357 Magnum Bullets tumbling - help

[mookiie]

I have a load for 357 magnum that I took to the range and the bullets are tumbling upon firing. I am shooting a Taurus Tracker. The load is a 158 grn flat nose copper plated bullet. I used 6.8 grns of unique powder. I know it is not the bullets because I used the same bullets in a 357 magnum load with 13.8 grns of Win 296 and they fire beautifully. So I am assuming I am using either to much or too little of the unique powder. The starting load was 6.5 grns and the maximum was 8.5 I believe. Does anyone have any suggestions on what load I should use next? I was thinking about going up to 7.5 grns or so. Does anyone have a good unique 357 mag load for a 158 grn bullet?
Thanks Guys!

 

[BADUNAME37]

With your current loads, are your primers flattened and are the cases difficult to extract from the cylinder?

If no, I would work up to a higher load, watching for signs of pressure. I have not loaded .357 for over 15 years. I used Unique with 158g Jacketed bullets and it seems my pet loads were around 7.4g of Unique. Double-check that, but that was a calmer load than factory and they shot extremely well!

I am going completely by memory on this as I no longer have my old .357 data.

 

[GP100man]

Mookiie

first thing is to mic the bullets , then slug the bore especially the throat , drive 1 completely thru ,measure , then drive 1 to the start of the front portion of the frame & stop take a wood dowell cut into workable lengthd & push the slug out the muzzle , measure ,same ???? different ????

Are you crimping them , the skin is only .003-.007 thick & easily cut by too much crimp then the rest will strip easier especially on a ruff forcing cone .

I found to keep the skin on I had to back off the crimp PERIOD ,causing inconsistent ignitions , even with fast powders , I traded the rest !!

I now invest in lead , white alloys & good moulds !!!


if ya can recover a bullet & inspect it what does it look like ??

 

[mookiie]

Friendly, Don't Fire! - The one thing that I saw on the primers that I have not seen before is that the indentation where the firing pin struck the primer actually looked as it it had a tiny whole in it where it gave way. That is what is making me think it may be to high pressure but again the load is supposed to be mild. They are Winchester Small Pistol Magnum primers and I have never noticed this before with any other load.

GP100man - I am fairly certain it is not an issue with these bullets as I shot the same bullets in the same gun on the same day the only difference was one had 7.1 grns of unique and these tumbled end over end down range producing rectangular strikes on the target and the others used 13.8 grns of Winchester 296. This makes me conclude it must be a powder issue because all other factors were the same - Bullet, gun, weather, distance, primers, and cases - powder was the only variable here.

Thank you both for your input.

 

[Philippe]

Pushing them too fast maybe?

 

[gamestalker]

I've been loading for the .357 mag. for about 30 or so years, and have never had anything even remotely simular happen. I've never used Unique either, so my perspective may be off a bit.
Then there is the blown primers. It may sound stupid to ask this, but are the primers extremely flattened, or just punched? I'll bet both?
Double check the powder weight being used, the bullet weight confirmed, and even confirm the powder to be sure you haven't inadvertantly loaded the wrong one, it happens. I wouldn't even consider such a possibility if not for the fact that your experiencing such extreme circumstances.
Speer data shows a 158 gr. SWC to have a charge range from 5.5 grs. to 6.0 grains with Unique. Maybe your powder charge is too high for that plated bullet. I've heard many suggest starting with lead data for plated bullets, and then working up slowly until your where you want it to perform, or signs indicate the maximum has been reached. In this respect, I noticed your powder charge exceeds Speer data by a good bit, .8 grains above the maximum. One thing for certain, I would not consider increasing the charge with the signs your experiencing at 6.8 grains, especially with a magnum primer.
And last, but not least is the primer you are using. You said your using a magnum primer. Unique doesn't require a magnum primer, and using one will most deffinitly increase pressures, especially with fast burning powders. Magnum primers are only necessary with powders that are difficult to ignite like ball powders or large dense compressed powder charges when it is recomended, certainly not for Unique.
My suggestions is to use a standard small pistol primer, decrease your powder charge by .8 grain, and make sure your OAL is not too short. I'll bet if you try this you'll stop blowing primers at the very least, and even possibly eliminate the tumbling bullet problem. Once you've stopped the primer issue and tumbling bullets you can slowly work up your powder charge in .1 gr. increments, if desired.
Good luck and be safe!

 

[buck460XVR]

I shoot tons of 158 grainers with 7.5 grains of Unique using a SP primer. It's my favorite plinkin' load in .357. I figure I'm only gettin' about 1000FPS outta it, so this velocity should be within limits of any good plated .357 bullet. I don't go lower than that because I use the same loads in my carbines and don't wanna risk a stuck bullet. I'd be a little leery of that W296/H110 load tho. That's under minimum in several books and that powder does funky things when downloaded. I love it for true magnum loadings, but for plinkin' I stick to Unique or W231.

 

[Sport45]

What are you using for a target? If you are using copy paper it could be tearing out and making you think the bullets are tumbling when they aren't. At magnum velocity this doesn't happen as bad. What do the holes look like when you shoot into a piece of wood or cardboard?

 

[mookiie]

Sport45 - I should put up a picture of the rectangular whole it ripped through a 1x2. Trust me their is no mistaking that they are tumbling.

 

[snuffy]

Speer data shows a 158 gr. SWC to have a charge range from 5.5 grs. to 6.0 grains with Unique. Maybe your powder charge is too high for that plated bullet.

