357 mag seating depth

[remmag]

Hey guys
I am fairly new to reloading ,let's see if you can help
I am loading 357 mag with 158 grain Hornady bullets using 2400 powder
I am working up a load and starting with the minimum
I have trimmed the cases at 1.580 per the manual
The show a coal of 1.590
When I seat the bullets it's to the shown coal I am not really seated to what looks correct in the cannelure
I have attached a pic of a seated bullet to 1.571 and it looks like I can crimp properly in the cannelure
I guess my question is , if I am starting with a shorter coal than the manual am I ok working up this load
It almost looks to me like I really need to seat a little farther

Thanks for any help

 

[USSR]

You always seat to the crimp groove or cannelure, regardless of what the manual's COAL says, UNLESS your COAL makes the cartridge too long for your cylinder (as in the case of using the .358429 bullet in the S&W Model 27/28).

Don

 

[remmag]

Don
Does mine look like it is correct on the cannelure or should I seat a little further?

 

[RealGun]

Hornady says case length 1.280 and COL 1.590, all the weights of XTPs the same (not FTX). The picture looks okay to me. I expect some crimp groove to show since, under magnification, the groove is a scoop, me figuring I want to be in the middle at the deepest point for maximum purchase on the bullet. Lead would be different because the groove is different. My loads look to be crowding the underside of the band on a SWC, because that is the deepest point of the crimp groove.

 

[Blue68f100]

Don
Does mine look like it is correct on the cannelure or should I seat a little further?

You need to seat the bullet deeper. Normally the top of the brass will be near the top of the cannelure.

 

[Reloadron]

I have trimmed the cases at 1.580 per the manual

Thought that seemed strange. With a case trim of 1.580" and a C.O.A.L. of 1.590" you would only have 0.010" of bullet out of the case. The suggested trim is 1.280".

Just seat the bullets a little deeper so you get a nice roll crimp into the cannelure and you will be fine. I have seen boxes of bullets when set side by side the cannelures are visibly different. In fact recently a member posted a picture reflecting the differences.

Ron

 

[remmag]

Thank you all for the help

 

[Walkalong]

I imagine the trim the case to 1.580 is a typo and he meant 1.280 with an OAL of 1.580.

As posted the correct OAL for the cartridge (coal) is whatever OAL you get when you crimp the case mouth into the middle of the cannelure.

 

[RealGun]

You need to seat the bullet deeper. Normally the top of the brass will be near the top of the cannelure.

That wouldn't match Hornady's book numbers. I would agree if talking about a lead bullet.

 

[Jesse Heywood]

Always seat to the crimp groove, unless the OAL is too long for your cylinder. Colt guns have a short cylinder, measuring 1.600, so the OAL will need to be 1.595 max. If the bullets hit the yolk, in front of the cylinder, the cylinder won't turn. Smith guns have a long cylinder, so 1.600 works for an max OAL.
As always, start with a charge that is under the max and work up.

 

[RealGun]

Always seat to the crimp groove, unless the OAL is too long for your cylinder. Colt guns have a short cylinder, measuring 1.600, so the OAL will need to be 1.595 max. If the bullets hit the yolk, in front of the cylinder, the cylinder won't turn. Smith guns have a long cylinder, so 1.600 works for an max OAL.
As always, start with a charge that is under the max and work up.

If you cannot seat to the crimp groove, how else should one proceed except to change bullets? I suppose trimming cases is an option, but we see in Hornady fired brass from FTX bullets that a unique trim length is a pain for managing brass.

 

[Jesse Heywood]

If you cannot seat to the crimp groove, how else should one proceed except to change bullets? I suppose trimming cases is an option, but we see in Hornady fired brass from FTX bullets that a unique trim length is a pain for managing brass.

Yes, trimming brass short is a pain. But, if you keep the brass separate at the range and through the loading process, it is less of an issue.
If you have enough neck tension, the crimp is less important. Then you can use a crimp that digs into, without deforming, the jacket.
You can also change bullets.

 

[rg1]

Some calibers with Hornady bullets, .357 Magnum being one of them, I prefer to leave the cases at the maximum length at 1.290". Seems to match the crimp groove much better for crimping. Depends on the cases as whether you can leave them longer. I measure several and trim to the longest length possible to just touch but not shorten the shortest case. I do prefer to seat to Hornady's recommended length at 1.590" but if cases are short and I can't get a good firm roll crimp I seat a few thousandths deeper. Since after sizing I check every case for length in rifle and pistol, most all my reloads have cases trimmed to maximum length and I don't mind checking or trimming every time I reload a case. Plus that will prevent a case left by another shooter from slipping by and being too long for my rifles chamber.

 

[RealGun]

Some calibers with Hornady bullets, .357 Magnum being one of them, I prefer to leave the cases at the maximum length at 1.290". Seems to match the crimp groove much better for crimping. Depends on the cases as whether you can leave them longer. I measure several and trim to the longest length possible to just touch but not shorten the shortest case. I do prefer to seat to Hornady's recommended length at 1.590" but if cases are short and I can't get a good firm roll crimp I seat a few thousandths deeper. Since after sizing I check every case for length in rifle and pistol, most all my reloads have cases trimmed to maximum length and I don't mind checking or trimming every time I reload a case. Plus that will prevent a case left by another shooter from slipping by and being too long for my rifles chamber.

Wondering how many thousandths in case length one must allow before a meaningful die adjustment is called for. I don't expect crimps to be very consistent without isolating case lengths into groups. But then you have to keep track, resorting each cleaned batch of fired brass. I don't see how there can be only a trim length for max. From what I have measured in the collection I have, I sure don't want to trim everything to a least common denominator, enough to make load data suspect at longer case length specs. I suppose I could isolate short cases to use on reduced loads for smaller guns. I might do that, actually.