new project lost in the caliber choice

Was having a similar debate and decided to go with a 6.5x47 / .284 Win switch barrel rig as every time I looked at something with "just a little more boiler room" I kept upselling myself, and then started to get seduced by 7mm ballistics etc etc. Couldn't settle on just one, so figured the second barrel was the way to fix the problem.

A big factor for me on the particular 6.5mm selection was ease of finding components and the relatively greater data out there for 6.5x47 vs some of the interesting (but more obscure) wildcats. Plenty of people are getting good velocity with the 130/140 class pills if using barrels on the longer end of the spectrum.

This is a must read in this debate http://demigodllc.com/articles/6.5-shootout-260-6.5x47-6.5-creedmoor/?p=3

Good velocities up to 140gr - http://www.6mmbr.com/gunweek072.html

Great load development info - http://www.6mmbr.com/gunweek084.html

Good luck choosing just one! Let us know what you decide and how it works out.

EDIT - I also wanted to avoid anything with a relatively short barrel life for this project, so necked down/overbore cartridges got a few points deducted in the rankings. Next time I'll do something a little more crazy.......
 
Ya .
Made my homework and I have contacted pacific tool and jgs for the reamer and I can get about anything is want....BUT finding the reloading dies...It's not impossible but a little bit more complicated.For the 6.5 super lr I need to contact the guy on 6mmar.com.
As for the 6.5 creedmoor the brass choice is turning me off, same thing for the fireforming. So it's starting to be more precise.
Still in the selection is the 6.5 super Lr / 6.5x47 lapua and still waiting for info from gap about the die availability for the 6/6.5 crusader.
 
kevin9934 said:
I am really interested into getting info on how to get those die? If you can't post it here maybe someone could pm me.
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Go to 6mmar.com and order from Robert Whitley (Justin will probably answer the phone). I picked up 2 sets a couple of months ago, all in was $520 with 2 bushings.
I picked up my reamer from Pacific Tool & Gauge(around $150 all in with go gauge) there are others as well, JGS...


BTW I am getting 3012fps with my .260AI, 29" barrel and 140gr Bergers and Reloader 17. I could easily get over 3100fps, maybe close to 3200fps but my accuracy is too good where its at.

I believe the .260AI to be significantly better than the .260 Rem, 6.5x47 and most other 6.5s with the exception of the 6.5x.284 and the .264 Win Mag(both long actions of course).
 
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I have played with the 260AI/ 6.5 Mystic for a number of years in F Open. Shoots superbly at 2.90" with the 140gr Berger VLD.

Since this is about using the AI mag, the fastest option is a 6.5 RSAUM. YES, it will fit but mag capacity is reduced.

Beyond that, a few thou here and there, longer/shorter neck, a few degrees in shoulder angle amounts to not much of anything.

Smaller case will go slower then larger case.... PERIOD.

for a mag fed rifle, I would be concerned about dead reliable feeding. We know the 308 and anything shaped like it will be slick through most mags and actions. Sharp shoulder, low taper cases might hang up in some set ups.

In competition or in the working world, one hangup will be very costly.

By all means build whatever makes you happy, I have wildcatted for many years fussing around with this and that. Was a lot of fun but really didn't end up with much different then production dull and boring.

Consider availability of components unless you really want to be a true wildcatter. Some chamberings have little to no options for components and delays for some are horrid. Dies make up a large portion of any build and wildcat/low volume dies always cost more. Same goes for reamers.

For a non standard chambering, expect to add $300 to 600 for the extra bits and pieces which doesn't include the chore or cost of the brass.

Yes, you can show a fancy chamber stamp on the side of the barrel but that is about the end of it.

Personally, the 260Rem does anything you could possible extract from a 308 AI mag (without going to a much larger case). Dull boring but it has all the things that make me interested.

The 6.5 Swede would be plan B but a slightly longer mag would be ideal but no entirely necessary.

Don't worry about seating any bullet below that boattail neck junction. Accuracy is maintained and you may loose less case capacity then you think,

Just remember that most of this was debated in the 70's and 80's.

Jerry
 
Mystic Precision said:
I have played with the 260AI/ 6.5 Mystic for a number of years in F Open. Shoots superbly at 2.90" with the 140gr Berger VLD.

Since this is about using the AI mag, the fastest option is a 6.5 RSAUM. YES, it will fit but mag capacity is reduced.

Beyond that, a few thou here and there, longer/shorter neck, a few degrees in shoulder angle amounts to not much of anything.

Smaller case will go slower then larger case.... PERIOD.

for a mag fed rifle, I would be concerned about dead reliable feeding. We know the 308 and anything shaped like it will be slick through most mags and actions. Sharp shoulder, low taper cases might hang up in some set ups.

In competition or in the working world, one hangup will be very costly.

By all means build whatever makes you happy, I have wildcatted for many years fussing around with this and that. Was a lot of fun but really didn't end up with much different then production dull and boring.

Consider availability of components unless you really want to be a true wildcatter. Some chamberings have little to no options for components and delays for some are horrid. Dies make up a large portion of any build and wildcat/low volume dies always cost more. Same goes for reamers.

For a non standard chambering, expect to add $300 to 600 for the extra bits and pieces which doesn't include the chore or cost of the brass.

Yes, you can show a fancy chamber stamp on the side of the barrel but that is about the end of it.

Personally, the 260Rem does anything you could possible extract from a 308 AI mag (without going to a much larger case). Dull boring but it has all the things that make me interested.

The 6.5 Swede would be plan B but a slightly longer mag would be ideal but no entirely necessary.

Don't worry about seating any bullet below that boattail neck junction. Accuracy is maintained and you may loose less case capacity then you think,

Just remember that most of this was debated in the 70's and 80's.

Jerry
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Does the 260ai is really enjoying a longer barrel life vs the 260..?because after all it's in the same velocity of the 6.5-284 norma.
I will call you this week so we can discuss about my project ....if you can understand my French accent!
 
The faster you go, the shorter your bore life. There is no free lunch.

Cartridge shape has never been proven to extend bore life. Burning powder at high pressures will.

The 260AI gets much better bore life then the 6.5-284 simply because it a much better match of case volume vs intended performance.

The 6.5-284 is just too big for 140's at 2900fps which is the best node for this bullet.

Decide what bullet, what speed vs what barrel specs. How you plan to run the ammo. THEN decide on the chambering that will fit the function needs first, then performance.

ALL of them will be equally accurate and limited by the barrel and installation.

Wildcats, by all means. Been there done that. have dies with my funky names on them. If you dont want to spend lots of money or fuss with this and that, get factory boring chamberings.

if you want to play, by all means. I have really enjoyed my time with wildcats.

There is no 1 right answer to this, anymore then there is 1 best flavor of ice cream.

The first thing is to start is sourcing the barrel. That will likely take several months. Then the reamer if a wildcat. Some are taking up to 1 yr to produce.

Then dies

Most everything else isn't so hard to source. If you want a custom action, then start that ball rolling cause many Rem type options are 1yr out or longer.

ANYTHING that is based on the 308 case diameter AND fits in a AI mag can only produce so much performance. ALL the case dimensions really are to the interest, curiosity and sometimes vanity of the user. Not good nor bad, right nor wrong.

Just make sure what you end up will function the way you want.

Its your money so build the rig that will fullfill your needs and wants.

It's all good...

Jerry
 
Mystic Precision said:
The faster you go, the shorter your bore life. There is no free lunch.

Cartridge shape has never been proven to extend bore life. Burning powder at high pressures will.

The 260AI gets much better bore life then the 6.5-284 simply because it a much better match of case volume vs intended performance.

The 6.5-284 is just too big for 140's at 2900fps which is the best node for this bullet.

Decide what bullet, what speed vs what barrel specs. How you plan to run the ammo. THEN decide on the chambering that will fit the function needs first, then performance.

ALL of them will be equally accurate and limited by the barrel and installation.

Wildcats, by all means. Been there done that. have dies with my funky names on them. If you dont want to spend lots of money or fuss with this and that, get factory boring chamberings.

if you want to play, by all means. I have really enjoyed my time with wildcats.

There is no 1 right answer to this, anymore then there is 1 best flavor of ice cream.

The first thing is to start is sourcing the barrel. That will likely take several months. Then the reamer if a wildcat. Some are taking up to 1 yr to produce.

Then dies

Most everything else isn't so hard to source. If you want a custom action, then start that ball rolling cause many Rem type options are 1yr out or longer.

