Powders for "full power" 357 magnum 125gr XTP

[rhodesengr]

I have been interested in exploring so-called "full power" loads for my 686 Competitor. I have settled on the Hornady 125gr XTP bullet for now. Looking at various commercial ammo, it is not really clear exactly what full power is but I see commercial ammo with 125gr JHP up to 1700fps and I see listed loads up to 1966FPS.

I have been loading Ramshot Enforcer at about 16.5gr which should be a bit over 1500fps. I did not get good data with my ProChrono last time I tried it and now have a LabRadar which will hopefully give me believable data.

Powders that would give 1800-1900fps include H110 and Win 296 both of which are available.

Just curious what others here are using and why. Nothing wrong with Enforcer as far as I can tell but I like to experiment with different powders. Enforcer is a very fine grain which seems to meter nicely.

I have single stage dies and a Dillon SDB.

 

[mikerjf]

I’ve only stuck a toe in, and don’t have a chrono, but I can say that based on feel 2400 and Power Pistol are up there, and CFE Pistol has been disappointing.

This is all 125 XTP and short barrel, btw.

 

[pistolpete10]

H110/296 should give best velocity.

 

[rhodesengr]

I’ve only stuck a toe in, and don’t have a chrono, but I can say that based on feel 2400 and Power Pistol are up there, and CFE Pistol has been disappointing.

This is all 125 XTP and short barrel, btw.

OK Thanks. Load data for PP is in the 1300fps range and 2400 is in the 1400fps range.

Looked at more 125gr JHP commercial ammo. Most are around 1400fps.

I don't know any rational reason for going up to 1700-1900fps. Just because I can and to gain experience, I guess.

My 686 is pretty heavy so I am not too concerned about recoil. I don't plan to shoot a lot of these high speed loads. Just to get the feel of it and see what I actually get.

 

[rhodesengr]

H110/296 should give best velocity.

I see that in the data. Have you used either of those?

 

[rockquarry]

You can get within 100 fps of H110/296 loads with #2400 and without the obnoxious blast and fireball of H110/296.

I use only #2400 for loading the .357 Magnum (160 grain cast SWC) and can't see an advantage to light bullet loads in this cartridge. However, if your accuracy turns out very good with that bullet and H110/ 296, stick with it. We all have different likes.

 

[LostintheOzone]

158 grn bullet is more or less standard for .357 mag. Increased velocity with 125 grn is a fact but I doubt it will be as accurate. I loaded lots of 125's for a bolt rifle and never was impressed with the bullet weight. I went up the load ladder with 3 or 4 jacketed bullet weights. Heavier bullets were more accurate. The rifle had a 4x scope and a very good after market trigger. I was bench resting the rifle so it was easy to determine the best bullet weight for accuracy.

Velocity isn't everything but it's fun to explore the limits. Powder was 2400. Good luck.

 

[Hair Trigger]

I have been interested in exploring so-called "full power" loads for my 686 Competitor. I have settled on the Hornady 125gr XTP bullet for now. Looking at various commercial ammo, it is not really clear exactly what full power is but I see commercial ammo with 125gr JHP up to 1700fps and I see listed loads up to 1966FPS.

Powders that would give 1800-1900fps include H110 and Win 296 both of which are available.

What barrel lengths are those loads getting 1700+ fps from? My guess is a carbine. The Hornady manual lists an 8" Colt Python as its test gun for .357M loads, and their max load for the 125 JHP gives 1500fps, using either H110 or Win 296. I wouldn't think your 686 with a 6" barrel would even go 1550 when using the load/velocity data Hornady states for the 8". That said, Alliant Power Pro 300-MP gave velocities at 1600 fps using 20.4 grains behind a 125 JHP, compared to H110 @ 19.9gr./1500 fps and Win 296 @ 20.3gr./1500 fps. The Power Pro is slower than either H110 or Win 296.

I've used the Power Pro 300-MP with 158 gr. JHP's in my .357M loads. It works well in 6" barrels, but I find I get some unburned powder residue in my 4" and 2-1/2" .357's, so I generally stay with Power Pistol for those guns. I have a M27-2 and M28-2 with 6" barrels, and a M19-3 with a 4" and a M66-1 with a 2-1/2" barrel

 

[BB57]

1) Colloidal ball powders like H110/Win 296 are popular because they have historically produced maximum velocities. With 125 gr bullets that max in an 8” barrel is about 1500 fps.

Those powders also work with loads from 125 to 180 grains.


