Quick question

Discussion in 'General Rifle Discussion' started by rugrat2553, Dec 26, 2009.

  1. rugrat2553

    rugrat2553 New Member

    Hello, I have a .300 wby mag that was just returned to me from a friend that hunts (I dont). With the gun he returned a few shells with it. Upon inspection it appears that he is/was using .300 win mag shells in my wby.

    I am asking if the .300 wim mag shells could have hurt my wby. I know that the wby is a larger shell than the win so the casing should have expanded to match the chamber.

    I dont have any way to look into the bbl where the shell would have expanded but if needed I can take it to the local gunsmith.

    The person will never be using the gun again.

    Thanks for the help.
  2. Ram Rod

    Ram Rod New Member

    Well, your question has gone unanswered long enough. I hunt them down every once in a while just for fun. Anyway.....here's what I think about it. If it were me and my rifle, there would be a 50/50 chance that I'd still call him a friend. Second, you may play as much a part of this ordeal because you failed to give proper instruction with the rifle, or you might have provided him the correct ammo for it. No matter, what's done is done.
    In my opinion here.... first depends on how many rounds were fired....with the shorter OAL of the 300WM in the 300WBY chamber dimensions, part of the chamber and the throat for sure took a peppering of hot gas and burning powder. That and the 300WM bullet's extreme jump to the rifling of the 300WBY may have pitted your barrel in the throat area. To what extent we could only guess. The hotter steel becomes, the softer it gets, so quite a few factors will figure in as to the amount of damage if any. I'm going to leave you with an image comparison of the two cartridges at the end of this reply. I don't have the exact dimensions at hand, but again....that's immaterial now since we both know they are different...very different. My best advice is to take it to a gunsmith.....I'm an aspiring gunsmith myself, and still gathering tools. Have your rifle checked for headspace first of all. Then if things are not right, the barrel will likely need to be removed and some work done. If you custom reload for your rifle, you may be able to overcome a certain amount of damage depending....since you can run out your OAL according to your specific chamber/leade over what the generic OAL is in factory ammo. If this is not the case and you only use factory ammo, and the amount of damge is negligible, I'd almost bet your accuracy will have changed somewhat. Again....no idea as to what extent. And everything might be alright as far as we know now. As far as the 300Wm expanding to your 300WBY chamber dimensions, I don't think it would have happened without a total blowout of the case, or a stuck case. Obviously your bolt did a heck of a good job supporting the cartridge and aligning it with the bore. Rifles of that caliber (double meaning here) should do just that. I know I'm not of much help here, and I still think you should take it to the smith to check before you use it again simply for safety reasons. Have you tried chambering a new 300WBY cartridge in it yet? You might also try that, then inspect the cartridge once it's ejected to see of there are any marks or scratches on it....bullet or case especially around the neck. Heck...if one of your cartridges won't even chamber or the bolt won't close all the way, then you'll know for sure you're in for some work and $. I would have your irresponsible friend (nothing personal here, but I hope you don't mind me calling him that) pay for it somehow. Personally, I have never loaned out a firearm of mine to anyone for good reasons, and I doubt I ever will. Best of luck to you, and I sincerely hope your rifle is as okay as the day you bought it.

  3. stalkingbear

    stalkingbear Well-Known Member

    I just now saw this post. The amount of rounds fired when hunting will be a LONG way to being enough to hurt your rifle. The .300 win ammo loses some pressure when expanding to fit the .300 weatherby chamber. That would offset any question of pressure. In short-it didn't hurt your rifle. I'm just suprized the cases didn't fail when expanding to fit the chamber.
  4. rugrat2553

    rugrat2553 New Member


    Thanks for the replies. I dont think that there were many shells fired through the gun. I do know that he will never be using any of my guns again.

    I was amazed when I saw the casing of a spent .300WM after expanding to match the chamber. The attached image shows a .300 MW round, empty casing, then .300 wby in that order.

  5. dteed4094

    dteed4094 Member

    300 w??

    I'd like to see a picture of a fired 300 WM next to an unfired round. Just out of couriosity.
  6. M14sRock

    M14sRock Active Member

    Many years ago a friend of mine had a Win Mod70 pushfeed in .300Wby. He did not believe me when I told him it was a .300 WEATHERBY MAG, and not to use .300WINCHESTER MAG ammo. He shot almost 40 rds of WinMag ammo through it, before he came to understand what I was telling him. His rifle was fine. He sent it back to Win service dept and they said it was fine for the same reason that StalkingBear stated in his reply.

    The cases did not blow, but they fireformed to fit the Wby chamber, just a bit short.

    I ended up buying his rifle from him and used it for a few years with no issues at all.

    Have yours check out and don't loan it to anyone again.
  7. rugrat2553

    rugrat2553 New Member

    Edited: Cant find delete button.
  8. cpttango30

    cpttango30 New Member

    Hey a new cartridge. The new fancy 300 weatherby short neck mag.

    It give you over even bullet release from the case.

    I too don't think it did any damage. But, if it were me I would still head over to a buddies house with a bore scope and look at it. For you if you don't have rich friends like I do then take it to the smith.
  9. Jpyle

    Jpyle New Member

    I've no knowledge of reloading or casing performance at all but that picture looks dangerously close to a catastrophic failure. What would have happened had that casing fully expanded, i.e. if the shoulder on the .300 wby had been 1/16" higher? Would the round have squibbed in the barrel?
  10. 753X0

    753X0 New Member

    Don't worry about it. At those # of rounds, it won't bother anything.
  11. masterPsmith

    masterPsmith New Member

    I'm a little late chiming in on this one, but, I agree totally with Bear. No damage...............