Reloading 357 fmj with xtp data

[Reefinmike]

I'm new to reloading and I'm sure this will be fine, but I want to be on the safe side. I've been reloading really light 158gr lswc in 38 cases and I'm amazed, my 15 yard groups out of my snubbie went from scattered all over the largest shoot n see target(13 or 14") with factory ammo down to 3" groups. But want to load up some hotter mAgnums just for that nice recoil.

My lees reloading manual only has data for various lead and xtp(from my understanding, simply hornady hollowpoints, also can use golden sabers etc, deep cavity jhp) bullets, not copper jacketed. At the gunshow I picked up a couple hundred 125 gr jacketed swc and loaded up 50 with 7.4gr win231 and 50 with 8.1 gr win 231. For the 125grxtp bullets, my manual calls for a starting load of 7.3gr(1335 fps) and 8.5gr(1514fps 42,700psi) for the max with win231.

From my understanding, xtp data is separate simply because they are a longer bullet due to the hp, decreasing case capacity, increasing pressures due to both case capacity and a larger bearing surface on the rifling.

Heading to the range tomorrow looking to test out these loads and looking to be reassured that my assumptions are correct. You know what they say - assuming makes a hand grenade out of your gun!

Mike

 

[T Bran]

Mike,
The only manual within reach at the moment is my Speer which shows 7.6 as a min and 8.3 as a max with their 125's using 231. You are within the range for the weight but the bearing surface could trip you up. Go to the powder manufacturer's website and check their data as you arent that far below max on your max loads.
T

 

[Reefinmike]

Hmmm... Winchester redirects to hodgens site for reload data and it only shows 125gr cast and hornaday xtp...

 

[joneb]

I don't load a lot of 125gr for 357 mag mostly 140 and up, if you can be patient some good info will come your way

 

[Reefinmike]

Hmmm... Honestly, I chose the 125 ovrper the 158gr jwc because they were cheaper, plus a good bit faster! I noticed my super accurate but very slow 158gr swc target loads have a great delay between the hammer drop and impact 75ft later!

I guess if i dont get any more advice between now and range time tomorrow, I'll just try the light 7.4gr loads. I'm not an expert reloader, manual, or physicist, but I couldn't see a problem shooting a projectile of the same weight as xtp data with a lower bearing surface which leads to lower pressures(safer)... Maybe copper fouling at the worst?

 

[ArchAngelCD]

Hodgdon is distributing all Hodgdon, IMR and Winchester powders and they supply load data for all those powders too. You can obtain current load data on their Data Site as a primary or secondary source. Unfortunately Lee copies their data from the powder manufacturers so the data on the Hodgdon Site is the same as you already have using an XTP bullet. (But it might help in the future)

 

[Steve C]

....loaded up 50 with 7.4gr win231 and 50 with 8.1 gr win 231

The old Winchester data lists 8.1 gr of W231 as maximum with a 125 gr JHP. Usually Hodgdon has wimped out and lowered loads that Winchester said was OK but in this case Hodgdon lists 8.3grs of W231 as max with the 125gr.

Just a suggestion. If you are trying to develop a load it is better to load fewer rounds at charge weights in smaller increments rather than 50 rounds at a start level and 50 at a maximum level. I know its annoying to load less than 50 or 100 rounds at a time because that would leave extra components and bullets left over from boxes of 100 and cartridge boxes that hold 50.

Best way for load developement is to load 10 rounds at the start level. then divide the difference between the start and max load by 4 and load the next 10 rounds with that much more powder. So to use up 50 cases to test load levels for accuracy and safety using the Hodgdon data of 7.3 start to 8.5 gr max you should load 10 rounds at 7.3, 7.6, 7.9, 8.2, and 8.5 grs which makes 50 rounds. Make sure you keep track of which ones are loaded at what charge and head for the range with 5 targets. Shoot the lightest load first and check for accuracy and look for pressure signs. Follow with the next heavier load, etc. If pressure signs appear, ie. pierced or cratered primers, sticky extraction, or extreem flattening then STOP as that and any heaveir load isn't safe to shoot and the previous load level is your maximum. Usually you will find one of the loads more accurate in your pistol which will be the logical selection to use when loading ammo with that combination of components from then on.

 

[Reefinmike]

Steve- I will load up a cylinder of several different loads before I head out tomorrow. The reason I loaded 50 slightly above minimum and 50 decently below max is beccause I shoot at a public range, open wed-sun, one target at a time, and cease fires are once every half hour or so... Wednesdays are usually pretty good for getting a spot, Thursday's ok, fridY sat and Sunday, might as well not go it's so crowded... The rest of my 357 brass is loaded with weak loads and 158gr wadcutters. Guess I'll pull some of those and make some intermediate loads. I know how to check for signs of pressure, swelling at the base, difficult extraction, and primer hits.

 

[ArchAngelCD]

The rest of my 357 brass is loaded with weak loads and 158gr wadcutters.

IMO .357 Magnum brass is too hard to come by to use it for building .38 Special pressure loads. That's what .38 Special brass is for. I save all my magnum brass for magnum loads. Just a thought...

 

[Reefinmike]

All I had at the time were 300 38's and 100 357'sand my press was hungry when it first exited the box... Now I have 900 38's and 200 357's. Once I shoot off the wadcutter 357's, they'll be for magnum loads only...

 

[Reefinmike]

Reporting back, all went well and no missing fingers! I started off shooting loads with 7.4 grains win231. Then went to 7.6, 7.9 and ended at the hottest I wanted to go with 8.1. No pressure signs and all extracted easily. Accuracy- not so hot, I was happy to hit the small target once each cylinder, but I was never expecting much shooting hot magnums out of a snubbie. Just wanted them for the boom factor for an upcoming camping/blasting rounds off18hrs a day trip. When I want to be accurate, I'll just throw in my light load 38 158gr lswc