Home Forums Hunting & Shooting Ask The Gunwriters 6.5x57 Mauser??'s

Actually, the problem with trying to rechamber a 7x57 to something like a 280 or 7x64 is not so much with the rear (base) of the cartridge but the neck. the 7x57 has a larger chamber (and cartridge)neck of about .324" vs .315" or so for the .280 & 7x64. The .280 is not long enough to clean up the old chamber neck and you end up with a stepped neck.

+1 on smithrjd. You have 0.012" extra at the base of the case. This would allow the x57 round brass to stretch more than it would in a chamber designed for it. You would prematurely wear out the brass at that location and run the risk of case separation. I had thought about it at one point, then did the math and realized I didn't want to take that risk. Then I found a Model 200 barrel in 6.5x57 for a deal so I snagged it.

Ohhh Kay...sounds like in order to get MO Speed I can only look at mebbe AI'ing the factory 6.5x57 chamber...or going ahead with rebarreling something to get what I want....or Just Leave It ALONE as is and enjoy what it has to offer.

Typical of my cheaparsed approach to try to step into a sumthin that won't really work as E A S Y as it 1st appeared. Oh Well.
Thanks All
Ron

Sir:

Perhaps my ancient memory has failed me. You are likely correct... I do remember that Ken Waters' 'smith advised setting the barrel back. And the above was likely the reason. Thank you for clarifying that issue...

GH

All of the mis matched chamber info was for 6.5x55 to 57 (larger base)or the 7mm to .280 (larger neck). As far as I can tell no problem going from 6.5x57 to 6.5-06. Do a chamber cast to check though.

Also look at the .260 AAR and 6.5x.257AI haven't shot one but handled one from Ackley's shop. AAR stands for all around rifle and even PO Ackley said might as well call it that as it should work. He compared it favorably to even the big magnums saying it was about ideal "bore capacity" for powders available back then,
whatever bore capacity means.

Agreed, that a rechamber is not a good idea due to case head size. The irony here is that for many years, US made 6.5 brass had a case head size of .470" as it was made from '06 brass.

Heck, even Today Hornady shows their 9,3x62 brass as having a base diameter of .470" when it should be .476".

You too are probably right. Depending on your reference, case head sizes are listed as different measurements. Some will list a case at .468" while others cite .470". This often causes a lot of confusion. I will look at reamer specs to see what the chamber size is also when considering any rechambering operation.

Just checked and there is a neck diameter difference 6.5x57 is .301 and 6.5-06 A-square is .299. So there would be a .002 step in the neck unless you set the barrel back about 6mm which is a lot. Other option is a custom reamer with the .301 neck. Guarantees you would need bushing or custom dies.

Another reference said the 6.5x65 Brenneke is designed to clean up the 57mm chamber. Since there is only about 200 fps between all of these it seems like esoterica deluxe with pretty obscure brass to boot for not much difference in velocity. Base size of all three is basically the same.

The 65 will clean up a 6.5x57 chamber but not a 6.5x55. the 6.5x55 case head is .480"ish while the 6.5x65 is only .476".

Tejano, are you looking at reamer specs or case drawings?

Bushing dies? Std dies will still resize just fine down to original specs, your chamber neck will just be sloppier than I prefer.

I always verify with a chamber cast before attempting any rechamber job because what something is supposed to be and what it really is are often two different things.

Chamber specs but from different sources. Couldn't find both from the same reamer source but they should be available.
Case neck dia. is almost the same .2961-.2969 for the 57mm to .297 for the .06.

Most of the difference is the thicker RWS brass. Probably be fine with the extra thickness of necking down 06 cases but necking up .25 caliber cases would probably be a poor fit.

6.5x65 RWS can use .270win cases sized in one pass is my understanding. That would be the way to go if dies are not in the custom class price range ( ie cost half as much as the rifle).

Better yet would be to use 9,3x62 brass, the parent of the 6.5x65.

I have an extra sizing die here somewhere. I forgot I had one and ordered another. A senior moment, lol.

Even thought all should be to a "standard" dimension, there seems to be a lot of variance. In the 6.5X55 I used Norma and Lapua brass, very much different from US 6.5X55 brass. In my 9.3X62 I use Lapua brass and I had to modify a standard 30-06 shell holder a bit so it would fit, even thought the recommended shell holder is said to be same as the 30-06. I would guess that different reamer sources (US or Europe) might have some differences as well. At least the 6.5X57 brass seems uniform, all of it is from Europe as far as I know.

Sent an EMail to ITD earlier today outlining some of these questions about doing a 6.5 '06 off a 6.5x57 Zastava and what are the issues they'll have to address. Haven't heard anything back so far, but it is a Friday afternoon anyway. I'm sure it'll be interesting to hear their take on this subject. Ya'll have a good weekend.
Ron

I would think that the 6.5-06 should clean up a 6.5X57 chamber with no issues. No diameter or length issues, and the bolt head should be the same as well. Should be enough length difference to take care of any shoulder position problems as well.

Assuming that ITD, or some where else, can do the 6.5x'06 chamber conversion ...and mebbe an AI at the same time...where do I find load info for the AI without a chrony? or enough info to determine whether or not an AI is worth the investment to only get a gain of 100fps or less.

At the price of RWS 6.5x57 brass running about $1.45 per round from Huntington's...the conversion may pay for itself pretty quickly by using domestic brass.
Ron

FYI: The 6.5-06 has been around for ever. Was the reamer made as a standard by it's maker before ASquare had it standardised via SAAMI?

I have a reamer made by Clymer. I think when I bought it they had their prints online, and the neck diamiter and throat were the same as on their 6.5x55 Swede. I have no idea how these spec are different from the 6.5-06 ASquare. I'd have to measure my reamer. I'd have a chamber cast done, and let them check their reamer if the case head to end-of-neck length dictates it to cleanup your chamber.

The SAMMI and CIP spec on these old rounds like the 7x57 and the 6.5x57 are often quite generous. When they originated it was often uch harder to maintain manufacturing spec, and thus by modern standards they are "over engineered." Case making procedures were also less developed. So, "over engineer."

Just my thoughts as a basement gunplumber.