6.5-300wm, 6.5-300wm ai?

[roger]

Sometimes marketting these new calibers is like needing a new wrench that fits between 9/16's and 5/8's.
Are they really needed...

[bobinthesky]

Especially when any old spanner will work!



It's fun to be different though!

[Dick284]

Originally Posted by roger

Sometimes marketting these new calibers is like needing a new wrench that fits between 9/16's and 5/8's.
Are they really needed...

19/32nd
37/64's
39/64's

[catnthehat]

Originally Posted by roger

Sometimes marketting these new calibers is like needing a new wrench that fits between 9/16's and 5/8's.
Are they really needed...

Of course they are not needed!
"They are just something someone designed to sell to someone who thinks they need them" as my dearly departed father used to tell me!
Cat

[elkhunter11]

I like the .264" bore size, and a 300win mag case would likely do well behind it, but the 300wby case is just too large to gain much with a .264" bore. The smallest bullet that can really utilize the 300wby case is .284".

[DaleJ]

Like the 264 on 300 Win Mag improved. Should give a bit more powder volume than 6.5-300 Wby if bullet is kept out of boiler room. The old 264 Mashburn was a full length 375 H&H with a long neck.

Problem with super long bullets and fast twist rifles will be friction and only way to deal with it is coated bullets. Moly coating has given way to newer improved coatings that are easier to work with and bore cleaning is simple, returning to previous accuracy by swabbing barrel with friction fighter with one quick swab.

frictionfighters.com out of Missasauga ON sells tungston disulfide.

[260 Rem]

Originally Posted by Brettmccoy

You're right. I do have fairly high standards as far as accuracy goes. Most of my rifles are capable of 1/2noa or better, with a couple of them consistently shooting better than 1/4moa.
N

For those of us that lust for sub 1/4 MOA rigs, would you be interested in starting a thread giving some details on your tack drivers?

[ForwardBias]

Originally Posted by Brettmccoy

You're right. I do have fairly high standards as far as accuracy goes. Most of my rifles are capable of 1/2noa or better, with a couple of them consistently shooting better than 1/4moa. And yes all but 2 are custom rigs. One of the factory rifles is the one I'd like to use in the 6.5-300 build, mainly because the barrel is shot out on it.
As far as bullets goes. I'm a big 6.5 fan and have been for years. This rifle will be used for both target shooting and hunting. On paper sectional density really means nothing. But the bc on the other hand, really comes into play at anything over 4-500yds. Sectional density, wile it isn't a whole bunch different between the .277 and the .264, every little bit helps. So I'll take what I can get. I've been shooting a semi custom commercial m98 in 270win for years. Love it. It's never failed to put down game. And is my go to hunting rifle every year. But I don't want a 270 cal rifle on this build. I want 6.5, and a hot 6.5, that not everyone has.
I know there's numerous other hot 6.5 cals out there both faster and slower or faster. Some better for one reason or another, availability of components, better barrel life, better efficiency. I planned on an overbore cartridge burning lots of powder, and moving fast. And with the available components that I have on the shelf. 6.5-300win mag seems like a good choice for me. And that's also wildcatting. Dream something up for a cal and case, and someone has done it already. Do some home work, and have at it. If it's what you want, do it and have fun, like a hotrod or a Harley, make what you want of it. I'm not a fan of weatherby so I just won't buy or build one. They build some classy rifles, just not my style. That's why I ask about this specific cal and case.
N

I can back Brett up on the above. One of the most fussy guys I've ever shot with, and does have a high standard for accuracy. One of the few people that can shoot as well as their rifle.

[Brettmccoy]

Originally Posted by bobinthesky

Brettmaccoy,
I'm not trying to talk anyone into or out of anything, far be it for me to do that. I was just taking you to task for a couple of comments you've made and I think I've made my point.
I shot several the 264 Win mags for years and they killed a lot of game. I thought it was the cat's meow right up until I purchased my first crono back in the mid eighties and discovered it had very little practical advantage over the 270 Winnie and it was nowhere close to the 270 Wby. Since then despite playing with 6.5 Swede's, my interest in the 6.5's has only been luke warm until the new Nosler and 6.5-300 have made their appearances. I also think the 6.5-300 using the Win case will be more efficient than using the Wby case without sacrificing much fps.
Good luck on your build and I'm looking forward to the range reports.

I will definatly keep you posted on the build. I'm supposed to giv a guy a call about a custom 6.5wsm thismorning. Sounds like it could be a very decent deal for what he has there. So there's a possibility I might pick that one up instead of building a rifle. But I'll see what he has to say, I'm very curious if anything. But I think 6.5-300 is still the one I'm after
Another fellow messaged me thismorning about a 6.5-300wm he had built a while back. Said he was getting 3500fps with a 129gr pill and retumbo. Which sounds very promising to me. Think I'd prefer at least a 140gr or heavier bullet. But we'll see how it goes

[Brettmccoy]

Originally Posted by DaleJ

Like the 264 on 300 Win Mag improved. Should give a bit more powder volume than 6.5-300 Wby if bullet is kept out of boiler room. The old 264 Mashburn was a full length 375 H&H with a long neck.

Problem with super long bullets and fast twist rifles will be friction and only way to deal with it is coated bullets. Moly coating has given way to newer improved coatings that are easier to work with and bore cleaning is simple, returning to previous accuracy by swabbing barrel with friction fighter with one quick swab.

frictionfighters.com out of Missasauga ON sells tungston disulfide.

My brother was telling me about Molly coating. This is a new idea to me, so I'm still doing homework on it. Sounds like a good way to wring some more velocity, and possibly barrel life out of these high velocity builds. And with this one being one of my first high velocity builds, aside from a 22-250 I had a lil while ago, am really looking into this.
Kinda wish I'd have known about it with my 22-250. I can't help but wonder what coating the bullets and barrel would have really done for it. The load I really liked with it was launching a 36gr varmint grenade at about 4600fps according to the book. But didn't get the chance to chrony the load before I sold the rifle.

[Brettmccoy]

Originally Posted by 260 Rem

For those of us that lust for sub 1/4 MOA rigs, would you be interested in starting a thread giving some details on your tack drivers?

1/4moa rigs are normally finicky to load for in my expierience. You have to be very fussy about every thing to do with loading for them. Weight matched brass, consistent seating depth, neck tension, charge weight, and a whole list of other things. I might start another thread in the future to talk about this, and I'm sure there's a lot of better people to talk accuracy with. I'm fussy but am nowhere near the top of the chart with accuracy and information. This thread has me busy already lol but in the future I may start another

[catnthehat]

Originally Posted by Brettmccoy

My brother was telling me about Molly coating. This is a new idea to me, so I'm still doing homework on it. Sounds like a good way to wring some more velocity, and possibly barrel life out of these high velocity builds. And with this one being one of my first high velocity builds, aside from a 22-250 I had a lil while ago, am really looking into this.
Kinda wish I'd have known about it with my 22-250. I can't help but wonder what coating the bullets and barrel would have really done for it. The load I really liked with it was launching a 36gr varmint grenade at about 4600fps according to the book. But didn't get the chance to chrony the load before I sold the rifle.

Moly coating is not ghevendxall and be all, especially when it comes to a accuracy .
We worked with it extensively in the early 90's and were not impressed enough to adopt it as step when building our match rifle Ammo
Other shooter's Results varied greatly ...
Cat

[Brettmccoy]

Originally Posted by catnthehat

Moly coating is not ghevendxall and be all, especially when it comes to a accuracy .
We worked with it extensively in the early 90's and were not impressed enough to adopt it as step when building our match rifle Ammo
Other shooter's Results varied greatly ...
Cat

Yeah like I said it's kind of a new concept to me. So still doing homework. And like dalej was saying there's other coatings on the market now. So this may or may not be the way to go, but it's interesting just the same

[DaleJ]

Originally Posted by Brettmccoy

Yeah like I said it's kind of a new concept to me. So still doing homework. And like dalej was saying there's other coatings on the market now. So this may or may not be the way to go, but it's interesting just the same

Shooting heavy for caliber bullets that require fast twist barrels tends to create high pressures spikes, sometimes preventing decent velocies. These high pressure and sometimes secondary high pressure spikes keep SD values too high for good long distance accuracy. I played with moly coating when it was first popular but it caused more issues than it ever solved, biggest problem was restoring velocity/accuracy after barrel cleaning. New friction fighter compounds are much easier to work with and accuracy quickly restored by running one patch of friction fighter through barrel sfter cleaning.

Bullets that require friction fighter are 257/155Gr, 264/190Gr, 277/200Gr, 284/225Gr, 308/255Gr, 338/375Gr, 375/450gr.

