Reloading Pains with the .460 S&W Magnum

[Quick Draw McGraw]

Hi guys,

Reloading for the .460 S&W Magnum has been one heck of a challenge. In loading 300 grain XTP Mags, I struggle to get any velocities even close to my reloading data whether it's from Hodgdon, Hornady, or Western Powders. I am not looking for blazing velocities, but if I can't exceed my .454 Casull's velocities, it makes the cartridge pointless. In that case, I'd rather sell it and just keep the. 454 SRH. Anyone have advice? My crimps are solid as I'm using a collette die. I don't know what I may be missing.

[Quick Draw McGraw]

Still open to suggestions but I think I foubd my problem. I got out the feeler gauges to check my cylinder gap and... 0.009"! That is huge!!!

[lar4570]

Make sure you are not too close to the chronograph, it can give false readings.
Looks like you should be able to get over 2000fps with H110 or LilGun

[lar4570]

.009" is rather large!
What gun and barrel length are you shooting

[Quick Draw McGraw]

Aug 6, 2021 17:04:48 GMT -5 lar4570 said:

Make sure you are not too close to the chronograph, it can give false readings.
Looks like you should be able to get over 2000fps with H110 or LilGun

I don't trust Lil' Gun due to how it is harsh on forcing cones. But with H110, I have not gotten out of the 1,600s despite what Hodgdon claims on their website. My chrony is a Labradar so it's not too sensitive on the distance.

[lar4570]

1600 is way too slow for the 460.
What barrel length do you have

[leadhound]

Any possibility of using factory ammo for a comparison?

[lar4570]

Just checked with a friend who has a 8 3/8" S&W 460. His top end, over book, loads with H110 are giving over 2200fps with 300gn LFN crimped in the grease groove for extra capacity.

[bradshaw]

Aug 6, 2021 13:48:41 GMT -5 Quick Draw McGraw said:

Hi guys,

Reloading for the .460 S&W Magnum has been one heck of a challenge. In loading 300 grain XTP Mags, I struggle to get any velocities even close to my reloading data whether it's from Hodgdon, Hornady, or Western Powders. I am not looking for blazing velocities, but if I can't exceed my .454 Casull's velocities, it makes the cartridge pointless. In that case, I'd rather sell it and just keep the. 454 SRH. Anyone have advice? My crimps are solid as I'm using a collette die. I don't know what I may be missing.

*****

Cylinder gap has little or no bearing on accuracy.

Cylinder gap affects muzzle velocity by bleeding bullet push relative to:
1) width of gap between CYLINDER FACE and BARREL FACE.
2) where the pressure dome occurs, which could be in the chamber, in the barrel/cylinder gap, in the forcing cone, or in the barrel.

As we learned with the .357 Maximum (1.605” case), Winchester 296, a.k.a. Hodgdon H-110, reaches erratic combustion in the long case. Whereas, Win 296/H-110 produces excellent velocity and accuracy in the standard 1.283” case for .357, .41, and 44 magnums. The .44 Mag achieves its pressure dome rather well infant of the chamber. With a 1.8” case, pressure dome of the.460 S&W Magnum may extend forward of the long-striding .44 Mag.

It is difficult to achieve velocity without pressure. Dick Casull’s .454 is a velocity cartridge. dick knew he had to tighten everything to focus pressure on the bullet.
David Bradshaw

[Quick Draw McGraw]

Aug 6, 2021 17:50:00 GMT -5 leadhound said:

Any possibility of using factory ammo for a comparison?

I have only tried the 200gr. FTX. I averaged 2,218 fps. I am thinking that canyon of a cylinder gap is not helping the heavier bullets.

Also, the barrel is 7.5 inches.

[Quick Draw McGraw]

Aug 6, 2021 19:12:03 GMT -5 bradshaw said:

Aug 6, 2021 13:48:41 GMT -5 Quick Draw McGraw said:

Hi guys,

Reloading for the .460 S&W Magnum has been one heck of a challenge. In loading 300 grain XTP Mags, I struggle to get any velocities even close to my reloading data whether it's from Hodgdon, Hornady, or Western Powders. I am not looking for blazing velocities, but if I can't exceed my .454 Casull's velocities, it makes the cartridge pointless. In that case, I'd rather sell it and just keep the. 454 SRH. Anyone have advice? My crimps are solid as I'm using a collette die. I don't know what I may be missing.

*****

Cylinder gap has little or no bearing on accuracy.

Cylinder gap affects muzzle velocity by bleeding bullet push relative to:
1) width of gap between CYLINDER FACE and BARREL FACE.
2) where the pressure dome occurs, which could be in the chamber, in the barrel/cylinder gap, in the forcing cone, or in the barrel.

As we learned with the .357 Maximum (1.605” case), Winchester 296, a.k.a. Hodgdon H-110, reaches erratic combustion in the long case. Whereas, Win 296/H-110 produces excellent velocity and accuracy in the standard 1.283” case for .357, .41, and 44 magnums. The .44 Mag achieves its pressure dome rather well infant of the chamber. With a 1.8” case, pressure dome of the.460 S&W Magnum may extend forward of the long-striding .44 Mag.

It is difficult to achieve velocity without pressure. Dick Casull’s .454 is a velocity cartridge. dick knew he had to tighten everything to focus pressure on the bullet.
David Bradshaw

Makes sense to me. The accuracy of the revolver is solid. But the velocity is not where it should be and I am betting that 0.009" cylinder gap os the main reason.

[45MAN]

Aug 6, 2021 23:16:40 GMT -5 Quick Draw McGraw said:

Aug 6, 2021 17:50:00 GMT -5 leadhound said:

Any possibility of using factory ammo for a comparison?

