.357 magnum seating depth problem

[RyanH]

Hello everyone; I have browsed this forum for a few years now but this is my first post.

I am currently reloading some .357 magnum (for lever action rifle), but have encountered a problem. The 125gr bullets (RNFP) I have bought come with a crimping grove, which when properly seated to the grove the overall length of the cartridge is 1.50” this deviates from my manual (lee) which says the overall length should be 1.58 min 1.59 max.

Should I seat the bullet to the crimp grove or ignore it and seat to the depth prescribed by my manual ?

Thanks for your time.

[madmo44mag]

If the bullet manufacturer has data use it otherwise use the data the best matches the bullet design you are loading.
I would just crimp in the canalure and call it good as long as the round loaded and cycled ok.

[Nick_C_S]

I would just crimp in the cannelure and call it good; as long as the round loaded and cycled ok.

. . . ^^ Exactly ^^

[g.willikers]

If you are suspicious of the info you have, ask the bullet maker for their recommendation.
It is possible that the Lee info, for the longer cartridge length, is not for that particular bullet.
Or the manual could actually have a misprint.
Or the load you are making changes things.
Maybe neither the bullet maker nor the manual is addressing your particular situation.
For example, hotter loads may require more internal case space and a longer cartridge length.
If you don't have a chronograph yet, definitely get one to remove all doubt.
(And try not to shoot it).
Otherwise it's just an educated guesstimate.

[44 AMP]

Understand that the listed max COAL is the max length that should be expected to work in the majority of firearms. Most guns, particularly autoloaders will work better with rounds slightly below the listed max length.

Also, some guns will work fine with rounds slightly over the listed max length.

Many, if not most manuals do not even list a min COAL.

Seat the bullet to the cannelure, check length, and if below max, test for functioning (feeding).

Lever guns can be tricky about what length they want for best functioning. AND it is entirely possible to load rounds too long to feed from the magazine tube.

COAL specs are guidelines, not hard and fast rules. Your specific gun might have a different idea of what it likes, and what it will tolerate.

[Nick_C_S]

Oh, and welcome to TFL

[buck460XVR]

Rounds for lever guns with tube feed need to be crimped in the cannelure to keep the bullet from being setback from recoil. Revolver rounds using cannelured bullets are crimped in the cannelure to keep bullets from jumping crimp under recoil. The OAL is dependent on case length and where the cannelure is located on that particular bullet. OAL shown is manuals is what was used to create their performance, using the components stated and their case length. It is not Gospel for revolver rounds crimped in a cannelure or pistol rounds taper crimped without a cannelure.


The difference in OAL from using different case length and bullets different than shown in the recipes is just another reason why we start low and work up.

[Bezoar]

if that .09 of an inch was all super vital, wed have been dead years ago.

overall length of a loaded round can vary alot. just measure factory ammunition.
hey look at wadcutters for starters.
you can get a hb wadcutter and can load it all sorts ofways really. to the crimping groove or flush with the case mouth. even use the same powder charge for both bullet positions in the loaded cartridge and nothing bad happens to your gun. just slightly different performance results.

[RyanH]

Thanks for the advice, I will start with a light load and crimp to the cannelure.