I had a question about OAL with .357 Magnum. I'm loading the brass with 125 gr. Remington SJHP's, my local store had a deal on a bag of 100. Due to the lack of data on this specific bullet I'm using the data for Jacketed Hollow Points from the Lee Reloading manual. My question is the book recommends an OAL of 1.580 inches with Jacketed Hollow points and the powder I'm using, but this leaves the cannelure outside the case mouth. You have to seat the bullet to an OAL of 1.54 to get the crimp to be just about the middle of the cannelure. In this occasion do you seat to the cannelure as the bullet is designed or would the bullet be too deep and cause pressure issues? I'm using 9.3 grains of Unique powder, a max load is 9.6 grains. Thanks!
.357 Magnum OAL
- Thread starter montana09
- Start date
It will cause a slight increase in pressure. If you weren't using a fairly fast powder up at maximum load, I would say to ignore it, as the others did, but Quickload suggests that with Unique, you need to reduce the charge by half a grain to 9.1 grains. This keeps the percent fill of the powder underneath the bullet constant and that keeps pressure pretty constant over this narrow range.
One reason that powder charge (Alliant's data) is higher than some other sources is the bullet used is the Speer Gold Dot. The Gold Dot has an electroplated jacket that is softer than a Remington cup-and-core construction bullet is. In a conversation with a Speer technician, he warned me that charges for the Gold Dot line are often higher than will create the same pressure with a conventional jacketed bullet.
I would actually make up 6 rounds with the first being 7.9 grains, then next 8.1, then 8.3, then 8.5 then 8.7, then 8.9, then 9.1. Load them one-at-a-time, then check for pressure signs. If these are for a revolver, fire from the lowest up and check that the case doesn't stick to the chamber and resist ejection. If you find one that does, don't fire anything higher. Just go down two steps from there and call it your maximum load. I would not go over 9.1 grains with the shorter depth and harder bullet if you don't want to put undue wear on your gun. Any rounds you have loaded past the sticky ejection point should be pulled with a bullet puller and reloaded with the smaller charges.
One reason that powder charge (Alliant's data) is higher than some other sources is the bullet used is the Speer Gold Dot. The Gold Dot has an electroplated jacket that is softer than a Remington cup-and-core construction bullet is. In a conversation with a Speer technician, he warned me that charges for the Gold Dot line are often higher than will create the same pressure with a conventional jacketed bullet.
I would actually make up 6 rounds with the first being 7.9 grains, then next 8.1, then 8.3, then 8.5 then 8.7, then 8.9, then 9.1. Load them one-at-a-time, then check for pressure signs. If these are for a revolver, fire from the lowest up and check that the case doesn't stick to the chamber and resist ejection. If you find one that does, don't fire anything higher. Just go down two steps from there and call it your maximum load. I would not go over 9.1 grains with the shorter depth and harder bullet if you don't want to put undue wear on your gun. Any rounds you have loaded past the sticky ejection point should be pulled with a bullet puller and reloaded with the smaller charges.
That is your problem, right there!
FORGET THIS!!!
UNLESS, You are using the SAME BULLET THEY ARE....
And, you've already said, that you're not.
You are making the all too common mistake of assuming that all bullets of the same diameter and weight are the same length. They are not. Some designs are longer (base to tip) than others.
It is entirely possible (and rather common) for two different bullets of the same weight, seated to the same exact depth in the case, to give you different overall loaded lengths. 0.04" difference in overall length can easily be due simply to differences in the "length" of the bullet "tip" between one design and another.
If you aren't using the exact same bullet they used in their data, then detailed data about a bullet you aren't using is null and void for your purposes.
UncleNick's advice here is very sound, but I would suggest a slightly different approach.
I would load in batches of 6 (or 5 if yours is a 5 shot), starting with the lowest load. Fire 5 of them, then look at round #6 (still loaded). Look for pressure signs on the fired cases (including sticky extraction) and look for evidence of bullet creep (jumping the crimp) on round #6.
Then repeat the process with the next higher powder charge. You are looking at two different things here, one is the overall pressure level of the load, and the other is if your crimp is enough for the bullet, load, and gun being used.
You may be in a situation where the bullets all stay in their proper place when you reach the max loading. But, you may be in a place where you get crimp jump before you reach max load. If so, adjusting the amount of crimp might cure that situation.
ALL reloading data are GUIDELINES, not immutable laws of Nature. Even IF we can get and use the exact same components used in the data, we are NOT using the same gun they did, and different results are possible. Similar results are likely, which is why the data is a usable guideline. Vastly different results, while unlikely, are possible.
Start low, work up slowly. Seat to the cannelure/crimp groove, CAREFULLY working up your load with that seating depth. DON'T worry about the published OAL or seating depth of a bullet you aren't using.
Good Luck!
Hammerhead
New member
9.3 Unique is hot with any 125 jacketed, work up as suggested by Uncle Nick
Speer #14 has Unique from 8.6 to 9.6 grains. With the Speer bullet, I worked up safely to the full 9.6. Then, I got ahold of a really spunky lot of Unique and had extremely difficult case extractions at 9.2 grains. With that same lot, I'm all the way down to the minimum 8.6 as the set loading - any more, and extractions become difficult. Here's the link I posted about it:
https://thefiringline.com/forums/showthread.php?t=594417
Do your diligence and properly work up the load.
Hammerhead
New member
I think a lot of that Speer data was worked up with 'old' Unique.
Plus they really like to push Unique fast, more so than other powders, so loader beware.
Plus they really like to push Unique fast, more so than other powders, so loader beware.
Thanks guys, I did work up to that loading of 9.3 grains of Unique from 8.6 grains. I had no problems at all with sticky extraction in my 686, and the loads definitely give off less muzzle blast and recoil than the Hornady factory .357 magnum loads with 125 gr. xtp's that I was comparing it too. All good and sound advice once again, thanks!
You don't need bullet manufacturer specific data. You need 158 grain jacketed data.
SAAMI minimum OAL for .357 Mag is 1.405". Load 'em where you need to. 1.540" will be fine.
Lee uses the powder maker's data(Alliant's in this case) too. They test nothing themselves. Doesn't mean it's bad or unsafe. Just that it's not theirs.
SAAMI minimum OAL for .357 Mag is 1.405". Load 'em where you need to. 1.540" will be fine.
Lee uses the powder maker's data(Alliant's in this case) too. They test nothing themselves. Doesn't mean it's bad or unsafe. Just that it's not theirs.