2) Recently Power Pro 300 MP has been used to produce higher velocities. With 125 gr bullets it increases the maximum Win 296/H110 max velocities by 100 fps to 1600 fps. However it’s more efficient with heavier bullets with about a 150 fps advantage with 158 gr bullets.

3) But there is no free lunch. All of those fairly slow burning colloidal ball powders use heavy charges around 20 grains. All that mass goes out the barrel at about three times the muzzle velocity of the bullet so those heavy powder charges generate a great deal more recoil - about 35% when compared to the same bullet at the same velocity with a medium speed flake powder like Unique with a max charge around 9 grains.

This is where the peanut gallery steps in with the “yeah, but…” comments and points out that those powders will only generate about 1400 fps in an 8” barrel. That’s true. The heavy colloidal ball powders will be faster, even in short barrels.

But as the barrel gets shorter, that velocity advantage decreases. For example in my 2 1/2” Model 66 and 686, a max load of unique gives me 1250 fps, compared to about 1300 fps with Win 296/H110. Is the extra 50 fps worth 35% more recoil? Not to me.

4) Those colloidal ball powders will also cause more forcing cone erosion, and those v shaped erosion cuts then create the potential for cracks, especially in the K frame 357s where the forcing cone is thinner at the 6 o’clock position.

Those colloidal ball powders became popular about the same time that the 125 gr bullet became the go to bullet for many law enforcement agencies who also started practicing with their duty loads in their K frame .357s.

As a result the shorter 125 gr bullet got the blame with the whackadoo theory that the hot gas could now race around the bullet and pre heat the forcing cone before the bullet arrived.

Thermodynamics says otherwise. In addition, the same effect isn’t seen with the really short 110 gr bullet. Why? Because those colloidal ball powders are not efficient with 110 gr bullets so they are not used in those loads.

In other words, it’s the powder that causes the damage. The 125 gr loads just cause more damage per shot as they use about 20 grains of powder compared to just 16 for the 158 gr loads. That’s an extra 25% more powder flowing through the forcing cone with the 125 gr load compared to the 158 gr load.

But if you switch to a flake powder, or even a flattened spherical powder like 2400 the forcing cone erosion is greatly reduced.

Those colloidal ball powders also leave large unburned and partially burned grains of powder. When one of the, falls out of one of the cylinders and ends up under the ejector star you’ll find yourself with a cylinder that won’t go back into the frame until you dump the rounds, and brush the grain out from where it’s coming between the cylinder and ejector star.


——

Consequently I am more inclined to stay with medium burn rate flake powders and accept a little bit less velocity for a lot less recoil and much cleaner burning that doesn’t create the threat of a jam.

 

[rhodesengr]

Thanks to all for the great replies. Definitely learning a lot. I will read in more detail after work.

can't see an advantage to light bullet loads in this cartridge.

It's the energy vs PF thing. When I looked at listed loads vs weight with similar PF, the energy was much higher with the lighter, faster bullet. PF is basically momentum which is mass*velocity (m*v) while energy is m*v*v or m* v^2.

Does that matter? I don't really know. There would be a difference in terminal performance but I don't have means to look at that (water jugs or ballistic gel). Can't do that sort of thing where I can shoot.

Hodgdon doesn't list their test barrel with their online data. Maybe they do in their book. But I assume it's all relative so whatever I can get with Enforcer will probably be slower than what I can get with 296 or 110. Western Powder does list their test barrel for the Enforcer data and they say 6".

 

[Troystat]

My model 27 likes 125 grain JHP's with W296 but I don't really enjoy shooting them.

 

[Hair Trigger]

Thanks to all for the great replies. Definitely learning a lot. I will read in more detail after work.



It's the energy vs PF thing. When I looked at listed loads vs weight with similar PF, the energy was much higher with the lighter, faster bullet. PF is basically momentum which is mass*velocity (m*v) while energy is m*v*v or m* v^2.

Does that matter? I don't really know. There would be a difference in terminal performance but I don't have means to look at that (water jugs or ballistic gel). Can't do that sort of thing where I can shoot.
.

I used to use 125 grain JHP's in my loads for my M66 many years ago, it was a preferred LE load. Out to about 20 yards, maybe a bit further, the 125 grain carried more energy than the 158 grain due to the greater initial velocity. The tradeoff is in the heavier bullet retaining energy downrange better than the lighter one, so at longer ranges from 20 yards or more, the 158 was the better round. LE used the lighter one because it had a bit less recoil and their engagements were usually 20 yards or less.

