6.5 Creedmoor in a .260 Remington?

TXAZ · August 8, 2020, 11:20 PM

Overheard at LGS today: You can shoot 6.5 Creedmoor out of a .260 Remington rifle....

I'm pretty sure these cartridges have different dimensions, even if the cartridge body diameter is the same for the two.

Guy claimed it gave you more ammo options if you had a .260.

TimW77 · August 9, 2020, 12:07 AM

I'd avoid going to that LGS at ALL COSTS!!!

Bad advise AND DANGEROUS!!!

TW

CarJunkieLS1 · August 9, 2020, 12:22 AM

I don't know if that can actually be done or not, but you can shoot a 300blk in a .223 that doesn't make it a good idea though.

TXAZ · August 9, 2020, 12:30 AM

Quote:

Originally Posted by TimW77

I'd avoid going to that LGS at ALL COSTS!!!

Bad advise AND DANGEROUS!!!

TW

It wasn’t an employee but a conversation between 2 customers looking for ammo options.

I wish I had made a video of it.

I don’t think you can do that but I don’t have a .260 to check.

std7mag · August 9, 2020, 07:55 AM

I'm not quite sure it would fit.
6.5 CM is based off of an improved 30 TC case necked down. With the improved, the case shoulder may interfere in the 260 chamber.
If you had a 260AI, it might, might chamber.
But doing so would give you potential for dangerous headspace issues!

TX Nimrod · August 9, 2020, 08:15 AM

You be the judge....

jmr40 · August 9, 2020, 08:53 AM

Looking at the above linked photo it appears that it might very well be possible for a 6.5 CM round to fit in a 260 chamber and it might actually fire. But I wouldn't want to be holding the rifle if it does.

There are lots of combos out there where one cartridge will fit the chamber and actually fire. Some are dangerous, others not. A 300 H&H will fit and fire safely on a 300 Weatherby chamber. It is the same principle as firing a 30-06 in a 30-06 AI chamber. In at least some rifles a 308 will chamber and fire in a 30-06.

I have a game warden friend who said he once arrested someone hunting at night. They had fired a 35 Rem cartridge through a 7mm Rem mag rifle. Somehow the rifle didn't come apart.

big al hunter · August 9, 2020, 10:34 AM

The shoulder diameter of the creedmoor is slightly larger than the shoulder diameter of the 260. So it might not chamber far enough to fire. But it probably could be jammed in with some effort, especially since the creedmoor is shorter and the 260 has some taper in the body. It would be similar to fire forming 7-30 Waters out of 30-30 win brass. The brass would probably split though. Not sure if the bullet would stay centered on the bore well enough to be safe. And I highly doubt it would be very accurate. All together I wouldn't try it. But that proves some folks don't understand what is going on....

TXAZ · August 9, 2020, 11:06 AM

Thanks guys.
I’m sure there are lots of cartridges that will chamber a disparate cartridge, and others that will fire a disparate cartridge, and even a few that will eject the cartridge.

Now that you’ve mentioned it, I think I could chamber a .22 LR or .410 shotgun shell in Boomer.

big al hunter · August 9, 2020, 11:25 AM

The shoulder diameter of the creedmoor is slightly larger than the shoulder diameter of the 260. So it might not chamber far enough to fire. But it probably could be jammed in with some effort, especially since the creedmoor is shorter and the 260 has some taper in the body. It would be similar to fire forming 7-30 Waters out of 30-30 win brass. The brass would probably split though. Not sure if the bullet would stay centered on the bore well enough to be safe. And I highly doubt it would be very accurate. All together I wouldn't try it. But that proves some folks don't understand what is going on....

TXAZ · August 9, 2020, 12:26 PM

Quote:

Originally Posted by big al hunter

(Good technical discussion on the dimensions deleted) ...

But that proves some folks don't understand what is going on....

DING DING DING!!! We have a winner!!!! Truer words were never spoken.

Bart B. · August 9, 2020, 02:08 PM

Big Al got the right answer.

Don Fischer · August 9, 2020, 04:39 PM

Why in the world would you want to fire a different cartridge in a chamber not designed to fire it?

