7mm Mauser vs. 6.5 Swede brass

hodaka · November 4, 2018, 03:25 PM

Have any of you resized 7mm Mauser brass down to a Swede? The Mauser is a bit longer but trimming is easy.

HiBC · November 4, 2018, 06:05 PM

Rim/case head diameter on 6.5x55 is .480. Its .473 on 7x57,8x57,308,30-06,etc

hodaka · November 4, 2018, 08:42 PM

Yes, I know there are some slight dimensional variances. I sized and trimmed 5 and i’m planning to give them a try. I have some Swede ammo that has the same case head diameter.

Nathan · November 4, 2018, 10:57 PM

Why not just buy the right cases?

BBarn · November 5, 2018, 02:46 AM

Don't try it. The difference in diameters HiBC referred to extend to the case body as well. Firing a case that's .007" too small is asking for trouble. Buy the right cases as Nathan suggested.

mete · November 5, 2018, 04:10 AM

It was a shame that the USA decided to use a different diameter. For a cartridge always known for accuracy that difference is stupid.
Your rifles chamber must match the cases you are using ! European rifle ? use European cases. American rifle ? use American brass !

std7mag · November 5, 2018, 05:19 AM

I'm in the don't do it camp.
Your dealing with 50,000 psi (roughly), is saving a couple of bucks worth life and limb?
Or life and limb of the person next to you at the range?

dahermit · November 5, 2018, 11:29 AM

Quote:

It was a shame that the USA decided to use a different diameter. For a cartridge always known for accuracy that difference is stupid.
Your rifles chamber must match the cases you are using ! European rifle ? use European cases. American rifle ? use American brass !

Uhhhh... Our (American), .30-06, .308 Win., 25-06, .257 Roberts, 6MM Rem. are based on a European head size cases (7x57, 8x57). It is the Swedish Mauser that is an "odd" case. When I had a Swedish Mauser Carbine, I had no problem using Remington 6.5 Swedish Mauser cases...American cases in a European rifle.

FITASC · November 5, 2018, 05:05 PM

^^^ Yep,

hodaka · November 6, 2018, 08:11 AM

With all of the encouragement I decided to give it a try. I sized and trimmed 5 cases. It was about like trimming 270 to 30-06. Loaded them with 120 HPBT’s and starting load of 4064. All fired and extracted fine. No splits or separations, seemed to fire form fine. Didn’t need to do it as I have plenty of Swede brass but wanted to experiment. Now I know. Regards.

azar92 · September 19, 2019, 10:05 AM

Sorry to bump an old thread, but I just thought I'd add that while the nominal head size of 6.5x55 is indeed 0.480", in practice 0.476-0.477" is what it typically measures.

I just grabbed various pieces of 6.5x55 from my stash and measured their head size (I should have some Remington R-P headstamped brass, but couldn't find it).

Code:

6.5x55 Case Head measurements	
FC		0.475
Frontier	0.475
PMC		0.477
S&B		0.4775
Win		0.476
Wolf		0.478
	
Average		0.4764

While using the correct sized brass would undoubtedly be better (and likely more accurate), I don't believe using 0.473" is as big of a deal as it's sometimes made out to be. That's only 0.002" smaller than Federal and Hornady brass (2005-2006 vintage).

azar92 · September 19, 2019, 11:03 AM

Found the Remington R-P brass. 0.475" head size, same as Federal (FC) and Hornady (Frontier).

**Unclenick** · September 20, 2019, 04:10 PM

If you look at the SAAMI drawing for 6.5×55, you find the head diameter given as a critical maximum of 0.4803" with a tolerance of -0.010". In other words, anything from 0.4703" to 0.4803" is SAAMI compliant. Most manufactured cases will aim at the middle of that range, as your data suggests.

The .30-06 has a head diameter of 0.473" -0.010", so the average will be about 0.468". That is smaller than 0.4703, but not a lot. Most guns will have extractor claws that can still work with that 0.002" under-spec number. Now, if you found some 30-06 at the low end of 0.463", then I would not be surprised if some Swedish Mausers occasionally slipped on trying to extract it, but not many.

T. O'Heir · September 21, 2019, 01:49 PM

"...shame that the USA decided to..." The USA had nothing to do with it. It was the assorted European militaries that did it.
Trying to figure out military nomenclature can give you brain damage. .308" does not mathematically convert to 7.62mm either. Nor is a .303 British even close to .303" diameter.

mikejonestkd · September 21, 2019, 01:57 PM

Quote:

Nor is a .303 British even close to .303" diameter.

The .303 brit is named for its Bore Diameter, using the standard method from black powder days which was still the convention when it was introduced

Quote:

.308" does not mathematically convert to 7.62mm either.

But, like the .303 Brit, it perfectly converts to .300" - the Bore Diameter....

November 4, 2018, 03:25 PM	#1
hodaka Senior Member Join Date: April 23, 2006 Location: South Texas Posts: 2,010	7mm Mauser vs. 6.5 Swede brass Have any of you resized 7mm Mauser brass down to a Swede? The Mauser is a bit longer but trimming is easy.

