38 super - varying OAL

[Aldrin]

I'm having an issue with varying lengths on 38 super. I'm trying to load to 1.235 and the some of the finished rounds will end up longer. Some well over 1.250. I've never had this happen before with compressed loaded 9mm major. I'm using 8.3g of 4756 and 9.7g of N105 and I have same problem with both. Any ideas?

[g56]

The most common cause of varying OAL is caused by the bullets not being consistent in shape. Most bullets contact point on the bullet seating stem is not the tip, its on the side of the bullet, most bullets are fairly consistent in shape, but they are never exact, and slight differences in shape will change the OAL measurements.

[thehandyman87]

I once called Dillon's customer support about inconsistent OAL I was having on .38 super rounds. According to them, if you're loading with a progressive press (i'm using a 650) then OAL variations of + or - .015 is not uncommon and can be expected depending on components. This is exaggerated if you're using inconsistent bullets and mixed brass.

[lcs]

I once called Dillon's customer support about inconsistent OAL I was having on .38 super rounds. According to them, if you're loading with a progressive press (i'm using a 650) then OAL variations of + or - .015 is not uncommon and can be expected depending on components. This is exaggerated if you're using inconsistent bullets and mixed brass.

+ or - .005 never had .o15 variance. .

[gng4life]

I've had up to +/- .008 in some slightly compress 9Major loads but that's it. Never seen .015 variation in my any of my loads...What seating die are you using? If a Dillon, what cup do you have in it? What bullet type/shape?

[XRe]

You don't have enough powder in those loads to push the bullet back out, really.

Double check that everything is OK with your seat die - nothing's loose on it, etc. Double check the bullets you're using, per g56. What gng4life is getting at is that if you're using the rounded punch, and your ogive on the bullets is inconsistent, you can flip the seating punch over and use the flatter side to seat from the nose of the bullet.

Also, double check your crimp - you want it to be at about .378".

If you're using the Montana Gold 121gr IFP, you might read this for some specific things about that bullet: http://re-gun.com/2011/05/montana-gold-bullets-121gr-ifp/ - I don't think the variances you're describing could be accounted to the bullet nose on the IFP, though.

[Aldrin]

OK, I think it may have been how my press was set up. I did have my 550 bolted directly to my bench but last night I set it up on a strong mount. I cranked out a small batch and the variations were +/-.03. It's weird that I never had a problem with any other caliber. The press was tight on the bench but something must have been moving or twisting. Thanks for the help guys.

[19852]

I have gotten inconsistencies as well using a Dillon progressive. It takes a while for it to settle down it seems. I found it useful to load up the shell plate like it was in full production to get repeatable results.