reason why, with a long-bodies case, a 40-degree shoulder is better. It was not P.O. Ackley's reason. To understand Ackley's formula, you have to remember his time, where available powders were limited, as were available rifles. Getting an new bolt so you could use one of the belted magnum cases was an expensive proposition back then. If your action was long enough, there were also no factory short magnums. Ackely came up with a way to get more performance in cases with a fairly easy method, and one that would still let you shoot factory rounds if that became necessary. Ackley was a hunter, not a target shooter.

Times have changed. If you want just a little more capacity than offered in a 6.5x47 Lapua, get a .260 Remington. For wildcatting for competition -- in .30 (hunter class) or 6mm (long range), the case seems to offer less work that some others. Nobody much worries about the shoulder angle here, though.

I'd note that several east coast shooters -- Joel Kendrick being the one I know best -- have gone back to making their 6x47 cases from reformed .243 or .308 Lapua cases. For whatever reason, the 6.5x47 case just didn't work as well. Early days, we shall see.

As to the 40 degree shoulder, it has been my experience that sizing the shoulder is collapsing the sidewall a bit. I think -- no proof -- that what sets the headspace is the body/shoulder junction. That datum line of the reamer print is just a number. When you size a case -- any case, but esp. the high shoulder angle cases -- you see the marks on the body/shoulder junction. That hard edge is softened just a bit when sized. It is a lot of work to get it right with a 40-degree shoulder.

Now, I've never sat down with cases that were identical except for shoulder angle & done accuracy studies. I wouldn't count them definitive anyway. Final accuracy seem TO ME to be more a matter of bullets and barrels than chambering. An since for such a test you could use the same bullets, it comes down to barrels. I've known too many competitors with seemingly shot-out barrels (no rifling left the first 4-5 inches of the bore) who keep winning with that barrel. Sure, they've fitted new barrels, sometimes 4 or 5. But that old one wins more. Who knows why.

Sizing a case with a 40-degree shoulder is just more work, & I'm lazy. The only theoretical reason for it is McPherson's "directing the primer wave back to the center of the case below the bullet" theory. So shoulder angle becomes a matter of case body length. 30-degrees for the PPC, 40 for the '06 length cases. Uh, sure. Someday McPherson will get something right & surprise us all. I don't think this is the time.

FWIW, and not too much.
 
have them

regrind that AI reamer to lapua specs.---it should cost about 20-30$....now you still have saved about 40$, and problem solved
 
6X47 Swiss Match

When you say 6X47 I'm assuming your talking about the Swiss Match.

I brought this cartridge to the United States in 2001/2002. I worked for the Anschutz Service Center in COS and we were also a Grunig/Elmiger importer. A man named Sep Gamunder from Switzerland would bring me once fired pieces of RUAG brass from the firing lines where the Swiss National Team trained. In the beginning obtaining brass was tough and I often resorted to forming cases from 308, 243, and 6mm Remington cases. Lots of work to generate enough to run a course gun. I still have a few hundred pieces of the RUAG and home growns floating around in a ziplock bag somewhere.

The first gun ever chambered was a Pre64 Winchester NRA Match Rifle that I built for a gentleman in CA. I made his dies and supplied him with 500 pieces of brass. It's pictured on my website with a salt/pepper laminate stock. The second was an AR-10 NRA match rifle owned by Shane Harless. This rifle shot a 12X clean at 1000 yards the first time out at the Tubb highpower range located at the NRA Whittington Center in Raton, NM. The reamer(s) were provided by David Kiff of Pacific Tool and Gauge as he was the only shop who even knew about the thing at the time. He made the original tooling for the swiss team.

This cartridge needs little improvement. It is tailor made around the 100+ grain class of match bullets available in 6mm. The RUAG factory ammo was loaded with the Hornaday Vmax bullets. This was back when Hornaday first began offering these bullets and the quality control was extra exceptional. The cartridge geometry between the case OAL and neck length was/is designed so that the boat tail/bearing surface junction and the neck/shoulder junction never see one another, mitigating the whole "doughnut" problem and the associated issues it can create with pressure and accuracy. If one were to "improve" this cartridge you would lose some of that neck length and the reduced case taper and steeper shoulder would almost certainly create issues if the rifle is a repeater using a traditional internal box magazine. The 6.5X47 is largely built around the 6X47. The primary differences being the smaller primer pocket and the larger neck to facilitate the larger caliber bullets.

Anything is possible and far be it from me to discourage anyone from experimenting, but I think you'll find that the slight increase in velocity and associated headaches of forming cases won't bring you the bells and whistles we all so diligently search for.

Cheers and all the best,

Chad

Chad Dixon
Gunmaker
LongRifles, Inc.
 
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Chad,

No, actually the long-range benchrest shooters are usually talking about the 6.5x47 Lapua case necked down to 6mm. Dave Tooley looked into importing the Swiss Match case, but the price RUAG quoted him, even as a dealer/distributor, was so high it didn't make sense.

I believe, but do not remember for sure, that the Swiss Match case uses a large rifle primer. The 6.5x47 Lapua, as you likely know, uses a small rifle primer. There are other, slight dimensional differences between the two.

Edit:

To fix too many typos for someone who is suppose to be a typesetter.
 
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Yes. the original RUAG brass in 6X47SM uses a standard large rifle primer.
 
I built a 6.5x47 Lapua as a hunting rifle about 2 years ago and it is the most accurate rifle I have ever shot, I would leave it as it is. Shane
 
Thanks Guys............

Since getting all of your opinions, I have decided to pass on that reamer. I didn't really want an ackley improved anyway, but for the price I thought I would entertain the idea. I actually would rather have a 6x47L, so I think I will have Dave Kiff build me one to my specs.

Al,

I don't have access to a fax machine, I don't know if you can e-mail those prints or not but, if you can, I wouldn't mind seeing what you have come up with.

Thanks to all for sharing your knowledge, a newbie like me really appreciates it.

Thanks Again,
Med.
 
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