357 magnum load going to try Saturday...First time! What do you think?

[Stopsign32v]

Well I've never loaded 357 magnum to magnum velocity. Mainly due to the fact of never having jacketed bullets.

Anyways I have some Xtreme copper plated bullets, Winchester 296, and some magnum primers so I threw a hand full together to try out in my new GP100 on Saturday.

My Lyman book showed 17gr as max. My Hodgdon showed 16.5 as max. And another reloading book I had I think showed 16gr as max. I also did some internet searching because I know 296 is not ideal for 357 magnum but in times like now it is what I have for magnum powder. Everyone says 296 likes to be at the limits with a magnum primer so that is what I'm giving it.

I measured ALL loads individually on the scale before loading and all are a true 16gr with a nice heavy crimp. My question is do you think I am GTG?

 

[Herman B]

I'm unsure your CP bullets are up to the velocities afforded by W296 - top shelf Magnum. Std plated bullets are not to exceed 1200 fps. Do your bullets have a cannelure? If not, they'll jump. Unless you give'em the mash crimp! And likely to spit.

I suggest a 'pause' and thoroughly evaluate.

 

[eddiememphis]

What weight bullets?

 

[jmorris]

Well I've never loaded 357 magnum to magnum velocity. Mainly due to the fact of never having jacketed bullets.

That’s a great reason. If you are using plated bullets, you are still not using jacketed bullets.

 

[Stopsign32v]

That’s a great reason. If you are using plated bullets, you are still not using jacketed bullets.

I did my research. Xtreme's load info:

"Load Info
Our Copper Plated Bullets can be run at mid-range jacketed velocities or higher end lead velocities. We recommend keeping velocities to less than 1500 FPS (Feet Per Second) and using only a light taper crimp"

My velocity shouldn't be much over 1100fps.

And to answer an above question, 158gr with a cannelure.

 

[joneb]

Plated bullets have a speed limit, W-296 has a do not reduce limit. This could be a issue, if you are using 158 gr plated in a revolver the remaining bullets in the cylinder may begin to pull out of the case. Increasing the crimp to prevent the bullet from jumping the crimp with a taper or roll crimp may cut the copper plating and copper fowl the barrel. I use a Lee collet crimp die for such endeavors which should not be confused wit the Lee FCD.

 

[Stopsign32v]

Plated bullets have a speed limit, W-296 has a do not reduce limit. This could be a issue, if you are using 158 gr plated in a revolver the remaining bullets in the cylinder may begin to pull out of the case. Increasing the crimp to prevent the bullet from jumping the crimp with a taper or roll crimp may cut the copper plating and copper fowl the barrel. I use a Lee collet crimp die for such endeavors which should not be confused wit the Lee FCD.

I used a Lee FCD. I will inspect the bore after the first few shots.

 

[Herman B]

My velocity shouldn't be much over 1100fps.

Not with 16 gr of W296. Hodgdon data w/ 158 XTP: min 15.0 for 1418 fps, max 16.7 for 1591.

You need a different powder for 1100 ft.

...all are a true 16gr with a nice heavy crimp.

A heavy crimp will damage a plated bullet...likely to spit.

I will inspect the bore after the first few shots.

Shoot paper to detect the dreaded spit. I would also measure every remaining round in the cyl after every shot so as not to lock it.

 

[jmorris]

They stop well below 1500 with their load data, using smaller charges of faster powders, for 158’s in 357, even suggest using 38 spl brass if you down load their manual.



16.0 is likely more than I would start with with the lower friction of a plated bullet, 1100 fps would be lower velocity than I would expect with that charge weight and a higher friction jacketed bullet of that weight.



I never like to crimp plated heavily, once you crack the thin plating they don’t get any better and it’s easy to swage them smaller with crimp ruining much chance of accuracy.

A good rule of thumb for plated bullets is to not exceed lead data. Same as you quoted them saying in #5.

 

[joneb]

I trim all my revolver brass to consistent length as the resized case lengths can vary more than .01". If you trim your brass be sure to chamfer the inside of the case mouth.

 

[Stopsign32v]

Not with 16 gr of W296. Hodgdon data w/ 158 XTP: min 15.0 for 1418 fps, max 16.7 for 1591.

You need a different powder for 1100 ft.

You are not going to get 1400fps out of 15gr of 296 in a revolver. The heck are you talking about?

 

[Stopsign32v]

They stop well below 1500 with their load data, using smaller charges of faster powders, for 158’s in 357, even suggest using 38 spl brass if you down load their manual.

View attachment 1008772

16.0 is likely more than I would start with with the lower friction of a plated bullet and I never like to crimp them heavily, once you crack the thin plating they don’t get any better.

A good rule of thumb for plated bullets is to use lead data.

But I'm going to be no where near 1500fps. More than likely I will be between 1100fps and 1200fps.

 

[jmorris]

But I'm going to be no where near 1500fps. More than likely I will be between 1100fps and 1200fps.

Sorry was adding data. See attachment in #9 should be well above 1100 with 16gn of 296 with a plated 158.

Hornady shows 1200 with 14.3gn with a jacketed bullet, and a slicker plated bullet will only be going faster.

You got them loaded up, give them a go and let us know how they do and how fast they are actually going.

 

[Stopsign32v]

Sorry was adding data. See attachment in #9 should be well above 1100 with 16gn of 296 with a plated 158.

Hornady shows 1200 with 14.3gn with a jacketed bullet, and a slicker plated bullet will only be going faster.