I stick to 158 grain on all my .357 loads now because they are a bit easier on the gun, especially the K frame's forcing cone.

 

[colt_saa]

I have been loading the Winchester 125 JHPs for decades with 21.7 grains of H110. I have gone through over 8,000 of that projectile so far and have 3900 still sitting in the loading room waiting.

I LOVE the Big Orange fireball and the low throaty KAaaaBOOM that H110/296 yields . I have burned well over 100 pounds of H110/296 over the last 40 years hand loading it in the 357 Magnum and the 41 Magnum cartridges

As to real world velocities for the 125 JHP, 357 loading (not test barrels) in a . . . . . .
2 1/8" Model 640 - 1234 FPS (AVG of 3 revolvers)
2 1/2" Model 19/66 - 1287 FPS (AVG of 2 revolvers)
3 1/2" Model 27 - 1315 FPS (AVG of 1 revolvers)
5" Model 627 - 1496 FPS (AVG of 2 revolvers)
6" Model 27 - 1531 FPS (AVG of 2 revolvers)
8" Python - 1599 FPS (AVG of 1 revolvers)
10" T/C Contender - 1780 FPS (AVG of 1 firearm)
18" Model 1982 - 2106 FPS (AVG of 1 lever gun)

These were strings of 5 shots per firearm all averaged together

One of my co-workers loved to show up at the public range with a cylinder full of these in his snubby Model 19. He called them the Attention Getter

this is the FUN load for the 357 Magnum revolvers and if you are lucky enough to own one of the 357 Magnum Desert Eagles, well the adore full power loads of H110/296 and are surprisingly accurate with the,

You are going to love your LabRadar. I have had mine for many years now.

Virtually no setup time and now that the bluetooth is active all the data goes right into your smart phone app. Get yourself an external USB battery and forget about using the AAs. You will be much happier and it will be rechargeable

 

[TheTinMan]

I have been loading the Winchester 125 JHPs for decades with 21.7 grains of H110. I have gone through over 8,000 of that projectile so far and have 3900 still sitting in the loading room waiting.

I LOVE the Big Orange fireball and the low throaty KAaaaBOOM that H110/296 yields . I have burned well over 100 pounds of H110/296 over the last 40 years hand loading it in the 357 Magnum and the 41 Magnum cartridges

As to real world velocities for the 125 JHP, 357 loading (not test barrels) in a . . . . . .
2 1/8" Model 640 - 1234 FPS (AVG of 3 revolvers)
2 1/2" Model 19/66 - 1287 FPS (AVG of 2 revolvers)
3 1/2" Model 27 - 1315 FPS (AVG of 1 revolvers)
5" Model 627 - 1496 FPS (AVG of 2 revolvers)
6" Model 27 - 1531 FPS (AVG of 2 revolvers)
8" Python - 1599 FPS (AVG of 1 revolvers)
10" T/C Contender - 1780 FPS (AVG of 1 firearm)
18" Model 1982 - 2106 FPS (AVG of 1 lever gun)

These were strings of 5 shots per firearm all averaged together

One of my co-workers loved to show up at the public range with a cylinder full of these in his snubby Model 19. He called them the Attention Getter

this is the FUN load for the 357 Magnum revolvers and if you are lucky enough to own one of the 357 Magnum Desert Eagles, well the adore full power loads of H110/296 and are surprisingly accurate with the,

You are going to love your LabRadar. I have had mine for many years now.

Virtually no setup time and now that the bluetooth is active all the data goes right into your smart phone app. Get yourself an external USB battery and forget about using the AAs. You will be much happier and it will be rechargeable

Thank you very much for sharing that data!

I am guessing that the 3-1/2” barrel results are an anomaly because of the data progression. Does it look that way to anyone else?

I want a Labradar!

 

[rosewood]

Hodgdon doesn't list their test barrel with their online data.

Actually they do.

 

[scooter123]

I've loaded up some 125 grain Magnums with 21.5 grains of H110. The muzzle blast was louder than a 500 Magnum and per witnesses the flame was 15 to 15 feet down the range. I haven't ever tried that load since, it is just too obnoxious. That blast is also too much, you can't see the target for 1 or 2 seconds after firing due to the flash, which means it's a poor choice for Defensive use. Finally, it will do some real flame cutting to the top strap of your revolver.

My "normal" 357 Magnum load is 14.6 grains of H110 and it produces 1240 fps from my 4 inch 620 and 1620 fps from my 20 inch Winchester 1892 with sub 1 inch accuracy at 100 yards with a rear tang peep sight.

