Plated bullets in 357 mag

[Jessesky]

Hey guys,

What are your opinions on copper plated bullets in 357? The manufacturer suggests 1200-1250 max FPS. I have a bunch of 158gr plated bullets laying around I’d like to use for plinking. So performance is irrelevant on tissue. Lots of manufacturers give healthy performance margins to save their behinds, do you think I could push these to 1400fps without leading?

 

[IMtheNRA]

Leading wont be a problem, but the copper may separate from the lead core. I had separation problems with Berry's 125-gr HPs and they blamed it on a "burr in the barrel'.

 

[rfwobbly]

The maximum velocity you can "push" any plated bullet to is determined by the plating thickness. The thicker the plating the higher the permissible velocity. So first you need to know the bullet maker. However, some manufacturers offer their bullets in different thicknesses, so you might even need the product number.

If you bought a bag of unidentified bullets at a gun show, then it's only safe to assume the thinnest plating and therefore the slowest speeds.

 

[LiveLife]

And "maximum" rated velocity may just be for copper plating failure point, not optimal performance/accuracy.

With regular thickness plated bullets (.004" - .008" rated to 1200-1250 fps), I have found accuracy deteriorates above mid-range jacketed load data. With thicker plated bullets with higher velocity rating (Like RMR, Speer TMJ/Gold Dot, I can use full jacketed load data without accuracy deterioration.

The manufacturer suggests 1200-1250 max FPS ,,, do you think I could push these to 1400fps without leading?

... first you need to know the bullet maker. However, some manufacturers offer their bullets in different thicknesses

I would stay below rated velocity. If you want to push 1400 fps, look at different plated bullets with higher velocity rating.

This post lists plating thickness and velocity ratings of most plated bullets as best as I could find for your reference (Regular and thicker plated) - https://www.thehighroad.org/index.p...ng-at-25-50-yards.808446/page-3#post-10470195

357 ... 158gr plated bullets ... 1400fps

RMR .357 158 gr plated bullets are thicker plated (.008"-.010") and rated to 1400 fps (They offer 5% THR discount with thehighroad5 code and THR ID in the order comment box and free shipping on all orders) - https://www.rmrbullets.com/shop/bullets/357-158-gr-plated-round-nose-flat-point-bullets-new/

I pushed RMR 9mm 100 gr Hardcore Match RN bullets (Thick plated rated to 1500 fps) to almost 1500 fps out of my carbines with no copper plating failure and the short stubby bullet stabilized well enough to produce nice round holes at 50/100 yards (no elongated or sideways holes on target ) - https://www.thehighroad.org/index.p...n-9mm-40s-w-45acp.799231/page-3#post-10245856

• 100 gr RMR HM RN 5.5 gr HP-38: 1493-1468-1432-1479-1454 fps
• 100 gr RMR HM RN 4.5-4.7 gr Promo: 1478-1475-1480-1471-1467 fps

 

[Walkalong]

X-Treme 158 Gr SWC @ 1.650 OAL.
WSP primer.
14.5 Grs 2400.
Heavy taper crimp.

72 Degrees 32% RH
6" Trooper Mk III

6 shots Powder Back Powder Forward Powder Level
HI 1216 1262 1264
LO 1120 1133 1107
AVG 1178 1194 1207
ES 96 129 162
SD 38 55 65

Good accuracy, no plating issues. (14.0 Grs 2400 subtract about 30ish FPS)

158 Gr XTP with the same load, same gun, same day. (Shot them back to back)
Heavy (ish) roll crimp.

6 shots Powder Back Powder Forward Powder Level
HI 1253 1254 1241
LO 1098 1075 1169
AVG 1195 1196 1202
ES 155 179 72
SD 53 67 29

Virtually the same FPS.

Check data, start low, be careful.

 

[Walkalong]

That said, I am shooting coated lead 158 Gr SWCs with 2400 now.

 

[Walkalong]

So performance is irrelevant on tissue. Lots of manufacturers give healthy performance margins to save their behinds, do you think I could push these to 1400fps without leading?

They can't handle it. Why assume they are "covering their tails"? They are not, they don't want their bullets to fail and get bad press. They give realistic limits to help us succeed with their bullets.

