[Pond, James Pond]

A puzzling visit to the range.

I took my 18 reloaded .44s and 12 .38s to test the different crimps for bullet retention.

A number of things worried me.

Firstly, that the crimps don't seem to work for the .44 and secondly, that my bullet depth die does not seem consistent and possibly thirdly that my FCD is not up to the job.
How crucial potentially these are, I leave to you lot to say....

I had 5 sets of 6 rounds. 2 in .38 (125gr CU-plated and VV N350) and 3 in .44. (200gr CU-plated and VV N350) The .38s were crimped with 0.5 or 0.75 turns of the Lee FCD. The .44s with 0.5, 0.75 and 1 full turn of the Lee FCD.

I chose one round in each group and measured its OAL. I then remeasured it after each shot of the other rounds in its group. The measurements are in mm.

Here are the sequences of OAL measurements for each calibre and crimp. The first number is before shooting any, the next is after the first shot and so on until the final OAL where the cartridge has endured the recoil of its 5 bed-fellows!

.38 Spl Max OAL in manual: 39.??mm (can't remember off-hand and the paper is in the garage and I can't be bothered to go out now) I can say that the OAL was not massively consistent, despite measuring each cartridge after loading it at the bench: caliper technique?

0.5 turn crimp
39.12, 39.05, 39.04, 39.05, 39.06, 39.06
0.75 turn crimp
39.27, 39.28, 39.28, 39.25, 39.25, 39.26

Here I think the 0.75 crimp is most consistent, but I think the 0.5 could do for my purposes.

.44 Magnum Max OAL 40.70mm
You will see from the first number in each sequence that the bullet seating depth is not very consistent at all, varying by 0.3mm amongst my 3 control cartridges! Is 0.3mm an issue in reloading? I don't know!!

0.5 turn crimp
40.76, 41.05, 41.18, 41.26, 41.32, 41.45
0.75 turn crimp
40.62, 40.89, 40.99, 41.00, 41.18, 41.23
1 full turn crimp
40.93, 41.02, 41.06, 41.10, 41.14, 41.09

So overall, the 0.5 round OAL extended from 40.76 to 41.45 and showed no signs of settling.
For the 0.75 it was 40.62 to 41.23. A lower degree of bullet egress showing signs of stopping.
The full turn round went from 40.93 to 41.09. The smallest increase and had shown signs of leveling off.

What does this tell you apart from the fact that perhaps I can't use calipers porperly?

Are there other more subtle signs relating to powder choices, velocities or bullet type?

To help, there is also a photo attached of a full turn crimped bullet that I used in the die adjustment phase and extracted with a bullet puller, so you can see the degree of deformation to the bullet.
Evident, but not brutal, I think... or is it?

Thoughts?