Plated bullets at near-max loads

[DarthNul]

I worked up a load for the X-treme plated 165 gr RNFP bullet in .40 S&W. I started with the published data that I could find for similar weight/profile jacketed bullets. I'm using Accurate #5 for this load.

I know the rule of thumb about not exceeding 1200 fps with plated bullets in pistols. And I also know about using "medium range" data for similar weight/profile jacketed bullets, but there's not really much overlap between these "rules" in .40 S&W.

The thing is, this bullet/powder combo just kept getting more accurate as the powder charge increased, and it's working best at 7.3 grains which is the max published load that I found for 165 gr jacketed bullets.

I see no signs of excessive pressure or recoil. Is there any reason not to use this load? It's the only reasonably accurate load I've found so far in my SA XD40, and it works very well in my Witness too as long as it's accurate? I would expect that if the softer (than jacketed) bullet was deforming under max load pressures it wouldn't be very accurate.

[BigPapa4147]

What you need to watch out for is leading. At higher velocities, the thin copper plating can get stripped from the lead core, allowing the bare lead to get worked into the rifling. If you keep an eye on it and don't find any leading after several magazines, you should be good to go. As always, this is just one man's opinion.

[serf 'rett]

I recently was working up loads for 9mm using Power Pistol under Berry’s 115 grain RNDS and found my groups tighten at the upper end of the range I was testing. The group was so good, I went ahead and loaded some more rounds. A few weeks later, someone had a chronograph at the range. We tested five rounds and found they were heading downrange at 1183 to 1212 fps.

[DarthNul]

What you need to watch out for is leading. At higher velocities, the thin copper plating can get stripped from the lead core,

I haven't seen any leading on the XD and I've run this load through it on three separate outings. I haven't cleaned the Witness since I tried the load on it a couple of days ago, but that load only represented 15 rounds of the 200 or so rounds that went through the gun.

Xtreme claims their plating is 0.010" thick which is supposed to be at least 2x the thickness of other plated brands. Maybe that helps?

[saands]

Actually, it isn't so much the leading that is the issue, it is that the plating can get stripped off the bullets and stay in the barrel as an obstruction for the next round ... at least that is what the guys at Berry's told me several years ago. After talking to them, I loaded up some 125gr 357 loads and worked them up (towards 1500 fps over H110 IIRC) ... I shot them at a target that was only about 2 yds away and cleaned the barrel after each shot to prevent the obstruction issue. What I saw was that they failed just before I got to my limit and that when they failed (in that S&W 586) they put a circular hole in the target (from the bullet) with a halo of little slices around the primary hole where the plating went through the paper.

I personally wouldn't push them past the recommended velocity (the manufacturer should be able to tell you what THEIR recommended max is) unless I had carefully tested many from the same batch to a velocity that is higher than that which I wanted to run routinely. Alliant Power Pistol might be able to get you those higher test velocities in the 40S&W if you know someone that will give you an ounce or two for testing. If the thicker plating is better, then the manufacturer ought to be willing to tell you to what speed you can push their product. The issue here is that if you obstruct the barrel, it can be very bad for your health and (less importantly) the health of your pistol.

Be safe ... you only have 10 original fingers and two eyes ...

Saands

ps ... you never said what velocity you are getting out of your XD ... are you even sure that you are exceeding 1200fps? That is actually pretty darn hot for a 165 out of a 4" bbl ...

[DarthNul]

when they failed (in that S&W 586) they put a circular hole in the target (from the bullet) with a halo of little slices around the primary hole where the plating went through the paper.

I still have the targets. I always bring them home for more extensive evaluation and I can tell you for sure that there are no halos. The holes from the load in question are cleaner than all the others. The plated bullets are flat nose. All the other loads I tested that day were Montana Gold JHPs. Flat nose seems to always make cleaner holes than hollow points.

I don't have a chrony (and if I did I doubt they'd let me set it up at the range) but I don't think I'm getting anywhere near 1200 fps. The estimate for the load data is closer to 1000. My concern is more about exceeding the "mid-range for jacketed bullets" rule. Although looking through a loadbook for .40 S&W, I'm finding loads that go as high as 8.5 gr of A #5 for 165gr Speer Gold Dots so I guess I'm not as close to max as I thought. The Accurate powder data doesn't list 165gr bullets but they put 155 gr bullets at 7.5gr max and Nosler 170gr JHPs at 7.2 max.

I always have Power Pistol on hand. It's my primary powder for 9mm. My results with PP have been mediocre in .40 caliber so far except with 155gr Hornady XTPs. I got a 1.27" group at 25' supported which I would never settle for with the Witness match, but so far it's the best I've gotten out of the XD since I got it from my bro-in-law in February. I know it's unfair to compare a tactical pistol to a target pistol but I want to squeeze out whatever I can.

