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Thread: Weird Groups from bullet tip deforming during feed. 350 Rem Mag

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    Member Float Pilot's Avatar
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    Default Weird Groups from bullet tip deforming during feed. 350 Rem Mag

    I was experimenting with some heavy jacket (.050) HAWK bullets today in the 350 Rem Mag.

    They use a very soft lead core and tip. They shoot just fine when loaded singles into the chamber, ,,,,

    HOWEVER,,, look what happen when they were fed via the magazine. The lead tips get whacked due to the crappy Ruger feed ramp. (which I already improved by a great margin)
    And they fly off in a predictable pattern depending on which number they are in the magazine.

    I then loaded some soft tip Speer 250 grain spitzers and the same thing happened. Here is a photo of the groups and the numbers show which shot it was.

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    Member marshall's Avatar
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    I can't dispute your ramp issues. I have 4 Ruger's and I tweaked the ramps on all of them out of boredom.

    It seems a bit strange that your shooting a 2" group with each different load and putting each load and number sequence in virtually the same location.

    All of mine shoot pretty **** good. If there is one thing in common with them it's that they climb slightly high and right after 4-5 shots and only about a 1/4" from the first shot.

  3. #3

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    Weird is right! How does that pattern compare with single feeds?

    No real comparison, but I'm shooting .429 and .458 Hawk FNs from leverguns with peep sights and I don't see patterns like that related to firing sequence. Maybe if I scoped them, but.... Nah!

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    Moderator hunt_ak's Avatar
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    Wow, that is bizarre....do you have a picture of a single loaded 3-shot group of the same bullets.

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    Supporting Member Amigo Will's Avatar
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    Truth is those are not that bad of groups for hunting. I believe you will get them better still
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    OK here is the exact same load, shot as singles.
    I received one e-mail suggesting that maybe the COL was being changed by the recoil. Thus all the rounds were a different COL. That might explain it....

    But it sure was tearing up the tips. The first round from the mag had a big piece of lead that was hanging off to one side.

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    That's an interesting possibility, especially if the deep seating for a 350 is getting down into the orgive.

    I was kinda wondering about how much influence nose deformation would have, especially at only 100 yards, but hadn't considered bullet shift. The regular pattern sure could bear that out, as each successive shot results in more movement of the round in the bottom of the mag.

    BTW- Back to the nose deformation issue, my light 375 can really flatten the noses on the bottom rounds, to the point that I have to use heavy crimps to stop bullet movement and not run through several mags while leaving one round in the bottom. If I don't shoot the last round I always eject it and shoot it first in the next batch. But with all that nose changing going on, I don't notice any change in group size or POI at 100.

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    Member hodgeman's Avatar
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    I had a lightweight .308 that would occasionally batter tips of rounds in the mag... but it didn't substantially chage POI.

    Have you tried measuring overall length of a round after being in the mag for a few rounds as opposed to the length at loading? Might be an interesting check and relatively easy to do.

  9. #9

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    I'm wondering if those tips are getting deformed from recoil so that they are blunt before they ever get shoved up the feed ramp and one is complexing the other.

    I also used a heavy crimp when I was shooting the 350 mag. if not they did get seated a little deaper from the recoil.....but not all the same.

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    Member Float Pilot's Avatar
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    Here are most of the bullet types I have tried in this rifle. Oddly enough it seems that the 357 diameter bullets seem to group better in this rifle than the 358 or larger.

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    Member AKDoug's Avatar
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    Just curious. What kind of groups do you get when mag feeding vs. single feeding the FTX and Ball-Tips since they really can't be deformed?
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    Member Float Pilot's Avatar
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    The
    Barnes TSX 200 gr, smooth chambering but shows high pressures
    The Hornady 200 grain flex tip, loads with no troubles, but can't take high velocities.
    Speer 220, occasional hang up, but good when loaded short.
    Sierra 225, smooth loading
    Nosler Ballistic and Accubond tip 225 grain is really not right for the 350 as the ojive starts too soon.
    The old Hornady 250gr round nose, very little exposed lead.
    and the 275 grain Barnes (no longer made)

    All feed reliably and have no difference in the groups between mag loading and single loading.
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    Premium Member MarineHawk's Avatar
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    I haven't done any personal expermiments on this, but Wayne Van Zwoll did and found that you can mangle the point of a bullet, as long as you don't mess with the base, and will see fairly small deviations, if any, at 100 and even 400 yds: http://books.google.com/books?id=dN2...page&q&f=false

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    Member Float Pilot's Avatar
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    I am going to see if it was a change in the COL or tip mangling.
    The Hawks were getting big chunks of lead partially cut off and the pieces were hanging off to one side. It can't be good to have a stray piece of lead in the bore. Plus I can't see that anything hanging off to one side of something that spins can't be all that great for accuracy.
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    Premium Member MarineHawk's Avatar
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    Quote Originally Posted by Float Pilot View Post
    I am going to see if it was a change in the COL or tip mangling.
    The Hawks were getting big chunks of lead partially cut off and the pieces were hanging off to one side. It can't be good to have a stray piece of lead in the bore. Plus I can't see that anything hanging off to one side of something that spins can't be all that great for accuracy.
    I've never seen anything like that before, but yes that should screw up your POI.

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    Member Diesel Nut's Avatar
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    I would agree that lead randomly pushed off-center will certainly impact your groups somewhat, but the biggest factor I see here is the repeatable change in impact location. Mangled bullet tips are not uniform, and the group placement is...this has to be a repeatable (read "measurable") change somewhere, and I'd almost have to believe it's the bullet seating depth...

    If you neck-size, a quick trick would be to try a slightly tighter collet and see what happens.

  17. #17
    Member Float Pilot's Avatar
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    These are full length re-sized. These loads are not all that brass friendly.
    I polished the expander ball down so the neck to bullet fit is pretty tight. I cannot find a Lee Factory Crimp Die for the 350 Rem Mag, so all I can do is try a limited roll crimp since the cannelures never end up in the right place.
    I will try some more experiments tomorrow.

    The tip mangling, while probably not the problem is oddly repeatable. It has to do with which side of the magazine the bullet comes up onto the fed ramp. I made up some dummy rounds and the tip damage repeats itself. (with the bullets that are effected)
    The ojive shape on the other bullets lets them slide right it.
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    Member Diesel Nut's Avatar
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    Here's more data to further muddy the waters...

    http://www.theboxotruth.com/docs/bot49.htm

    I look forward to further testing FP, as this is something I've been interested in for awhile. I'm fairly certain I'll have similar issues with my .375 H&H if (when) I develop loads for an exposed tip bullet.

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    Quote Originally Posted by Float Pilot View Post
    OK here is the exact same load, shot as singles.
    I received one e-mail suggesting that maybe the COL was being changed by the recoil. Thus all the rounds were a different COL. That might explain it....

    But it sure was tearing up the tips. The first round from the mag had a big piece of lead that was hanging off to one side.

    That is a great shooting load. I hope you get it sorted out with the tips or seating issue. That 350 seems like a great shooter! Scotty
    Semper Fi

  20. #20
    Member Float Pilot's Avatar
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    It did group OK when single loaded, but nobody else noted that the group moved over 2 inches and off the diamond target.

    While it is not this rifle, I dramatically changed the accuracy of a 6.8mm SPC AR carbine just by changing the feed ramps.

    Here are before and after groups with the feed ramp being the only thing changed.
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