300 Win mag rechambered
can a 300 Win Mag be rechambered to 338 Lapua
Thanks
Thanks
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A 338 bullet in a bore meant for 308 is a really tight fit.
http://en.wikipedia.org/wiki/.338_Lapua_Magnum
http://en.wikipedia.org/wiki/.300_Winchester_Magnum
The Lapua is a bigger case, your action may or may not be readily adaptable.0 -
I need to reword this I am just woundering if I can use the action and rebarrel the 300 to 338 0 -
What make is your action ??? 0 -
its a winchester model 70
gun was made in the late 90"s or early 20000 -
Is that action/mag box long enough for the 338 Lapooey? 0 -
Cartridge and bolt face are wider so the feed lips and the bolt will need reworked. Also, I doubt the magazine is long enough to accommodate it, the .338 is about 5/16" longer tham the .300WinMag 0 -
The Winchester M70 actions are sufficiently large to accept the 375 RUM cartridges, which are within the same general size as the Lapua; so I'd expect that a 338 Lapua would work through the M70 action, although when I had a 338 Win rebarrelled to 375 RUM it needed a different follower, but the rails remained unchanged. 0 -
There is a more efficient, readily available, and less expensive cartridge to use. It will fit your bolt face, too. It is the 338 RUM. It WILL do everything the 338 Lapua will do.
Best0 -
wwiiman,
quote:its a winchester model 70
gun was made in the late 90"s or early 2000
Let's start at the beginning rather that jumping right into the middle of things.
The rim and head diameter of the .338 Lapua is 0.588", so get your calipers out and look at that dimension. It is not in the neighborhood of any other cartridge except the Rigby (parent case) and the newer .338 Norman Magnum. Why am I after this particular dimension? Thread tenon diameter.
Remington has acknowledged that their 0.700" diameter bolt with lugs is about the minimum allowable for this cartridge. Their thread tenon is 1.062" in diameter. The Lapua uses up a great deal of this tenon diameter with it's body diameter. In other words, the chamber wall is getting thin. Not so thin as to create a potential problem but the minimum allowable.
Savage tried using their small diameter thread tenon and then thought a lot better of changing it. They now use the 'large tenon' of 1.125" in diameter just for cartridges such as the Lapua and Norma Mag.
From Savage FAQ's:
"Up until 2001 all Savage actions utilized a barrel with a nominal barrel thread diameter of 1.05". Soon after Savage started introduced Super Short and Ultra Mags in 2001, they began utilizing a slightly larger barrel thread diameter of 1.125" for those rifles only. Some standard magnum chamberings (i.e. 300 Winchester Magnum etc.) were also fabricated using the larger barrel thread at that same time."
The Winchester Model 70 thread tenon is 1.000" threaded 16 TPI. The newer version is 1.000" threaded 28 TPI.
Now, if 1.062" is considered to be the industry standard minimum, the Winchester tenon is definitively undersize.
.338 Lapua SAAMI Maximum overall cartridge length: 3.681" (250 gr. Scenar)
.338 Lapua CIP Maximum overall cartridge length: 3.75#8243; (300 gr. Scenar)
The Remington and Winchester magazine boxes for magnum cartridges have a maximum interior length of 3.600" + a little extra. Checking the standards above, you might wind up a little short on magazine space without opting for a DBM system set up for the CIP length cartridges.
I've have put .300 RUM cartridges in Winchester M70's and they work fine as long as you have the proper magazine box and you adjust the rails for feeding these cartridges from the magazine box. But this is the biggest case which works without bobbles.
You are perfectly capable of doing as you see fit but I suggest that you rethink this project by using another type of action or simply switch cartridges as has been suggested.
Best.0
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