[serf 'rett]

I shot them at a target that was only about 2 yds away and ...and that when they failed (in that S&W 586) they put a circular hole in the target (from the bullet) with a halo of little slices around the primary hole where the plating went through the paper.

I'm wondering if the "halo" would show up at greater distances?

[JASmith]

Part of the reason that the "heavier" loads work better is that there needs to be enough pressure to cause the base of the bullet to upset and make a tight seal. If this doesn't occur two things happen: 1) the accuracy drops; and 2) gas jetting through the gaps between the bullet and the rifling can cause leading.

I didn't tumble to this insight until I read the pertinent parts of the Oregon trail load handbook (http://www.laser-cast.com/) to try to figure out why my ultralight loads weren't as accurate as I wanted. Going to pressures (above about 15 ksi for the LaserCast) worked.

Thankfully, I didn't get the leading.

I'm sure the pressure vs hardness insight sits in several different references, but that's where I found it.

[saands]

I don't think that the halo would show up too far from the muzzle ... the little pieces of plating would bleed energy really fast and I suspect that they would just fall to the ground not too far downrange ... would they make it 5-7 yds ... maybe? I wanted to see it for sure, so I set up the test really close.

Saands

[T. O'Heir]

Plated bullets are not jacketed bullets. They use cast bullet data.

[BDS-THR]

I have found that for plated bullets (Rainier, PowerBond, X-Treme, etc.) with diameters that match jacketed bullet diameters (.355", .400", .451", etc.), I need to use jacketed load data to maintain consistent chamber pressures and resulting accuracy.

For plated bullets (Berry's) with larger diameters (.356", .401", 452", etc.), I need to use lead load data or start-mid range jacketed load data for my .355"/.400"/.451" barrels.

Keep in mind that many factory barrels are oversized and larger than typical jacketed bullet diameters of .355", .400", .451" (many are .001"-.002"+ over). If you have oversized barrel, you are going to have more high pressure gas leakage around the bullet due to less tight bullet-to-barrel fit and higher powder charges would be needed to produce more consistent chamber pressures (which explains the OP's experience). Slug your barrel and if you have oversized barrel, Berry's larger diameter bullets will be better suited for you.

As to plating stripping off the lead core, my experience with plating on current commercial plated bullets is that they are thick enough to not cut into or strip off, even at high-to-near max load data range. However, if you apply too much roll crimp to the point where you are cutting through the plating, you may experience plating separation and the "halo" effect. If you experience any leading with plated bullets under 1200 fps, you are over roll crimping the bullet and cutting through the plating, not due to plating failure.

[DarthNul]

Plated bullets are not jacketed bullets.

I don't think anyone in the thread is confusing the two.

They use cast bullet data.

It's not that simple. That is one of three common guidelines for loading plated bullets. It makes sense from the perspective of hardness and resistance to elastic and permanent deformation of the bullet in the barrel. In terms of lubricity and pressure potential related to lubricity, plated bullets seem to perform closer to jacketed bullets.

The other two guidelines are: Keep it under 1,200 fps and use mid-range jacketed bullet data for a similar weight and profile.

Sometimes these guidelines are mutually exclusive.

[Sevens]

For the OP: If you are doing your due diligence and you don't see signs of excess pressure, and you don't see deposits of anything building up in your bore, and your loads cycle, the ejected brass passes all examinations when carefully inspected and your loads are accurate and reliable, then NO, I can't see any good reason NOT to use them. Sounds like a good load for you and one that you worked toward to get to. Thumbs up. Maybe use caution before shooting these same loads in a different handgun.

I shoot a lot of plated bullets in many calibers. My best short suggestion is that if you are on the fence, lean toward the WARM side rather than the weak side. Plated bullets may not be jacketed bullets, but they will get stuck in your bore if you try to treat them like swaged wadcutters and push them at some silly 700 fps. Stick a plated bullet in your bore and you will beg, borrow and plead for it to be a pure lead bullet... but you will beat it out of the bore just like a jacketed bullet.

Don't baby these bullets. There's a wide range between "mouse fart" and "blow the roof off" and they should be used on the warmer end of mid-range rather than the weak side.

They may not be true jacketed bullets, but they are wussies, either. Run them for what they are -- BULLETS. Give them pressure and some speed and shoot them. Don't "poof" them out of your handgun.

[GP100man]

When I ran the 358s thru a GP100 the accuracy started south around 1100 fps , HPs will allow the core to be blown out so if ya go that route take time to check the bore after each shot on ya test rounds.