.357 how am I doing?

[johngalt]

The crimp looks heavy to me. I usually seat them so the case mouth is at the top of crimp groove.

Seating deeper does increase pressure, but a couple .001 won't matter much.

 

[ggibson511960]

Crimping Uniformity

There is no answer to how adequate a crimp is, only subjective opinion. SAAMI publishes no dimensional information on what a crimp should look like. We all think we know what a crimp should look like, but that's the best we can do. Look at a bunch of factory rounds and you will see roll crimps, taper crimps and collet compression crimps. If one could exactly duplicate the same dimensional crimp there is no guarantee that case mouth ductility or hardness would render the whole exercise moot. Results are what matter. If bullets don't back out or get pushed in, and accuracy is O.K. without excessive pressure, than declare success. There is wisdom in what benchrest shooters do. I don't follow that sport at all, but I hear that they very carefully machine throats and case necks to achieve uniform neck I.D. then go with no crimp. Makes sense. I have read of exacting handloaders rigging up pull test fixtures to measure the pull weight of bullets in case necks, but there is nothing I know of in published literature about the correct bullet pull weight, or force curve to yank a bullet out of a neck.

 

[mikld]

Just seat it deeper and don't worry about book OAL. Any 357 Magnum round that is not sticking out the end of the cylinder and crimped in the cannalure (middle of the cannalure or deeper) will work safely...

 

[rwsmith]

Let me add...

The .38/.357 was derived from an old black powder cartridge that about filled the case with the powder. When it was switched over to smokeless powder, many types of powder don't fill the case at all., leaving a lot of airspace inside. Because of this, .38/.357 and .44/.44 mag are very forgiving to bullet depth. So a 1/10 of an inch isn't going to make much difference.

Now this is not true with cartridges invented with smokeless powder and higher pressure in mind, like 9mm, .40 call, 10 mm, etc. because they are made for higher pressure with very little airspace and the bullet depth on those are way more critical. Even so, sometimes I load a medium load and have a few thousandths of leeway to get the bullet where I want, especially if I seat a little shallow, I can lengthen the OAL. But I can only shorten it a few thousandths and none if I'm close to a full pressure load.

 

[sparkyvega]

Looks OK to me, seating depth not so critical so long as the cylinder turns. I roll crimp a little less, but YMMV. No need to overthink it. One thing to try is to load up a dummy and measure the crimp jump after 5 firings or even more.

 

[Leslie Sapp]

My take is that the crimp should lock in tight behind the front of the the cannelure or crimp groove in order to lessen any bullet setback from recoil.

I doubt that amount of setback would make any real difference, but it just bothers me to see potential movement in the cartridge.

 

[Rambler42]

Crimp looks just fine to me. I load my .357 just like it. For .38 Special I use a lighter crimp.

 

[stansdds]

How much deeper I'm at 1.158 now?

I was under the impression seating deeper increase pressures ?

Proper bullet seating is dependent upon the length of the brass and the location of the crimping groove or cannelure on the bullet. The published lengths are correct for the components used by whatever company developed that particular load and does not exceed SAAMI specifications.

Unless you are at or very near a maximum load, seating a few thousandths of an inch deeper should not put your ammo into the danger zone. If you are at or very near maximum safe pressure, then do not seat any deeper.