Loading 38 +p loads in 357 brass

[Dudedog]

OK Easy Way

Get the chrono
Shoot some of the 38 +P over it to get the vel from your gun
Load the .357 case at the starting .357 charge with powder X, vel will most likely will be higher that the .38 +P
If it is work down .2 at a time to bracket it, if its low work up. Fine tune to .1 if it suits you fancy.
You now have the charge you need to duplicate the velocity of the .38 +P load in a .357 case.
Powder forward/powder back may come in to play with the larger case.

Another way would be to ignore the vel, since you might be after feel only and load for feel,
either way a simple ladder is the solution.
POI/POA matter but at most distances SD happens with a pistol the difference 100-200fps makes won't matter

I like to load some practice ammo that is close to my SD ammo,
However I would say that more trigger time with softer ammo that is more pleasant to shoot lots of might be of more benefit than than ammo that is a very close match that may not be as pleasant to shoot a lot of....shoot lots!
Trigger time is more important, IMWO

When practicing calm I can usually feel about 30 fps in a 9mm round,
Running around in the middle of a match with my heart rate up and my brain (hopefully) on high speed makes a difference, hardly noticed when I went to a different
batch of ammo in the middle of a stage that was about 100fps hotter. (messed up and grabbed wrong ammo can on the way to the match......)
Might not have even noticed if it wasn't for the fact I knew that mag had different ammo.

Alliant does not give a spread like Hodgdon does but for fun
Hodgdon data
Bullet 158 XTP
Powder Universal Clays
.38 SP start 4.0 678 max 4.4 778 (no +P data)
.357 start 5.8 1026 max 6.3 1133
So just for fun lets say the vel increase/decrease per .1 is linear (which it isn't but for fun)
So lets call it about 21 FPS per .1 in a 357 case (using the start of 5.8 1026 and the max of 6.3 1133 .5gr =107fps) extrapolating down gives us
4.4 774
4.5 795
4.6 816
4.7 837
4.8 858
4.9 879
5 900
5.1 921
5.2 942
5.3 963
5.4 984
5.5 963
5.6 984
5.7 1005
5.8 1026
5.9 1047
6 1068
6.1 1089
6.2 1110
6.3 1133
So guesstimating 4.4 in the .357 case is a bit lower than 4.4 in the .38 case 774 vs 778
When I am retired and have time it might be fun to load the ladder and see how far off from a straight line the real data points would fall.
And yes I know extrapolation in this case is prone to error and not really valid until proven, but it was just for fun, but since we are going down pressure wise I would feel halfway comfortable with the numbers, going up from listed data would be a different story.
The .4gr in the .38 case gets use 100fps or 25fps per .1 (linear assumption)
so about 10% change more in the smaller case.

I am not saying any of this is valid or safe data other than the charges and charge ranges Hodgdon listed, just playing with numbers.

 

[joneb]

I gave up on Unique many years ago, didn't care for how it metered and did not like the soot. I've been happy with some unique alternatives, Accurate #5, True Blue, VV n-340 and WSF.
For Accurate #5 and VV n-340 gave me very good performance for down loaded 357 mag to the 38 spl +P range.

 

[forrest r]

Kinda late to the party as usual. Never gave this thread much thought until know simply because I've used lyman reloading manuals for years and they'd used these types of breakdowns for decades. If you look at the starting data in the lyman manuals since 1980 you will see a bullet/starting loads/max loads.
38spl starting loads ='s 38s&w pressures
357mag starting loads ='s hot 38spl/38spl p+ pressures

Per lyman 50th edition starting loads using unique in the 357mag cases 4" bbl
110gr jacketed hp 7.4gr/1052fps
125gr jacketed hp 7.0gr/990fps
140gr jacketed hp 7.0gr/949fps
158gr jacketed hp 6.4gr/887fps
Per lyman 3rd edition cast handbook starting loads using unique in the 357mag cases 4" bbl
120gr cast rn 6.9gr/1088fps
133gr cast swc 6.2gr/1006fps
148gr cast wc 5.8gr/960fps

Lyman doesn't list unique for their cast bullets in the 150gr to 170gr weight range. I have shot a lot of cast 160gr rn bullets in 357 cases using 6.0gr of unique with excellent results that will duplicate 38spl p+ results in the 357mag cases.

