Powder coated bullets: What max velocity can be run and what BHN required to do it?

[JimGnitecki]

1. At how high a muzzle velocity can you launch a powder coated cast bullet (following load tables of course)?

2. What BHN is needed, or optimal, with the high velocity?

I am asking these questions because in an effort to improve trajectory, to delay transonic effects, and to improve bullet stability, I tried increasing velocity by shooting 405g commercially cast, conventionally lubricated bullets, at 1500 to 1600 fps velocites.

The results were bad: no grouping whatsover right from the first group fired, and sure enough, when I checked the barrel condition afterwards, I had, for the first time ever, lead fouling of the barrel, and a LOT of it. It took me 1.5 hours to get it out via chemical and patching and brushing.

This is despite the fact that I had been shooting 464g to 500g powder coated bullets at up to 1400 fps with NO leading whatsoever. In fact, only unburned powder fragments in an otherwise pristine barrel. Those 464g to 500g powder coated bullets actually produced groups as good as 0.8 MOA at 150 meters = 164 yards. But, that's a s fast as the load tables will allow, so if I want to go faster (and I do), I need to know how fast powder coated bullets can be driven and what BHN constraints, if any, apply.

So, I am wondering if I could get a mold that produces a lighter weight bullet (say 400g or thereabouts), powder coat the those bullets, and launch them at the higher velocities that the load tables say are permissable and achievable with those lighter weight bullets, and see what accuracy I can get.

The usage would be purely paper target and steel gong targets. NO hunting, so expansion or brittleness don't matter.

Jim G

 

[Yarddog]

You can hot rod pc bullets. Must find out what your gun likes. ; ) PS bullet fit to barrel is the trick
Y/D

 

[Palladan44]

You mentioned wanting top accuracy at a moderate range.
The answer is probably going to be the straight hard cast that's sized to the barrel. I've even ordered some from Missouri Bullet Co. (They will customize your bullets to your specs) and coat them if you want too...if you decide you're not ready to buy a specific mold just yet.

The fastest ive personally pushed coated is 1400, and dont recall any issues.
This should be a fun experiment for you.
Good luck!

 

[AJC1]

I'm running 350s round about 1550. That's only with bhn 9 cast. If I wanted to go faster I'd run my mag mix at bhn 12. I've seen reports of people running combinations of lubes. I haven't needed that so I dont....

 

[sparkyv]

I've chrony'd coated MBC 320 grainers at 1,398fps with great satisfaction and no significant leading. At least satisfactorily at paper, I haven't hunted with it. Standard MBC bullets are 18 BHN.

 

[P Flados]

I have been over 2000 fps and under 2 MOA in a 35 cal with a coated bullet made from range scrap (medium hardness). Some have done 2500 fps to 3000 fps with good results (https://castboolits.gunloads.com/sh...ullets-What-I-have-learned-and-observed/page1). Fit of the bullet is generally more important than hardness up to a threshold speed. At very high speeds, a harder alloy may be needed.

 

[JimGnitecki]

The above replies are very helpful, and also encouraging!

Jim G

 

[JimGnitecki]

https://castboolits.gunloads.com/sh...ullets-What-I-have-learned-and-observed/page3I have been over 2000 fps and under 2 MOA in a 35 cal with a coated bullet made from range scrap (medium hardness). Some have done 2500 fps to 3000 fps with good results (). Fit of the bullet is generally more important than hardness up to a threshold speed. At very high speeds, a harder alloy may be needed.

Thank-you P Flados! Over 2000 fps is probably going to be more than enough! I could not go to the link you posted, because several weeks ago I was, for some unkonwn reason, "banned" from The website! I say "for some unknown reason" because although I had registered there months ago, and had read a huge numbr of threads on bullet casting and powder coating, I had NEVER posted! So, I was mystified as to why I was banned!

I tried contacting the admin there 3 times asking why, but never got a reply. My guess is that someone hacked my account there and tried to either do fraudulent sales or insulted the heck out of someone enough to get banned. I'll probably never know what actually happened, but it's ok, I found another bullet casting forum, although the new forum has far less powder coating history on it to read.

