Cases trimmed too SHORT - problem?

[tl_3237]

Can anyone advise what are the potential untoward effects of using cases that are trimmed too short?

I recently scored some once fired 35 Rem brass after months of searching. Having a brain fart (at my age they are coming more frequently) I misread the case length as 1.902 instead of 1.920 soooo, my cases are now trimmed to be 0.020" shorter than max (ARRGH).

I am loading 37.5 gr H380 behind a Lyman cast 358315 with gas check.

We all know the pressure danger from LONG cases but what about SHORT cases?

Are these safe to fire?

[Tim Ault]

You'll be ok ,but you may not be able to crimp in the proper location on that cast bullet.Just seat to your normal OAL.


Tim

[knight0334]

Pressures with shorter cases are more of a concern than longer cases with the same powder load. You'll increase pressures if you seat the bullet at the same depth in the case as you would the longer case. You can compensate for it by seating the bullet shallower by .018" or using slightly less powder.

After a couple reloads your case may lengthen back to the spec's length depending on pressures and the case's design.

[Posit]

Normally, " trim to" length is .10 below max length... probably true for your 35... if so you're .08 below the "trim to" length. If you're.18 below the "trim to" length... I'd be really careful. If you really want to shoot them, I would definitely reduce powder to compensate for the shorter case, and seat the bullet further out as well. And don't expect the accuracy you normally achieve - you're gonna have more distance ("jump") to the lands.

[tl_3237]

Thanks for the comments...

Unfortunately I reloaded the cases before I discovered the brain-fart. realized the goof when I was resting in bed.

I've reloaded to the normal OAL (base face to bullet tip) that I always used. so the bullets should be seated to same depth below the neck that their would otherwise have been; volumetrically I would expect the nominal case and short case internally to be the same. Also the 'jump' should be the same.

The only thing that I would think would be different is the total case tension on the bullet since there is less neck (.020") holding it. But then again I'm not an interior ballistician - hence my question.

[Posit]

Same OAL in a shorter case means the bullet is not seated as deeply in the case/neck as normal... not as far below the mouth of the case... so I agree neck tension is probably the only significant change. The Book says the bullet should be seated at least one (bullet) diameter below the case mouth - Assuming that to be true, I would shoot them - but I might stand behind a tree, reach around it to fire the first one - but I'm a little paranoid about things that go 'boom'. Be interesting to know what your results are.

[Pete D.]

As long as you have seated the bullets so that you have the same COAL as before, you will be fine. The small difference in neck tension is not going to have any greater effect than normal variations in tensions that are, for example, due to slightly different crimp pressures from cartridge to cartridge.
Pressure problems could occur if you had reduced the internal capacity of the case. You have not done that.
Pete

[max384]

As others have already said, overpressure shouldn't be a problem because OAL is still the same, thus case capacity is the same. If anything, you may have some underpressure problems if the neck tension is diminished too greatly.

What type of gun are you firing it out of? If it's a tube or magazine fed rifle, you may have problems with the bullets backing out a bit because of the decreased neck tension.

[SteveWag]

The ONLY problem you may have will be the need to reset your seating die to properly crimp the neck. If your satisfied with the crimp or lack of, shoot away!!!!
Steve

[Huggy]

Can anyone advise what are the potential untoward effects of using cases that are trimmed too short?

I recently scored some once fired 35 Rem brass after months of searching. Having a brain fart (at my age they are coming more frequently) I misread the case length as 1.902 instead of 1.920 soooo, my cases are now trimmed to be 0.020" shorter than max (ARRGH).

I am loading 37.5 gr H380 behind a Lyman cast 358315 with gas check.

We all know the pressure danger from LONG cases but what about SHORT cases?

Are these safe to fire?

I came across some 35 Rem brass a few weeks ago, and posted it in the Pay It Forward thread. I don't know anyone with 35 Rem, but gotta habit of grabbing brass when I find it. If you can use it, PM your addy and it's yours.