Reloading Question

[8uck5nort]

I have been wondering about this since my deer season experience with the .357 mag rifle since I had mixed results. (In truth the more I have replayed the shot in my mind it was probably from my shot placement more than anything else, but work with me here).

 

I am relatively new (less than 18 months reloading experience) so this may sound like a very basic question. If someone has a powder of choice for the 357 mag/max going out a 16 + inch barrel I am interested in your opinion, oh and now onto the question(s). Is it better to have a slower burning powder for the 357 mag/max rather than a quicker burning powder, which from what I understand, is usually associated with shorter barrels and/or pistol cartridges? So do you want something that burns faster building the pressure rapidly or something that burns slower building pressure down the length of the barrel, and how do you go about figuring that out exactly? I assume you chronograph for velocity and just look for excess pressure signs on your fired rounds...

 

I read somewhere that faster burning pistol cartridge powders do not accelerate the projectile down the full length of the barrel when used in rilfes. If I remember correctly it implied that you lost velocity due to this and it was unsafe to "add a different powder" to increase the burn rate and thus increase velocity... I honestly don't know if this is total hogwash or is there something to it.

 

As always I appreciate your responses,

 

Darin

[machinist1]

8uck5nort,

What bullet weight are you using? What powder? My Sierra manual lists .357 mag losds for lever action rifles with a 18.5 inch barrel. My manual shows the Sierra 158 gr. JHC/JSP bullet with WW296 and a CCI 550 primer. Using 15.0 grns.(starting load)1600FPS,17.0grns.(max load) at 1800 FPS. WW296 is the slowest powder shownn for .357 mag in my manual. As per saefty, start at minimuum starting loads.

Bob

 

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[lemski4]

Call any, or all of the powder company's, and bullet company's and ask for a lab tech. Explain what you are working with, cartridge, action type, barrel length and they should be able to help you out.I routinely call Hodgdon and Sierra from time to time and they are very helpful. I know Sierra keeps a log on the information they give you, and the next time you call, even about something totally different they may ask about your last call and how everything came out, for their information and they might put more research into it if they think their is enough interest in it.

[gun nutty]

I read somewhere that faster burning pistol cartridge powders do not accelerate the projectile down the full length of the barrel when used in rilfes. If I remember correctly it implied that you lost velocity due to this and it was unsafe to "add a different powder" to increase the burn rate and thus increase velocity... I honestly don't know if this is total hogwash or is there something to it.

 

I've seen a number of articles where the author started with a long barrel and shortened it in increments - an inch at a time - trying different loads and powders. My recollection is that the results were consistent: for a given pressure and charge, powders that gave higher velocities in longer barrels gave higher velocities in the shorter barrels.

 

The only exception that I'm aware of to this would be the 22LR, where the bullet will start to slow down after 18-20 inches due to friction. That 24"-barreled 22LR rifle sitting in your gun case is inefficient.

 

Powders that give higher velocity are probably going to give a louder report and muzzle flash in shorter barrels.

 

Many reloading manuals list the .357 Magnum in both the Rifle (tested with 18" - 20" barrels) and Pistol sections (usually 4" to 6"). You can compare powders in the manuals for a given bullet weight and have a fair idea on what power to use for optimum velocity. Read three or four manuals and look for trends. Most of the powder companies have online manuals.

 

My Hodgdon Number 27 manual lists IMR4227, H4227 and H110 as top performers for jacketed bullets out of an 18.5" barrel. At least for the group of 7 or so powders tested.

[Sailormilan2]

You need to go with the slower buring powders in a rifle. Hornady lists as the 2 best powders for their test gun, a 16" barrel Rossi Model 92, as being H110 and W296. For bullet weigts of 125 gr - 158 gr. For 158 gr, a max load of 15.5 gr(H110) or 15.7 gr (W296) gave a velocity of 1700 fps using Winchester Small Pistol primers.

[AzRednek]

For pistol calibers in Rifles I get the best shot to shot accuracy using slower burning powders, 2400 being my favorite. I've found I get better accuracy using a heavy crimp and mag primer with the slow powders. I no longer have a crony and honestly don't know if I move the slugs down range faster. Relying on published data, the slower the powder the faster the velocity. With my short barreled Rossi lever in 357. My reloads print tight clusters at 50 yards. At 75 yds I have to aim about 6 inches high and the shot to shot accuracy is mediocre at best. At a 100 yards I'm doing good to get it into a 12 inch circle. The 100 yrd bullet holes indicate some end over end tumbling.

 

I've had some good results using faster burning Unique and Herco in 357 handgun loads at handgun distances. If I put those same fast burning loads into my Rossi rifle accuracy takes a nose dive especially with Unique. With the faster powders a heavy crimp or mag primer does nothing to improve my accuracy. I use just enough crimp to keep the slug in place in a tubular mag.

[8uck5nort]

Appreciate the feedback. Thank You!

 

lemski4:

That is a great idea on calling the powder manufacturers. Never really though of calling them for a cartridge specific question.

 

machinist1:

I was using 158 and 140(?) gr Hornady and Speer bullets. I have a pretty accurate load at the 50 yard mark with HP38 (I am at work so can't confirm, but I am pretty sure that is the powder). Just didn't know if I could get more out of it with a different powder.

 

I tried Herco and never got much accuracy at all. What I noticed was the HP38 was one of the faster burning powders according to the Lee reloading book I have. It just got me thinking and I in turn tried to dig up some information.

 

I have not had much experience with any other types of powder so I was looking see what others were using and why they use it.

 

I will be trying some different ones now working up some 44 mag loads as well through a rifle.

 

Darin

[AzRednek]

I used HP-38 during the shortages for 357 and 38 Special plinking loads. HP-38 and HS-6 were the only handgun powders I could get at the time. Both calibers were loaded below max with home cast lead bullets. Friend and I shot up hundreds in various revolvers and my Rossi lever action rifle. The over all accuracy with HP-38 wasn't to bad especially in the 38 loads. The 357 loads without gas checked bullets eventually leaded up the bores and accuracy went south. I don't recall doing much the plinker loads in the Rossi rifle on paper. New Year's day of 2010 my daughter-in-law using both 38 and 357's loaded with HP-38 did a terrific job rolling beer and pop cans of the top of abandoned washer, dryer and refrigerator with the Rossi rifle at ranges of apx 40-50 yards.