Hot 125 gr JHP .357 Magnum load with 2400

its been a while since I've loaded .357 magnum with lighter 125 gr jacketed bullets since havering so much fun experimenting with 158 gr LSWC hard cast.

I loaded a cylinder full of 125 gr hornandy JHP bullets tonight with 16 gr of 2400 behind it. Shot them through my 6 inch Highway Patrolman. Results: almost felt like shooting 38 special with a lot of muzzle flash in the dark. They did not feel all that powerful at all. Not what ive become accustomed to with the hot 125 gr load.

What do yall build up to for this load?

That load is just plumb handy in my 6" magnum.
Right close to the factory ammo and does well with my iron sights.

I though about dropping down to 15grs but why ?

Good shooting.

I haven't loaded 125gr in many years but I load my 140gr XTP to that level. Depending on which manual you want to pick from, you have 0.9-1.7grs more available.

.

I imagine the weight/bulk of the N frame makes a considerable difference in the feel when they're fired. I use 16gr. of VV N110, which has around the same burn rate as 2400. It's .4gr under max. But I only have L frames, and it feels fairly stout in those.

Andy

Your 16gr of 2400 sounds like some of mine from years ago. 15.8gr with a nosler 158gr sp at almost 1600fps from a 8" DW revolver . I found I got better results with even heavier bullets . Much prefer a speer 170gr sp with 14.4 gr of old 2400 for deer and 12,3gr 2400 and 180grHC for hogs..
158gr are most light loads more like factory fodder of today down to 38sp velocity .

Lyman sez....

Lyman sez max 17.7 grains of 2400 for a 125 gr jhp.

That sounds about right because the max for my 140 grain jhp is 16 gr. 2400. I've been up to 15.4 gr of 2400 in my 686 and I'm good for about a dozen rounds then it feels like I'll do permanent damage to my hands and wrists.

I would guess that over 17 grains would feel about the same way with a 125 grain bullet.

Speer #10 lists 125gr jacketed SP or HP starting @17.5gr 2400 (1399fps) with a max @ 19.5gr (1555fps). It does want you to use a Mag. primer for either load. It also puts a warning "max loads listed should be used with caution.
PS: what I find interesting is that the 357 mag (rifle) loading data is identical using 2400 just the FPS are different due to the 18.5" barrel length on the lever gun. Speer #10 lists their data from a Ruger Security 6 with a 6" barrel.

I just carefully loaded 16.5 grains of 2400 into 11 rounds. Fired 6 through the Chrony F-1 and kept getting "Error 9" on all six shots. I tried turning it off and on, I tried changing positions. It's a sunny day at 6:15 central time and the sun hasn't even gone down yet.

WHAT IS WRONG WITH THIS CHRONOGRAPH?! The online manual for that brand says nothing about Error 9. That was 30 minutes of reloading and shooting wasted that I'll never get back.

Maybe your Chrony was sayin' " I don't want to talk about it!"

Muzzle blast..........
Back off the screen to 15 feet if you can and see if it will work.

I normally run my Pro Chrono at 7 feet for handgun loads but had to move it to 10 feet with my 357 Mag loads. Never had a single reading at 7 feet. Don

Like everyone else says, move back a few feet, your too close.

LOL! My deck is 10 feet wide, if I moved it back anymore it would fall off into the flowerbed/yard...or I would have to back up through a window.

But I'll try something different tomorrow.

Doug.38PR said:

I just carefully loaded 16.5 grains of 2400 into 11 rounds. Fired 6 through the Chrony F-1 and kept getting "Error 9" on all six shots. I tried turning it off and on, I tried changing positions. It's a sunny day at 6:15 central time and the sun hasn't even gone down yet.

WHAT IS WRONG WITH THIS CHRONOGRAPH?!

Click to expand...

It's a Chrony! I tried to chronograph loads with two different
ones with no luck; error messages and false readings. My C.E.
Pro Chrono digital is reliable as long as I stay 10-12 ft back
from it. If you want to duplicate 125 gr 357 factory loads,
about 1400 fps out of a 4" barrel, with 2400 you're going to
have to use the earlier data. 17.5 grs with a magnun primer
under a 125 gr Sierra HP runs about 1370 fps out of my 4"
S&W 28-2. Still a bit short.

Okay,
I backed up another 15 feet and changed positions. It worked. Chronograph is working great. Unfortunately, my 6 inch Highway Patrolman and the 16.5 gr of 2400 behind a 125 gr JHP is not.

Here are the results:

.357 Magnum 125 gr., JHP Hornandy 6 inch 1977 Smith & Wesson Highway Patrolman M-28-2
16.5 grains 2400: 1141, 1166, 1131, 1159, 1208, 1159, 1146, 1175, 1159, 1156, 1153

compared to:

.357 Magnum 158 gr., LSWC (Hard) 6 inch 1977 Smith & Wesson Highway Patrolman M-28-2
14.3 grains 2400: 1216, 1205, 1238, 1204, 1215, 1243, 1269

15.0 grains 2400: 1356, 1363, 1363

.357 Magnum 158 gr. LSWC (Hard) 4 inch 1980 Colt Python
14 grains 2400: 1246, 1234, 1260, 1238, 1176, 1233
14.4 grains 2400 (more or less) 2400: 1298, 1216, 1288, 1265, 1293, 1281
14.3 grains 2400: 1220, 1256, 1220, 1263, 1200, 1178
14.4 grains 2400: 1258, 1219, 1219,
14.5 grains 2400:1311, 1341, 1323, 1333
14.6 grains 2400: 1353, 1345

