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Old 10-05-2018, 05:34 PM
Peconga Peconga is offline
Join Date: Jun 2010
Location: Boise, Idaho
Posts: 303

Originally Posted by s11033 View Post
I think that with my idea of ordering the barrels rough-chambered for 6.5 Creed, I might be able to make everyone happy.
Have you double-checked the datum points for the 6.5 Creedmoor vs the 6.5 Swede to see if this is even possible? The case diameter of the (short+wide) Creedmoor is significantly larger than the (long+skinny) Swede case, when measured at the same distance from the base (11.74mm vs 11.07mm) This means that you can't simply run a Swede finish reamer into a Creedmoor chamber and expect it to turn out properly, since there will be a large section of "leftover" chamber that will be oversize relative to the Swede case. This is the same problem that people run into when they try to re-chamber a .308 / 7.62x51 barrel to .30-06; the end result is not only sloppy and very hard on brass, but is also potentially unsafe.

Note that on a Mauser, you could simply chop off the threaded section of the breech end of a Creedmoor barrel, re-thread, and then finish with a Swede reamer, since you would be removing fresh metal on the (much) shorter chamber at that point. However, this is not practical on a factory Springfield 1903/03-A3 barrel, which has a tapered breech and pre-cut extractor slot.

A second consideration would be chamber pressure, since the 6.5 Creedmoor is a comparatively high pressure cartridge, with SAAMI spec of 62,000 PSI Max Avg Pressure (MAP). Compare this to the MIL-STD for the .30-06 M2 cartridge at 42,000 PSI (60,000 MAP for civilian) or the 6.5 Swede at 45,000 PSI. Thus, offering a short-chambered 6.5 Creedmoor barrel for a 1903/03-A3 is simply begging for a blow-up, since the youngest Springfield action is now more than 75 years old, and this doesn't even take into account the risk of a customer naively installing a brand new 6.5 Creedmoor barrel on a "Low Number" Springfield 1903.

In conclusion, I would definitely stick with the classic 6.5x55 Swede cartridge for this project, at least for the Springfield.
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