[Brettmccoy]

Originally Posted by DaleJ

Shooting heavy for caliber bullets that require fast twist barrels tends to create high pressures spikes, sometimes preventing decent velocies. These high pressure and sometimes secondary high pressure spikes keep SD values too high for good long distance accuracy. I played with moly coating when it was first popular but it caused more issues than it ever solved, biggest problem was restoring velocity/accuracy after barrel cleaning. New friction fighter compounds are much easier to work with and accuracy quickly restored by running one patch of friction fighter through barrel sfter cleaning.

Bullets that require friction fighter are 257/155Gr, 264/190Gr, 277/200Gr, 284/225Gr, 308/255Gr, 338/375Gr, 375/450gr.

Good to know. Thanks dalej. I'll keep it in mind once I have this animal in my hands

[Salavee]

Originally Posted by David Henry

As short as the neck is on a 300 Win Mag case for holding 30 caliber bullets I cant help but think you could make a wiser choice in wildcat chamberings for holding the 6.5's.

.. like maybe the .308 Norma.

[sikwhiskey]

Originally Posted by Salavee

.. like maybe the .308 Norma.

Or the 338wm.

[Brettmccoy]

Originally Posted by sikwhiskey

Or the 338wm.

338wm necked down would just be a 264wm would it not? The rifle I'm useing for a donor action is already a 264wm. I want hotter than that case will provide

[bobinthesky]

The 300 win mag's short neck doesn't seem to bother it's accuracy too much but I guess it could if your reducing it to .264 and not setting the neck back a bit.

[Brettmccoy]

Originally Posted by bobinthesky

The 300 win mag's short neck doesn't seem to bother it's accuracy too much but I guess it could if your reducing it to .264 and not setting the neck back a bit.

Guess I'll find out lol. I know with my 6.5-06 I only seat the bullet half way down the neck with a 140gr vldh, and it shoots amazing.

[bobinthesky]

That happens a lot with light bullets, that's why I've never agreed with the whole "it's neck is too short" thing.

[fps plus]

I built some 270 on 300 win mag case as well as some 7 mm on 300 mag case
The were couple of guys in the maple creek , Irvine area shooting the 270 version and it was extremely flat shooting
300 win mag is very tough brass
The 6.5 version would be a fine cartridge

[Diesel_wiesel]

ever thought of a 257 Arnold?????

[Brettmccoy]

Originally Posted by Diesel_wiesel

ever thought of a 257 Arnold?????

Can't say I've heard of the 257 Arnold. I did think about a hot 257. A good friend of mine has a 257-300wm barrel he said he'd give me a hell of a deal on. But being a big 6.5 fan I chose that route instead

[bobinthesky]

My understanding is that it's a 264 mag necked to to 257, I can't see enough difference in the 257 Arnold from the 257 Wby to be bothered with trying to find dies and load data.

[25-284]

I have owned a Arnold , and have had a few 257 wbys both great rounds as stated there is no reason to have a Arnold , as they are almost twins. I now shoot a 6.5x300win improved and I can tell you that throat erosion is a factor , you have to look at it this way, if you get your load r&d done early you will get many years of hunting with a hammer in your hands. It's like tires it can be fun burning them off . I'm hopeing for 500 rounds

[roger]

Great thread!
I like ultra velocity.
500 rounds in true hunting gun is several lifetimes

[Brettmccoy]

Originally Posted by 25-284

I have owned a Arnold , and have had a few 257 wbys both great rounds as stated there is no reason to have a Arnold , as they are almost twins. I now shoot a 6.5x300win improved and I can tell you that throat erosion is a factor , you have to look at it this way, if you get your load r&d done early you will get many years of hunting with a hammer in your hands. It's like tires it can be fun burning them off . I'm hopeing for 500 rounds

As far as hunting accuracy goes you should get more than 500 rounds through it I would imagine. I'm sure hunting accuracy is still attainable at 1000+, but would never win a match with it.
What kind of velocitys are you getting with a 140gr in your 6.5-300ai?

[catnthehat]

I was still able to hit gnats st 500 pretty regular after 2,500 rounds through my 6.5WSM
When Mick re-chambered it he had to cut 4"off the shank to do the new chamber - rifling was gonzo that far up
Cat

[25-284]

Wow 2500. I'm going to shoot more often, I'm getting around 3500 fps with 125gr pt. I'm sure it's got more room for more, those 6.5 s fly flat