Cases trimmed too small

[jphares44]

I must be some kind of stupid. I got a new Little Crow Gunworks trimmer for 7mm Rem Mag, and when trying to get it setup, went a bit overboard on the first 3 cases, trimming way under the recommended trim length of 2.490". In fact, these 3 are under the SAAMI minimum and measure 2.472".

I guess my question is...did I just trash 3 cases? Are these safe to use? I was hoping to use these as foulers/blow-off's, loading them with a middle-of-the-road charge weight and seating a bullet at the neck/shoulder junction. Would anyone caution against this plan? How short is too short?

Also, this got me wondering...what do trim length differences do to performance and precision, if anything? Say most cases are right at 2.490", but several are at 2.485". Should I expect some kind of difference? I'm likely not a good enough shooter to see a difference anyway, but I'm curious the effects.

As far as the LCG trimmer, I got it setup pretty good, but noticed getting the trim length just right still depended a lot on me and using the "right feel" or the "magic touch" and maybe isn't as mindless/stupid-proof as the Lee trimmer I was using prior. I have a lot of cases that ended up +/- 1 or 2 thou from my target. If anyone has some magic sauce, tips or tricks, with the LCG trimmer I'm all ears.

Thanks!

 

[Vicomb]

I did the same thing! I went ahead and loaded, shot, resized and remeasured and eventually they stretched back over spec.

 

[jphares44]

I did the same thing! I went ahead and loaded, shot, resized and remeasured and eventually they stretched back over spec.

Yay, I'm not alone! That's good to hear, and sort of what I expected. They are definitely a little stubby compared to all the others so wanted to be sure I wasn't getting into some sort of "danger zone"

Thanks for the reply!

 

[Caseknife]

I'd mark the 3 cases with a sharpie, but otherwise wouldn't worry too much. If you cut half the length of the neck off, may have issues, but should be fine. Only really run into issues if the case is too long and not allowing the neck to release the bullet due to it being jammed.

 

[jphares44]

I'd mark the 3 cases with a sharpie, but otherwise wouldn't worry too much. If you cut half the length of the neck off, may have issues, but should be fine. Only really run into issues if the case is too long and not allowing the neck to release the bullet due to it being jammed.

Sweet, thanks! Yeah, I know when they're too long, that's another story altogether.

 

[Pickettpuncher]

I’ve read somewhere you could go .010 under the trim length and be fine. I’m sure you could go a hair more and be fine

 

[Caseknife]

Kind of like a haircut, it'll grow back

 

[Mtnmilsurp]

Have you ever measured factory load cases? I’ve found federal and hornady to measure.010 to .015 below SAAMI minimum for 6.5x55

 

[jphares44]

Have you ever measured factory load cases? I’ve found federal and hornady to measure.010 to .015 below SAAMI minimum for 6.5x55

Interesting, I have both Federal and Hornady cases laying around so I’ll have to take a look at that.

 

[BrBa]

Have you ever measured factory load cases? I’ve found federal and hornady to measure.010 to .015 below SAAMI minimum for 6.5x55

Most U.S. made brass for 6.5x55 is also undersized at the case head (.471 to .473), rather than the correct size of .480 like European brass.

 

[A382DWDZQ]

That’s fine. I have made some short necked 350 Norma Mag and 338 Win Mag when using 300 WM and 7remmag brass respectively. Both shot fine, great actually. I think the uniformity is important. So for those three, I’d probably fire them and then send two to Hornady to get tapped, and maybe use the other to make dummy rounds. Or you could trim them all to that size too, but three is not that many to repurpose.

 

[Vern400]

18 thou under? You might keep them separate for just general principle. But shoot the heck out of them.