Do you know what length barrel they are using? I honestly didn't consider the plated bullet causing it to go faster than the jacketed, crap. I might get closer to 1300fps. I might give Xtreme a call tomorrow and ask their opinion. How much faster in general are the plated bullets over an XTP?

Edit: Their above data still shows 10fps less than 1300 anyways...

 

[jmorris]

8 3/8” model 27, in the Hornady manual.

Hodgdon shows 1418fps, again with a jacketed bullet with only 15.0 grains, don’t know what barrel length they used.



If your plans are to chronograph them I would shoot a few rounds up close at a cardboard target to make sure the bullets are not coming apart.

When plated bullets have reached their limits, they will spew lead in a pinwheel on paper up close.



Better to test first than chancing a frag on your chronograph.

 

[jmorris]

If you really wanted to go the route of safe vs sorry, you could always load up a few more using starting loads and working up before you get to the 16 grain loads and see how they do first.

 

[Stopsign32v]

If you really wanted to go the route of safe vs sorry, you could always load up a few more using starting loads and working up before you get to the 16 grain loads and see how they do first.

Thanks for the tip above, I will do that first. I didn't work my way up because everything I've read says 296 only does good at max. Plus the reloading book only gave roughly a 1gr difference (15gr to 16gr) from starting to max if I recall correctly.

I will look at the bore and do the above cardboard trick first before sending them all.

 

[jmorris]

I wouldn’t go below published starting loads but start is always a good place to…well, start.

 

[Herman B]

I also did some internet searching because I know 296 is not ideal for 357 magnum...

It's an excellent, widely used powder since the 60's for hot magnum rounds (also 41, 44, 454, etc.). For non-magnum, pooftah rounds - no.

Our Copper Plated Bullets can be run at mid-range jacketed velocities or higher end lead velocities. We recommend keeping velocities to less than 1500 FPS and using only a light taper crimp.

Quite a difference between velocities, mid-jacket/high-lead vs. 1500 ft. Bless their marketing spirit. Incidentally, a heavy roll crimp and plated copper is a questionable mix.

You are not going to get 1400 fps out of 15gr of 296 in a revolver. The heck are you talking about?

Homework. And Hodgdon's 10" barrel with the XTP. Nosler data: JHP, 14.8 gr max, 1540, 8.3" bbl.

I will inspect the bore after the first few shots.

He was referring to 'jump' so need to check COL after every fired round. Check it all; throat, forcing cone and bore for debris. Cases for unburnt powder, potentially indicative of inadequate crimp.

I speculate Xtreme will tell you 16.0 exceeds their max recommendation by a significant margin. Let us know what you learn and be safe!

 

[buck460XVR]

I know 296 is not ideal for 357 magnum

I don't know where you got that from, but for legitimate magnum loads in .357, you cannot get any better than W296/H110.

My experience tells me you will get more than 1100 fps from 16g under a 158 plated. My experience is also accuracy will probably not be the best. But you should be fine to shoot them.

 

[Bfh_auto]

Accuracy will probably not be the best.
I have run plated bullets as high as 2400 fps without the smear one of the earlier posts showed.
I was attempting to find bullet failure.
The firearm I was using had a fire lapped barrel and 1-30 twist.
My Blackhawk also has a lapped barrel and doesn't destroy plated bullets with magnum loads. Once again accuracy is poor compared to lead or jacketed.
Moral of the story. Don't expect great accuracy.
If you want accurate magnum loads for cheap run properly sized lead.
H110/W296 are my favorite 357 powders. Good luck.

 

[RealGun]

I'm unsure your CP bullets are up to the velocities afforded by W296 - top shelf Magnum. Std plated bullets are not to exceed 1200 fps. Do your bullets have a cannelure? If not, they'll jump. Unless you give'em the mash crimp! And likely to spit.

I suggest a 'pause' and thoroughly evaluate.

No need to read further. Reevaluate premise.

 

[EricBu]

Good advice passed on above, I've used their's and other's plated for .357, and they've held up well for medium .357 loads. The only thing I would add...after you adjust all your dies, take the first couple you load, and break 'em down. That will tell you if your crimp is breaking the plate. I'd surmise unless you went out and bought a purpose made taper crimp die for your .357, or specifically looked for that when you bought your die set..........it's going to be a roll crimp die you have. Plated (and coated for that matter) bullets can be damaged if your a bit to exuberant on your roll crimp. When you pull a couple, you'll immediately know if you're splitting the crimp, or deforming the bullet. If those have a cannulure, you're golden...shouldn't be an issue to crimp enough to stop jumping without causing damage. If you're stage in the reloading journey hasn't yet led to purchasing a bullet puller, now is a good time to get one!

 

[eddiememphis]

The firearm I was using had a fire lapped barrel and 1-30 twist.

I have never heard of such a slow rate. Is it for .357? I thought .357's were best around 15 or so. Aren't roundball muskets in to 1:30 range?

 

[Hooda Thunkit]

I have never heard of such a slow rate. Is it for .357? I thought .357's were best around 15 or so. Aren't roundball muskets in to 1:30 range?

Roundball rifles are in the neighborhood of 1-48" or even slower at 1-60".

I have a 50 cal muzzleloader that is 60" twist. Patched round ball shoots very well.

As to the OP - I shoot 15.4gr W296 behind a 358156 checked lead bullet, in a 6.5" Ruger Blackhawk.
I get about 1250-1300 fps out of that load.

More powder than that does not get more velocity in that combination. More powder just makes more noise and flash. And burns more powder.