Jim G

 

[JimGnitecki]

On fit of the bullet: My Pedersoli's bore diameter, as measured by my gunsmith, is apparently .4563". I have tried .460" sized bullets with success. Then I tried .459" and saw maybe a slight improvement in group size. I plan to try .458" with the last 40 of the 500g class bullets I had cast in the past, that I had not yet consumed,using the same powder charge, COAL, etc as before, just to see if the additional reduction makes a difference.

Jim G

 

[AJC1]

Thank-you P Flados! Over 2000 psi is probably going to be more than enough! I could not go to the link you posted, because several weeks ago I was, for some unkonwn reason, "banned" from The website! I say "for some unknown reason" because although I had registered there months ago, and had read a huge numbr of threads on bullet casting and powder coating, I had NEVER posted! So, I was mystified as to why I was banned!

I tried contacting the admin there 3 times asking why, but never got a reply. My guess is that someone hacked my account there and tried to either do fraudulent sales or insulted the heck out of someone enough to get banned. I'll probably never know what actually happened, but it's ok, I found another bullet casting forum, although the new forum has far less powder coating history on it to read.

Jim G

I've been trying to join that group for a while with no luck so I just read everything and don't worry about involvement. Sucks I can't ask questions though...

 

[Charlie98]

Fit of the bullet is generally more important than hardness up to a threshold speed. At very high speeds, a harder alloy may be needed.

On fit of the bullet: My Pedersoli's bore diameter, as measured by my gunsmith, is apparently .4563". I have tried .460" sized bullets with success. Then I tried .459" and saw maybe a slight improvement in group size. I plan to try .458" with the last 40 of the 500g class bullets I had cast in the past, that I had not yet consumed,using the same powder charge, COAL, etc as before, just to see if the additional reduction makes a difference.

Jim G

That has always been my mantra: Bullet fit is paramount.

I've driven 'hard cast' commercially made, cheapo bullets to nearly 2000fps without issues, and that with that nasty, hard red or blue lube. I drive boutique dry lubed bullets (Montana Bullet Works) to 2200+ fps out of my .348WCF without leading issues... but all those bullets are sized for my bores.

Jim, I would continue to work with your sizing trials before making a big transition. Your barrel will tell you pretty directly when you get the wrong diameter, as you come down through the sizes. Once you have that established, you can move on to things like powder coat, etc.

 

[Show Me]

1. At how high a muzzle velocity can you launch a powder coated cast bullet (following load tables of course)?

2. What BHN is needed, or optimal, with the high velocity?

I am asking these questions because in an effort to improve trajectory, to delay transonic effects, and to improve bullet stability, I tried increasing velocity by shooting 405g commercially cast, conventionally lubricated bullets, at 1500 to 1600 fps velocites.

The results were bad: no grouping whatsover right from the first group fired, and sure enough, when I checked the barrel condition afterwards, I had, for the first time ever, lead fouling of the barrel, and a LOT of it. It took me 1.5 hours to get it out via chemical and patching and brushing.

This is despite the fact that I had been shooting 464g to 500g powder coated bullets at up to 1400 fps with NO leading whatsoever. In fact, only unburned powder fragments in an otherwise pristine barrel. Those 464g to 500g powder coated bullets actually produced groups as good as 0.8 MOA at 150 meters = 164 yards. But, that's a s fast as the load tables will allow, so if I want to go faster (and I do), I need to know how fast powder coated bullets can be driven and what BHN constraints, if any, apply.

So, I am wondering if I could get a mold that produces a lighter weight bullet (say 400g or thereabouts), powder coat the those bullets, and launch them at the higher velocities that the load tables say are permissable and achievable with those lighter weight bullets, and see what accuracy I can get.

The usage would be purely paper target and steel gong targets. NO hunting, so expansion or brittleness don't matter.

Jim G

Hint. Worn out bronze brush wrapped with bronze wool from hardware store strips lead and powder residue , smokeless or black powder unbelievably fast. Personally bullet fit is top concern. Personally the speed I poke holes is secondary. Oh what you'll learn.

 

[JimGnitecki]

That has always been my mantra: Bullet fit is paramount.

I've driven 'hard cast' commercially made, cheapo bullets to nearly 2000fps without issues, and that with that nasty, hard red or blue lube. I drive boutique dry lubed bullets (Montana Bullet Works) to 2200+ fps out of my .348WCF without leading issues... but all those bullets are sized for my bores.

