Join the #1 community for gun owners of the Northwest
We believe the 2nd Amendment is best defended through grass-roots organization, education, and advocacy centered around individual gun owners. It is our mission to encourage, organize, and support these efforts throughout Oregon, Washington, Idaho, Montana, and Wyoming.
for revolvers,only if shooting cast bullets,where you will be crimping into the crimp groove IF there is a huge difference in the case lengths.
For autos that supposedly head space on the case mouth,more important.
some say the above is a bunch of hooey and trimming cases is never needed.
I like mine the same length because anything we do to make things consistant aids n accuracy.
I trim my revolver brass to ensure a consistent crimp. I have noticed variations in case lengths of .010", I have better results when cases are +or- .002" in length . I have vary rarely trimmed rimless acp brass.
Think of it this way. Would you reasonably expect anything mechanical to run well if it's components are "out of specification"? As stated above, revolvers are less of a problem except for crimping issues if you let your brass get a little too long. However, autoloaders are more sensitive to the issue, and I have experienced problems with feeding .44 mag revolver cartridges through a lever-action carbine when I hadn't paid close enough attention to case length. Keeping your brass "spec" just makes for better quality and more dependable ammuntion feeding.
It may not be necessary to trim your cases, but you have to check first! Because I don't run most of my .45 ACP loads at "Full Throttle" I've rarely if ever trimmed any, but I do check them. My magnum revolver loads will need attention more often, and the bottle neck rifle case even more so.
You need to keep the case length consistent, but you gotta check 'em first.
The quickest way to check the case length is in the trimmer, LOL.
I think the reason hand loads sometimes get a bad rap is lack of attention to detail. With that attention, we can turn out better loads than the factory - more consistent.
The above posters are right on. It's your crimp die which won't index properly and consistently with different case lengths. Cannelure or not, you won't get a consistent crimp. With revolvers, that can allow bullets to pull out on recoil. With autos, it can even set them back. Let's not even talk about high powered rifles.
Trimming and lightly chamfering is just part of the fun of reloading.
$.02
PS If your case is too long, the crimp die can actually "bell out" the whole case causing feeding and extraction problems.
If our Supporting Vendors don't have what you're looking for, use these links before making a purchase and we will receive a small percentage of the sale