 

[Rlg#17]

Longshot will get you over 1,500 fps with a 125 grain, maybe a tad over depending on the revolver etc. I don’t think you are going to hit 1800 fps in a revolver, maybe with a rifle….

It doesn’t seem to be as obnoxious as a 110 loaded round, I quit using the powder several years ago after using the Longshot.

I’ve had similar results even with the heavy weight bullets in .357, 10mm and the bigger magnums.

More bang for the buck if you will.

Regards from the Commonwealth,
Rick Gibbs

 

[rosewood]

Longshot will get you over 1,500 fps with a 125 grain, maybe a tad over depending on the revolver etc. I don’t think you are going to hit 1800 fps in a revolver, maybe with a rifle….

It doesn’t seem to be as obnoxious as a 110 loaded round, I quit using the powder several years ago after using the Longshot.

I’ve had similar results even with the heavy weight bullets in .357, 10mm and the bigger magnums.

More bang for the buck if you will.

Regards from the Commonwealth,
Rick Gibbs

I switched to longshot for snub nose 357 mag revolvers. You lose about 100 FPS or so, but it is still better than 9mm and the longshot greatly reduces muzzle blast and flash. Longshot is a duller yellow instead of bright white so does less damage to night vision.

I like it in 10mm and 40 also.

Rosewood

 

[BB57]

I have been loading the Winchester 125 JHPs for decades with 21.7 grains of H110. I have gone through over 8,000 of that projectile so far and have 3900 still sitting in the loading room waiting.

I LOVE the Big Orange fireball and the low throaty KAaaaBOOM that H110/296 yields . I have burned well over 100 pounds of H110/296 over the last 40 years hand loading it in the 357 Magnum and the 41 Magnum cartridges

As to real world velocities for the 125 JHP, 357 loading (not test barrels) in a . . . . . .
2 1/8" Model 640 - 1234 FPS (AVG of 3 revolvers)
2 1/2" Model 19/66 - 1287 FPS (AVG of 2 revolvers)
3 1/2" Model 27 - 1315 FPS (AVG of 1 revolvers)
5" Model 627 - 1496 FPS (AVG of 2 revolvers)
6" Model 27 - 1531 FPS (AVG of 2 revolvers)
8" Python - 1599 FPS (AVG of 1 revolvers)
10" T/C Contender - 1780 FPS (AVG of 1 firearm)
18" Model 1982 - 2106 FPS (AVG of 1 lever gun)

These were strings of 5 shots per firearm all averaged together

One of my co-workers loved to show up at the public range with a cylinder full of these in his snubby Model 19. He called them the Attention Getter

this is the FUN load for the 357 Magnum revolvers and if you are lucky enough to own one of the 357 Magnum Desert Eagles, well the adore full power loads of H110/296 and are surprisingly accurate with them

I’m liking this post for the confirmation of my data showing almost no advantage over a medium speed flake powder like Unique in short barrel revolvers.

My 2 1/2” data (average of 2 revolvers) with Unique is just 13 fps less than your average with H110/Win 296.

My 3” data (average of 2 revolvers) is just 15 fps slower than your 3 1/2” revolvers. I suspect your revolver has larger than average chambers and or bore and or cylinder gap dimensions. I’ve seen variation in velocity within the same model and barrel length as high as 150 fps when those variables stack at different extremes.)


—-

I am not a fan of the increased recoil (about 35%) of H110/Win 296, or the increased muzzle flash.

I’ve never felt the need to get attention or otherwise compensate on a firing range.

I regard it much like I regarded the guy in the F250 with loud exhausts and high profile tires that had to drive over really small bumps in the street at 10 mph in a 35 mph zone.

Flashy and attention getting, but not in a good way, and for all practical F-250 purposes totally useless.

 

[rhodesengr]

I LOVE the Big Orange fireball and the low throaty KAaaaBOOM that H110/296 yields

You are going to love your LabRadar. I have had mine for many years now. Virtually no setup time and now that the bluetooth is active

Thanks for the detailed post. I do think this load is more about "gee whiz" and "fun factor" rather than anything particularly practical.

I bought my Lab Radar a few months back when they only had the non-BT version. I don't know if it is upgradable or not. I bought pretty much all the accessories including the battery pack, SD card, Tripod, carry bag.

I have Longshot on hand so I can try that as well. I use that in my #00 buckshot rounds that I developed and had tested. That work is described in a thread called Project Buckshot on Shotgun World/reloading if anyone is interested.