6mm remington ackley improved cartridge dimensions

[ballisticsman49]

Does anyone have a reliable site which contains 6mm Al cartridge dimensions. I need them!

Thanks in advance.

 

[tiny68]

Well since it is not a standard cartridge adapted by SAMMI, I don't think there are standard dimensions and it is considered a wildcat. However, attached is the first page from the Sierra manual which gives its view of the specs. I think these are pretty close to my 6AI. Sorry for the poor resolution. My scanner is pretty old.

Luck, tiny

 

[Cheechako]

ballistics

As Tiny said, the 244 Ackley is an improved cartridge and there are no official drawings or measurements. The critical dimension is the junction of neck and shoulder which is what will control the headspace. All other dimensions are secondary.

It's the usual practice to chamber an Ackley .004' short in order to get a crush fit when fire-forming. Using the standard 244 Remington dimensions this would mean a base to neck dimension of 1.8780'. You'll notice that the Sierra drawing shows 1.8720', a full .010' shorter than the parent case. Many think that .004' short is not enough and go for more when chambering. Evidently Sierra agrees. I do too.

The best bet when making a 244 Ackley is to buy a reamer and headspace gauge as a set. If that's not possible make sure the gunsmith sets the barrel back and chambers for a good crush fit with several case brands.

JMHO

Ray

 

[tiny68]

Totally agree with Cheechako. My chamber is deeper than I would like. I can't fire factory 6mm Rem loads and get them to all go off. Sometimes 50% is the best. I ended up having to form a false shoulder with a 0.257 expander for another 0.030' into the neck. This gives a nice tight fit for fire forming. I use the COW method and loaded a 100 brass at once. Pretty easy, but I would sure prefer to just shove in a factory load and shoot. tiny

 

[ballisticsman49]

That was all really helpful thankyou.

B'man

 

[Ackman]

Actually, it's not a wildcat. Factory ammunition can be fired in an improved chamber. Can't do that with a wildcat and brass must be made. That's the difference. Improved cartridges aren't wildcats.

 

[tiny68]

Factory ammunition can be fired in an improved chamber.

Can't in my chamber. Maybe my gunsmith ran the reamer a little to deep or maybe it was his reamer design, but factory ammo doesn't work in my. tiny

 

[Ackman]

Factory ammunition can be fired in an improved chamber.

Can't in my chamber. Maybe my gunsmith ran the reamer a little to deep or maybe it was his reamer design, but factory ammo doesn't work in my. tiny

Screwups don't count.

 

[Cheechako]

Ackman

You are right. Nit-pickin, yes. But right. I am both a wildcatter and a nit-picker, and should have known better.

Ray

 

[rsilvers]

Actually, it's not a wildcat. Factory ammunition can be fired in an improved chamber. Can't do that with a wildcat and brass must be made. That's the difference. Improved cartridges aren't wildcats.

Improved cartridges are wildcats because there is no official standard and you cannot fire them in a factory chamber for the parent round.

 

[1000yardstare]

The Sierra Manual defines a wildcat as "A non-standard cartridge or chambering.....for which factory chambered guns and factory loaded ammunition has never been produced".

This would certainly classify the 6mm Rem AI as a wildcat.

It also de-classifies the .280 Rem AI as a wildcat because Norma is now producing the cartridge.

 

[Ackman]

Actually, it's not a wildcat. Factory ammunition can be fired in an improved chamber. Can't do that with a wildcat and brass must be made. That's the difference. Improved cartridges aren't wildcats.

Improved cartridges are wildcats because there is no official standard and you cannot fire them in a factory chamber for the parent round.

No, and you don't get it.....you've got it backwards. It's about shooting factory ammunition in an improved chamber.....that's one of the points behind improved cartrdges to begin with. Read the Ackley books.

 

[Ackman]

The Sierra Manual defines a wildcat as "A non-standard cartridge or chambering.....for which factory chambered guns and factory loaded ammunition has never been produced".

This would certainly classify the 6mm Rem AI as a wildcat.

It also de-classifies the .280 Rem AI as a wildcat because Norma is now producing the cartridge.

Don't put so much faith into everything the Sierra manual says. It's not gospel, and they're wrong.

 

[1000yardstare]

OK. Let`s try the Hornady manual definition. A wildcat is "A non-commercial cartridge design".

 

[rsilvers]

I have the Ackley books. Great until he says (page 121, VII) "They [government] have a habit of dumping semi-automatic weapons (which are easily converted to full-automatic) which have no value from a sporting standpoint, which are ideal for illegal uses.. Some of the large manufacturers are also guilty of the same activities by converting military, full-automatic (complete with carry handle, plastic stock, and stamped parts) to semi-automatic, and then have the audacity to advertise such a monstrosity as a desirable sporting arm. It can be nothing more than a "sales gimmick" and the sames of such weapons certainly are not going to be to the legitimate sporting public, because no real sportsman could be interested in such a rifle."

As per what Sierra says, I am not sure I would cease to call a cartridge a wildcat just because a company makes ammo on their Dillon Super 1050XL and offers it for sale.

What about the 50 GI? http://www.guncrafterindustries.com/ According to Sierra and Hornady, that is not a wildcat. 300 Whisper? Lazzeroni? 6.5 Creedmore? None are in SAAMI. A big ammo company like Remington, Federal, or Winchester won't even offer ammo for commercial sale if it is not in SAAMI.

 

[1000yardstare]

The Nosler manual defines a wildcat is "A cartridge that is not commercially available.....requiring a fireforming process".

Seems the bullet manufacturers are focusing on the lack of factory production of a cartridge in their definition of a wildcat.

 

[Ackman]

OK. Let`s try the Hornady manual definition. A wildcat is "A non-commercial cartridge design".

Believe whatever you like. But wildcat chambers won't accept factory ammunition, and the brass isn't factory available. Factory brass/ammunition can be fired in an improved chamber.....that's how it's made and that's what makes it "improved." And that's always been the definition. You guys who like to argue about stuff when you're just ignorant.......

Cheekako's right, it's really just a nitpick. But you know, there're just so many postings about things by people who've no idea what they're talking about.

 

[1000yardstare]

I have been reloading for 50 years and have always relied on the manuals from the bullet manufacturers for reliable information. But now I am being told that three bullet manufacturers are mistaken in their definition of a wildcat.

So lets try a fourth. From the Speer manual. A wildcat is "A cartridge formed by altering an existing commercial case to make a style that is not available from ammunition companies. Industry and commercial standards do not exist for wildcat cartridges."