460 S&W Load Data Conundrum

[BigBoreBubba]

Hi all, first time posting here, though I’ve been a lurker for a long time.

My question is actually in several parts. I’m still fairly new to reloading, but have loaded quite a few rounds in quite a few calibers. However, this is my first go-around loading the 460.
I will be loading 300gr. XTP Mags. Here’s where the “conundrum” starts. I’ll be using H-110 powder, but I’m getting tremendously conflicting load data. My Lyman manual lists a starting load of 34.0 with a max of 38.0, my Lee manual lists a starting load of 38.0 and a max of 42.5, while my Hornady manual lists a starting load of 33.4 and a max of 39.2.
Listed velocity is also very conflicting. Lyman lists 1798 fps @ 34.0gr while Hornady lists 1400 fps @ 33.4.
Lyman load data tops out at 1966 fps @ 38.0, while Lee data starts at 38.0 for 1825 fps. Meanwhile Hornady data tops out at 39.2gr for 1550fps and Lee data tops out at 42.5gr for 2034 fps. This seems like wildly differing data from three well respected sources.
I know that H-110 doesn’t like to be under charged and usually does best towards the top end of load data, but this is a much bigger spread than I have ever seen between starting and max.


To add to this mess, all of my books say Large Pistol Magnum or Large Rifle primers, and to use the appropriately according to your brass. I know that is the case with 500 S&W (which I also load), but in it’s case, the brass is stamped with an “R” if it takes a rifle primer. None of my 460 brass is marked as such. I have a mix of Starline, Hornady and Federal brass. So, I proceeded to measure primer pocket depths on about 50 pieces of brass. I got numbers ranging from 0.1275 through 0.132, with the average being 0.129-0.1305. That’s a spread of nearly 0.005, mostly within Starline brass. So, I’m not even sure which primers to use now….

Any advice, especially based on experience, would be greatly appreciated. Thanks ahead of time.

 

[Mk-211]

Go to the source, Hodgdon.

Starting is 38 grs. Max is 42.5, this will give you 1,824 FPS and 2,034 FPS. Says to use large rifle magnum primers. You can use standard if you can't find magnum or don't want to spend the extra cash.

The numbers are coming from a 10 3/4" barrel and might be why you're seeing different numbers from other manufacturers. Check the barrel length on their numbers.

Seat the primers just below flush on the pocket, if you're worried about it buy a primer pocket uniformer.

Most reloading manuals have different numbers, none are ever the same to the point of nauseum! Stick with the manufacturers data and you'll be safe.

 

[BigBoreBubba]

Go to the source, Hodgdon.

Starting is 38 grs. Max is 42.5, this will give you 1,824 FPS and 2,034 FPS. Says to use large rifle magnum primers. You can use standard if you can't find magnum or don't want to spend the extra cash.

The numbers are coming from a 10 3/4" barrel and might be why you're seeing different numbers from other manufacturers. Check the barrel length on their numbers.

Seat the primers just below flush on the pocket, if you're worried about it buy a primer pocket uniformer.

Most reloading manuals have different numbers, none are ever the same to the point of nauseum! Stick with the manufacturers data and you'll be safe.

I didn’t even think to check Hodgdon…. It would seem that their data is the same as the Lee data. It just scares me a little the the start and max loads are way above what Lyman and Hornady list. As for primers, I do have Large Rifle, but no Large Rifle Magnums (though I do need some).

 

[Mk-211]

Some manufacturers download a bit to be on the safe side. They know what they can get away with when they publish the numbers.

The regular rifle primers that you have are ok to use as long as they fit in the brass. Magnum primers are a little bit hotter then standard so that you get positive ignition on every round.

Load up a dozen or so rounds with the starting load, take them to the range and shoot'em up. If everything checks out ok, load up a box or two and go back to the range and do some target practice.

Be safe, have fun!

 

[CarJunkieLS1]

I've always used Rifle Magnum Primers. With a giant case full of H-110 I want all the "spark" I can get. And my understanding is that the primer cups on pistol primers aren't thick enough to hold back the 60k psi that the cartridge can be loaded to.

Also excellent choice on the 300gr XTP Mags those bullets shoot very well in my 460.

 

[Barr]

From what I can tell Lee re-publishes other component manufacturers data. Great for one source amalgamation of data for many bullet types and mixes.

I am running into the same issue for .454 Casull loads I am developing, limited data selection with varying charges. I start near the bottom charge and work up to max.

H110 really shines in both the cartridges near max loads. H110 is so slow burning that unlike many powder charges it is a dense charge that many cartridges actually compress its charges safely. Long sustained burns w flat pressure curve really gives top velocities in carbine or long revolver barrels.

 

[Howland937]

my books say Large Pistol Magnum or Large Rifle primers, and to use the appropriately according to your brass

They show large pistol or large rifle? Then you really need to figure out what your brass is cut for since they're not interchangeable in the way small primers are.
Usually, if a powder manufacturer offers data for a specific bullet, and the bullet mftr offers data for their bullet with said powder, I start with the lower if the 2 and go from there. Misprints do happen on occasion.

 

[reddog81]

460 S&W has a max SAAMI pressure of 65,000, however most manufacturers limit their loads to around 55,000 PSI due to sticky extraction with max loads. I'm guessing the various reloading manuals have different limits that they pushed the cartridge to. The differing FPS is due to different guns/universal receivers being used with differing barrel lengths.

 

[BigBoreBubba]

Thanks guys. Some good information here. I loaded a few test rounds last night. I went with middle of the road data. 5 rounds each at 37.5, 38.0 and 38.5. I may load a few more at 36.5 and 37.0 as well. These charges gave decent case fill. Not compressed, but fairly close to the base of the bullet.

 

[Barr]

Lighter mid range loads are great w Longshot or Unique for practice sessions. 270 gr bullets at 1300-1500 fps.

 

[FROGO207]

OP I ran into the issue with my 500 brass as well. If I had any worries I would just get a LR primer pocket uniformer and run them all through the process. Then they will all work with the LRP with no problems. Just the way I would approach things.

I always fall back to the propellant manufacturers data if things are all over the map.

 

[sparkyv]

Starline brass uses LRP. That's all I use for 460S&W.
https://www.starlinebrass.com/460-sw-mag-brass



Yes, there are gaps in load data. I refer to as much data as I can get my hands on, and I usually start in the middle of what they all say, and work up from there. At just over the Lee max data shown below with a 300gr coated hardcast TCFP (not XTP), I came nowhere near 2,034fps in my 5" bbl but had no sticky extraction. 1,597 was the fastest I could get. H110 is probably the best powder for the 460S&W out there. Hard to screw up with it.

Meanwhile Hornady data tops out at 39.2gr for 1550fps and Lee data tops out at 42.5gr for 2034 fps. This seems like wildly differing data from three well respected sources.

 

[1976B.L.Johns.]

I didn't go and check your numbers against my manuals, but I will use your numbers as an example as it really doesn't matter.

If I have conflicting numbers , I will sometimes take the average and start there (on the low end), Lyman 34 plus Lee 38 divide by 2, I'll kinda skip a step and start at 36 grains of H-110. As mentioned above, (Post # 6) H110 likes to be more than less!

Just saying, use at your own discretion.

B.L.

 

[shell70634]

I had the same problem when I got my 460 Smith. After looking at all the data, I went with data from the powder manufacturers. I believe the Lee book is a compilation from multiple known sources. It's great for a cross reference but would rather trust those companies that have actually tested the loads themselves. Pay close attention to the materials they use to build the ammo they tested. If you have questions, call them. Powder and bullet manufacturers have always treated me well when I ask questions, even stupid ones.