38 Spl +P with Lyman 358477 SWC - Test Results

[38SPL HV]

Got out of the house today and drove out to BLM to test some loads with the excellent 358477 SWC in 38 Spl +P:

Firearm: S&W Model 10 4” (cylinder to barrel gap .008”)

Bullet: Lyman 358477 155 grs

Cases: Starline 38 Spl +P

(All 10 shot strings)

Load #1: 38 Spl +P, 6.5 grs HS-6, Winchester Small Pistol
Hi 966 fps
Lo 933 fps
ES 33
SD 10

I get tighter extremes and better accuracy using Winchester primers with ball powders like HS-6; even better than magnum level primers.

Load #2: 38 Spl +P, 5.9 grs Accurate #5, Winchester Small Pistol
Hi 871 fps
Lo 813 fps
Avg 831
ES 58
SD 15

This load duplicates statistically the velocity of Remington’s HTP (2024 manufacture) 38 Spl +P 158 gr LHP from my revolver.

Load #3: 38 Spl +P, 6.3 grs Accurate #5, Winchester Small Pistol
Hi 937 fps
Lo 882 fps
Avg 900 fps
ES 55
SD 14

This load duplicates for all practical purposes the velocity of Rem/Federal/Win “FBI” loads from a 4” revolver.

 

[Warren Sear]

For those interested, here is a picture of the 358477. I have one of these molds, and it is my favorite for this caliber. Nominal weight is given as 150 grains.

 

[Model 15-4ever]

I've used both propellants extensively. Your loads are on the relatively light side. Current data is very weak. One thing to check with all revolver loads is the amount of unburned powder residue left over, which is an issue with weak loads of slower-burning powders like HS-6 and Accurate No.5.

 

[glenwolde]

I have a four-cavity mold for the 358477. I've never used it. I only recently started casting again after a very long hiatus. So far I've produced some 358432 and the RCBS 150 KT. I didn't start with the 358477 because I have some issues with my left hand and I'm thinking it's going to be too heavy for me. It's painful enough with a two cavity steel mold. If I get some inventory up I'll try it. Maybe it will be OK.

 

[38SPL HV]

I've used both propellants extensively. Your loads are on the relatively light side. Current data is very weak. One thing to check with all revolver loads is the amount of unburned powder residue left over, which is an issue with weak loads of slower-burning powders like HS-6 and Accurate No.5.

…they are not on the light side unless you want to exceed current reloading manuals. I have less residue using HS-6 and Accurate #5 at these levels than my time honored Unique (even current formula). Unburned powder, none especially noted. Heck, what do I know, I’ve only been reloading for 50 yrs + lol

 

[Alk8944]

I expect everyone who reloads knows this but OP shows the primer for all of his loads as the Winchester 1 1/2. The Number 1 1/2 is Remington's designation for it's Small pistol primer. Winchester simply uses letters and calls its primer the SPP.This would concern me about the accuracy of anything else in his post! Simply a caution.

 

[alwslate]

The loads listed are on the light side. 6 grs of Longshot or Power Pistol will give the cast bullet in use over 1,000 fps out of a 4" barrel without exceeding +P pressure. I have chronoed a 158 gr cast SWC out of my 4" model 10 at around 1020 fps with 5.3 grs of 231. By Lyman's data that should just be barely +p, not excessive.

 

[Forrest r]

Thank you for taking the time to post your testing. Always interesting as usual & looking forward to more results.

There's a lot of things that can and will affect the outcome of the velocities/results of anyone's testing. 38spl hv's model 10 has constantly showed lower velocities that expected or reported by others. I've posted this very thing asking him about it.

8/1000's" cylinder gap is huge!!!! Firearms loose +/- 10fps of velocity for every 1/1000th " of gap. I've personally tested this and found it to be true. Having owned dan wesson revolvers that I could set the gap on it was a cave man simple process running the same loads over a chronograph.

On a side note:
That 8" bbl pictured above never did get the velocities it was supposed to. It was barely faster than the 2 6" bbl's pictured above.

At the end of the day 38spl hv model 10's bbl might have issues along with the excessive cylinder gap causing low velocity reports.

People test in different ways, a 2" bbl'd ca undercover that has a 3/1000th's cylinder gap. Took a couple tries swapping out cranes to get it there. (Highly recommend 38spl hv either shim or change out the crane to get to +/- 4/1000th's). Anyway took 5 different powders and 10 different bullets to test. Loaded up 5 rounds of each bullet/powder combo using max p+ data. I shot the 50 round strings of each powder/10 bullet combo's over a chronograph listing the velocities for each bullet. This told me the velocities for each bullet and adding them all together told me what to expect on average when using that powder.