That speer data is for their dead soft, pure swaged lead bullets. That's why it's so low. A cast bullet of just about any harder alloy can be pushed as fast as jacketed bullets. Lyman 48th manual lists 6.4 to 8.3 for 158 grain jacketed.

BUT they,(Lyman), don't list unique with lead bullets over 141 grains in 357 magnum in the 3rd edition of the cast bullet handbook.

My take on the plated bullet is that they behave more like a lead bullet because the plating is thin and the core is pure lead. I'd say to simply try a different powder.

That 296 load IS way low on all levels. Lyman lists 18.0 grains in the cast bullet manual, with no reduction or starting load listed. The 48th lists 16.3 to 16.7 for 158 jacketed. That makes your load of 13.8, 2.3 grains light for jacketed or 4.2 light for lead.

The problem with WW-296 or the same powder H-110 is erratic ignition in reduced loads. Squibs stick one bullet in the barrel caused by partial burning of the powder, then another shell is fired behind the stuck bullet,,,---KABOOM!

 

[ArchAngelCD]

From everything I know with plated bullets you should use lead bullet data. With a 158gr LSWC bullet the MAX charge weight listed on the Alliant site is 6.0gr Unique. Your charge of 6.8gr Unique is way over the recommended charge weight. Alliant lists a Max charge of 7.7gr Unique with a Speer GDHP bullet but the data is much lower for lead bullets. I have a feeling the bullet is reacting to the extreme pressure being generated causing the tumbling. The pierced primers you are reporting are also something to pay attention to.

 

[Walkalong]

It is strange that the bullet loaded "heavy" with W296 shot great while the "lighter" load with Unique did not.

Perhaps the pressure is greater with the faster powder despite velocities being slower, and the bullet can't take it. It can obviously take the velocity, so the only thing left is the pressure.

Plated bullets do not act like lead or jacketed. I am looking forward to the data with Berrys bullets that is coming soon. It will add to some of the older plated data we have, as well as the plated data in the up to date Accurate and Vihtavuori data.

http://www.thehighroad.org/showpost.php?p=6195350&postcount=11

 

[41 Mag]

Thats the difference between Unique and 296. the Unique is fast and hits hard from the get go where while the 296 will get magnum velocities it start off with a much slower push on the bullet then builds fast after it gets going. So to speak.

Mookie have you looked at trying 2400? It will sometimes fill a void between the two ends of the burn rate, and usually has a pretty decent load spread to work with.

 

[Sport45]

I should put up a picture of the rectangular whole it ripped through a 1x2.

You should. We like seeing stuff like that.

 

[243winxb]

copper plated bullet

Use midrange* lead loading data. Your load may be to hot. Light crimp.

 

[Walkalong]

Be careful with low end lead data and plated bullets. You can stick a bullet. It takes more oomph to get them out of the barrel than a lead bullet.

 

[GooseGestapo]

The Unique load is quite warm for a plated bullet.
The punctured primer is telling you the pressures for your load are quite high. Perhaps not enough to cause sticky extraction or flattened primers but enough that a long firing pin is getting perforation.

The H110 load is actually a light load, pressure wise, so that adds to the notion that the Unique load is a bit heavy for YOUR BULLET. Back off to 5.5-6.0gr and retry the accuracy check. I think that you'll be pleased with the results.

For years, my practice and occasional "snake" or other pest removal load for my duty .357mag was a "loose" load of 6.0gr of Unique. It typically kicked a bit less and mostly less muzzle blast but hit to poi/poa of my sight in for duty ammo (issued, typically 145gr Winchester Silver-Tip).

I use cast bullets sized to .358" and have used as much as 7.8gr of Unique with no problems. I have also used as much as 16.5gr of H110. However, there is a LOT of difference between a gas-checked cast bullet and an electro-plated bullet.

 

[buck460XVR]

It may help to know what kind of Plated Bullet the OP is using and what THAT manufacturer recommends....otherwise we are all just speculating. This is from Berry's website.....

FAQ: How do I load Berry's Preferred Plated Bullets?
Plated bullets occupy a position between cast bullets and jacketed bullets. They are soft lead, but have a hard outer shell on them. When loading plated bullets we have found best results using low- to mid-range jacketed data in the load manual. You must use data for a bullet that has the same weight and profile as the one you are loading. Do not exceed mid-range loads. Do not use magnum loads.

Using their recommendations, 6.8 is at the low end according to my load manuals. But other brands may differ. Berry's also recommend keeping their bullets below 1200 fps. This is something easily done even with a mid-range Unique load with a 158 bullet outta a .357 case.

 

[mookiie]

GooseGestapo - in your 6.0 gr unique loads do you use a magnum primer or a regular small pistol primer?

 

[rcmodel]

Magnum primers are never necessary for any powder except the slowest burning ball powders like H110/W296.

You will get better results with fast to medium burn rate flake type powders like Unique using standard primers.

rc

 

[ArchAngelCD]

Magnum primers are never necessary for any powder except the slowest burning ball powders like H110/W296.

You will get better results with fast to medium burn rate flake type powders like Unique using standard primers.

rc

That's the truth, the whole truth and nothing but the truth.

 

[mookiie]

Alright I have decided to try 5.8 grns of unique with a small pistol primer. I will let you know how that works out for me next time I hit the range.

 

[ArchAngelCD]

Alright I have decided to try 5.8 grns of unique with a small pistol primer. I will let you know how that works out for me next time I hit the range.

That sounds like a much better place to start...