im a beginer and have a question about seating my bullets
12-27-2004, 04:34 AM
#11
Nontypical Buck
Join Date: Feb 2003
Location: Body in SE WI, mind in U.P.
Posts: 4,781
RE: im a beginer and have a question about seating my bullets
C.O.L.s are meaningless unless you can measure from the point on the ogive of the bullet that engages the rifling, so that you are making the same measurement everytime. A stoney point tool with oal and a bullet comparitor would be an easy way to get an accurate measurement.
12-27-2004, 07:15 PM
#12
Spike
Join Date: Dec 2004
Location: Oshkosh WI.
Posts: 19
RE: im a beginer and have a question about seating my bullets
I may someday get a stoney point OAL guage, but until then I use this method; I size a fired case just a little ways down the neck, just enough to loosley hold the bullet. You should be able to push the bullet in with your hand. Seat a bullet into this case with your seating die adjusted way back from where you would normally end up. Chamber this round with no primer or powder, the bolt should seat the bullet to where it would be if you wanted it to contact the throat of the rifling. Measure the bullet tip to give you the OAL,(over all length), of a bullet in contact with the beginning of the rifling. Now run that shell into the seater die, bring the seating stem down to contact the bullet. Turning the seating stem down further will give you an idea how much to turn it to get .010, .020, etc. from the lands.
12-29-2004, 12:36 AM
#13
Nontypical Buck
Join Date: Jun 2004
Location: A flat lander lost in the mountains of Northern,AZ
Posts: 3,171
RE: im a beginer and have a question about seating my bullets
Jp4,
even that method is about worthless too it will get you roughly in the ball park just like all the other methods but it wont be consistant, I dont know if you ever measured individual bullets from a package of bullets but the overall lengths of each bullet are not consistantly the same length. I have done this with sierra match hollow points being a match bullet you would think they would be the most consistant... Wrong I have had bullet lengths vary as much as .010 from the next bullet from the same package. You may be ok with Jp4's method with ballistic tips and FMJ's.
[quote] Briman "C.O.L.s are meaningless unless you can measure from the point on the ogive of the bullet that engages the rifling, so that you are making the same measurement everytime. A stoney point tool with oal and a bullet comparitor would be an easy way to get an accurate measurement." [quote\]
Briman is completely correct about the COL, But if you have a good load precise COL doesnt really matter. All COL adjustment is good for is to tighten up your group that last 1/8th to a 1/4 inch. with my match 308 loads there is no real difference in groups size between 2.770 and 2.800 COL with both COL's my groups at 100 yards are so close in size you cant tell both groups look like a ragged 30 caliber holes.
even that method is about worthless too it will get you roughly in the ball park just like all the other methods but it wont be consistant, I dont know if you ever measured individual bullets from a package of bullets but the overall lengths of each bullet are not consistantly the same length. I have done this with sierra match hollow points being a match bullet you would think they would be the most consistant... Wrong I have had bullet lengths vary as much as .010 from the next bullet from the same package. You may be ok with Jp4's method with ballistic tips and FMJ's.
[quote] Briman "C.O.L.s are meaningless unless you can measure from the point on the ogive of the bullet that engages the rifling, so that you are making the same measurement everytime. A stoney point tool with oal and a bullet comparitor would be an easy way to get an accurate measurement." [quote\]
Briman is completely correct about the COL, But if you have a good load precise COL doesnt really matter. All COL adjustment is good for is to tighten up your group that last 1/8th to a 1/4 inch. with my match 308 loads there is no real difference in groups size between 2.770 and 2.800 COL with both COL's my groups at 100 yards are so close in size you cant tell both groups look like a ragged 30 caliber holes.