Alliant lists a MAX load of 6.8gr of unique/158gr lswc in their 2005 manual. 10% of 6.8gr puts the starting load @ 6.1gr.

Don't know if any of this helps but this is what lyman has been putting out for awhile now.

 

[horsey300]

I would like to thank you for your help and your suggestions

I've never tried unique, but with my bullseye in a .357 mag case, it's a Lil closer to what you're talking about.
http://www.alliantpowder.com/reload...owderlist.aspx&type=1&powderid=1&cartridge=28
Alliant says that with it in a 6" barrel with 158s, max load in a .357 case is 4.8 gr=939 fps
Comparatively, same bullet and barrel length, 38+p max is 3.9 @874 fps
http://www.alliantpowder.com/reloaders/powderlist.aspx?type=1&powderid=1&cartridge=27
And good ol 38 sp data shows 3.5 gr max@814 fps.
http://www.alliantpowder.com/reloaders/powderlist.aspx?type=1&powderid=1&cartridge=26

That being said, in our house there are practice/low recoil rounds, and there are also rounds charged with 2400 for full force hunting loads, to keep from having ANYONE mix them up, I gave up the bullseye .357 combo, and just kept the lighter loads in .38 sp brass. This may be a moot point in your situation, but I thought it was worth mentioning.

 

[Mostly Lead]

What I want to do is make practice ammo
that will match my daughters carry ammo

That's sounds like a great idea.

What are the spec's for her carry ammo?

I wanted to start off lower then magnum first for her and trying to keep the noise level as low as I can

Also a good idea, though the two goals are quite different. You might consider using a lighter bullet initially too.

Factory .357 loads got me into reloading - they were not that fun to shoot (in my gun) and was looking for something more pleasant.

 

[Varminterror]

Add 10% to the 38spcl load data when using 357mag cases and it will be VERY close in velocity.

I hate cleaning chamber rings, so I use 357mag brass for almost all of my loading in 357 revolvers - even powder puff mousephart loads which barely clear the barrel. Just scale the 38spcl data up by 10% when using the longer case and you’ll see very similar results. This isn’t new, not novel, even used to be published in some manuals.

 

[LUCKYDAWG13]

She is using federal 125 gr on the box it's going 950 fps

 

[Mostly Lead]

She is using federal 125 gr on the box it's going 950 fps

Ah, that will be a challenge to match. Standard .38 Special loads can exceed that speed with Unique.

My carry ammo was Federal Hydra-shoks, 158gn at 1240fps. Didn't think about factory carry ammo being lighter than the average round.

 

[Varminterror]

I load a pipsqueak load for my MIL to practice with her LCR - she uses the 90grn Hornady Critical Defense Lite round as her carry solution, stated to run 1200fps, but I didn’t try to match the speed, but rather produce an even lower recoil, low cost practice round. 93grn Meister LRN over 4.0grn bullseye in 38spcl cases (which would be 4.4grn in a 357mag case) which should pump out about 850fps, maybe a tad slower in the short LCR.

I also run a 125 plated Rainer over 5.0grn of HP-38/W231 in 357mag cases, which should leave at about 950fps. This isn’t even a minimum load.

 

[LUCKYDAWG13]

Well made up some test loads with Unique 6.5gr and 7.gr I used 125gr JHP and 158gr JFP same load's when I get off work next Tuesday I will see if they
shoot to about the same point of aim as her carry loads just looking to get about same felt recoil or a little less and center mass hits at 5 to 10 yards
I also have some 2400 to try if the Unique does not pan out for us will also pick up other factory carry ammo to try out

 

[CoalTrain49]

Well made up some test loads with Unique 6.5gr and 7.gr I used 125gr JHP and 158gr JFP same load's when I get off work next Tuesday I will see if they
shoot to about the same point of aim as her carry loads just looking to get about same felt recoil or a little less and center mass hits at 5 to 10 yards
I also have some 2400 to try if the Unique does not pan out for us will also pick up other factory carry ammo to try out

2400 is the slap-your-pappy 1400 fps default powder for 357. The stuff legends are made of. Don't say I didn't warn ya.

