"Slugging the Bore" question

Discussion in 'Ammunition & Reloading' started by Professor, May 1, 2014.

  1. Professor

    Professor New Member

    77
    0
    0
    I'm still playing with my 7.65 Argentine Mauser (also called Belgian Mauser) and researching how to reload ammo for it. Because of it's age, I want to slug the bore instead of "guess" on bullet diameter. My basic question is how to best slug the bore:

    Method #1: Someone I know has suggested the following method, using low-melting point lead. The first step is to block the bore using something tight fitting such as a disposable ear plug. This ear plug is inserted into the muzzle and then pushed down the barrel about 5 inches. Next, molten lead is then poured down the barrel and forms a "slug" on top of the inserted ear plug. Then this slug is then pushed thru the barrel using wooden dowels until it comes out the other end (chamber). - Will this method work? (I have never heard of this method before.)

    I have further been advised to get BOTH measurements from the slug, the lands AND the grooves, and that the final bullet diameter should fall BETWEEN those two measurements. Any advice? Thanks!
     
  2. Professor

    Professor New Member

    77
    0
    0
    I forgot to mention that my concern is that the slug formed by the molten lead will contract (smaller diameter) as it cools to room temperature..
     

  3. seancslaughter

    seancslaughter New Member

    1,714
    0
    0
    Take it to a gunsmith and have them do it it's safer


    Sent from my iPhone using Firearms Talk
     
  4. JonM

    JonM Moderator

    20,110
    12
    38
    Dont pour molten lead in a bore it will make a mess like you have never see before... And thats IF it does not explode in your face when it hits a spot of oil...

    To properly slug a bore soft lead like a fishing weight is greased and the bore is greased and the lead weight is forced from the chamber end out the muzzle .
     
  5. jpattersonnh

    jpattersonnh Active Member

    5,360
    3
    38
    It should be an egg shape close to the bore diameter!
     
  6. JonM

    JonM Moderator

    20,110
    12
    38
    Couple of other things about molten lead. It melts a scootch over 620F to keep it molten enough to pour it needs to be around 750-800F. If you pour molten lead into a clean metal container it will stick like glue. For lead to come free from steel or aluminum it needs a coating of carbon like you get from burning a match under steel or aluminum leaving soot behind.

    Next problem is your spot on about shrinkage. It will shrink as it cools giving incorrect readings.

    Next problem is whatever you plug the bore with will melt or burn under the 700+degree heat. Instantly.

    Next problem is that it only takes about 400-600F of heat to start damaging hardened steel through annealing. Pouring 700F+ degree molten lead IF you can pour it without it silver dragoning yourself, IF you can keep it n the barrel, IF you can get it out again, IF you can pour it without damaging the barrel steel, IF you can get it to mold without shrinking you have worked a miracle.

    It only takes a tiny drop of water or oil or any liquid for the dragon to appear. In the video below he is tossing water from a long way off into only a tiny bit of lead. If you get that stuff on you it will eat you to the bone. Not something to mess with lightly.

    [ame]http://m.youtube.com/watch?v=sn3oChBpeUw[/ame]
     
  7. JonM

    JonM Moderator

    20,110
    12
    38
    Yes definately. I didn't have a lot of time when I wrote the first reply.
     
  8. Professor

    Professor New Member

    77
    0
    0
    I have to agree with the above posts....especially the comments about molten lead running down the bore. Glad I asked the question. Thanks
     
  9. seancslaughter

    seancslaughter New Member

    1,714
    0
    0
    From my quick google search it seems a lot of argentine reloaders use .312 150 grain hornady sp 3120 as the bullet


    Sent from my iPhone using Firearms Talk
     
  10. jd45

    jd45 New Member

    173
    0
    0
    Whoever advised to split the difference between the land diameter & the groove diameter to get your optimal bullet diameter is off the mark, IMHO, cause if you go with that dimension, the bullet won't be completely filling the grooves, which I'd think, is what you want for best accuracy. If I'm wrong, someone please correct me. jd45
     
  11. Professor

    Professor New Member

    77
    0
    0
    I may have misunderstood...or I may have repeated it incorrectly. According to the advice I was given if bullet diameter is LARGER than groove diameter (too tight a fit) it can lead to dangerously high pressure. So...perhaps bullet diameter should be the same as groove diameter but must not be more than that? Any thoughts?
     
  12. JonM

    JonM Moderator

    20,110
    12
    38
    it needs to be a scootch over the groove size. usually between .001 to .003 over. this seals the bore just enough to build pressure safely. the tighter the fit the more pressure builds thats the reason for starting with light powder charges and working up. each bore even when made one after the other on the exact same machine can be slightly different.
     
  13. Professor

    Professor New Member

    77
    0
    0
    Thanks, nhsuper44. Live Free or Die, indeed.