ANYTHING that is based on the 308 case diameter AND fits in a AI mag can only produce so much performance. ALL the case dimensions really are to the interest, curiosity and sometimes vanity of the user. Not good nor bad, right nor wrong.

Just make sure what you end up will function the way you want.

Its your money so build the rig that will fullfill your needs and wants.

It's all good...

Jerry
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Well said Jerry!
 
Speaking of the 6.5, has anyone experienced issues with 6.5x47 and pierced primers? I'm going to make one out of a 700 currently in .308 and was wondering if the small primers on the 6.5x47 would mean I'd need to get a firing pin hole bushing?
 
I'd stick with a 260, no monkeying around with brass, lapua brass will allow you to easily push 140's to 2900fps out of a 26" barrel, without primer pocket issues.


redshooter said:
Can anyone comment further on the 260 Imp? It looks to me like it's the equal to anything in a short action cartridge without a magnum sized bolt face.

I haven't paid much attention to the dimensions but it looks like the 260 Imp has just a wee bit more space for powder and a little less neck. Everything I seem to find is Techno weenies raving about the great design of this or that, or someone disguising an add as an artical. The only benefit I can see is the neck and oal of the case, and that's only on the surface.

Let's do a little reading between the lines shall we?

I see plenty of raving about how heavy bullets in the 260 need to be seated deeper and how in the Hornady manual the Creedmore exceeds the top performance of the plain 260. Hornady is obviously selling their pet cartridge. First thought is does seating an A-Max deeper in the 260 case actually eat up that much powder space. Use a little critical thinking and you'll see that the Hornady manual isn't comparing Apples to Apples, top speeds are attained through powders not shown in the 260 Rem section. The 260 OAL in the 140 section is less than 2.80 as well (what kind of sleazery is this???). Also for the 123gr A-Max Hornady only lists data for the Creedmore, the 260 only lists 129gr. Apply a little more critical thinking and the obvious fact that even Hornady lists more loads at a solid 2900 fps for the 129/260 combo leads me to believe that the 260 needs to wash the stink of Creedmore off it's foot!!!!! I'm not convinced (yet) there is any advantage to improving a 260 beyond the brass life. If there is a significant advantage then is it more of the same with the other 6.5mm wildcats of similar capacity and the 260 Imp?

What's the real advantage? It looks like pretty much none. IF the 260 Imp can give 50 or so fps more in the real world. Maybe then I can be convinced I should part with the extra $40 to get those 260 Imp Redding dies, and bugger around with the brass, pistol powder and breakfast...
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Alpheus said:
Speaking of the 6.5, has anyone experienced issues with 6.5x47 and pierced primers? I'm going to make one out of a 700 currently in .308 and was wondering if the small primers on the 6.5x47 would mean I'd need to get a firing pin hole bushing?
Click to expand...

If an action doesn't piece primers now, why would it pierce primers in another chambering?

I bet most of these problems can be traced back to silly high pressures in an attempt to make a small case behave like a large one.

There is no replacement for displacement.

Jerry
 
derrick1978 said:
I'd stick with a 260, no monkeying around with brass, lapua brass will allow you to easily push 140's to 2900fps out of a 26" barrel, without primer pocket issues.
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:D The gent going to do the work has a 260 reamer but not a 260 AI reamer. I'm quite happy to go with the reg version and save the bs with the brass. Although I may run the remainder of my IVI brass through the 260 die just because it's been tough stuff. Once it's been sized and the neck turned I should be in brass for a few years. I'm not looking forward to the prep though...as far as I'm concerned the only bs with reloading is brass prep.
 
kevin9934 said:
Yes, but if the accuracy node for the 115 Dtacs/berger vld is below 3150 which it appears to be then the 6x47, 243, 243 AI, 6 SLR and possibly the 6XC are all probably a better bet?
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The accuracy node is driven primarily by the barrel twist rate. Nobody can arbitrarily pick 3150 FPS without attaching that velocity to a corresponding twist rate. If you cant get 3150 out of a cartridge, then just pick the correct barrel twist rate for the speed you can get. I'm estimating the twist rate for 3150 would be no faster than a 1 in 8.5. Tubbs recommends 1 in 7.5 for the 6XC. I used a 1 in 7.5 for a 6x47 Lapua and it shot 1/8 MOA with 115 DTACs and using 6XC brass running about 3000 fps.

More speed translates to slower twist rate.
Less speed translates to faster twist rate.
 
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