I have only tried the 200gr. FTX. I averaged 2,218 fps. I am thinking that canyon of a cylinder gap is not helping the heavier bullets.

Also, the barrel is 7.5 inches.

THE 2,218 fps SOUNDS ABOUT RIGHT. A FRIEND WAS GETTING 2,000 fps OUT OF A 10.5" BFR WITH 325gr SWIFT BULLETS (DO NOT RECALL IF IT WAS A RELOAD OR FACTORY AMMO). ANOTHER FRIEND COULD NEVER GET VELOCITIES IN HIS XVR WITH 300gr BULLETS THAT HE THOUGHT HE SHUD BE ABLE TO GET. I HAVE 2 XVR's BUT HAVE NEVER RELOADED FOR THEM. THE 460  XVR WAS PUT TOGETHER TO SHOOT 200gr BULLETS REAL FAST, AND SOMEHOW I FIGURE THAT IN THAT DESIGN CRITERIA HEAVY BULLETS WILL NOT WORK WELL. MAYBE SLOWER POWDERS THAN 296/H110 ARE NEEDED?

[domino300]

singleactions.proboards.com/thread/31370/460

Recent thread results same, 460 better with light bullets.

[bradshaw]

Aug 7, 2021 7:06:25 GMT -5 45MAN said:

Aug 6, 2021 23:16:40 GMT -5 Quick Draw McGraw said:

I have only tried the 200gr. FTX. I averaged 2,218 fps. I am thinking that canyon of a cylinder gap is not helping the heavier bullets.

Also, the barrel is 7.5 inches.

THE 2,218 fps SOUNDS ABOUT RIGHT. A FRIEND WAS GETTING 2,000 fps OUT OF A 10.5" BFR WITH 325gr SWIFT BULLETS (DO NOT RECALL IF IT WAS A RELOAD OR FACTORY AMMO). ANOTHER FRIEND COULD NEVER GET VELOCITIES IN HIS XVR WITH 300gr BULLETS THAT HE THOUGHT HE SHUD BE ABLE TO GET. I HAVE 2 XVR's BUT HAVE NEVER RELOADED FOR THEM. THE 460  XVR WAS PUT TOGETHER TO SHOOT 200gr BULLETS REAL FAST, AND SOMEHOW I FIGURE THAT IN THAT DESIGN CRITERIA HEAVY BULLETS WILL NOT WORK WELL. MAYBE SLOWER POWDERS THAN 296/H110 ARE NEEDED?

*****

45MAN.... I believe the X-frame 460 S&W Magnum has a GAIN twist, as you note optimized for velocity with pointed 200 grain .45 bullet. (Ronnie Wells may be able to explain the S&W gain twist process.) From my rocking chair it appears S&W was out to one-up Dick Casull’s .454 Casull. Casull gained publicity through velocity, albeit in a revolver suitable for the belt. In general, to lengthen the barrel increases velocity. The rule applies to cylinder gap as well; less gap equals more velocity.

The fastest way to stabilize a heavy bullet is to spin it faster. A huge velocity boost is required too match the stability provided by a slightly faster twist.

A bullet on the ragged edge of stability YAWS. Yaw reduces the BALLISTIC COEFFICIENT of a bullet and increases WIND DRAG. Worse, yaw causes a bullet to veer, ruining accuracy. A revolver bullet with the ballistic coefficient of a watermelon tolerates a range of twists. Which is fortunate for revolver shooters who use a range of bullets weights. Twist becomes more specific to the rifle shooter shooting a long, heavy bullet. Especially when the bullet wears a BOAT TAIL. I believe twist for a rifle bullet involves more than bullet length. It is my experience a very long boattail is more BORE-SENSITIVE than a similar bullet with short boattail. A flat base bullet is less bore-sensitive and twist-sensitive than a boat tail. My own shooting, coupled with observation of others, on the Handgun Silhouette firing line and long range riflery supports these observations.

Roy Weatherby made his reputation with velocity, realizing a velocity boost from slower twist. Most revolver shooters don’t live in that stratosphere. We continue to throw watermelons from sixguns.
David Bradshaw

[Quick Draw McGraw]

Aug 7, 2021 7:06:25 GMT -5 45MAN said:

Aug 6, 2021 23:16:40 GMT -5 Quick Draw McGraw said:

I have only tried the 200gr. FTX. I averaged 2,218 fps. I am thinking that canyon of a cylinder gap is not helping the heavier bullets.

Also, the barrel is 7.5 inches.

THE 2,218 fps SOUNDS ABOUT RIGHT. A FRIEND WAS GETTING 2,000 fps OUT OF A 10.5" BFR WITH 325gr SWIFT BULLETS (DO NOT RECALL IF IT WAS A RELOAD OR FACTORY AMMO). ANOTHER FRIEND COULD NEVER GET VELOCITIES IN HIS XVR WITH 300gr BULLETS THAT HE THOUGHT HE SHUD BE ABLE TO GET. I HAVE 2 XVR's BUT HAVE NEVER RELOADED FOR THEM. THE 460  XVR WAS PUT TOGETHER TO SHOOT 200gr BULLETS REAL FAST, AND SOMEHOW I FIGURE THAT IN THAT DESIGN CRITERIA HEAVY BULLETS WILL NOT WORK WELL. MAYBE SLOWER POWDERS THAN 296/H110 ARE NEEDED?

I've tried some slower powders, but I think now I may try some additional powders. My experience with heavy bullets has been limited. I have mainly used 300 grain bullets. But 400 grain bullets that I loaded were not as accurate.