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View Full Version : 7-08 to 7 x 57 ?



wmitty
01-13-2013, 05:17 PM
Are there any hidden flaws in the idea of taking a 7-08 Rem barrel for a 700 and trimming the shank to allow re-chambering it to 7 x 57 Mauser? I realize the 7-08 is a larger capacity cartridge and has less shoulder taper which prevents a simple rechambering operation. It would appear that the chamber could be cleaned up by adding a thread and then cutting the shank off a proportionate amount; along with the counterbore and re-chambering for the longer car-tridge.

pietro
01-13-2013, 06:47 PM
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Yes - The 7x57 would be too long if the "700" is a SA (short action).

If, however, your donor "700" is a LA, then it "might" be possible. If the rechambering in the set-back bbl doesn't get rid of the remains of the 7mm-08 (.308 case) chamber, you'll have to try to take off another thread & try again.
I'm thinkin', that if it goes that far, a new barrel reinforce/tenon shoulder's going to need to be also recut/threaded.


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flounderman
01-13-2013, 07:36 PM
you can go to a 7mm ackley with a rechamber.

leftiye
01-15-2013, 02:22 AM
The 7mm308 shoulder is bigger than the 7mm Mauser shoulder, so you must cut enough off of the barrel to remove the 308 shoulder as you cut the new chamber to correct depth. You may find it tricky to cut the new thread in a way so as to continue the old thread as you'll have to move the barrel shoulder forward after you cut the shank of the barrel off. Proby just better to cut off the whole barrel shank, rethread and rechamber. The mentioned Ackley chamber shouldn't require this - I'd guess. Much better to use a 7mm08 than a 7mm mag for this purpose though. You wouldn't have enough barrel diameter left to do it after cutting off most of the mag chamber. I'm lucky, my latest project is this same thing 7mm08 to 7 mauser, but I'm fitting it to a 93 Mauser, and I get to turn the threads off and relocate the shoulder before re threading the barrel shank. But I'll still have to cut some off of the rear of the barrel.

wmitty
01-19-2013, 03:43 PM
leftiye: I see now what what you mean by following the existing threads; that may be beyond the capabilities that exist. I see you fellows have thought this thru to a greater extent than I... actually, i'd hoped to make use of one of the cheap 7 mm mag barrels that are available but came to the same conclusion - not enough diameter left to allow rechambering/ shoulder location for recoil lug. Sure would like a 700 in 7 x 57, though.

flounderman
01-19-2013, 04:25 PM
the 284 will clean up a 308 chamber. If you are putting the barrel on a short action I don't know how much room you would have for a 7mm. the 284 has about the same capacity as the 280 in a shorter case.

Willbird
01-19-2013, 05:04 PM
the 284 will clean up a 308 chamber. If you are putting the barrel on a short action I don't know how much room you would have for a 7mm. the 284 has about the same capacity as the 280 in a shorter case.

If you neck the 284 to 6mm (IE 6-284) a 107 grain sierra will be too long to fit the magazine, so I would think that most 7mm bullets would be even longer. I have seen an article or two on making a rem short action mag into a medium length by taking the magazine box back to where it would be in a remington model 7 action. The model 7 action is shorter but still takes a 308 length round, they do that by moving the rear of the mag box closer to the trigger cutout. You would I think use a shortened long action mag box.

Willbird
01-19-2013, 05:10 PM
Here is a magazine box Brownells sells to allow you to lengthen the mag box rearwards .110"

http://wyattsoutdoor.com/product_info.php/cPath/1/products_id/34

The mfg webpage linked above shows how the action is altered.

leftiye
01-19-2013, 07:00 PM
FWIW, I think you could cut the shank off and still have enough diameter to rethread and rechamber a .7mm-08 barrel for a 700 action to 7mm mauser. Though I am guessing, but i've been quite close to this issue lately. If not, I would say 7mm Ackley improved as the least troublesome path to a 7mm in a 7mm-08 700 action (if the length isn't a problem, then in either long or short action). Willbird's long magazine is a cool way out if 7mm Mauser won't fit the short action magazines. If (and only if) that magazine is long enough.

Willbird
01-20-2013, 11:22 AM
Depending on how many rounds you REALLY need, you can load one round into a rem magazine that is "too long"....I do it with 6-284 all the time when I want to use the 107 sierra, the bullet nose lays up in the feed ramp, works fine. The 105 amax seats deeper and fits into the magazine.

Drphilwv
11-16-2014, 02:54 PM
I'm curious as to why you would want to do that. I have both 7x57 and 7-08 and can't think of a reason to go away from the 7-08. Lots of 308 to form brass, accurate as hell, eats any bullet you load into it. Could just do a 7-08 improved if you wanted a touch more case capacity I suppose. Seems an easier option than a rechambering.

wmitty
11-19-2014, 03:15 AM
I just have a strange affinity for the old cartridge; no doubt the 7-08 would make a lot more sense. I wound up rebarreling an old Spanish M 93 I'd acquired as a kid. Glad I did; it's a lot of fun shooting cast in a rifle you bought 47 years back.

usmc1963
04-06-2015, 06:04 PM
i miss my m 93 wife shot first deer with it now she keeps it locked in her gun safe and i got her 7-08 :sad:

UBER7MM
05-09-2015, 06:47 PM
Might be easier to work with a 98 Mil Mauser as a donor action and buy a new barrel blank in 7mm.

Just a thought.