Realistic .357 Mag velocity

[oso]

To make reasonably full use of the energy potential of the .357 Magnum I use my lever rifle. I wonder if I've put more rounds through that than my S&W 28 and Ruger Sec Six together. I do shoot more 38 Special but not in 357 mag chambers.

[Paul105]

Took my new Labradar out for a spin a while back. The 2 3/4" M66-8 seems to be one of those "fast" guns.


Labradar Muzzle Velocity (familiarization run)
60 Deg F
S&W M66-8 2.75" .357 Mag

130gr Fed Hydra-Shok JHP "Personal Defense" PD357HS2 H …….. 1,416 fps avg (84 fps ES) -- two rounds
140gr Underwood Xtreme Penetrator (Philips head mono metal).. 1,422 fps avg ( 5 fps ES) -- two rounds
158gr Horn Xtp - 15.0gr A2400 Std small pistol, new Starline...… 1,316 fps avg (49 fps ES) -- six rounds
165gr CSWCGC (358156) - 13.0gr A2400 New Starline ...… 1,180 fps avg (84 fps ES) -- six rounds
180gr Buff Bore …………………………………………………………………………….. 1,312 fps avg ( 6 fps ES) -- two rounds
185gr LFNGC (Beartooth), 15.0gr Lil'Gun, CCI 400 New Starline.. 1,228 fps avg (14 fps ES) – two rounds
200gr WLNGC (leadheads), 13.4gr H110, Fed 205, New Starline.. 1,102 fps avg ( 4 fps ES) – two rounds
200gr WLNGC (leadheads), 14.4gr H110, Fed 205, New Starline.. 1,155 fps avg ( 2 fps ES) – two rounds
(purported to be the “Doubletap” load info)
200gr WLNGC (leadheads) handload with Lil Gun ………………………. 1,266 fps avg ( 2 fps ES) -- two rounds
Load data not given -- maybe too much of a good thing. Spent cases fell from chambers, and no obvious signs of over pressure. Recoil was heavy. Don't even know if this stabilizes.

The 13.0gr A2400 is my 99 % use load. If even needed, I would limit useage of the 180, 185, and 200gr loads in J & K Frame guns

Also ran two Buff Bore 180s thru 16" Rossi M92 carbine ……………. 1,894 fps avg ( 6 fps ES) -- two rounds

Just some more data points.

FWIW,

Paul

[megasupermagnum]

Absolutely, small differences in barrel length are no guarantee that the longer one will be faster. I would think a 6" should be faster than a 2 3/4". My 4 5/8" blackhawk seems to be very similar to most 6" guns.

[fatelk]

I did some load testing today. I tried loads with H108, AA#9, H110, and 2400. It seems that both of my revolvers are on the "slow" side for velocity. Nearly all velocities were slower than book velocities for the same load. I realize that's not unusual.

From searching around, I found that 15.5gr H110 is a popular charge with a 158gr cast bullet. This clocked at about 1150fps in the 4" model 66, and 1250+ in the 6" 586. I can live with that. I wasn't really trying to wring out accuracy today, but did shoot a cylinder full at a bullseye 20 yards away, and got a nice 1.5" group. 1150 seems slow for a full-charge .357 load, seems more like a mid-range Unique load, but it is what it is. Unfortunately I don't have any factory ammo to test in that gun. I even wondered about my chronograph, so I broke out my spare. It was right on par with the other one.

The H108 was more consistent with velocity; 14.0gr was about 50fps faster in both guns than the H110. I didn't test it for accuracy. After getting home I was searching around online and found a warning to not use Winchester SPM primers with H108 as they could cause pressure spikes, and those were the exact primers I was using. I'll try some more with non-magnum primers.

[dtknowles]

I did some load testing today. I tried loads with H108, AA#9, H110, and 2400. It seems that both of my revolvers are on the "slow" side for velocity. Nearly all velocities were slower than book velocities for the same load. I realize that's not unusual.

From searching around, I found that 15.5gr H110 is a popular charge with a 158gr cast bullet. This clocked at about 1150fps in the 4" model 66, and 1250+ in the 6" 586. I can live with that. I wasn't really trying to wring out accuracy today, but did shoot a cylinder full at a bullseye 20 yards away, and got a nice 1.5" group. 1150 seems slow for a full-charge .357 load, seems more like a mid-range Unique load, but it is what it is. Unfortunately I don't have any factory ammo to test in that gun. I even wondered about my chronograph, so I broke out my spare. It was right on par with the other one.