 

[Jessesky]

They can't handle it. Why assume they are "covering their tails"? They are not, they don't want their bullets to fail and get bad press. They give realistic limits to help us succeed with their bullets.

Of course. But I’m sure the bullet won’t catastrophically fail at 1300fps if the manufacturer recommends 1250. I’m sure they have terminal performance in their minds as well. For my purposes I’m trying to save money on plinking and wanted to see how far I could push them before observable negatives.

It’s kind of like rope (I like to rock climb) a rope may have a working weight of 800lb but the tensile test is 800lb. It certainly can handle more, but for safety and for performance they limited it to 800lb.

I have a ton of these plated bullets laying around from my 38 and wanted to see if it had a dual application

 

[Walkalong]

I’m sure they have terminal performance in their minds as well.

I seriously doubt that comes into play. Rope/chain limits (Breaking vs safe) is a bad comparison.

You can always prove it to yourself with H110 if you like.

 

[cheygriz]

I use Rainier and FMP plated bullets. Never had a problem loading to 1350-1400.

 

[Toprudder]

I'm sure I will have someone disagree with me, but from my personal experience, I don't like to push plated bullets hard in revolvers. I had evidence of plating failure when I pushed some 44mag plated bullets to 1200fps in my revolver. I found slivers of copper when cleaning the gun, and also had leading in the barrel. (Yes, if the plating fails, you CAN get leading in the barrel).

I think the plating can fail quicker in revolvers, due to the large jump the bullet has to go before it hits the lands and forms a gas seal. All of the hot gasses passing the bullet before this happens is like a cutting torch. I switched to jacketed Zero bullets and have not looked back. The prices for their bullets are in line with some brands of plated bullets.

http://www.rozedist.com/mm5/merchant.mvc?Screen=CTGY&Store_Code=RZD&Category_Code=ZBJ-38S

 

[Bfh_auto]

I ran them over 1400. But it was in a lever action with a polished barrel.
Revolvers and rough barrels are hard on them.

 

[RealGun]

Hey guys,

What are your opinions on copper plated bullets in 357? The manufacturer suggests 1200-1250 max FPS. I have a bunch of 158gr plated bullets laying around I’d like to use for plinking. So performance is irrelevant on tissue. Lots of manufacturers give healthy performance margins to save their behinds, do you think I could push these to 1400fps without leading?

You have a fundamental problem in not having a data source for such a load. I would not get in the habit of playing around with loads over max. We should not encourage anyone to do so.

 

[Jessesky]

You have a fundamental problem in not having a data source for such a load. I would not get in the habit of playing around with loads over max.

Well, i have published loads that comfortably push a 158 gr at 1400fps. The loads are with jacketed bullets and a lead bullet should generate less pressure than a jacketed bullet so I figured I’m safe

 

[Toprudder]

Well, i have published loads that comfortably push a 158 gr at 1400fps. The loads are with jacketed bullets and a lead bullet should generate less pressure than a jacketed bullet so I figured I’m safe

Everyone should keep in mind the barrel lengths used to create the load data. This information sometimes gets hidden in some sources. Alliant, for instance, does not list barrel length in their printed manual, but they do on their website. Some of the Alliant 357mag data was created with 10" barrel, some with 6" barrel. That can make a huge difference! I can get 1800fps with 357mag 158gn bullets, but that is from a 16" barrel.

 

[RealGun]

Well, i have published loads that comfortably push a 158 gr at 1400fps. The loads are with jacketed bullets and a lead bullet should generate less pressure than a jacketed bullet so I figured I’m safe

But you are still ignoring the spec set by the bullet manufacturer. You should have more respect for it. We extrapolate only when necessary, and even then start low and work up. You indicated "plinking", so why get crazy with it?

 

[RealGun]

Xtreme sent me plated, when I ordered plain lead. I decided not to take their offer to accept them back for replacement. I am doing well with them, a 158 gr SWC at .358, no roll crimp. I am using the minimum load for Unique at 6.5 gr and it shoots well without heavy recoil...pretty much in the plinking or target class but well beyond a 38 Special shooting experience. If I was going to get into a heavier load, I would want a bullet with a crimp groove to allow a firm roll crimp. I also have some I loaded with 7.3 gr BE-86, another mid level load that shoots really well.