November 5, 2018, 04:10 AM	#6
mete Senior Member Join Date: June 14, 2004 Location: NY State Posts: 6,575	It was a shame that the USA decided to use a different diameter. For a cartridge always known for accuracy that difference is stupid. Your rifles chamber must match the cases you are using ! European rifle ? use European cases. American rifle ? use American brass ! __________________ And Watson , bring your revolver !

November 5, 2018, 05:19 AM	#7
std7mag Senior Member Join Date: June 23, 2013 Location: Central Taxylvania.. Posts: 3,609	I'm in the don't do it camp. Your dealing with 50,000 psi (roughly), is saving a couple of bucks worth life and limb? Or life and limb of the person next to you at the range? __________________ 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...

November 5, 2018, 05:05 PM	#9
FITASC Senior Member Join Date: December 6, 2014 Posts: 6,446	^^^ Yep, __________________ "I believe that people have a right to decide their own destinies; people own themselves. I also believe that, in a democracy, government exists because (and only so long as) individual citizens give it a 'temporary license to exist'—in exchange for a promise that it will behave itself. In a democracy, you own the government—it doesn't own you."- Frank Zappa

September 19, 2019, 10:05 AM	#11
azar92 Senior Member Join Date: April 16, 2009 Location: Utah Posts: 209	Sorry to bump an old thread, but I just thought I'd add that while the nominal head size of 6.5x55 is indeed 0.480", in practice 0.476-0.477" is what it typically measures. I just grabbed various pieces of 6.5x55 from my stash and measured their head size (I should have some Remington R-P headstamped brass, but couldn't find it). Code: 6.5x55 Case Head measurements FC 0.475 Frontier 0.475 PMC 0.477 S&B 0.4775 Win 0.476 Wolf 0.478 Average 0.4764 While using the correct sized brass would undoubtedly be better (and likely more accurate), I don't believe using 0.473" is as big of a deal as it's sometimes made out to be. That's only 0.002" smaller than Federal and Hornady brass (2005-2006 vintage).

November 4, 2018, 06:05 PM	#2
HiBC Senior Member Join Date: November 13, 2006 Posts: 8,288	Rim/case head diameter on 6.5x55 is .480. Its .473 on 7x57,8x57,308,30-06,etc

November 4, 2018, 08:42 PM	#3
hodaka Senior Member Join Date: April 23, 2006 Location: South Texas Posts: 2,010	Yes, I know there are some slight dimensional variances. I sized and trimmed 5 and i’m planning to give them a try. I have some Swede ammo that has the same case head diameter.

November 4, 2018, 10:57 PM	#4
Nathan Senior Member Join Date: July 1, 2001 Posts: 6,332	Why not just buy the right cases?

November 5, 2018, 02:46 AM	#5
BBarn Senior Member Join Date: December 22, 2015 Posts: 887	Don't try it. The difference in diameters HiBC referred to extend to the case body as well. Firing a case that's .007" too small is asking for trouble. Buy the right cases as Nathan suggested.

November 6, 2018, 08:11 AM	#10
hodaka Senior Member Join Date: April 23, 2006 Location: South Texas Posts: 2,010	With all of the encouragement I decided to give it a try. I sized and trimmed 5 cases. It was about like trimming 270 to 30-06. Loaded them with 120 HPBT’s and starting load of 4064. All fired and extracted fine. No splits or separations, seemed to fire form fine. Didn’t need to do it as I have plenty of Swede brass but wanted to experiment. Now I know. Regards.

September 19, 2019, 11:03 AM	#12
azar92 Senior Member Join Date: April 16, 2009 Location: Utah Posts: 209	Found the Remington R-P brass. 0.475" head size, same as Federal (FC) and Hornady (Frontier).

September 20, 2019, 04:10 PM	#13
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,063	If you look at the SAAMI drawing for 6.5×55, you find the head diameter given as a critical maximum of 0.4803" with a tolerance of -0.010". In other words, anything from 0.4703" to 0.4803" is SAAMI compliant. Most manufactured cases will aim at the middle of that range, as your data suggests. The .30-06 has a head diameter of 0.473" -0.010", so the average will be about 0.468". That is smaller than 0.4703, but not a lot. Most guns will have extractor claws that can still work with that 0.002" under-spec number. Now, if you found some 30-06 at the low end of 0.463", then I would not be surprised if some Swedish Mausers occasionally slipped on trying to extract it, but not many. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

September 21, 2019, 01:49 PM	#14
T. O'Heir Senior Member Join Date: February 13, 2002 Location: Canada Posts: 12,453	"...shame that the USA decided to..." The USA had nothing to do with it. It was the assorted European militaries that did it. Trying to figure out military nomenclature can give you brain damage. .308" does not mathematically convert to 7.62mm either. Nor is a .303 British even close to .303" diameter. __________________ Spelling and grammar count!