Rechamber 6.5 X 55 M70 to 6.5-284?

[tominboise]

I have a Winchester M70 Classic featherweight (CRF) in 6.5X55.  Would I gain much, if anything, by rechambering to 6.5 - 284?  Also, would it be a simple rechamber job?

Thanks, Tom

[John Traveler]

Tom,

The re-chambering you asked about should be a straight-forward rechambering job plus modifying the receiver rails to feed the fatter .284 Winchester case reliably.  The bolt face and extractor should work as is.

You should gain probably 200 fps muzzle velocity with the medium-heavy bullets, and accuracy should be at least as good as the original 6.5x55 caliber IF the featherweight barrel was accurate.  Long-range competitive shooters like this wildcat for it's windbucking characteristics.

Be advised, however, that the 6.5x284 is a semi-wildcat, brass is expensive, and the conversion would reduce the resale value of your rifle.

HTH
John

[gunnut69]

A peek at the reamer dimensions is available at the link shown below.  It seems to be, from a cursor look, a simple re-chamber but remember there are major case changes needed.  The 284 case while it uses a standard case head has a larger body.  This is garranteed to cause major feeding problems which will have to be remedied.  Also with the Featherweight barrel profile the barrel reenforce is terminated rather quickly.. The reenforce is the large diameter ara of the barrel just in front of the receiver ring.   The 6.5-284 being larger in diameter for it's entire length(especially at the shoulder) you may be getting to a dangerous level of thinness at the front of the cartridge's shoulder.  The barrel at that may be just too thin..  

http://www.clymertool.com/

[Mikey]

tom:  why bother.  The 6.5 Swede will do anything you want, unless you are trying to reach out beyond the capabilities of the bullet and caliber.  If you are thinking about a real hot, long range 6.5, you may wish to consider the 6.5-06.  Heck, you've got the Model 70 and with the 55mm length of the 6.5 it's prolly one of the long actions (not the shorter 308 length action), and a rebarrel might be all you need.  That would give you everything the 6.5-284 would give you and more.  Just another 2 cents worth here.  Mikey.

[John Traveler]

Gunut69,

THANK YOU for the advisory on the barrel chamber reinforce dimensions

I'd forgotton about that on the Featherweight M70.

John

[tominboise]

Thank you all for the quick input.  I probably won't bother, based on Gunnuts input, but being a typical rifle looney, I am always looking for something different.  Since the rifle is indeed the "long action", I was wondering if I could improve my ballistics relatively inexpensively.  However, being a true gun nut, I will most likely buy yet another rifle more appropriately barreled for the 6.5-284 round  :wink:

thanks again for the quick responses...............

[445supermag]

6.6x55 in a modern action can be loaded up to any of 6.5x06 or the 6.5x284 vol.. The 6.5 sweed can be loaded up in a win mod 70 to 55000 psi.. 6.5x284 was foe a short action, 6.5x06 was the poormans 6.5x55 when that brass was hard to come by. Now the 6.5 swed, in a modern action will do any thing the others do, and that ,s a fact.

[gunnut69]

the Swede is a great round but even loaded to modern pressuresit can't matck the greater volumes of the 6.5x284 and 6.5-06.  I have 5 M96 and M94's now and just bought a clasic featherweight in 6.5x55 and truly love the 264 mag.  If your looking for more power remember one simply truism, bigger cases hold more powder.  That's all. period.  Sure we can wish that case shapes and neck radius's and such can make a cartridge perform at a higher level but they really don't.  The super short mags are the rage now and they perform withing tolerance ranges for their case capacities as compared to available rounds with similar case capacities.  The factories produce a bit more but then by using powders specifically formulated for a case size and bullet weight the factories can do the same thing with currently available cartridges.  Witness the 'light magnum' loads available for several cartridges.  The rumors of barrel erosion is most likely corrrect.  Browning would probably not bother with bore plating unless it was needed..  Still with large overbore capacities one must accept throat erosion as a fact of life and a cost of doing business at those levels.  Don't hotrod the 6.5x55 trying to create a 6.5-06 or a 6.5-06 into a 264.

[Siskiyou]

Some must tinker.  Let me assure you that the 6.5 addiction can be very controlling.  Kin folk has around a dozen 6.5 rifles built on a number of cases.  He is always calling me in the fall telling me about shooting bucks with one of them.  

A couple of years ago he brought out his 6.5-.284 Winchester.  With it he took both his bucks using 120 grain bullets loaded to about 3300 fps.  Cases have not been a problem.  I believe he bought bulk cases.  ( I have thought of building a .30-284 but decided against it.) Velocity is not his goal.  This year he killed a buck with a 6.5 Swede using 156 grain bullets.  The same load he used to kill two bucks with one shot twenty some years ago.

He even gave me a 6.5 Swede along with ammo.  First shot with it bagged a buck.

The other night he told me that he was building one on another case.  Clearly the enthused must be loaders.

Your M70 in 6.5 Swede is one of my dream guns.  As a reloader I would have a lot of fun developing a load for it.  My minimum goal would be the 140 gr. bullet, pushed by H4831 or H4831SC around 2800 feet per second.  This would be very effective beyond 400 yards.  But the "6.5 Whatever" is not my addiction.  Or is it!

Siskiyou

[taxmiser]

I designed an improved 6.5X55 rather like an Ackley Improved.  It made a great cartridge even better.  If your "smith" would like to use my reamer to rechamber your rifle drop me a note.  RCBS made me a half dozen sets of dies and the cost was about $90.00 each.
Dale

[RoyB]

I did just this. I bought a brand new Model 70 Featherweight in 6.5 X 55 and ran my 6.5-284 reamer into the chamber. Very easy to do and it feeds the 6.5-284 cartridges fine without any magazine or rail modifications. The velocity was greatly improved over what I was able to obtain from the 6.5 Sweed.  But was it worth it, in a word, no.  But then again, most of the rifles we build, we build for fun.  I just like having different calibers available and I already have a couple of 6.5 X 55 rifles.

[gunnut69]

If you think you'd like more horsepower than a Swede try the 264 Winchester..  There's enough capacity there to really turn the caliber into a long distance champ..  I really haven't found a need for anything hotted than a 6.5x55 but just had to have a 264 supergrade.  It truly is a thing of beauty and shoots pretty good, it can do better.  I'll rebed the action(that hot melt glop has to go) and perhaps the entire barrel...  I want to work a load for the 140 Nosler Partition.  The clasic featherweight was a purchase from a friend with a need.  It only shot so so with the first load I tried(from a 96 sporter I'd built) so I'll try something else.  I usually work up an accuracy load with the 120 grain Sierra for this round.  It is sometiems a little scarey.  The first one I built was manufactured nearly 100 years before.  The first load we tried( a hefty charge of 4831) with the 140 grain Sierra tried it's level best to shoot into a single hole...  We switched it to the excellant 125 grain Nosler partition for deer hunting and the owner was more than happy, except for one thing.  He likes to collect bullets recovered from game he's killed, the swede and the 125 noslers sdon't stay in deer very often...  I'm really not hooked on the 6.5,  I'm just hooked on guns, et al..