 

[Jessesky]

Everyone should keep in mind the barrel lengths used to create the load data. This information sometimes gets hidden in some sources. Alliant, for instance, does not list barrel length in their printed manual, but they do on their website. Some of the Alliant 357mag data was created with 10" barrel, some with 6" barrel. That can make a huge difference! I can get 1800fps with 357mag 158gn bullets, but that is from a 16" barrel.

For sure, I use Ammoguide.com and the barrel length is listed within a half inch of mine

 

[mcb]

Back when Berry's was still fairly new I was playing with 180gr 40-cal bullets in my Limted-10 and my Revolver. I found that by the time I got them to Major Power Factor (~950fps) the plating started to peel. I would get funny bullet holes and accuracy got pretty bad. It was a shame as at the time Berry's was about the only plated or jacket round nose 40-cal on the market and for the revolver that was nice.





I am sure Berry has improved their technology/process and it might not be an issue with current production if I tried them again. That was over 10 years ago but I thought I would share what can happen when you push them to hard.

ETA: I suspect if I had reduced the amount of crimp I was using back then I might have reduce, but probably not eliminated, the plating peeling issue.

 

[Jessesky]

But you are still ignoring the spec set by the bullet manufacturer. You should have more respect for it. We extrapolate only when necessary, and even then start low and work up. You indicated "plinking", so why get crazy with it?

Definitely important to respect it, and I will. I know it’s only for plunking but I enjoy full power loads for plinking and/or practice. I suppose I’ll use these up with titegroup and order some JSP for my H110 loads

 

[Walkalong]

Well, i have published loads that comfortably push a 158 gr at 1400fps. The loads are with jacketed bullets and a lead bullet should generate less pressure than a jacketed bullet so I figured I’m safe

Plated isn't lead. If you study data with plated bullets as well as jacketed included you'll find that sometimes the max charge weight is less with plated. You are assuming a lot.

 

[Walkalong]

Definitely important to respect it, and I will. I know it’s only for plunking but I enjoy full power loads for plinking and/or practice. I suppose I’ll use these up with titegroup and order some JSP for my H110 loads

A wise man.

 

[Bfh_auto]

Well, i have published loads that comfortably push a 158 gr at 1400fps. The loads are with jacketed bullets and a lead bullet should generate less pressure than a jacketed bullet so I figured I’m safe

Both lead and plated are a larger diameter than jacketed. This seals better causing higher pressure with a lower charge.
I wouldn't replace jacketed bullets with plated ones. You can try working up to it, but don't be surprised if you get poor results as you near the top.

 

[Jessesky]

Both lead and plated are a larger diameter than jacketed. This seals better causing higher pressure with a lower charge.
I wouldn't replace jacketed bullets with plated ones. You can try working up to it, but don't be surprised if you get poor results as you near the top.

I’m not disagreeing, but I do enjoy a good conversation. It’s my understanding that while lead creates a better seal by “swaging” down the bore, that copper jackets require more force to engrave to the rifling because it is a harder material. Because of that there is more friction with the bore and more pressure behind the bullet. That being said there’s too many factors in play for me to say for sure, but I have heard both sides of the argument.

 

[tightgroup tiger]

I pushed some copper plated bullets over their maximum recommended speed and the copper plating welded it's self to the bore of my barrel. I didn't discover it until I got home. It was hard to clean out. It also leaded the heck out of it.
Stay within the maximum speed the manufacturer puts on their bullets and you won't have any problems.
Most plated bullets start out as soft lead bullet cores and the lead isn't hard enough to resist stripping in the riflings when the plating fails and pushed to fast with a thin plating on them, they will strip in the rifling like a lead bullet does when it's to soft.
Lead bullets that can be ran at 1400 and up are gas checked and/or hard cast. They are hard the whole way through.
Plated bullets, their softer core won't help support the plating of the bullet at that speed unless the mfg says they will. Then they probably have thicker plating and a harder core.