At the end of the day I was getting 990+ fps with 1 powder. I guess I can call other peoples loads on the lite side if they're only getting +/- 20fps out of firearms with 4" bbl's.

 

[38SPL HV]

.008” is certainly at the high end of the S&W Mod 10 spec. My HDs measure .004” and the HD four inch is noticeably “faster” with same loads. I recall vented test barrels used in 38 Spl ammo testing is .008…

 

[38SPL HV]

I expect everyone who reloads knows this but OP shows the primer for all of his loads as the Winchester 1 1/2. The Number 1 1/2 is Remington's designation for it's Small pistol primer. Winchester simply uses letters and calls its primer the SPP.This would concern me about the accuracy of anything else in his post! Simply a caution.

Old habits die hard…old Western primers were 1 1/2 also. I made corrections. I also still use Hercules at times and my friends at the coffee counter correct me. lol

By the way, your comment that “this would concern me about the accuracy of anything else in his post” is uncalled for…I draw the line when people question my integrity. Next time don’t bother reading my posts.

 

[38SPL HV]

The loads listed are on the light side. 6 grs of Longshot or Power Pistol will give the cast bullet in use over 1,000 fps out of a 4" barrel without exceeding +P pressure. I have chronoed a 158 gr cast SWC out of my 4" model 10 at around 1020 fps with 5.3 grs of 231. By Lyman's data that should just be barely +p, not excessive.

Yes, I also like the 6.0 grs load with Power Pistol and use in larger frame guns as my HDs. In my Model 10 I load to duplicate the velocity of factory Rem/Fed 38 Spl +P 158 gr LHP loadings…I recognize I can go higher with the manual but why…890-900fps is good enough for me. I got my turbo charged Blackhawks reserved for my hotter loads but even there prefer loading 357 Mag cases in these since I now have an ample supply of the longer cases. No more “poor man’s” 357 Mags using 38 Spl cases!

 

[Skyhunter]

Lyman mold #358477 has been a favorite of mine for the .38 Spl. since I started casting my own bullets back in 1973. It's been a stellar performer for all my applications. I cast an HP version of that bullet as well.
My all-time favorite for my .357's is Ray Thompson's excellent #358156 SWC. That one works well on everything from paper targets to bullfrogs to deer!

WYT-P
Skyhunter

 

[Skeet 028]

Old Habits do die hard. Indeed Western primers used the same number system as Remington. and Winchester used a number system as in the picture below. The old Westerns are SRPs and numbered 6 1/2 the old Wins are numbered 108...the primers pictured are 40s 50s and 60s..the Alcan SPPs on the right may be early 1970 though...Same colored box as the S&W after they bought out Alcan...And it's still Hercules...says so on the cans

 

[38SPL HV]

Thank you for taking the time to post your testing. Always interesting as usual & looking forward to more results.

There's a lot of things that can and will affect the outcome of the velocities/results of anyone's testing. 38spl hv's model 10 has constantly showed lower velocities that expected or reported by others. I've posted this very thing asking him about it.

8/1000's" cylinder gap is huge!!!! Firearms loose +/- 10fps of velocity for every 1/1000th " of gap. I've personally tested this and found it to be true. Having owned dan wesson revolvers that I could set the gap on it was a cave man simple process running the same loads over a chronograph.

On a side note:
That 8" bbl pictured above never did get the velocities it was supposed to. It was barely faster than the 2 6" bbl's pictured above.

At the end of the day 38spl hv model 10's bbl might have issues along with the excessive cylinder gap causing low velocity reports.

People test in different ways, a 2" bbl'd ca undercover that has a 3/1000th's cylinder gap. Took a couple tries swapping out cranes to get it there. (Highly recommend 38spl hv either shim or change out the crane to get to +/- 4/1000th's). Anyway took 5 different powders and 10 different bullets to test. Loaded up 5 rounds of each bullet/powder combo using max p+ data. I shot the 50 round strings of each powder/10 bullet combo's over a chronograph listing the velocities for each bullet. This told me the velocities for each bullet and adding them all together told me what to expect on average when using that powder.

At the end of the day I was getting 990+ fps with 1 powder. I guess I can call other peoples loads on the lite side if they're only getting +/- 20fps out of firearms with 4" bbl's.

I did have a chance to speak with my friend who happens to be an accomplished gunsmith specializing in S&W revolvers…he said my .008 gap is still within S&W specification...max is .010. It's a coincidence that SAAMI has a .008” in their vented test barrel setups...oh well. She shoots accurately at least in my hands.

As noted my 4” S&W HD gets higher velocities than expected…that measures .004”. My hair is already grayed so I’m personally not going to worry about it and still enjoy the fun; always appreciate your inputs.

…others by the way are getting grumpy in their old age, I am also an old gent, lol…but always keep positive with what I’ve been through in life.