TXAZ · August 9, 2020, 06:55 PM

Quote:

Originally Posted by Don Fischer

Why in the world would you want to fire a different cartridge in a chamber not designed to fire it?

Being desperate or of diminished mental capacity?

Bart B. · August 10, 2020, 09:58 AM

Is it safe to rebarrel an action originally used for a 51,000 psi small case cartridge with a barrel using a bigger case 65,000 psi cartridge?

Or rechamber a 7mm barrel for a 51,000 psi small case cartridge to a larger case 65,000 psi 7mm cartridge?

I think it's safe. Both has been done for decades with Winchester 70 and Remington 7XX stuff.

Remington74 · August 10, 2020, 11:39 AM

I got a feeling that is gonna hurt!

jaysouth · August 10, 2020, 10:28 PM

When living in Arlington,VA, I had a neighbor who was a Major in the marine corp working as a clerk at the pentagon. He honestly thought that a 7.62x39 would fire and operate in an M-14, but not vice versa. Said he heard it in the office.

stagpanther · August 11, 2020, 07:12 AM

Quote:

Why in the world would you want to fire a different cartridge in a chamber not designed to fire it?

By accident. Inattention. Stupidity--whatever you want to call it. One day I might tell the story of when I accidentally fired a 308 win cartridge in a 270 win rifle (it did not blow up and the bullet hit the target; but it could have had a worse outcome and unless the manufacturer specifically says so--never fire a cartridge in a weapon it was not chambered for).

TX Nimrod · August 11, 2020, 09:35 AM

Quote:

Is it safe to rebarrel an action originally used for a 51,000 psi small case cartridge with a barrel using a bigger case 65,000 psi cartridge? Or rechamber a 7mm barrel for a 51,000 psi small case cartridge to a larger case 65,000 psi 7mm cartridge? I think it's safe. Both has been done for decades with Winchester 70 and Remington 7XX stuff.

For the actions mentioned I’m sure it is safe as long as the action is in good condition. However, I would balk at the idea if the action was an older ‘03 or M98 etc. Bolt setback can happen, especially if the surface hardening is worn off from excessive use or the steel was improperly heat treated. But you know that.

.

reynolds357 · August 11, 2020, 05:43 PM

Quote:

Originally Posted by Don Fischer

Why in the world would you want to fire a different cartridge in a chamber not designed to fire it?

Combination of boredom and alcohol.
Back in the day, I tried to blow up a 98 Mauser and couldnt do it. (Alcohol and boredom)
It was safe. 50 ft pull rope and big tree for cover.

Scorch · August 11, 2020, 06:27 PM

If the OP could find those two old gents, he should challenge them to try that stunt. The shoulder of the 6.5 Creedmore is larger the shoulder of the 260 Remington, so it would involve swaging the case down to be able to close the action. Don't get me wrong, I'm not saying it cant be done! I've seen 308s fired in 30-06 chambers, 270s fired in 30-06s, 8X57 fired in 30-06, 300 Savage fired in 308, 243 fired in 6mm, stuff like that. But it would be challenging to say the least.

TXAZ · August 11, 2020, 07:02 PM

Quote:

Originally Posted by Scorch

If the OP could find those two old gents, he should challenge them to try that stunt. The shoulder of the 6.5 Creedmore is larger the shoulder of the 260 Remington, so it would involve swaging the case down to be able to close the action. Don't get me wrong, I'm not saying it cant be done! I've seen 308s fired in 30-06 chambers, 270s fired in 30-06s, 8X57 fired in 30-06, 300 Savage fired in 308, 243 fired in 6mm, stuff like that. But it would be challenging to say the least.

I can answer that one in 6 languages. (They all start with NO.)

Not interested in discussing anything with them, some of that bad juju might rub off, or their estate’s lawyer may say I put them up to it.
Nope.

Don Fischer · August 12, 2020, 12:31 PM

Quote:

Originally Posted by jaysouth

When living in Arlington,VA, I had a neighbor who was a Major in the marine corp working as a clerk at the pentagon. He honestly thought that a 7.62x39 would fire and operate in an M-14, but not vice versa. Said he heard it in the office.