.357 Magnum 180 gr. SJHP 4 inch 1980 Colt Python
Remington: 1129, 1131, 1125, 1123, 1123

and even compared to:


9mm 124 gr, FMJ, Beretta M9

9mm NATO 124 gr Winchester: 1157, 1163, 1169, 1153

9mm 124 gr 7.8 gr AA7: 1144, 1162, 1168

9mm+P+ 124 gr Federal Hydrashok Law Enforcement: 1118, 1156, 1127, 1127, 1129, 1115, 1150, 1123, 1135, 1142, 1151 (NOTE: these Beretta rounds I clocked right after I clocked the 125 gr Highway Patrolman rounds)

.38 Special +P 158 gr. LRN. 4 inch 1961 Colt Official Police

Buffalo Bore LHP: 1181, 1193, 1199, 1194, 1150, 1188 Feet Per Second


There is either something very wrong my gun or these loads are VERY weak. It's a 6 inch .357 bloody MAGNUM...and it can barely keep up with heavier bullets some of which are fired from a shorter barrel and even average handgun calibers in .38 Special and 9mm?????

This is really disappointing. This is why I posted, in another thread on here, asking about closing the cylinder gap between cylinder and force cone. As though maybe the round is losing too much powder in between to maintain the full magnum force of the loading. Because the gun actually does have that magnum thunderclap when fired and even has a bite to your face as the soundwave hit it compared to other non-magnum guns like the Official Police and Beretta and their top notch loads


EDIT: My wife just walked into my office and ask me how my chronographing went. (she was upstairs at her desk working and I was down in the backyard shooting) I told her the results were disappointing. Too slow. Not as powerful as I was expecting. "Really?" she asks, "Because when you fire that particular gun it goes *BWUHOOOM* It's a lot louder compared to other guns you fire out there." (plus our little Terrier was scared and seeking comfort from her)

I kind of gave up trying to reach the velocities with my loads that the 357 mag Hornady Critical Defense was giving me in my GP-100 4.1 inch barrel. the box says 1500 fps, no barrel length. They shot 1443 out of my 4" barrel. My hottest hand loads only got to 1256 with 15.0gr H110. But then I was pushing a 158gr FP and they were only pushing 125gr FTX. I am happy with my load I really don't need more speed. Don

Something very odd just happened. Just for grins, I loaded one more 125 gr .357 Shell with 17.1 grains of powder in it, dropped it in the highway patrolman. Fired at a target 35 yards off, fired the gun, the bullet hit the target. However, when the gun went off I felt like somebody just threw a little dirt on my gun arm. I was startled. Looked at my arm and saw a couple of grains of powder. I looked down the barrel and saw what looked like something stuck in the barrel. And about 1/3 of the O was blocked from light going through the barrel. I went inside to get a flashlight to get a better look and when I opened the gun again and looked it was gone. I did, however, notice quite a few grains of unburned powder in the barrel...and now that I think about it I have been noticing a little bit of grain in the barrel since I've been shooting these.

I wonder, now, if there is something wrong with the powder. If it's not burning completely like it should in a magnum load.

I've never loaded anything lighter than 158 grains in a .357. But if your really wanting to amp it up, you might want to look at a slower powder like H110.

Doug.38PR said:

I wonder, now, if there is something wrong with the powder. If it's not burning completely like it should in a magnum load.

Click to expand...

What you saw in the barrel was probably just smoke from the
load just fired. Are you using magnum primers? 2400 is a
slow burning pistol powder and it will burn cleaner with higher
pressure but it always leaves a few grains in the bore. With a
125 gr bullet 2400 will burn more efficiently than H110. The
difficulty of getting good velocity with jacketed bullets out of
the 357 is one reason that I load mostly cast bullets in it.
Not trying to be rude but you seem to persist in blaming your
loads for not performing above what's to be expected. Again,
if you expect to see high velocity out of your gun with 125 gr
JHPs you're going to have to use a load that will achieve it.
Older data went up to 19.5 grs of 2400 with a magnum primer
and were within the std. pressure guidelines for the 357
before it was watered down so to speak. You're not going to
get the same velocity with 3 grs less powder.

alwslate said:

What you saw in the barrel was probably just smoke from the
load just fired. Are you using magnum primers? 2400 is a
slow burning pistol powder and it will burn cleaner with higher
pressure but it always leaves a few grains in the bore. With a
125 gr bullet 2400 will burn more efficiently than H110. The
difficulty of getting good velocity with jacketed bullets out of
the 357 is one reason that I load mostly cast bullets in it.
Not trying to be rude but you seem to persist in blaming your
loads for not performing above what's to be expected. Again,
if you expect to see high velocity out of your gun with 125 gr
JHPs you're going to have to use a load that will achieve it.
Older data went up to 19.5 grs of 2400 with a magnum primer
and were within the std. pressure guidelines for the 357
before it was watered down so to speak. You're not going to
get the same velocity with 3 grs less powder.

Click to expand...

1) No, it wasn't smoke. It was something solid and stationary. And something blew excess powder or something back onto my arm.

2) No, I wasn't using magnum primers (although I do have plenty). I don't believe my manuals call for using a Magnum primer in 2400.

3) My reloading manuals call for a maximum load of 17.5 grains of 2400.

4) My Lyman manual calls for, I think, 1150 ft per second, for just 15 grains of 2400 and, I think, 1400 ft per second for 17.5 grains out of a 4 inch barrel. In light of this, I think my 6 inch barrel should have done much better than it did.

Would you really recommend going up past 17.5 grains with current 2400 powder and a magnum primer? Not being sarcastic and I know the answer is probably "yes" but I would just like to understand a little bit more before proceeding