357BBB 158 X-Treme and Unique

[Ojaileveraction]

Shooting 158 X-Teme cast lead bullets over 4.7 grains of Unique yesterday. A recipe from the Hornady section of the One Book/One Caliber 357 book.
Wanted to use it to re-sight in the WGRS I reconfigured from another Thread.
The Sight was working but the loads were going everywhere. A little low, a little high, Real high and to the left or right. Shoot were off by 10 or more yards.
I'm pretty sure I wasn't getting enough speed to consistently stabilize the bullet. It was suggested that it is a 1000 fps and I was shooting out to 100 yards.
I did a lot of reloading of various loads during the time the area the range was closed. I have more to try out, HP30, Titegroup, a larger dose of Unique. Hopefully this week.

[JEBar]

looking forward to following your process

[Mistered]

4.7 gr of Unique is too light of a charge for a 158 gr bullet. Alliants' website shows a minimum of 6 gr. for 158 gr bullet.
http://www.alliantpowder.com/reloaders/ ... rtridge=28
Unique is a not that fast of a powder for a 4.7 grain load and this load is a squib waiting to happen in a rifle.

[clovishound]

Are these Xtreme plated bullets? I use Xtreme plated 158 gr HPs over Universal, which is very similar to Unique.

I use the middle of the range Hogdgon lists on their website for rifle loads for cast bullets for the .357 magnum. The velocities listed are over 1200 fps, so this is why I use the HPs. They are rated up to 1500 fps. If you are using the other 158 gr bullets they offer, 1200 fps is the max. If you push them too fast, the plating can separate and this will ruin accuracy. Of more concern is not pushing them fast enough. Too low on the ladder for cast bullets is a recipe for a squib with plated. They act somewhere in between cast and jacketed.

I have found that the plated bullets work best for me when I use a medium speed powder that has a good overlap between jacketed and cast data. I load them a little on the hotter side to avoid squibs.

[Abnermal]

Never have loaded cast in .357-loaded and shot a whole bunch of cast in .38 Special. My Cowboy Action load for both rifle and pistol is a 158 cast bullet on top of 4.5 grains of Unique. Never shot any of them at more than 25 yards or so. Some day I'll get the Chrony out and clock a few,just for giggles.

[Ojaileveraction]

I couldn't find any rifle data for the 357 mag on the Alliant website.
Cowboy Pistol loads are listed at 4.5gr of Unigue for cast RNFP at 859 fps.
Pretty close given the velocity increase from a rifle.

[Mistered]

couldn't find any rifle data for the 357 mag on the Alliant website.

Many sites do not offer separate rifle data for handgun cartridges. In this case just use the standard supplied data as it would not have been different for a rifle - I.E. they will never create data specifically for a rifle that could not be used in a handgun. If a site does happen to offer rifle data it's usually for CAS shooting and is most likely lower velocity than their standard hand gun data. In effect don't load on 'rifle data'
Only as it may not be provided for all powders.

[Ojaileveraction]

It was cold and windy at the range this morning we. I was tempted to foget about sighting the reversed WGRS but we are expecting a dusting of snow over night and any snow will shut a Southern California highway down, so I braved through.
A stouter load of Unique , over six grain, was a consistent load and very satisfactory on the 50 meter pig silhouettes. As it turns out the adjustments I made Satuday to the sight were right on for the full size Cicken and Pig Silhouette, using this load.

Another load of Titegroup theoretically 1000fps was as unpredictable as the low end load of Unique from the earlier post.

A HP 38 load was also very consistent. I will have to check my notes for the muzzle velosity of the Unique and HP 38 loads. Edit: 1240 and 1140 respectively

What is really nice is having the WGRS setting on top of the BBB 357 and not hanging over the trigger.

[Mistered]

Sounds like the heavier load of Unique tightened things up.
Unique becomes very unpredictable at very low charge weights as it is not necessarily considered a ‘fast’ burning powder - more like on the faster end of slow burning. Much less than 6 grains and there just isn’t enough to build much pressure for accuracy.
I can hardly believe the one book data showed a load this low.

[Abnermal]

What is really nice is having the WGRS setting on top of the BBB 357 and not hanging over the trigger.

Well,no wonder you were having problems!

[Mistered]

I might load up a few 6 grain Unique loads and try them myself and see what happens. I’ll have to scrounge around to see if I have some 158 grain cast bullets but I should have some.

[docscott]

http://www.handloads.com/articles/default.asp?id=30

[Ojaileveraction]

Sounds like the heavier load of Unique tightened things up.
Unique becomes very unpredictable at very low charge weights as it is not necessarily considered a ‘fast’ burning powder - more like on the faster end of slow burning. Much less than 6 grains and there just isn’t enough to build much pressure for accuracy.
I can hardly believe the one book data showed a load this low.

Yes I believe you are correct, pressure sensitivity is the problem with both the Low Unique and Titegroup loads.

[Mistered]

Well Hodgden shows a starting load of 4.5 grains of Titegroup with a 158 gr cast bullet and this will no doubt be a better load than 4.7 grains of Unique however I firmly believe for RIFLES, loads should never be less than 1000 - 1200 FPS due to the possibility of poor ignition and a squib.