Bullets tumbling?

Discussion in 'Range Reports' started by Tommycourt, Feb 14, 2016.

  1. Tommycourt

    Tommycourt Tommycourt

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    Today was my range day and as usual I headed toward the range and fired approx. 130 rounds. As many of you know, presently I have been using Power Pistol powder, 230gr RN Berry plated bullets and Winchester large primers. My powder load of Power Pistol is :6.7-6.9 grains. I have noticed this before on my targets using the Power Pistol powder vs. TiteGroup. The holes from Power Pistol seem to be elongated whereas the TiteGroup holes are perfect circles. I measure powder on every shell I load so I can maintain my consistancy. Accuracy also seems a bit different from TiteGroup. The TiteGroup tends to have a slight tad of better accuracy. Does the oblong holes indicate that my rounds are starting to tumble or "boat tail"? This is not a 1 time thing, I have noticed this quite a bit lately. I have noticed this from 28 feet to 40 feet distance. Beyond that the targets really get fuzzy with these old eyes. Any explanation would sure be appreciated.

    Tommy
     
  2. gunslinger669

    gunslinger669 Active Member

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    Keyholing can be caused by several things(never heard it called boat tail- I only know that to describe the rear shape of a bullet)- severe barrel fouling, damaged rifling, under powered loads, weak crimp over slow burning powder, striking something during flight or a disparity between bore and bullet diameter.

    Having "listened" to your posts, I'm pretty sure we can rule out barrel fouling, under powered loads or striking something in mid-flight.

    Have you slugged your barrel to learn the bore's true diameter? Put a micrometer on the bullets?
     

  3. VThillman

    VThillman Active Member

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    In this here case, first thing is to add to the history. If you haven't shot any of the Titegroup loads lately, you need to - to see if they have started keyholing too. If they don't, that takes the gun almost out of the picture and gets the history up to date.

    Power Pistol is Pretty Popular Powder (couldn't resist that), and you have triple-checked the charge in the manuals, so it oughta be something else causing the boat to tail, eh?

    :cool:
     
  4. phideaux

    phideaux Well-Known Member Lifetime Supporter

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    It is a mismatch of load criteria, bullet weight , and charge , type of powder.

    Bullets too heavy for twist, will not stabilize.


    IF the rifling is good in bore.

    and yes....PPPPP....VT.


    Jim
     
  5. Tommycourt

    Tommycourt Tommycourt

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    I thank you guys for your input. I have fired the TiteGroup which was last week and NOT getting any oblong or "key-holing" rounds but did with Power Pistol. Possibly the amount of powder used is not sufficient enough to stabilize the bullet and thus wiggling down range. I really do not care to increase the amount of powder used although the powder difference between Power Pistol and Titegroup is substantial. 5.4 grns. for TiteGroup and 6.7-6.9 on Power Pistol. I really need to save my pennies and invest in a chronograph and will try to do that and give me a better idea of fps. I still have a good 3lbs of Power Pistol yet but since these are range rounds, I am not going to worry too much about the key- holing. I remember years ago we had this problem with 185grn SWC but can't remember what we did to fix it. One other problem I have is we have very little ground in where we can set up a chronograph because what is not considered Reservation ground, the BLM has confiscated and don't allow any shooting. Politics as usual. Thanks all for your suggestions and help and I will continue to work on straightening this out. Very much appreciated!!!!

    Tommy
     
  6. VThillman

    VThillman Active Member

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    If it's any consolation... early on in Vietnam, there was evidence that M16 bullets were keyholing after they got out there a ways. The troops were not complaining - for fairly obvious reasons - but I vaguely recall reading that replacement guns had a faster twist in their barrels.