I need some help interpreting my data.

[Jaak]

I am trying to find an accurate loading for my S&W 686+ with a PC Lee 358-158-RF bullet. The 868's cylinder throats all measure .3580 give or take .0001 either way and the bore slugs out at 0.3570inch. Five of the seven throats measure .3580 exactly. I started with H110 and my Shooting Chrony shows velocities all over the place. Here's what I've gathered:




Grains
15.0
15.2
15.4
15.6
15.8




1195
1284
1165
1193
1289



1205
1297
1166
1245
1251



1199
1269
1262
1229
1303



1327
1293
1307
1340
1350



1279
1164
1129
1141
1267



1351
1347
1241
1236
1197



1319
1218
1239
1175
1344



1264
1305
1202
1267
1183



1346
1202
1172
1196
1242



1194
1191
1296
1246
1282










Average
1,267.9
1,257.0
1,217.9
1,226.8
1,270.8


Min
1,194.0
1,164.0
1,129.0
1,141.0
1,183.0


Max
1,351.0
1,347.0
1,307.0
1,340.0
1,350.0


Standard Deviation
65.6
59.4
60.3
55.1
55.3


Spread
157.0
183.0
178.0
199.0
167.0




I was expecting a somewhat linear slope trending upwards. Obviously something went wrong so I loaded up ten cartridges double checking everything. The bullets were weighed out to a max spread of 0.8 grains. The casings were all Winchester head stamp and trimmed to exactly 1.28 inches with two quality calipers used to double check length of every case. The powder was weighed out by a Frankford IntelliDropper and each load was double checked on a 505 balance scale. Each drop was 15.6gr, give or take three-hundredths of a Grain. (I was impressed with the FID's consistency)

I shot five rounds through the 686+



686+ 6"
Velocity



1263



1269



1334



1233



1220






Standard Deviation
44.2


Min
1220


Max
1334


Spread
114


Average
1263.8







A spread of 114fps. What the hell is this? An SD of 44. Bullturds. At this point either I am doing something wrong with my loads, or my 686+ is a turd. I pull out my Contender to double check the last five rounds.



Contender 10"
Velocity



1597



1579



1588



1600



1588






Standard Deviation
8.3


Min
1579


Max
1600


Spread
21


Average
1590.4







Holy Hanna! Now that's what I'm talkin' 'bout! A spread of 21 and an SD of 8! I'll take that any day! But the velocity scares me. Every manual that I have access to says this should be sprinting at 1100fps - 1400fps. I am absolutely sure I loaded 15.6 grains of H110. The 686+ was in the expected range, but the Contender was... not.

What is going on?

[sigep1764]

My thots go towards the crimp. It may be that the crimp on the lower velocity rounds may have been a little looser than the higher velocity rounds, thus not getting a complete burn as the higher velocity rounds. The longer barrel of the contender has more time to burn the powder. I could be wrong.

[sigep1764]

This also explains the faster velocities in the contender, longer burn time. Doesnt h110 and 2400 do their best work at higher loads?

[Bazoo]

Hmm, wonder if bullets are being pulled under recoil in the 686.

Higher velocity than expected in the contender will be due to barrel smoothness, lack of barrel/cylinder gap, perhaps tighter chamber, and different twist rate.

[Jaak]

My thots go towards the crimp. It may be that the crimp on the lower velocity rounds may have been a little looser than the higher velocity rounds, thus not getting a complete burn as the higher velocity rounds. The longer barrel of the contender has more time to burn the powder. I could be wrong.


This also explains the faster velocities in the contender, longer burn time. Doesnt h110 and 2400 do their best work at higher loads?

I applied a very heavy crimp, just as prescribed.

[sigep1764]

Also the contender has one chamber. The 686 has 6 or 7 depending on the model. Getting those to be as close to the same as possible will help the issue. Dougguy does that service here.

