38 spl. Brass True OAL???

[Hootmix]

Have the Lyman 49th. Edition, but my 38 spl. brass (all brands) only measures 1.145 OAL w/ 358429 Lyman (old nose pour, i found these in a box while cleaning up, got them years ago) crimped in crimping grove my OAL is 1.435,, Lyman book say's (reads) OAL at 1.537 ?? " THE BOOK" shows (picture) brass at 1.155 but to trim brass to 1.149 . I plan on loading 3.6gns. of ww231, (shooting in a Uberti 72 OT) should be good to go, just wondering why my brass is short or is 38spl. brass this length?

having coffee, Hootmix.

[metricmonkeywrench]

lots of stuff in what seems like a simple question. Look up the SAMMI spec for .38. to be "within specification" the brass needs to be 1.155-.020 or 1.135 to 1.155. Trim to length puts the brass back to a "serviceable" known length, even some factory brass have some +/- lengths within the same box. Straight wall pistol cases for the most part do not flow and "grow" like rifle. Trimming to have consistent lengths helps with maintaining a consistent crimp for a given load/brass/bullet combination.

Onto the bullet, the OAL published was based on their brass (unknown length) with their cast bullet, if you had a drawing of the bullet (358429) to know where the top of the crimp is then you could conceivably back into an estimation of the case length used. Back to the SAMMI spec, .38 loads OAL length can run from 1.275 to a max of 1.550 (to fit most all revolver cylinders). As your bullet may not be to the -429 spec it may end up long or short when loaded to the crimp groove, you would have to compare against the -429 to know if there is a difference. Loads can often be tuned by seating the bullet out or in a bit to get the best performance once you get to your base load. The difference will show up on the chronograph as you change seating depths (making the firing chamber larger or smaller)

So long as you are within max OAL and with a good powder charge (didn't look up your proposed load) you likely will not have any problems.

[dannyd]

For that light load if you switch to a taper crimp and not roll crimp then the issue goes away. I only shoot light load so haven't use roll crimp in years.

[DCB]

The 358429 bullet is 170gr bullet +-. be sure to crimp may have a problem with flash over. I crimp on the groove and get 1.40" OAL.

[Hootmix]

This is the info. i'm needing thank you all, DCB, you are correct this a 170+- gn. and like i posted mine came to 1.435 so close, i guess.
Will load a few and work up.
now, more coffee, Hootmix.