Bullet tip modification

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by 4ked Horn, Jan 27, 2006.

  1. 4ked Horn

    4ked Horn Writers Guild

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    What would be the draw backs to modifying a SGK from a soft point to a HP? Am I correct that I could seat the bullets ogive closer to the lands and still be mag length? Do I need a soft point for deer, elk and black bear? (or would a HP be a bad idea?) How much would this affect the BC if I only went to the top of the copper jacket?

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  2. Buffalobob

    Buffalobob Writers Guild

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    Basically you can just buy a Speer grand slam and save yourself the trouble of cutting an filing. You lose about 0.08 of the BC by flattening the nose.
     

  3. davewilson

    davewilson Well-Known Member

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    Buff, i'm curious where you came up with the .08 number. it seems like there would be more of a deduction than that.
     
  4. Buffalobob

    Buffalobob Writers Guild

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    Speer manual #10


    308 cal 150 and 165 gr mag tip and grand slam vs spitzer. can be over 0.1 for the heavier bullets . So in a way you are right. Can be higher or lower.

    Don't know if they still manufactur these bullets but recognized the profile from 4ked horns drawing
     
  5. James Jones

    James Jones Well-Known Member

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    With the fact being stated that the BC loss is minimal then I'd go for it if you like the way the bullet performs .
    I'm not sure where but I read some plac one time that the basic ledad tipped bullets loose their tip after about 100 feet of flight anyway due to the heat build up being higher than the melting point of lead
    I though this was kinda BS because if that were so then at about 200 yds you would have a copper cup full of liquid lead !! , I don't think they took into account that modern bullets are not pure lead

    But hell if you like your current bullets performance then sure file the point off , but I personaly woulden't go through the trouble of making it a hollow point
     
  6. Buffalobob

    Buffalobob Writers Guild

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    At 600yds the reduction in BC will give you a velocity reduction of about 200fps. Winddrift will be increased by 6-8 inches. Any increase in accuracy from getting closer to the lands will be lost in the susceptibility to the wind and possibly bullet imbalance. All of this is so you can use your magazine and have avavilable a second and third shot? It seems to me you are trading three inaccurate shots for one accurate shot.

    Other consideration is all of this grinding of lead. With young children around, lead dust and shavings and filings need to need to be avoided at home. CDC has lowered the blood lead levels for children to about 10ug/dl and there are still adverse effects at this level.
     
  7. 4ked Horn

    4ked Horn Writers Guild

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    JD The bullet melting thing is a myth. If you held a torch on the tip of a bullet for 2 seconds which is a longer than normal "time of flight" it would not melt away. There is no way the air will get that hot that fast.

    Making it a hollow point is easier than filing the tip off.
     
  8. 4ked Horn

    4ked Horn Writers Guild

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    I'm going to set the bullets up to use the mag one way or the other. Removing the tip will let me move the front edge of the bearing surface closer to the lands by the length of the tip I remove. So that isn't really a trade off.

    I'm not excited about losing 200 FPS at 600 yards and I am concerned about the consistancy of drilling a hollow point. This alone might cause me to simply remove the lead tip and leave the end of the bullet flat. I will have to think about that.

    As far as the dust concern goes, I will be either drilling the tips or facing them on a lathe type set up. If my kids are going to ingest or inhale the lead they will have to chew it first. In other words I wont have filings or dust. It will come off in chips. So we are good there. A quick sweep up and all is well.

    Thanks for all the input. It is certainly giving me lots to think about.
     
  9. James Jones

    James Jones Well-Known Member

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    I figured that the lead melting thing was BS.
    What type of action are you using ? you may be able to get a new longer mag box of have your existing one lengthined
     
  10. Wild_Bill

    Wild_Bill Well-Known Member

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    Hi i am using my 7mm A Max bullets up for hunting in a 7mm SAUM and i get my Meplate uniformer and trim the tip off then i drill the plastic pin out of the centre they shoot well and i can seat them out to give me more capacity in the case and get the boat tail junction above the doghnut. You can get a Meplate trimmer from Kevin Cram afetr you trim of the lead level with the jacket you can use the internal deburer to hollow point your bullet the projectiles are verry uniform as the tools are for triming match bullets to have the same length so triming the lead of a huntiung bullet is easy and accurate . David tubb also makes one without the centre tool so you can flat point them using a batery drill we have also trimed Military FMJ bullets to just show lead then they can be shot on ranges where FMJ bullets are not able to be shot it also makes them expand and work like a soft point for hunting game like goats and pigs.

    Cheers Bill
    Australia
     
  11. 4ked Horn

    4ked Horn Writers Guild

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    Hey guys. Good news. I assumed that the factory chamber in my brothers .338 (and my nephews .243) was long like my .308. All 3 guns are Rem 700s. Mine is a VLS heavy. In my .308 I can't load to mag length and get anywhere near the lands. I was wrong, man was I wrong. I was prepping brass this evening and decided to try the "Bullet in a fired case" method of determining the COL. Well I got VERY consistant results this way and I also have PLENTY of room when putting these rounds in the mag. I won't worry any more about trimming the lead tips. If my brother has any concerns about deformed tips then he will just have to be careful with them. /ubbthreads/images/graemlins/smile.gif

    We can keep the high BC. We can keep the same terminal expansion. We can keep the same Sierra consistancy. And we can leave behind the nonsence associated with trying to accuately modify 100 bullets. /ubbthreads/images/graemlins/cool.gif

    Isn't that funny. I could have saved this concern if I had tried the chamber first. Oh well, another lesson learned. I just wish my .308 was chambered like this. /ubbthreads/images/graemlins/wink.gif