The H108 was more consistent with velocity; 14.0gr was about 50fps faster in both guns than the H110. I didn't test it for accuracy. After getting home I was searching around online and found a warning to not use Winchester SPM primers with H108 as they could cause pressure spikes, and those were the exact primers I was using. I'll try some more with non-magnum primers.

When was the last time you checked your scale. Your velocities do seem low.

Tim

[fatelk]

When was the last time you checked your scale. Your velocities do seem low.

Tim

It may be time to retire the old Ohaus scale. I've been using it for 30 years. I just checked it against a couple extra scales that I have, and it's nearly 2/10gr heavy compared to the others, at 10gr, 25gr, and 50gr. Not sure why that could be, but I'm pretty sure that 2/10 of a grain wouldn't make anywhere near the kind of difference we're seeing.

[Forrest r]

Not all bullets are created equal, bullet design can make a load very as much as 70fps. A couple years back I did some head to head testing using these bullets along with 2 others not pictured and 5 different powders in a snubnosed 38spl.
[IMG][/IMG]

I wanted to develop a 357 load for a 586 l-comp. The l-comp has a 3" bbl shroud (full length ejector rod) and a 2 1/2" bbl with a comp in the last 1/2" of bbl shroud.
[IMG][/IMG]

I chose the mihec 158gr fn hp for a test bullet (top picture top row 2nd from left/green). Decided to do a little head to head testing with 2400 vs h110 vs mp-300. Figured while I was at it might as well make up a bunch of hot/full house loads of each powder and do testing in different bbl length's while I was at it. So I loaded up a pile of reloads using the 3 different powders and that mihec bullet. For test firearms I used.

2 1/2" bbl (1 revolver)
4" bbl (2 revolvers)
6" bbl (2 revolvers)
8" bbl (1 revolver0
10" contender

At the end of the day I got:
2 1/2" bbl ='s 1200fps with 2400 and 1150+fps with h110 & mp-300
4" bbl ='s 1300+fps for all powders with the h110 & mp-300 starting to edge ahead/faster
6" bbl ='s 1450+fps with the h110 & mp-300 1400+fps with 2400
8" bbl ='s 1500fps+ with h110 & mp-300 1450+fps with 2400
10" bbl ='s 1600+fps with h110 & mp-300 1500+fps with 2400

That 8" bbl never did have good velocities, never bothered to replace it because I just don't use it that often.

Ended up using the fn/170gr version of that mihec bullet in the l-comp. Same load of 2400/same 1200fps out of that 2 1/2" bbl.
[IMG][/IMG]

[dvnv]

In working up loads for the "magnums" (K frames excluded), H110 has ended up the best performer when both velocity and accuracy is considered.
You probably already know this, but H110 accuracy is generally best when the loaded to the base of the bullet, maybe with just a smidge (technical term) of compression.

I save LilGun for the 218 Bee, where it also shines.

[Silver Jack Hammer]

I only cast 358421 when the government tells me to stay at home, but wouldn’t cast boolits at 1500 fps lead your bore? I’ve got a brace of seldom used Ruger 3 screw Blackhawk’s in .357 with 4 5/8” barrels.

[megasupermagnum]

I did some load testing today. I tried loads with H108, AA#9, H110, and 2400. It seems that both of my revolvers are on the "slow" side for velocity. Nearly all velocities were slower than book velocities for the same load. I realize that's not unusual.

From searching around, I found that 15.5gr H110 is a popular charge with a 158gr cast bullet. This clocked at about 1150fps in the 4" model 66, and 1250+ in the 6" 586. I can live with that. I wasn't really trying to wring out accuracy today, but did shoot a cylinder full at a bullseye 20 yards away, and got a nice 1.5" group. 1150 seems slow for a full-charge .357 load, seems more like a mid-range Unique load, but it is what it is. Unfortunately I don't have any factory ammo to test in that gun. I even wondered about my chronograph, so I broke out my spare. It was right on par with the other one.

The H108 was more consistent with velocity; 14.0gr was about 50fps faster in both guns than the H110. I didn't test it for accuracy. After getting home I was searching around online and found a warning to not use Winchester SPM primers with H108 as they could cause pressure spikes, and those were the exact primers I was using. I'll try some more with non-magnum primers.

