Title says it all, I have acquired quite a few 115gr cast .358 truncated boolets.

The only powder I have is Unique. Looking through some of my reloading books, I am showing anywhere from 5.2-7.0gr for Normal pressures. Seems like quite the spread. Now I know I need to load a little lite considering these are cast. According to the site I ordered them from they are "92/6/2 lead alloy that produces a BHN of 16-17". Has anyone had any expenence loading 38spl with such a lite boolet ? Will be shooting these out of a S&W 637 +p.

That’s a really light bullet for a .38 spcl. I think you will have problems with accuracy. I had trouble with 130s, switched back to 158 and everything was fine. You may want to try them out before you load up a bunch.

Unless you are trying to replicate a personal defense load, since you are shooting it from a 2" 637, I'd load it to the minimum and call it a day. My 637 is a fav, but is hard on my hand with +P loads.

I load the 105 swc for .38 special, which casts for me around 110gns. I haven't used Unique in a while but I would trust the data you have if it's from a well known publication. Those bullets pictured look powder or hitec coated so pressures shouldn't be an issue so long as you don't damage the coating during seating. Light loads of Unique in the long 38 case may leave some unburnt power. No big deal really. I've seen the that scenario yield some pretty accurate loads. The downside to unburnt powder is it can get under your extractor causing reliability issues with a revolver.

I too load a 105 grain swc in 38 and 357. There are so many variables. I use Unique. Just have to experiment with powder charge and seating depth, to begin with. You should be able to get them to work. Being light, they may shoot low in a fixed sighted gun.

Unique in a .38spl hull is quite a slow burning powder.Like mentionned above,the charge you'll need to have it clean burning will be a little stout;but since you want +P performance,your choice of powder is good.
Personnally,if you intend to just shoot it for fun,well be my guest.But if it is for SD,I'd go with a slightly heavier bullet and of a different shape.
As for ''being lead,you'll need to load light'',I say if the bullet fits the chamber mouths,you can push it to the limit of +P pressure without problem.Better test by batches increasing slowly by small increments to get there.

I use a lot of Universal which is about as close to Unique as you will find. Most manuals give almost identical data. I use 5.0gr of Universal for several different weight bullets from 110-158 with great results. You didn't say how "hot" you wanted your loads to be but I would try 5.0gr of Unique and work my way up if you want more velocity. For light plinking loads I prefer Bullseye. at around 3gr per bullet, a pound would probably last you several years

Just Unique.................. ?

You need to break down and buy a faster burning powder ,
so you can use 50% less powder and also get better accuracy.

Just my 2 cents.

Thanks so much for the quick replies ! I have only been reloading for about a year. Started with little bunny loads using trail boss. I live in an apartment and have 2 young children, so I basically have everything stashed in locked large plastic ammo boxes. Also only have a few sets of dies and a hand press. But I enjoy the act of reloading. I normally load Speer LSWCHP 158gr at 4.6gr of unique. I have not really stepped into the +p world yet.

I loaded some 125 grain bullets that were similar when
I started out. Then, I only had Bullseye. By the timeI bought some
Unique I'd run out of them so moved to 158 grain LSWCs.

Although my loads were light, they shot very well from a Ruger Blackhawk. .357.

Typically lighter bullet shoot low in snub nosed 38spl's. Light loads are needed to raise the bullet to the poa. Light loads & unique is not a good combo, the loads will be extremely erratic.

Just use 80% Alliants load data for the 125 GDHP


(ie: 20% less than 5.7 grains) as 5.7 is the MAX.


So around 4.5 to 4.6 grains


10% less for start load and another 10% because you have lead and not jacketed (actually you can use jacketed data for lead but that's another story and you are just starting.)



Alliant Powder - Reloader's Guide

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Still Running Against the Wind

Unique is a pretty slow powder for 38 Special, and especially slow for such a light weight bullet. I think you would be better served with a faster burning powder, Bullseye, Accurate Arms #2, and Winchester W-231/Hogdgon HP38 immediately come to mind.

I load 125 cast RN in spec cases over 3.5 W231/HP38 and they shoot fine out of several SWs, mostly inside 10 yards as that's what snubs are primarily designed for. Suggest start around 4 and work from there to get performance you want

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Tommy

"Go ask the gun". John Wooters, author of The Complete Book of Practical Handloading

I load that same bullet (BBI brand) for practice in 3 different airweights. As others have suggested, get some faster powder. Bullseye will serve you well for target/plinking loads in virtually ALL the common handgun cartridges.

The only reason to inventory other powders in its class is if you seek to discover the absolute best match-grade accuracy with a particular bullet in a particular gun....might be Bullseye in one case, something else in another. You don't really need both, but WST is another excellent choice where Bullseye would be applicable.

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Carry.."hope" isn't a strategy

For best results that "Hardball" alloy should be shot to a medium pressure at least if it is to fill the lands. I am not sure that you want to do that with a 637. You may get minor leading with these and the cure is a heavier softer bullet.

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Front sight and squeeze

Another reason I suggest to new reloaders (or any for that matter) to find a load in their reloading manual before they buy components. Many fewer headaches and question/waiting that way any they won't be buying any unusable components...

And since many reloaders use lead load data for coated/PCed bullets (I've loaded a bit over 1,200 PCed bullets with lead bullet data/methods) I would begin with starting loads for a cast lead bullet (In my Lyman Cast Bullet #4 pg 254)...

I've been reloading for past 30+ years now and I've used over 20 different handgun powders to load 13 different handgun cartridges. For last few years I have been trying to simplify my life and so I have cut my handgun powders down to just 3...Winchester 231, Unique and H110. With these 3 powders I load everything from 25ACP to "Ruger only" 45 Colt.