RDub
Member
Hello
This study will compare some of the popular 158gr 357 Mag factory loads against some of the more popular hand loads using a 158gr jacketed bullet, some old standbys and some newer powders, with respect to velocity and accuracy. I’ve been insatiably curious about this for some time. Now I have enough material on hand to put a decent study together.
For the handloads I’ll be using Hornady 158gr XTPs, new Winchester cases, primers are noted on the targets as well as loads.
The focus here was on top performers so I didn’t include some of the medium burning powders.
Average velocity, velocity spread, standard deviation and temperature are also noted on the targets.
Two guns will be used, a four inch Smith 686 and a six inch Taurus 608 eight-shot.
Velocity data was collected with an Oehler Model 33 chronograph. Skyscreens centered 10’ from muzzle.
Elevation 2700’ RH 45%
Targets will be at 25 yards. Circles are 5½”
All handloads were hand weighed.
Factory loads that will be evaluated;
Remington Express 158gr. JSP
Winchester 158gr. JSP
Hornady 158gr. XTP
And some Buffalo Bore 158gr JHP
The powders that will be loaded are;
296; old and new lots
H-110; old and new lots
2400
IMR 4227
AA #9
AA#7 (four rds)
ENFORCER
N-110
300-MP
Lil’Gun
Blue Dot
Two side notes I wanted to look at with the H-110/296 loads.
First, I have some very old lots of powder that I got back in the late seventies/early eighties. I have wondered if this powder has lost anything over this amount of time. I got some new powder so I can compare old and new.
Also I wanted to compare the CCI 550 primer against the Win WSPM primer with H-110/296. I used the new lots of powder to do this. The WSPM primer is supposed to be pretty hot.
Let’s first take a look at the factory loads;
Remington 158gr JSP:
Powder charge; 16.6grs of a powder that looks very much like 296/H-110.
https://s20.postimg.cc/hup5xqnul/DSC00922.jpg
https://s20.postimg.cc/kdauyf9kt/DSC00923.jpg
The bullet weighed 158.9grs
https://s20.postimg.cc/w3osft2d9/DSC00924.jpg
Winchester 158gr JSP:
Powder charge also 16.6grs.
https://s20.postimg.cc/8tamk4px9/DSC00926.jpg
https://s20.postimg.cc/fxsft5x6l/DSC00927.jpg
Bullet weighed 157.3grs.
https://s20.postimg.cc/4mudijfp9/DSC00928.jpg
Buffalo Bore 158gr JHP:
Powder charge 19.8grs of a shiny coarse sandy looking powder.
https://s20.postimg.cc/zfihvd4ql/DSC00930.jpg
https://s20.postimg.cc/6bu9z4gn1/DSC00931.jpg
The JHP bullet weighed 158.9grs.
https://s20.postimg.cc/k48our7el/DSC00932.jpg
And of course Buffalo Bore uses Starline brass.
I regret not taking a Hornady round apart before shooting them all up.
So, after loading all this up and spending a day out at the range, here is what I came up with..
Four inch 686;
I only had enough of the Hornady rounds to fire in the 6” this time, but I did shoot some out of the 4” gun last winter.
Factory loads shot pretty well out of the 4” gun. At 1320fps the Buffalo Bore is the stand alone performer. High velocity along with decent accuracy, as advertised. All the cases in every load fell out of the chambers after firing.
Handloads:
14.0grs ENFORCER; Ramshots data lists 14.0grs as maximum. Worked up to this point with no issues.
16.0grs IMR4227; An old lot in a DuPont metal can. This would be the time the batteries in my chronograph craped out. However I remember seeing velocities around 1080fps.
296/H-110; Well there is no difference between the old lots and the new, not enough to matter. These have always been good performers.
15.2 2400; This is THE quintessential 357 Mag load for decades. Fast and accurate.
13.8-14.5grs AA #9; Present AA loading data lists 13.8grs as max. I’ve seen older manuals which go much higher. 13.8grs did pretty well. However 0.7grs more powder produced a 0 fps velocity gain, so I went no further.
18.6 300-MP; Well, this powder is proving to be nothing short of phenomenal. Highest velocity tested and the most accurate, and you don’t need a magnum primer. Might just be my go-to powder from now on.. It does have quite a bark to it..
18.0grs Lil’Gun; Lots of flash and blast for not much velocity.
15.3 N-110; Compressed load.. about 110%. Good performer, only 22fps spread.
10.8grs Blue Dot; Great load!
11.5grs Blue Dot; Not as accurate as 10.8grs but serviceable.
Target #19; I had not tried 300-MP with 125gr bullets yet. This exceeds the fastest 125gr factory load. I thought exceeding the Rem UMC 125gr load was not possible until now.
Six inch Taurus;
For some reason the Remington factory load didn’t like the 6” Taurus, but the rest shot very well. Notice that the Buffalo Bore load lost its advantage with the 6” barrel. It was surpassed by 300-MP, 2400 and N-110.
H-110/296; Same as the 4” results, but notice the lower velocity with WSPM primers. I think CCI 550 are still the primer to use in this application.
IMR 4227; Chronograph working now.. Accurate, but slow.
N-110; Not as accurate in the longer barrel.
300-MP; Top performer as expected.
AA #7; I had four cases left, so what do I do with these?.. I’ll throw 11.5grs of AA #7 in them as see what happens. Well I wish I had four more!
Here is a graph of the entire project;
Well that’s about it.. My curiosity is satisfied.. Hope this answers more questions than it creates.
Lots of fun.
This study will compare some of the popular 158gr 357 Mag factory loads against some of the more popular hand loads using a 158gr jacketed bullet, some old standbys and some newer powders, with respect to velocity and accuracy. I’ve been insatiably curious about this for some time. Now I have enough material on hand to put a decent study together.
For the handloads I’ll be using Hornady 158gr XTPs, new Winchester cases, primers are noted on the targets as well as loads.
The focus here was on top performers so I didn’t include some of the medium burning powders.
Average velocity, velocity spread, standard deviation and temperature are also noted on the targets.
Two guns will be used, a four inch Smith 686 and a six inch Taurus 608 eight-shot.
Velocity data was collected with an Oehler Model 33 chronograph. Skyscreens centered 10’ from muzzle.
Elevation 2700’ RH 45%
Targets will be at 25 yards. Circles are 5½”
All handloads were hand weighed.
Factory loads that will be evaluated;
Remington Express 158gr. JSP
Winchester 158gr. JSP
Hornady 158gr. XTP
And some Buffalo Bore 158gr JHP

