Please explain 6.5-284 The 6.5 the way I understand it is the size of the bore / rifling, the 284???? Thanks!!

A wildcat cartridge popular for long range target shooting. 284 is the parent case the 284 winchester, an early short mag of sorts with a rebated rim. Neck it down to 6.5 MM and you have a 6.5/284

The 6.5 is the bore diameter in millimeters (=.264"). The 284 refers to the parent case - the .284 Winchester. So, the 6.5-284 is basically the .284 Winchester case necked down to 6.5mm. This is very common in the wildcatting world, and is the way that many of today's favorites were originated: 270 and 25-06 from the 30-06, 243, 260 Rem, and 7mm-08 from the .308. The list goes on and on and some get downright exotic, but the principle is the same.

And just to throw more fuel on the fire, I believe that the 6.5-284 Norma and the version made by Hornady are dimensionally different (only slightly, but still). - Dan

O.K. then, if you were going to chamber for 6.5-284 what would make more sence, to go with the winchester or Norma profile. Tight neck .294 or sami .297???? what advantage to either would there be???? I intend to use Lapua brass and 142 MK's

I just ordered the Winnie version reamer (its going to be a hunting rifle more than a pager puncher) from Dave Manson.

Personally I think I would go with the Winchester version as I believe the brass is less expensive than the Norma brass?

Win. brass is less expensive than Norma brass, BUT, with the Win. stuff, you have to form it for your chamber, as there is no factory standard 6.5-.284 Winchester. It is a wildcat, whereas the 6.5-.284 Norma is a factory standardized cartridge that comes already formed....

Sealdoggy, to be exact, the 6.5mm refers to the .256" land (bore) diameter, rather than the .284" groove (rifling) diameter.
If that's not confusing enough, I'll add that the 257 Roberts shoots 6.5mm bullets.
As for whether or not to use a tight neck, it all depends on what you'll be using it for. You wouldn't want a tight neck on a field gun, since a couple specks of dirt may give you chambering troubles. That chamber design is intended for folks taking their time (more or less) single feeding the gun while hunting paper circles.
Also, if you have a tight neck you must really watch your brass, and make sure it is sized, turned, reamed and trimmed as necessary, so it will go into the chamber in the fist place.
Upside is that it generally gives more concentric alignment with the bore, and thus greater accuracy. The sort of detail that has nothing to do with dropping against the nearest stump and shouldering the rifle to hit that 10pt whitetail you just stumbled across.

[ 09-20-2003, 10:52: Message edited by: Bwana-be ]

Win/Norma/Lapua brass..... The current Win brass is about .002/.003 SMALLER at the case head, the web or solid part. So if you have a reamer ground for current Win brass it MAY not accept Norma/Lapua brass. If it is big enough for Norma/Lap the Win brass should function just fine. I have reamers for .291 nk. and for .296 nk. and both have their places. The Lapua brass that I've used is very concentric so SAAMI dimension chambers can be quite accurate.

Bwana-be,
When you next decide to shoot some 6.5 bullets out of a .257 Roberts would you please post the time and place. I'd like to see that. The thread title definitely applies here. Jim

[ 09-21-2003, 19:09: Message edited by: Jim White ]

Dear Jim White:

1. Please avail yourself of a caliper.
2. Measure the bullet.
3. Come back to table, into our company: we have a delicious crow pie for you, ready to eat.

Warm regards,
Carcano

Oooh, Carcano, now you've started it! On the subject, I believe Hornady makes 6.5-284 brass to the American dimension (for lack of a better phrase). - Dan

[ 09-21-2003, 19:52: Message edited by: dan belisle ]

Carcano.......my caliper reads .257 for the Roberts, and .264 for the 6.5-284......What's yours read?

And would you like some cat custard with your crow pie - pretty please ? Let me serve you...

Carcano

.257" = 6.5268mm
.264" = 6.7056mm

Carcano,
You can take your cat custard and use it as a lubricant to put your crow pie where the sun don't shine. You can use all the conversion tables you care to and you still can't shoot a .264 diameter bullet down a bore thats designed to shoot a .257 diameter bullet without getting cat custard and crow pie all over the place!!

So why is it that every box of .264" bullets has 6.5mm printed on it?

Rifle caliber designations are commonly mixed up with bore sizes and the groove diameter. The bore on a .257 is not .257. The bore is the diameter before it is rifled. A .257 Roberts will and does shoot a 6.5 mm bullet. The 6.5 has a bore diameter of 6.5. A .270 Winchester shoots a .277 bullet. Eat the crow pie but ask Caracano for one of his good german beers to wash down the feathers. I don't always agree with his opinions but I can't remember when I have seen him wrong regarding facts in relation to firearms.

[ 09-22-2003, 10:18: Message edited by: Customstox ]

[ 09-22-2003, 16:09: Message edited by: Fritz Kraut ]

So what you are telling all the new reloaders is that they can go down to the sporting goods store and buy a box of 6.5 (.264) bullets and take them home and load up some rounds for their .257 Roberts or 25/06 or any other 25 caliber cartridge?

If I can shoot .007" larger bullet in a .257 Roberts, then I should be able to shoot 7mm (.284) bullets in a .270 Win (.277)? If so, 'they' have been limiting my bullet selection in .270 under false pretenses...

This also means that the magic bullet didn't have to come from Lee Harvey Oswald's Carcano, but could have come from Jack Ruby's .257 Roberts!

Next you'll be telling me the .218 Bee, .38 Special, and .44 Mag really aren't those dimensions either...

Oh, that's what happened.......I loaded my new 25-06 custom rifle from Customstox with a reload consisting of a caseful of 4831 behind a 140 gr. 6.5 Matchking bullet and touched 'er off...... Kaboom!!!!!!! Real downrange performance.......

SEALDOGGY,

The term "Bore Diameter" is misused a lot. The term "Bore Diameter" represents the measurement across the top of the lands. The "Groove Diameter" is the diameter we purchase bullets for. The designation 6.5 refers to a "Groove Diameter" of .264. The 25-06 and .257 Roberts etc., are designed to be used in a barrel with a "Groove Diameter" of .257.

So, when you go to buy bullets for your 6.5 X 284, make sure they measure .264 in diameter and you will be fine.


Malm

To whom it may concern,
I just measured a 100gr. Sierra marked .257 and it measured .257"? I know, I wont be shooting any .264's in my .257's. Maybe that's why they recommend slugging the barrel on your 8m/m Mauser, so you don't accidentally shoot .323's in your .318 bore?
Stepchild

My goodness sakes alive..I have been shooting the .257 when it was called the Neider and bullet diameter for it is .257. It does not shoot a .264 diameter bullet. If you want to interpolate the metric data---24.40 x .257 or .264 they both could be called 6.5mm. But the diameter of the bullets are quite different..For goodness sakes read your loading manuals. If you run a .264 diameter bullet down a .257 you are putting yourself in harms way..That seven thousands difference can upset your whole shooting experience.

.257====25-35==257Rem Roberts==25-06==257 Wethby
Mag

.264====260 REM==6.5 Arisaka==6.5x55==6.5Rem mag==264 Win mag==

METric conversions are very good when measuring case length or COL. Be very careful when trying to convert American bullets into advertised bullet box metrics...

Jesus guys, wake up and look what was said. There can be a great descrepancy in nomenclature. The .257 Roberts and I have 3 of them, shoot a bulltt that is 6.5 mm in diameter. End of story. Old Model 70 even proved it, he just doesnt know the dimensions. That bullet will not function in a 6.5 caliber rifle. Eat the figgin crow, their might be some brain food in it.

customstox----Eat crow for posting an opinion??
Rather polemic in your advancement of 6.5 aka .257 Roberts. Where can I get some of those 140 grain Match Kings in 6.5 (.257)dia that OLE70 is shooting in that 25-06. Shot a lot of different rifles in 6.5 (.257)dia, but never loaded a 140 Match King. If he's shooting a 6.5mm (.257)dia bullet in that rifle that weighs in at 140 grains, that rifle must have a freebore job that want quit, and being fired as a single shot. Give me some good loads with that 140 grain Match Kings in 25-06 6.5mm(.257) dia..and I will send you some using the highest bullet I load up to in 25-06, the 6.5 (.257)dia 120 grain..

Snowbound,
Sorry, you are right I was a bit aggresive but more out of frustration. The point being and even in Model 70 post, "Carcano.......my caliper reads .257 for the Roberts, and .264 for the 6.5-284"; what is .257" when converted? It is 6.5 mm and the .264 is 6.68mm. It is not to say that you can shoot a Nosler 6.5 bullet in a .257 Roberts, it doesnt fit and that was not the point. The point may have originaly been stated in fun, although it was mathematicaly correct, but the confusion still reigns because of the way we identify certain rounds and it changes with round to round.

Now I can get you a lot of bullets and loads for a 6.68mm 140 grain bullet. Damn, we could go on for ever with this.

customstox--I think the confusion comes in at the word 6.5mm bullet...most people immediately think of the .264 round. And are used to seeing it marked on the box with 6.5mm followed by .264 dia.
I have loaded lots of both .257 and .264 bullets. Load right now for about 20 different cartridges. Started early, about 1950-51 timeframe, 45-70 and cast bullets in old 30-40 Krag. Sounds like you do custom gun work ????

Jeez, next thing you know they will be telling me that 30 caliber bullets are really .308" and that the groove diameter of a cut rifled bbl is NOT the same as a button job..

Carcano,
Why would I want to get out a caliper that measures in millimeters? I work in thousandths and am not interested in millimeters. And as far as your German beer you can keep that also. Make mine Budweiser. King of Beers. Anybody that drinks their beer warm is uncivilized in my humble opinion. Jim White
Prescott, AZ
Working in inches
Drinking Bud

Whatever you do SEALDOGGY, consider using Lapua brass! It is cheaper than either Norma or Hornady brass (at least at Sinclair it is), and Lapua brass is normally tops for dimensional integrity. In a word, it is GREAT brass! So, if it was me I'd plan to use Lapua brass, and make sure my chamber was cut accordingly.
- mike

Jim, I fully agree with your statement about warm beers. But even a warm beer is better than a US-brewed no-beer (with due exception for some good micro breweries, and for Samuel Adams).

Now, as to the original topic, it 's simple enough once you remove the blindfold before your eyes. Bwana-be wrote correctly, and even with an added amusement smiley for the hermeneutically challenged:
"If that's not confusing enough, I'll add that the 257 Roberts shoots 6.5mm bullets. "

You felt it fitting to fire off a peevish quip in response, but shot your own foot with that one. Typical case of drawing too fast and having the finger on the trigger.
And that's it.
Now eat your dish, and I'll gladly grant you license to have an ice-cold Budweiser or Coors with it. Good beer must not wasted.

Best regards,
Carcano

Snowbound,
I build custom gunstocks, and of course, I have my part time job of adding to the confusion.

Now you guys got Sealdoggy wondering whether he was going to build a 25-284, or a 6.5-284......