That is not too surprising, 15.5 gr H110 is listed as a starting load. Most manuals I'm seeing show a max with a 158 grain at 17 grains. I have used Lil'Gun, before the internet told me how hot it burned. It works great. The reason I no longer use it, is that it is a twin to H110. Since most of my strong loads used H110, there is no reason to switch. I don't understand why Lil'gun exists at all. I'm sure there is somewhere it has an ever so slight advantage to h110, but in handguns, Lil'gun is a redundant powder. Another good one is Vhitavouri N110, and may even have a leg up on H110 in terms of speed. I always got better accuracy with H110. AA #9 has always been a rather mundane performer for me.

[MT Gianni]

If you want velocity you are shorting yourself by not trying MP300.

[fatelk]

Thanks everyone. You’ve given me lots to consider, and a few options to try.

My Lyman manual listed 15.9gr H110 as max for the most similar bullet I could see, but I wondered how much of the difference could be from the powder-coated Lee bullet I’m using. Maybe I’m just being too conservative with my load work up. I don’t want to push it too much, considering the K frame model 66, but in reality it doesn’t get shot much with .357 Magnums, mostly just .38s. Most of the magnums I load will be used in the 586, and even then I don’t shoot a lot of them.

One thing I saw than made me wonder about either a chronograph issue, or that the H110 was still a bit light, was the occasional low velocity with the H110 loads. With the 6” gun, I’d have some that would clock high 1200s/low 1300s, then one would clock 1090. That seemed odd.

[357Mag]

Fatelk -

Howdy !

My go to .357Mag load is: 14.5gr WW296 ( H 110 same stuff ) and SP Mag under a ( Lyman ) SWC of
158-172br. This was the minimum charge Winchester ( Olin ) recommended using this powder in
.357Mag.

It has always shot superbly in 4,5, and 6” “N”- frames, and in a Marlin 1894SC.


With regards,
357Mag

[megasupermagnum]

Thanks everyone. You’ve given me lots to consider, and a few options to try.

My Lyman manual listed 15.9gr H110 as max for the most similar bullet I could see, but I wondered how much of the difference could be from the powder-coated Lee bullet I’m using. Maybe I’m just being too conservative with my load work up. I don’t want to push it too much, considering the K frame model 66, but in reality it doesn’t get shot much with .357 Magnums, mostly just .38s. Most of the magnums I load will be used in the 586, and even then I don’t shoot a lot of them.

One thing I saw than made me wonder about either a chronograph issue, or that the H110 was still a bit light, was the occasional low velocity with the H110 loads. With the 6” gun, I’d have some that would clock high 1200s/low 1300s, then one would clock 1090. That seemed odd.

Are you using magnum primers? 15.5 is a good safe load, and should certainly not be seeing 200 fps velocity swings. I'm looking at the Lyman 50th manual, and for a 158 grain jacketed bullet they list 17 grains H110 as max. This is safe in any 357 magnum ever made. I wouldn't shoot 20,000 of them in a lighter gun for fear of wearing it out, but they are not dangerous. Whether or not this is the most accurate or not is not certain. I've found great accuracy over that maximum. I wish there was a SAMMI +p spec of say 45,000 psi.

[Silvercreek Farmer]

If you want velocity you are shorting yourself by not trying MP300.

+1 "Original" 357 mag specs are attainable with published data. Very accurate as well.

[Larry Gibson]

Keep in mind when making comparisons of your chronographed data with published data that the published data may be muzzle velocity. I most often test using the Oehler M43 with the start screen at 15' from the muzzle. It gives both screen velocity and muzzle velocity (based on screened velocity/ feet from muzzle/B.C. of the bullet). I have compared the corrected velocity using a MagnetoSpeed attached to the muzzle during the same test.

If you comparing your chronographed velocities with published data which may be and probably are muzzle velocities there can be a discrepancy simple because of the two different measurments on top of other variations. With the 357 magnum I found, with the same bullet [358156], chronographed velocities at 15' give 7 - 10 fps lower velocities at sub- sonic levels. When the bullet is pushed trans-sonic at about 1200 fps there is usually a 20+ fps difference between chronographed and muzzle velocity. When pushed to 1400 - 1500 + fps the difference can be as much as 40+ fps difference. .

[megasupermagnum]

Keep in mind when making comparisons of your chronographed data with published data that the published data may be muzzle velocity. I most often test using the Oehler M43 with the start screen at 15' from the muzzle. It gives both screen velocity and muzzle velocity (based on screened velocity/ feet from muzzle/B.C. of the bullet). I have compared the corrected velocity using a MagnetoSpeed attached to the muzzle during the same test.

If you comparing your chronographed velocities with published data which may be and probably are muzzle velocities there can be a discrepancy simple because of the two different measurments on top of other variations. With the 357 magnum I found, with the same bullet [358156], chronographed velocities at 15' give 7 - 10 fps lower velocities at sub- sonic levels. When the bullet is pushed trans-sonic at about 1200 fps there is usually a 20+ fps difference between chronographed and muzzle velocity. When pushed to 1400 - 1500 + fps the difference can be as much as 40+ fps difference. .

I knew it makes a huge difference with shotguns, I had no idea the effect was that great with bullets too. Most of my testing is done around 6'-8'.

[fatelk]

OK, I had a chance to get out again today. Here's what I came up with:
.357 Magnum- Lee 358-158-RF powder coated- RP brass- WSPM primers
S&W 586 6" barrel
16.0gr H110: 1287, 1353, 1373
16.5gr H110: 1305, 1412, 1401, 1388
17.0gr H110: 1395, 1332, 1370, 1303, 1366

S&W 66 4" barrel
16.5gr H110: 1225, 1203, 1223, 1279, 1205

I also loaded up some rounds with 14.0 and 14.5gr of H108, with standard primers (CCI500) instead of magnum. I only shot a couple across the chronograph when it started raining, so chronograph time was over. Velocities with these were low, around 1200fps. Anyone tinkered much with H108?

There were no sticky cases in any of these loads. I know that primer flattening is a generally unreliable indicator of pressure, but the WSPM primers always look flatter than the CCI 500s, no matter the load. Two of the 17.0gr H110 cases (fired in the 66) had primers that did look a little flatter than the others.
I also realized one issue that might be a factor in the inconsistent velocities; the brass I've been using is RP, but it's of unknown vintage, definitely not all 1x. Would that account for much?

One thing I did today that I'd never done before: I set up both chronographs in line with each other. They are both inexpensive so I've never known how much to rely on them for accuracy. The Caldwell unit read consistently 10-15 fps faster than the Chrony F1 a few feet behind it.

[derek45]

5" 686

17gr win296/H110

158xtp

1242fps.
---------------------------
17.3gr w296/h110

158xtp

1269fps.

17.2 w296/H110
LEE 158grSWC-GC ( closer to 168gr with lube & gas-check)
1489fps


22gr w296/H110
125gr rem SJHP
1639 fps

140grXTP
19.6gr w296/H110
1442fps ave.

---------------------------

14.7gr 2400
158 SWC
1275fps

15.8gr 2400
158 SWC
1364fps

[tazman]

OK, I had a chance to get out again today. Here's what I came up with:
.357 Magnum- Lee 358-158-RF powder coated- RP brass- WSPM primers
S&W 586 6" barrel
16.0gr H110: 1287, 1353, 1373
16.5gr H110: 1305, 1412, 1401, 1388
17.0gr H110: 1395, 1332, 1370, 1303, 1366

S&W 66 4" barrel
16.5gr H110: 1225, 1203, 1223, 1279, 1205

I also loaded up some rounds with 14.0 and 14.5gr of H108, with standard primers (CCI500) instead of magnum. I only shot a couple across the chronograph when it started raining, so chronograph time was over. Velocities with these were low, around 1200fps. Anyone tinkered much with H108?

There were no sticky cases in any of these loads. I know that primer flattening is a generally unreliable indicator of pressure, but the WSPM primers always look flatter than the CCI 500s, no matter the load. Two of the 17.0gr H110 cases (fired in the 66) had primers that did look a little flatter than the others.
I also realized one issue that might be a factor in the inconsistent velocities; the brass I've been using is RP, but it's of unknown vintage, definitely not all 1x. Would that account for much?

One thing I did today that I'd never done before: I set up both chronographs in line with each other. They are both inexpensive so I've never known how much to rely on them for accuracy. The Caldwell unit read consistently 10-15 fps faster than the Chrony F1 a few feet behind it.

I have read that when you start getting the same or slightly less velocity with H110/296 that you need to drop back to the last charge before the increase stopped. Supposedly, if you continue to increase charge weight, you run the risk of bad things happening.
It has been a long time since I saw that article. I can't remember where I read it.