[Jaak]

Also the contender has one chamber. The 686 has 6 or 7 depending on the model. Getting those to be as close to the same as possible will help the issue. Dougguy does that service here.

I forgot to mention that I loaded and shot the revolver one cartridge at a time with all shots fired from the same position in the cylinder.

[dverna]

Have you calculated how much a 100 fps ES affects bullet drop at 50 yards? Not many folks can shoot well enough for it to matter.

How did the loads group? Chasing ES and SD might be important in wringing out a rifle load, but not so much with pistol loads at short range. If the load is shooting good groups, I would not worry about the statistics.

H110 is not a forgiving powder and others will chime in on that. I do not use it.

[littlejack]

I don't have any expieriance with the 357 cartridge and H110. However, I have loaded and shot hundreds in both my .41 magnum
revolvers. I can tell you for certain that H110 burns a lot more efficient with heavy powder charges. That is why the load data with H110 doesn't have a drastic drop in starting loads. So either stoke them hot, or switch to a faster powder, ie Alliant 2400, AA9 or there abouts. Are you using magnum primers? What size are the boolits you're using?

[Greg S]

Couple of quick thoughts, barrel cylinder gap, primer and mainspring tension.

SPMag primers are recommended for H110. If you are using them in all loads the only other difference between the two test beds is BC gap and firing pin striking force and protrusion. Check your strain screw and FP protrusion. Looking for .050 for protrusion. If this was a used specimen, was an action job performed prior?

If short protrusion, there are extended firing pins available. If it has a week hammer fall, a new strain screw or mainspring may be required.

[justindad]

What barrel lengths do you have for the Contender and for your revolver?
*
How far away is your chronograph?

[Tatume]

I ran a one-way analysis of variance on your original data. There is no significant difference between the means of any two velocities within the five loads.

Source: DF: SS: MS: Test Stat, F: Critical F: P-Value:
Treatment: 4 23522.68 5880.67 1.674461 2.578738 0.172539
Error: 45 158039.00 3511.977778
Total: 49 181561.68

[Forrest r]

It's good that you used 2 firearms to check the same load.

I'd be taking a hard look at the firing pin hits/lack of consistent hits.

[Tatume]

H110 is not a forgiving powder and others will chime in on that. I do not use it.

I agree, and add that my results with H110 and cast bullets are inferior compared to 2400. With jacketed bullets H110 can be very good, but the prevailing conjecture is that cast bullets do not resist movement enough for pressure to build to an optimal level.

[jdgabbard]

I agree, and add that my results with H110 and cast bullets are inferior compared to 2400. With jacketed bullets H110 can be very good, but the prevailing conjecture is that cast bullets do not resist movement enough for pressure to build to an optimal level.

LIGHT lead bullets I would agree with. If you start getting to heavies, where it has to work a little harder you build pressure a little better. But overall H110 is not my favorite. I prefer 2400, if I can ever get any more of it....

[Larry Gibson]

Jaak

As you discovered, H110 is not the best powder in a 357 revolver with cast bullets of 160 gr or less weight to use. Such bullets simply do not have the mass nor the friction coefficient for the H110 to ignite and burn as efficiently as other powders....in revolvers. The use of standard SP primers other than WSP primers or "magnum" SP primers will exacerbate the ignition of the H110 and efficiency of burn. So will shooting in colder weather. Additionally, in revolvers, the cylinder throats are essentially "free bores" which contribute to ignition and irregular burn. Then there is the barrel/cylinder gap which will vent pressure before peak psi is reached. All contribute to the "poor" ES/SDs you've gotten with the revolver. That is as it is. Best to switch to a better performing powder in revolvers with cast bullets such as 2400 or Blue Dot for magnum level loads.

As to the H110s performance in the closed breach Contender, nothing "hot" or out of the ordinary there. The velocities and their ES/SD is exactly as it should be. The Contender's closed breach barrel has none of the inherent revolver features mentioned to cause the ignition/burn problems that occur in revolvers. Also the closed breach Contender 10" barrel w/o the free bore and barrel cylinder gap is going to produce the higher velocity as you found. Your load in the Contender is pretty much the same as I have found in 3 separate Contender barrels and is consistent with Contender data in manuals.

[TurnipEaterDown]

I find W296/H110 to work fine in 44 Mag & 475 Linebaugh w/ cast (PB & GC) as long as it is loaded full charge. Very good groups - 50 yd 1-2 in 5 shot revolver groups w/ numerous bullets, good gun and well worn. (260-320 gr in 44, 400 gr in 475)

From a quick reference in a Lyman manual 357 data, both the revolver and TC data shown above are all that I think should be expected from a 357 in the guns shown - not a low pressure range of use being discussed for 296/110 in other words.

I would say that small sample statistics can be pretty misleading, and that the comment from Don (re: use - group expectation from revolver loads) is a good comment. Maybe the load shown groups very poorly in the poster's revolver, but if it groups good, I think I would disregard the statistics and just use it. Shoot it at 50 & 100 (if you want) and see what it does. Many loads I have that shoot good groups at useful range don't really have good looking small sample statistics, but they meet their goal.

Primer swaps will also sometimes tighten velocity and group spreads, and this can be evident more so with hard to ignite powders.

Also, an ambient temperature drop from 40 to just 20 °F can produce additional variability in revolver load velocity uniformity if the load is boarderline.

(edited to note weight in loads mentioned that shoot "well" in my experience, and my experience of ambient change effect)

[gwpercle]

With the 357 magnum I have had better accuracy results with 2400 and just lately some very promising groups with Accurate #7 ... Needs more work ...
I'm looking to try some Accurate #9 in heavy 357 magnum loads in place of 2400 ... as it might be the better for that application ... but only the target will tell .

I still haven't found any powders better than Bullseye , Unique and 2400, but some days they just aren't available ...so you gotta load whatever powders you can get !

Good luck with the H110 ... I don't have any advice for this one , used it very little and it didn't work for me .
Try different , hotter primers ... sometimes primers make a big difference in a load .
Gary

[TNsailorman]

My experience with H110 in a .41 magnum was that the loads above starting loads were by far the best in terms of accuracy. That is one reason I do not load H110 in the .41 magnum anymore, I do not like to run chamber pressures at the very limit of safety. And there was that warning in my manuals to "NOT" load H110 below the starting listed load. And there was a very narrow range between the starting load and the maximum load. That was enough for me. I quit using H110 in the .41. I gave away a 1/2 bottle of H110 and sure could use it now as it is about the only listed powder I can find for the 410 shotshell. james

[Jaak]

Couple of quick thoughts, barrel cylinder gap, primer and mainspring tension.

SPMag primers are recommended for H110. If you are using them in all loads the only other difference between the two test beds is BC gap and firing pin striking force and protrusion. Check your strain screw and FP protrusion. Looking for .050 for protrusion. If this was a used specimen, was an action job performed prior?

If short protrusion, there are extended firing pins available. If it has a week hammer fall, a new strain screw or mainspring may be required.

I've never used H110 before so I'm following the manuals exactly. Even to the point of using the same brand of primer recommendations. In this case it was Winchester SPP Magnum.

[Tatume]

Have you shot the loads for accuracy?

[20:1]

Have you shot the loads for accuracy?

OP- If accuracy is your primary goal, then this would be the next step. What crimping die are you using, and have you tried a faster burning powder yet? I've always found better accuracy in .357 max loads with H110/296 with jacketed bullets rather than cast. There are other excellent powders out there. Also, I didn't notice if you're using magnum primers.

[ACC]

Been shooting H110/W296 since most on this list were just children(Yes I am old) all I can say is crimp, crimp, crimp! It has to be uniform.

No excuses! Crimp.

ACC

[jsizemore]

I've got 2 -1lb H-110 containers. Older jug has a steel cap and is from the mid 90's. Price tag is $15.50. Load data on the front has ,357 mag loads for 125gr JHP and 158gr JSP. It was not very accurate with 125's at silhouette so I went with another powder. Powder is still in good shape. Newer jug is less than 4 years old with a plastic cap. I paid $40 for it. Only 357 load is for a 180gr Nosler Partition. I load 410 shells with both jugs. It's tough on hull crimp folds but works great.

I don't have data for your particular bullet but the RCBS cast bullet manual from 1986 that shows load data for their 158gr SWC that's in the neighborhood of your 686 velocities. I've also got a Contender load manual from 1997 with Hodgdon Load data for 158-160gr bullets that is right there with your 10" Contender. I used to load 180's with H-110 to hunt deer in the Contender back in the 80-90's.

[fredj338]

I didnt see it but I assume you used mag primers? H110 is not my fav magnum powder. Its basically a max effort loading for best results also doesnt play well at low air temps. I used to shoot HMSill with an 8" & had great results there, jacketed or lead, but for 357mag, I seem to get better results with 2400 & lead bullets.

[Willie T]

Maybe I missed it but did you measure what diameter your mold drops? What diameter did you size your bullets to? Cylinder throats .001 bigger than bore is perfect. Bullets sized about the same difference over throat diameter may tighten up velocity in your revolver if the cylinder throats are that uniform but I don’t pay much attention to it in my handguns. I have two Lee 158 molds. One is a tumble lube SWC that I load in .38’s. The other is a gas checked SWC. The gas checked SWC is the only one I load with H-110. CCI Magnum primers are used. My Blackhawk has throats .358-.3585. Bore slugs. .357. My mold drops at .360. I size them to .359. Powder charge is 15.3 grains H-110. Heavy roll crimp in the crimp groove.
In my 686 I also load 15.3 grains of H-110. Everything about the 686 is a little tighter than the Blackhawk except accuracy with cast. The 686 slugs .3565. Cylinder throats are all spot on .357. I size to .358 for it. With both revolvers I let the cylinder throats minutely size the cast bullets. As luck would have it in both revolvers, they both wind up barely over bore size coming out of the cylinder. Both shoot pretty well but I have not been able to quite match the accuracy I get with a 158 XTP. Conversely I can not match the accuracy I get with a gas checked conventional lubed bullet if I powder coat.
These are targets with the cast loads I worked up in my revolvers and a jacketed load for comparison.
My jacketed load is 15.6 grains of H-110.(.3 gr more than my cast load)
All groups are two handed slow fire @ 25 yards.

This is a wheel full of gas checked 158 SWC in the 686 with H-110. Flattening the target on the table closed the holes up some but it grouped close to an inch.
321771
For comparison it does not match the accuracy of XTP’s pushed with H-110.
321772
As you can see here the 686 does not match my Blackhawk with the SWC’s and H-110.
321773
The only one of these I have chronographed is the gas checked SWC’s and H-110 in the 4 5/8” Blackhawk. Only shot one so extreme spread and SD remain unknown. The load is not blazing fast but works well enough on 100 yard silhouettes to satisfy my ability.
321774
I like H-110 in .357 Magnum.

[Digital Dan]

My lawn is quite fond of H110.

[dverna]

Maybe I missed it but did you measure what diameter your mold drops? What diameter did you size your bullets to? Cylinder throats .001 bigger than bore is perfect. Bullets sized about the same difference over throat diameter may tighten up velocity in your revolver if the cylinder throats are that uniform but I don’t pay much attention to it in my handguns. I have two Lee 158 molds. One is a tumble lube SWC that I load in .38’s. The other is a gas checked SWC. The gas checked SWC is the only one I load with H-110. CCI Magnum primers are used. My Blackhawk has throats .358-.3585. Bore slugs. .357. My mold drops at .360. I size them to .359. Powder charge is 15.3 grains H-110. Heavy roll crimp in the crimp groove.
In my 686 I also load 15.3 grains of H-110. Everything about the 686 is a little tighter than the Blackhawk except accuracy with cast. The 686 slugs .3565. Cylinder throats are all spot on .357. I size to .358 for it. With both revolvers I let the cylinder throats minutely size the cast bullets. As luck would have it in both revolvers, they both wind up barely over bore size coming out of the cylinder. Both shoot pretty well but I have not been able to quite match the accuracy I get with a 158 XTP. Conversely I can not match the accuracy I get with a gas checked conventional lubed bullet if I powder coat.
These are targets with the cast loads I worked up in my revolvers and a jacketed load for comparison.
My jacketed load is 15.6 grains of H-110.(.3 gr more than my cast load)
All groups are two handed slow fire @ 25 yards.

This is a wheel full of gas checked 158 SWC in the 686 with H-110. Flattening the target on the table closed the holes up some but it grouped close to an inch.
321771
For comparison it does not match the accuracy of XTP’s pushed with H-110.
321772
As you can see here the 686 does not match my Blackhawk with the SWC’s and H-110.
321773
The only one of these I have chronographed is the gas checked SWC’s and H-110 in the 4 5/8” Blackhawk. Only shot one so extreme spread and SD remain unknown. The load is not blazing fast but works well enough on 100 yard silhouettes to satisfy my ability.
321774
I like H-110 in .357 Magnum.

Great post.

Man, I wish I could shoot like that. 1" groups at 25 yards!!!

[Willie T]

You are too kind Don. I am nothing special. I just like to shoot a lot. All I really have to show for it is tinnitus and hearing aids…

[Jaak]

Thanks for all the comments and input. I am going to try some 2400 on Monday. I'll post my results from that attempt in a new post.

[mnewcomb59]

I don't know what data source you were using, but you were well below Hodgdon's max load. H110 works better within 0.5 gr of max load. Many sources say NEVER reduce below 3% of max load. You reduced it by 11%. Going 2.7 gr below max like your starting load is just a waste of powder, primers, bullets and time. Whenever you want a reduced load with H110 what you actually want is a different powder. Shoot a few lighter loads to check for pressure, but don't expect much. As long as no pressure with lighter loads, work up closer to max and groups, ES and SD tighten up.


You could probably immensely tighten up your ES by using a 359 bullet that is larger than your throats. That would allow you to build pressure as the bullet is leaving the crimp and swaging to the throats. Or, screw H110 and use a better powder for the job. If you only want 1200 fps you can get there with powders as fast as Unique and Power Pistol and load twice as many loads per pound. 1200 fps is doable with 2400 but still kinda wasting powder and getting high ES. I wouldn't go any lower than 13.5 of 2400 with your 158 before switching to a faster powder.

My most accurate max effort revolver loads are with 2400. 14.8 gr with a powder coated 158-RF is good for 6 shots in under an inch at 25. My silhouette load is the NOE 154 gas check that seats more shallow and 15.3 gr will put all 6 in 5/8" at 25 over and over and it will put all 6 into about 8" at 200 yards, which is the limits of my eyes and the sight radius. Won a few blue, white and red ribbons with that bullet and load. It might shoot even tighter with a scope. 2400 also shoots great with 125 and 135 gr bullets. The Lee 125-rf and the Ranch Dog 135-RF will both shoot 6 shots under an inch at 25.

My last tip is you said you used "a very heavy crimp". After a certain point, more crimp can lower case neck tension because the brass buckles away from the bullet body, reducing friction. You are already trimming cases, which is the most important step for a consistent case neck tension, so I would crimp about 1/2 turn on the die. Put a full length resized case in the die and back the die out until it doesn't crimp at all, then tighten the die body between 3/8 and 5/8 of a turn. 3/4 of a turn or more can start to reduce your neck tension, giving inconsistent ignition.