View Full Version : Winchester action thread 1.062"X28TPI
I dismantled a new M70 classic SS in 308Win today for truing and bolt body bushing and I discovered the barrel thread to be 1.062" with 28 tpi. I am wondering why Winchester went to such a fine thread on the tenion. I have two guesses as to why, #1: to make the chamber stronger by not only moving up from the normal 1.000" to 1.062" but also with shallower threads. guess #2: To allow more room for error when cutting/locating the extractor cut in the barrel.
What do you think??
01-23-2010, 11:05 PM
You guess is as good as mine.
I do have a question for you. A good friend just bought a new Model 70 in 300 WSM. It shoots so bad, he has decided to install a custom barrel.
My question is, how tight was that Factory Winchester Barrel. He asked me about helping him get it off. I have one of those big Brownell Barrel Wrenches........jackie
01-23-2010, 11:48 PM
I'm not sure why they did it but fine threads are stronger so they have a higher torque capacity as well as it leaves more solid material on the barrel. IMO its a win-win situation, theoretically speaking, although in the real world I don't think you would ever see a ounce of difference.
If I were designing it I would have made it like that from the start but I wouldn't go back and change the blue prints at a later date.
The M70s in the WSSM cartridges have that same thread. This is the first I've heard about the new FN made M70s.
I use a homemade barrel wrench that uses PVC sleeves so as to not mar the barrel. That wouldn't grip it though. I made an aluminium sleeve and that would grip enough but the barrel still woulden't budge ( it would have with a long cheater but you reach a certian point and you wonder what's gunna give next) so I added a little heat with a propane torch, applied alot of torque and a smart blow with a 5 pound hammer and it came right off. Some form of locktite on the threads. I must say I'm impressed with this new Winchester, full length aluminium bedding block, a half a** bedding job, nice one piece trigger gaurd/floorplate and a enclosed trigger assy. (time will tell if thats better, but it sure breaks nice).
01-24-2010, 09:54 AM
I found the same thing on my new Coyote and what I was able to find out they changed the threads because there was chamber issues with the new short magnums. Apparently they had egg shaped chambers and there wasn’t enough support in the one inch tendon for those calibers. Also the larger fine thread was to eliminate the interrupted thread that all the Winchesters have. I cannot positively verify all this but this is what I found in my research. The one I have was of the last production Winchesters before the went belly up and it is a Std. . . . 243 Win. never have been able to get this thing to shoot.
01-24-2010, 12:47 PM
I have one of those and had to use a little heat to get it to break. On the 300wsm's you will find that the idiots broched the threads out when they cut the raceways.I was having the same accuracy problems until I recut the action threads deep enought as to have threads.there were hardly any at 9 and 3 o'clock. The rifle now shoots very well and is consistent
01-28-2010, 03:50 PM
Maybe following , or close to , the thread patterns of the Browning products???
01-28-2010, 05:25 PM
I have a winchester coyote chambered id 300wsm I am wondering if there are any of the custom actions using the 1.062" with 28 tpi thread. If one was to look for a used bench gun barrel what manufacture would you look for?
01-28-2010, 09:10 PM
Many Custom Actions, (Panda, Batt, Stiller), feature a 1.062 18 tpi, I don't know of any finer than that.........jackie
01-29-2010, 12:27 AM
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