The powders that will be loaded are;
296; old and new lots
H-110; old and new lots
2400
IMR 4227
AA #9
AA#7 (four rds)
ENFORCER
N-110
300-MP
Lil’Gun
Blue Dot

Two side notes I wanted to look at with the H-110/296 loads.
First, I have some very old lots of powder that I got back in the late seventies/early eighties. I have wondered if this powder has lost anything over this amount of time. I got some new powder so I can compare old and new.
Also I wanted to compare the CCI 550 primer against the Win WSPM primer with H-110/296. I used the new lots of powder to do this. The WSPM primer is supposed to be pretty hot.
Let’s first take a look at the factory loads;
Remington 158gr JSP:

Powder charge; 16.6grs of a powder that looks very much like 296/H-110.
https://s20.postimg.cc/hup5xqnul/DSC00922.jpg
https://s20.postimg.cc/kdauyf9kt/DSC00923.jpg
The bullet weighed 158.9grs
https://s20.postimg.cc/w3osft2d9/DSC00924.jpg
Winchester 158gr JSP:

Powder charge also 16.6grs.
https://s20.postimg.cc/8tamk4px9/DSC00926.jpg
https://s20.postimg.cc/fxsft5x6l/DSC00927.jpg
Bullet weighed 157.3grs.
https://s20.postimg.cc/4mudijfp9/DSC00928.jpg
Buffalo Bore 158gr JHP:

Powder charge 19.8grs of a shiny coarse sandy looking powder.
https://s20.postimg.cc/zfihvd4ql/DSC00930.jpg
https://s20.postimg.cc/6bu9z4gn1/DSC00931.jpg
The JHP bullet weighed 158.9grs.
https://s20.postimg.cc/k48our7el/DSC00932.jpg
And of course Buffalo Bore uses Starline brass.
I regret not taking a Hornady round apart before shooting them all up.
So, after loading all this up and spending a day out at the range, here is what I came up with..
Four inch 686;

I only had enough of the Hornady rounds to fire in the 6” this time, but I did shoot some out of the 4” gun last winter.

Factory loads shot pretty well out of the 4” gun. At 1320fps the Buffalo Bore is the stand alone performer. High velocity along with decent accuracy, as advertised. All the cases in every load fell out of the chambers after firing.
Handloads:
14.0grs ENFORCER; Ramshots data lists 14.0grs as maximum. Worked up to this point with no issues.
16.0grs IMR4227; An old lot in a DuPont metal can. This would be the time the batteries in my chronograph craped out. However I remember seeing velocities around 1080fps.
296/H-110; Well there is no difference between the old lots and the new, not enough to matter. These have always been good performers.
15.2 2400; This is THE quintessential 357 Mag load for decades. Fast and accurate.
13.8-14.5grs AA #9; Present AA loading data lists 13.8grs as max. I’ve seen older manuals which go much higher. 13.8grs did pretty well. However 0.7grs more powder produced a 0 fps velocity gain, so I went no further.
18.6 300-MP; Well, this powder is proving to be nothing short of phenomenal. Highest velocity tested and the most accurate, and you don’t need a magnum primer. Might just be my go-to powder from now on.. It does have quite a bark to it..
18.0grs Lil’Gun; Lots of flash and blast for not much velocity.
15.3 N-110; Compressed load.. about 110%. Good performer, only 22fps spread.
10.8grs Blue Dot; Great load!
11.5grs Blue Dot; Not as accurate as 10.8grs but serviceable.
Target #19; I had not tried 300-MP with 125gr bullets yet. This exceeds the fastest 125gr factory load. I thought exceeding the Rem UMC 125gr load was not possible until now.
Six inch Taurus;

For some reason the Remington factory load didn’t like the 6” Taurus, but the rest shot very well. Notice that the Buffalo Bore load lost its advantage with the 6” barrel. It was surpassed by 300-MP, 2400 and N-110.
H-110/296; Same as the 4” results, but notice the lower velocity with WSPM primers. I think CCI 550 are still the primer to use in this application.
IMR 4227; Chronograph working now.. Accurate, but slow.
N-110; Not as accurate in the longer barrel.
300-MP; Top performer as expected.
AA #7; I had four cases left, so what do I do with these?.. I’ll throw 11.5grs of AA #7 in them as see what happens. Well I wish I had four more!
Here is a graph of the entire project;

Well that’s about it.. My curiosity is satisfied.. Hope this answers more questions than it creates.
Lots of fun.
Last edited: