I need some help interpreting my data.

[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.

For comparison it does not match the accuracy of XTP’s pushed with H-110.

As you can see here the 686 does not match my Blackhawk with the SWC’s and H-110.

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.

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.

For comparison it does not match the accuracy of XTP’s pushed with H-110.

As you can see here the 686 does not match my Blackhawk with the SWC’s and H-110.

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.

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.