Maybe I shouldn't let the cat out of the bag. worked as an instructor on the rifle range where I was stationed in Germany in the late 1960's. Wasn't the corp but AF. Something I came to discover was the more rank some those guy's had the more dangerous they were with a gun and the worse they shot!

The status of being in the military does not automatically translate in to a great shooter. That Major working as a clerk in the pentagon probably only fired a gun once a year to qualify and not qualifying is a hard thing to do. There are some great shooter's in the military and there are even more duds!

jackstrawIII · August 13, 2020, 12:39 PM

Gonna be a big fat N.O. on this one.

Creed is wider in the shoulder than the 260 Rem at the same distance from the base.

Look at a photo of the two side by side. It should be obvious why this won't work.

big al hunter · August 14, 2020, 11:02 PM

Quote:

. Look at a photo of the two side by side. It should be obvious why this won't work.

It's obvious to you, me and most of the people on this forum. But...make it idiot proof, and someone will make a better idiot....and give them a hammer.

It's not impossible, but it wouldn't be as simple as loading a 44 special in a 44 mag. Brass is soft and easily manipulated. You would only have to swage the shoulder down about .006-.008 inches depending on the chamber and ammo tolerances. Given enough incentive or alcohol I am certain I could make it fit. But that doesn't make it a good idea.

But it might make a fun scientific experiment.....now to find a gun cheap enough and the money to purchase it....and someone else to pull the trigger

August 8, 2020, 11:20 PM	#1
TXAZ Senior Member Join Date: September 5, 2010 Location: McMurdo Sound Texas Posts: 4,322	6.5 Creedmoor in a .260 Remington? Overheard at LGS today: You can shoot 6.5 Creedmoor out of a .260 Remington rifle.... I'm pretty sure these cartridges have different dimensions, even if the cartridge body diameter is the same for the two. Guy claimed it gave you more ammo options if you had a .260. __________________ Cave illos in guns et backhoes

August 9, 2020, 12:07 AM	#2
TimW77 Senior Member Join Date: September 22, 2008 Posts: 485	6.5 C-M in .260 I'd avoid going to that LGS at ALL COSTS!!! Bad advise AND DANGEROUS!!! TW

August 9, 2020, 07:55 AM	#5
std7mag Senior Member Join Date: June 23, 2013 Location: Central Taxylvania.. Posts: 3,611	I'm not quite sure it would fit. 6.5 CM is based off of an improved 30 TC case necked down. With the improved, the case shoulder may interfere in the 260 chamber. If you had a 260AI, it might, might chamber. But doing so would give you potential for dangerous headspace issues! __________________ When our own government declares itself as "tyrannical", where does that leave us??!! "Januarary 6th insurrection". Funny, I didn't see a single piece of rope...

August 9, 2020, 08:53 AM	#7
jmr40 Senior Member Join Date: June 15, 2008 Location: Georgia Posts: 10,978	Looking at the above linked photo it appears that it might very well be possible for a 6.5 CM round to fit in a 260 chamber and it might actually fire. But I wouldn't want to be holding the rifle if it does. There are lots of combos out there where one cartridge will fit the chamber and actually fire. Some are dangerous, others not. A 300 H&H will fit and fire safely on a 300 Weatherby chamber. It is the same principle as firing a 30-06 in a 30-06 AI chamber. In at least some rifles a 308 will chamber and fire in a 30-06. I have a game warden friend who said he once arrested someone hunting at night. They had fired a 35 Rem cartridge through a 7mm Rem mag rifle. Somehow the rifle didn't come apart. __________________ "If you're still doing things the same way you were doing them 10 years ago, you're doing it wrong" Winston Churchill

August 9, 2020, 10:34 AM	#8
big al hunter Senior Member Join Date: March 12, 2011 Location: Washington state Posts: 1,558	The shoulder diameter of the creedmoor is slightly larger than the shoulder diameter of the 260. So it might not chamber far enough to fire. But it probably could be jammed in with some effort, especially since the creedmoor is shorter and the 260 has some taper in the body. It would be similar to fire forming 7-30 Waters out of 30-30 win brass. The brass would probably split though. Not sure if the bullet would stay centered on the bore well enough to be safe. And I highly doubt it would be very accurate. All together I wouldn't try it. But that proves some folks don't understand what is going on.... __________________ You can't fix stupid....however ignorance can be cured through education!

