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What would cause my bullet to do this????

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10 July 2004, 19:08
Mrgunslinger
What would cause my bullet to do this????
I am shooting cast bullets from a lyman mold.
They are 40 cal 175 gr.
I size them to .401 after tumble lubing them and then lube again.
At 11 yds 8 out of 10 will key hole.
I am thinking either they are sized to small or to big,dont know. Thats why I am asking!
Or do they need lubed better?
Or what would cause this?
Thanks!!!!!!
10 July 2004, 22:53
jh45gun
I would guess not big enough or maybe two heavy of a bullet to stabilize. Or not enough powder to stabilize? You shooting these in a pistol or a rifle? You need to add more info. Jim
11 July 2004, 01:28
felix
The boolit is not spinning correctly. Barrel too small up front, or boolit too small towards end of barrel. Clean the barrel excessively, getting rid of all copper/lube/lead. Shoot 5 or a clip full. If keyholing still exists, then the boolits are too small in diameter. Keep in mind the boolits can be knocked out of kilter by their slamming into battery not straight on. A longer boolit will prove this problem. Have several 200 grainers on hand for a check out. ... felix
11 July 2004, 02:54
Junior1942
Try not sizing them. Shoot them as cast.
11 July 2004, 18:32
ffffg
try the green hill formula, given me by mr brooks a mold maker in butte montana.. maximum lenght= 150 x diameter x diameter/divided by the twist rate.. this will give you the maximum length of bullet for the twist your using before it will start keyholing.. i have a drilling and the bullets that i used at first were sized down from .366 to .361.. the lube was sparse, the sized down off center, the leading was severe, accuracy was good, no key holeing.. the bullet weight is 200 grains for the .360 caliber... your 174 grain bullet doesnt seem too long but you didnt give the twist rate.. put a very tight patch in the gun push it down until it makes one revolution (or half rev X 2) and measure how far it went down. if it is not the twist rate there has to be other clues to the problem, excess pressure, leading, etc?? a bad base or nick in the crown will cause a off course push also..
dave
12 July 2004, 01:06
Bad Ass Wallace
I am geussing that you are loading them in a 38/40 Winchester. If an old M92 the bore may be very worn and oversized. Try lubing and shooting as cast. My rifle is made in 1896 with a excellent bore but prefers that Lyman bullet unsized .4032. Sized to 401 some show slight tipping on paper targets.
12 July 2004, 17:35
Mrgunslinger
I am shooting a 40 caliber glock.
13 July 2004, 07:34
45 2.1
Load and alloy hardness? 40 S&W or 10 mm?
13 July 2004, 08:23
z1r
Could be polygonal rifling.
13 July 2004, 08:29
sundog
z1r, took the words right outa my mouth. Also, is not the 175 on the light end for a .40? I'd try a cast friendly after market barrel and same or a little bit larger boolit. sundog
13 July 2004, 08:29
BAShooter
Mrngunslinger,

Check the crimp diameter. An exccesive crimping sizes the bullet. I saw this effect in a 1911 .40S&W Caliber with cooper plated bullets.
Effect must be worst with plain cast bullets because sliding surface is softer than cooper plated.

Hope this helps

BA Shooter
13 July 2004, 14:52
fredj338
If you are shooting cast bullets from your Glock w/ poly. rifling, they need to be very hard. The dia. of .401 should work. I shoot the same bullet from an H&K & S&W 40s & accuracy is almost as good as jacketed. Again the bullet needs to be very hard alloy, push them to at least 900fps & they should shoot.
14 July 2004, 07:29
scot
Don't mess with cast bullets in a Glock. It won't work right. They do tell you that in the instructions. They are not kidding! If you must play, get a conventionally rifled barrel.