 

[ArchAngelCD]

I also have some 2400 to try if the Unique does not pan out for us will also pick up other factory carry ammo to try out

I use HS-6 for my .38 Special +P ammo and it works well for me. If you decide to try it use a magnum primer for a cleaner burn and lower SD numbers. My SD numbers are single digit with magnum primers.

 

[buck460XVR]

I don't know why this is so difficult. Loading a .38+p load in a .357 case does not make it a .38+p load......just makes for a .357 mouse fart load.

the data I'm looking at is (+p) 158gr JHP 38 spl 5.2 gr of Unique 761 fps

...the start load of Unique for .357, from the same manual, under the same JHP, will net you a tad more velocity, but makes about the same pressure. This means recoil and noise will be similar when shot from the same gun. You could drop down a tad from the start load iffin' you want, if your bullet clears the barrel at 750FPS in a .38 case, it will exit the barrel going 750FPS from a .357 case. Going down from start recipes may create more of a powder position issue tho.

 

[Mr.Revolverguy]

ArchAngelCD beat me to it, if you can get yourself some HS-6 with a magnum primer. For some reason I have found the 140gr cast bullet performs better for me in punching paper and accuracy.

 

[LUCKYDAWG13]

l shot some of my test loads the 158 gr bullets shot well with just about all my loads the 125gr shot ok but not great going to load up some DEWC
and see how they run in her revolver

 

[ArchAngelCD]

l shot some of my test loads the 158 gr bullets shot well with just about all my loads the 125gr shot ok but not great going to load up some DEWC
and see how they run in her revolver

Full wadcutter bullets are known for accuracy, you will probably like the results, even at the elevated velocities.

 

[RealGun]

I want to load up some loads for my daughters 357 what I want to do is use 357 brass and use 38 special +p data My question is
will I still get +p velocity or will it drop down to 38 special What I want to do is make practice ammo
that will match my daughters carry ammo also would like to use Unique powder for this
what do you think

What is your daughter's "carry ammo"? What are you trying to match? Okay, I found it on another page. I believe what you had in mind is to match the recoil. That could be trial and error, because I think that has as much to do with pressure as velocity. Add to that Unique has sharp recoil when pushed hard. It is faster burning than a magnum powder. I believe that means the pressure spikes, and the shooter feels it.

 

[Mr_Flintstone]

You probably won’t notice the difference loading .38 special +P data in a .357 mag case. The easiest way to get .38 +P velocity out of .357 is to use Trail Boss near max .357 load data.

 

[buck460XVR]

I just hafta say this again.........

I don't know why this is so difficult.

The OP just asked a very simple question about reloading and should have been able to just get a simple answer. He does NOT need to get a different powder, different primers, nor does he need to use a different bullet. He asked about using a 158gr JHP and Unique, whether using a .38+p load in a .357 case would reduce velocity(yes) and how to match +p ammo in .357 cases with the components he had(look in a manual). Again, very simple questions with very simple answers, of which he has gotten, mixed in somewhere with a bunch of other replies trying to get him to go in a completely different direction, using different powders, different primers and different projectiles. He is using the correct and very suitable components for what he is trying to accomplish and with the components he has, he can accomplish what he wants....very easily. No need to confuse and complicate things.


Sheesh........

 

[Rule3]

I just hafta say this again.........



The OP just asked a very simple question about reloading and should have been able to just get a simple answer. He does NOT need to get a different powder, different primers, nor does he need to use a different bullet. He asked about using a 158gr JHP and Unique, whether using a .38+p load in a .357 case would reduce velocity(yes) and how to match +p ammo in .357 cases with the components he had(look in a manual). Again, very simple questions with very simple answers, of which he has gotten, mixed in somewhere with a bunch of other replies trying to get him to go in a completely different direction, using different powders, different primers and different projectiles. He is using the correct and very suitable components for what he is trying to accomplish and with the components he has, he can accomplish what he wants....very easily. No need to confuse and complicate things.


Sheesh........

And you were expecting something different?