Reloading the 460 S&W Mag

[LEADPOISON]

I plan on loading some S&W Mag with @ 39gr of IMR 4227 under Hornady XTP Mag 300gr bullets in some starline brass. I have successfully loaded some of these in Hornady brass. My question is really about max COAL. Is it practical to test a dummy round seated overly long to where cylinder binds and gradually seat it deeper until cylinder will turn. Would it be acceptable to load it to this max COAL similar to loading a rifle round to max length that will function in a magazine. Would I likely gain accuracy due to a shorter jump to forcing cone? Would velocity decrease due to increased case capacity with shallower seated bullet. Would pressure drop also due to same, or is there different effect being closer to forcing cone? I know there are no absolutes. I would appreciate any guidance you could offer. Thanks for your time.

 

[BLUEDOT37]

Of course the diameter of your throats will need to be larger than the bullet's diameter, first off, to be able to seat them out that far. Tight throats wouldn't allow it.

Whether it would be more accurate I can't say for sure, (though I think not from an article I read some time ago, IIRC), but with it seated that far out you'll have less bullet-case tension & no cannelure to crimp it in, possibly resulting in poor ignition with that large charge of slow powder.

Yes, it would have less pressure (& velocity) which wouldn't help with ignition either. Additionally, I'd think that the reduced bullet-case tension would increase the likelyhood of jump crimp, promptly tying up the cylinder.

.

 

[ruggyh]

Remember you have to go through the forcing cone before you get to the lands. There is little value in handgun cartridges chasing this in revolvers.

You would need to seat the 300 XTP MAG more than an eighth of an inch out to get to close to cylinder length.

This well beyond the cannelure and getting a good crimp would be problematic. A good crimp is required to prevent bullet jump.

Case volume is not an issue with this bullet powder combination. Very good powder choice for this bullet.

Just crimp in the cannelure with the 300 XTP MAG in a consistent manner and work your load up and you will be fine.

You will need to check your 460 brass length over time because of sizing growth. Trimming to a set length allows for a consistent crimp.

Work your loads up slow, watch your extraction, its the best clue for whats going on with this cartridge.

Be safe and good luck
Ruggy

 

[slayer1962]

reloading .460

I bought 5 boxes or Hornady ammo have not been thrilled with accuracy! I bought the dies and plan on starting working up a load for it. I guess a heavy hollow point works best? How about hard cast lead ? wonder with these velocities.

 

[ruggyh]

I guess a heavy hollow point works best? How about hard cast lead ? wonder with these velocities.

These threads should help

http://smith-wessonforum.com/reloading/429535-im-just-about-set-get-460-5-s-w-what-bullet-diameters-can-used.html

http://smith-wessonforum.com/reloading/117045-heaviest-bullet-load-460-s-w-mag.html

Good Luck and be safe
Ruggy

 

[slayer1962]

thanks for the information

I really appreciate the help. I have been a little slow with searching on this site. I am fun on a few others just need to try it more on here I guess. I have my empty clean cases (had to shoot them to get empties but you do what you have to do in life lol) . Will start with the 300 grain XTP!

 

[buck460XVR]

Will start with the 300 grain XTP!

I hope you meant the 300 gr XTP-MAG. The .452 300 gr XTP is meant for .45 Colt velocities. While they work well for reduced loads in the .460, iffin you want legitimate .460 velocities, you need to use the MAGS or other appropriate bullet. If you are using Hornady brass from their 200 gr SST ammo, you may want to check for case length as it may be shorter than standard brass and thus will affect case capacity. As ruggyh said, work up slowly in small increments as sometimes it doesn't take much more powder to make for a substantial increase in pressure, if you experience sticky extraction, you need to back down. Some PC X-Frames came with tight throats and thus will produce more pressure, so remember, start at minimum till you know your gun.

 

[BLUEDOT37]

Hornady rates the 300gr XTP-MAG (#45235) @ 1200-2200fps.

Hornady rates the 300gr XTP (#45230) @ 800-1700fps.

Hornady #8's manual's max 460 load for the 300gr XTP-MAG tops out at 1650fps.

Go figure.

.

 

[gwpercle]

Leave yourself a little room, heavy recoiling loads tend to walk out the bullets, unless heavily crimped and everything holds tight, one case can let the bullet slip forward just enough to "stop the show".
Seating them out in revolvers doesn't aid accuracy like a rifle, I just saw some tests on short rounds in long chambers ( 38 short colt, 38 special , 357 magnum...fired out of 357 maximum ) and the results were inconclusive. Don't obsess over seating the bullets out as far as possible in revolvers.
Gary

 

[roscoepc]

A bit of info from Wikipedia about the 460:


Case type
Rimmed, aight

Bullet diameter
.452 in (11.5 mm)

Neck diameter
.478 in (12.1 mm)

Base diameter
.478 in (12.1 mm)

Rim diameter
.520 in (13.2 mm)

Rim thickness
.059 in (1.5 mm)

Case length
1.80 in (46 mm)

Overall length
2.300 in (58.4 mm)

Primer type
Large rifle magnum

Maximum pressure
65,000 psi (450 MPa)

https://en.wikipedia.org/wiki/.460_S&W_Magnum

Edit: A pic might be helpful also!

 

[venomballistics]

My main concern with this experiment is bullet creep
While the 460's ship with excellent muzzle brakes, the recoil prior to the bullet clearing the brake is quite substantial though of very short duration.
I think you'll find it harder to keep things from flaking out than you think here.

 

[BLUEDOT37]

A bit of info from Wikipedia about the 460:

Overall length
2.300 in (58.4 mm)

.

The picture you attached, as well as SAAMI's drawing, show the max. COL as 2.290"

(Hornady #8 has it wrong too. They have the max COL as 2.275")
.

 

[roscoepc]

.

The picture you attached, as well as SAAMI's drawing, show the max. COL as 2.290"

(Hornady #8 has it wrong too. They have the max COL as 2.275")
.

Thanks!!