Trimming Brass

[fishnbob]

I'm fixing to begin reloading 357 mags for a rifle for the first time and it dawned on me that I've never trimmed the brass for my pistols, do I need to trim them for a rifle?:?:
Is case length as critical in pistol caliber rifles as bottle necks? Where does the headspace occur in a straight wall pistol case in a rifle chamber?

[versifier]

Headspace is the rim thickness on any rimmed straightwall case. If any stretching is to occur, it will happen at the same place on the head where the web thins on rifle cases.

I do not believe I have ever trimmed any handgun case in over thirty-five years of stuffing cartridges.

That does not mean I never check them. I do handgun rounds in large batches and I always measure a few dozen grabbed randomly in every batch after sizing, usually while inspecting for neck cracks. (With bottleneck cases I measure all of them, every time.)

I would be willing to bet that there are some lever rifles out there wherein the cases might stretch a bit over time, even if I have yet to meet one personally. The two gents I know who shoot cowboy action both use only .38specs in their revolvers & rifles and neither ever has any problems with case length. I don't know if that is why or if they just prefer to use the abundance of free .38spec cases from the range bucket instead of buying .357's.

[Paul B]

Probably the only reason to trim handgun brass would be if crimps were affected. If on case made a really deep crimp and the next one a shallow crimp then that could/would be a problem. I haven't run into that in 54 years of reloading but the only handgun chambered rifle I ever owned was a Marlin M94 and crimps were OK with several brands of brass.
Paul B.

[fishnbob]

Thanks gentlemen, you have both answered my question. I also went over on Cast Boolits side and searched threads and came up with a wealth of info & reasoning. I have been reloading rifle since 1964 and guage each case before reloading and I started reloading 38's in about 1975 and always checked a few as versifier said and never had to trim one. After I asked the headspace question, it came to me that straightwall cases headspace on the rim as I was driving back home. Lapse of memory, it happens more & more frequently.

[j1]

Not me I never forget anything, I think. If you forgot it how would you remember that you forgot it?