HP38 and 44 mag questions.

[v8stang289]

I wanted a midrange load for the 44 mag and I have a pound of HP38 powder.

I couldn't find any specific load data on HP38 with a 240 gn xtp, but I did find data on HP38 with a 240 gn jacketed bullet in my manual. So I started with that data and loaded small batches in increments from 9 up to 10.5 gns (the max in the load data was 11 grains)

I intended to start with the lower powder loadings and work up the next time I go to the range, paying attention to pressure signs and velocity.

What concerns me is that I noticed the loading manual shows the max with UNIQUE and 240gn xtp as 10.3. Since HP38 is a bit faster than UNIQUE, it seems to me if 10.3 gns of Unique is a Max load then 10.5 grains HP38 would be over max.

Am I correct in this reasoning? Should I go ahead and pull these?

I am using Hornady 240 gn XTP, Starline brass, CCI 300 LPP, seated to the crimp groove ~1.6".
Gun is a S&W 29-3 with 8-3/8" barrel

Thanks.

 

[Sam1911]

Follow the information in your manual. A 240 grain jacketed bullet is a 240 gr. jacketed bullet. XTP or whatever other kind -- they work with the same charge weights.

DON'T look at charges listed for some other powder and try to draw conclusions about the load you're using based on something different!

Since HP38 is a bit faster than UNIQUE

Gads, the stupid "burn rate" chart strikes again! Use the data for the powder you're loading. TRUST the published data for the powder you're loading. I wish the burn rate charts hadn't been published. You can't say, "oh the burn rate chart says that powder's faster than this one so the charge should be...whatever." It just doesn't work that way.

Go with the book! Always.

 

[v8stang289]

Thanks Sam, I'm just trying to err on the side of caution. I was just looking at the powders the manual had listed for the XTP when I saw the Unique data. In my experience, when using the same bullet, W231/HP38 usually lists smaller charge weights than Unique. So it just seemed odd to me and got me to thinking.

 

[ReloaderFred]

Sam gave you good advice. Follow it and you'll be fine.

Loading data is developed with pressure testing equipment. They work up to the pressure limits for the caliber and bullet weight combination with each powder. This is why velocities are different for the various powders with the same pressures. Different powders build their pressures in different ways.

Hope this helps.

Fred

 

[oldpapps]

V8,

Not quite what you are working with but similar.

I worked up some 240 grain Lead SWC with 231/HP-38.
At 10.0 grains, I clocked 1116.8 FPS (average of a valid statistical sampling).
After slowly working up to 10.5 grains, I started having ejector drag (to me this indicates higher pressures and I don't want that), more interesting to me, I clocked an average of 1126.3 FPS (this was only a sampling of 6 rounds fired and not a valid test but good enough for me).

A half a grain for 10 FPS and noticeably higher pressures. That's less than standard deviation!

How this will relate to your jacketed bullets, I don't know.

Have you tried 2400 or H110/296 or Lil'Gun or so many others?

Always error on the side of safety.

 

[Sam1911]

Gotcha. Yeah, you'll be fine with the load data they wrote. I know sometimes the various loads with different powders might not seem to make sense when compared one to another, but we really can't say what the load development testers saw that made them stop where they did with any particular powder.

And, of course, if you're working up from your starting load and get some noticeable pressure signs, don't go farther. You can't rely on pressure signs to tell you exactly when your load is too high pressure (as in, "I just keep loading hotter until I get X,Y,Z pressure signs..."). That's dangerous because many guns might not give you any pressure signs until it's too late. However, there's no reason if you DO get signs that you should keep pushing.

 

[brutus51]

I agree, stick with what the load manuals advise and please cross-reference the loads with more than one source of data. burn rates aren't the only consideration different powders have different ignition rates based on case capacity and geometry of the powder itself (ball powder vs. flake for example).
Case in point, Unique is my favorite powder for lite .44's and .45 Colt. As a result of the powder shortage I'm all out of Unique so, I've been using Universal clays as a substitute, same burn rate, same powder charge (8gr.).
While I haven't had a chance to chorny the loads but I can feel a slight increase in felt recoil. Other than that performance is equivalent and I also noticed that in addition to being cleaner burning and less smoky Universal meters better.
Sadly I would have never discovered this if it weren't for the powder shortage.
Had an ample supply of Universal on hand as I use it for trap loads. Now I have to buy store bought trap loads so I don't run out of that powder.

 

[v8stang289]

Just as an update, I shot the loads today over a chrono.

The 10.5 grain loads had slightly flattened primers and extraction was a bit sticky, they are definitely over pressure in my gun. I shot 4 of them and they averaged 1204 fps. I will pull the rest.

Based on my findings my load is going to be 9.5 grains. It averaged 1116 fps and was very accurate and mild shooting.

Thanks for all replies and advice.

 

[beatledog7]

If he's working with published data for Powder A, a reloader should avoid all thoughts of Powders B-Z. In fact, he shouldn't think about Powder A either. He should just weight out the listed amount and load it.

Then he should burn the burn rate charts.