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Posted: 4/6/2009 6:03:03 PM EDT
| I just received a batch of 30 cal 150gr FMJBT bullets. I noticed that the cannelure is approx .05 in more toward the tip of the bullet then the Lake CIty 150 FMJs I have been using. When the bullet is seated to the correct OAL the end of the case is well below the cannelure when previously it was at the cannelure. Should I just shoot them like this? Thanks much. |
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The meplat of the two bullets in relation to the cannelure is not as important in the internal ballistics scheme of things as is the distance from some point on the ogive (that point that strikes the lands first on the way out) to the cannelure. If the new bullet has a different ogive profile then the change in cannelure could be correct.
Then, the other important restraint on O.A.L. is the maximum length that can be fed through the magazine and autoloader. Depending on the end use of the rounds you are going to be assembling, you might consider ignoring the cannelure, not crimping at all, and setting the O.A.L. to control the jump-to-land distance (provided it is below the suitable magazine maximum). |
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The cannelure is located............where the bullet manufacturer wants it.
Then, the various manufacturers vary as to where............they want to put it (on what some may call a "generic" bullet). And, sometimes..............from the same mfn for the "same" bullet............it varies where it's located (lot to lot variations). YMWV. Aloha, Mark |
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