August 9, 2020, 12:22 AM	#3
CarJunkieLS1 Senior Member Join Date: October 1, 2013 Posts: 689	I don't know if that can actually be done or not, but you can shoot a 300blk in a .223 that doesn't make it a good idea though.

August 9, 2020, 11:06 AM	#9
TXAZ Senior Member Join Date: September 5, 2010 Location: McMurdo Sound Texas Posts: 4,322	Thanks guys. I’m sure there are lots of cartridges that will chamber a disparate cartridge, and others that will fire a disparate cartridge, and even a few that will eject the cartridge. Now that you’ve mentioned it, I think I could chamber a .22 LR or .410 shotgun shell in Boomer. __________________ Cave illos in guns et backhoes

August 9, 2020, 11:25 AM	#10
big al hunter Senior Member Join Date: March 12, 2011 Location: Washington state Posts: 1,558	The shoulder diameter of the creedmoor is slightly larger than the shoulder diameter of the 260. So it might not chamber far enough to fire. But it probably could be jammed in with some effort, especially since the creedmoor is shorter and the 260 has some taper in the body. It would be similar to fire forming 7-30 Waters out of 30-30 win brass. The brass would probably split though. Not sure if the bullet would stay centered on the bore well enough to be safe. And I highly doubt it would be very accurate. All together I wouldn't try it. But that proves some folks don't understand what is going on.... __________________ You can't fix stupid....however ignorance can be cured through education!

August 9, 2020, 02:08 PM	#12
Bart B. Senior Member Join Date: February 15, 2009 Posts: 8,927	Big Al got the right answer.

August 9, 2020, 04:39 PM	#13
Don Fischer Senior Member Join Date: March 2, 2017 Posts: 1,868	Why in the world would you want to fire a different cartridge in a chamber not designed to fire it?

August 10, 2020, 09:58 AM	#15
Bart B. Senior Member Join Date: February 15, 2009 Posts: 8,927	Is it safe to rebarrel an action originally used for a 51,000 psi small case cartridge with a barrel using a bigger case 65,000 psi cartridge? Or rechamber a 7mm barrel for a 51,000 psi small case cartridge to a larger case 65,000 psi 7mm cartridge? I think it's safe. Both has been done for decades with Winchester 70 and Remington 7XX stuff. Last edited by Bart B.; August 10, 2020 at 02:24 PM.

August 10, 2020, 11:39 AM	#16
Remington74 Senior Member Join Date: August 5, 2012 Location: Carthage, NY Posts: 231	I got a feeling that is gonna hurt!

August 10, 2020, 10:28 PM	#17
jaysouth Senior Member Join Date: February 27, 2001 Location: Richmond, VA Posts: 788	When living in Arlington,VA, I had a neighbor who was a Major in the marine corp working as a clerk at the pentagon. He honestly thought that a 7.62x39 would fire and operate in an M-14, but not vice versa. Said he heard it in the office.

August 11, 2020, 06:27 PM	#21
Scorch Senior Member Join Date: February 13, 2006 Location: Washington state Posts: 15,249	If the OP could find those two old gents, he should challenge them to try that stunt. The shoulder of the 6.5 Creedmore is larger the shoulder of the 260 Remington, so it would involve swaging the case down to be able to close the action. Don't get me wrong, I'm not saying it cant be done! I've seen 308s fired in 30-06 chambers, 270s fired in 30-06s, 8X57 fired in 30-06, 300 Savage fired in 308, 243 fired in 6mm, stuff like that. But it would be challenging to say the least. __________________ Never try to educate someone who resists knowledge at all costs. But what do I know? Summit Arms Services

August 13, 2020, 12:39 PM	#24
jackstrawIII Senior Member Join Date: July 20, 2016 Location: Upstate NY. Posts: 912	Gonna be a big fat N.O. on this one. Creed is wider in the shoulder than the 260 Rem at the same distance from the base. Look at a photo of the two side by side. It should be obvious why this won't work. __________________ In God we trust.