Q: I have started reloading for a Marlin .30-30 but have struck a problem with cases collapsing during the bullet seating/crimping operation. Can you tell me where I am going wrong?
Alan Lewis
A: There are several possible causes of your problem. Because it is necessary to crimp loads for tubular magazine use, it is essential that cases all be of uniform length. A too-short or too-long case will result in a crimp that falls below or above the bullet crimping groove. When this happens, the shoulder of the case may collapse during the bullet seating/crimping operation.
A case length of 2.035” plus or minus 0.003” is about right. Maximum allowable case length is 2.040”.
Another possible cause of your problem, but less likely, is one I once encountered with bullets whose cannelure was no more than a series of serrations on the bullet. It proved impossible to crimp them, as any attempt to do so resulted in collapsed shoulders.
Also, take care to adjust the crimping die so that the case mouth is forced no deeper than the cannelure depth allows. An unduly heavy crimp will reduce bullet pull, possibly cause collapsed shoulders, and result in poor accuracy.
Because .30-30 brass quickly stretches when fired in lever-actions, case length should be checked after every sizing. And because chambers can be less than perfectly round, it pays to full-length resize. Finally, after your cases have had their third trim, discard them.
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