Jim, I would continue to work with your sizing trials before making a big transition. Your barrel will tell you pretty directly when you get the wrong diameter, as you come down through the sizes. Once you have that established, you can move on to things like powder coat, etc.

I plan to load up those .458" diameter bullets in the next day or two, and then look for a warmer, non-snowy day to get to the range. We are having a relatively mild an dry winter here in Southern Alberta, Canada this year, which is nice after last year's brutally cold and snowy winter! But, given our central plains location, it normally requires an unseasonably warm and SUNNY day to stay outdoors for a couple of hours. The sunshine is important, because at our 3000 foot elevation, it makes any actual temperature feel much warmer! Today, we have thick clouds, no visible sunshine, and it's snowing!

The Lee .458" pass-through sizing die insert is the smallest I have, because with the .4563" bore diameter, that's only .0017" larger rthan bore diameter, and I have read that Pedsersoli rifles like at least that much interference with the bore.

Even if I can get the current heavy bullet to shoot a bit more accurately by optimizing bullet fit, I think I still want to try an approximately 400 grain powder coated bullet, because despite the inferior ballistic coefficient, it can be launched at notably higher muzzle velocity, which will flatten the rainbow trajectory a bit, and keep the bullet above transonic velocity effects at least a bit longer. Rough simulations using the Hornady online trajectory caclulator show the possibility of a 400g bullet, even with a very low BC of .225, getting out to 250 yards before hitting the speed of sound. That's better than the 200 to 225 yards where the heavier bullets cross 1120 fps.

It would also reduce the bullet OAL versus diameter ratio, which should enhance stability, because it will give any transonic aerodynamic forces a shorter lever arm with which to deflect the bullet. There would also be a bit less recoil - not MUCH less, but every bit helps to restrict the rifle's ability to move during firing.

Jim G

 

[JimGnitecki]

Hint. Worn out bronze brush wrapped with bronze wool from hardware store strips lead and powder residue , smokeless or black powder unbelievably fast. . . .

The Eastwood powder coating I am using is amazing. After a range session in which anywhere from 40 to 80 rounds of 464g to 500g 1.4" long 45-70 bullets are fired, at 1400 fps, each with with a power factor of 700 and an energy content of over 2000 ft lb, I have an almost totally visibly clean barrel containing only a modest amount of unburned Accurate 5744 powder granules (confirmed via Lee pocket microscope to be unburned 5744 particles)!

When I disastrously fired those 30 405g conventionally lubed commercially cast bullets, they left long streaks of lead all along the barrel! Wipe-Out's foam cleaner and specific lead remover, after multiple tries, using the specified processes and duration, got only SOME of the Lead out (maybe half), even with persistent brushing and patching. But my trusty Millet M-Pro7, using brushing and patching, got the rest out much more quickly. M-Pro7 is expensive (especially after the most recent inflationary price increase), but it does work incredibly well. It's also EASY to use, has no discernible smell (important to The Wife), and is remarkably non-damaging to my very dry winter hands.

Jim G

 

[archeryrob]

I just ran a ladder round session this summer for 30.06 with 173 grain bullets. I loaded from 2000 - 2600 fps and they all shot fine and nothing leaded. All rounds were Gas checked and powder coated. Lead was Wheel weight about an 11 bhn and water quenched, then powder coated, shaken and quenched right out of the toaster oven. Assuming a 15 bhn or more. The fastest consistent group I got was 2400 fps. The groups were okay up to 2600, but nothing to be happy about.

You can read it here. This is the first ladder round session I did and have since made a barrel cooler. After several ladder steps I would change targets and consistently shots 1, 2 and 3 on target and 4 drifting as the barrel got much hotter. Shooting the gun back in with less rounds when much better.

Shooting the 30.06 Cast bullet, ladder rounds

So it took a long time, but I finally got around to it. The groups are not going to be super tight. I was using a lead sled, but on a fold up plastic table in a farm field. It was still pretty easy…

archeryrob1.wordpress.com

 

[JimGnitecki]

I just ran a ladder round session this summer for 30.06 with 173 grain bullets. I loaded from 2000 - 2600 fps and they all shot fine and nothing leaded. All rounds were Gas checked and powder coated. Lead was Wheel weight about an 11 bhn and water quenched, then powder coated, shaken and quenched right out of the toaster oven. Assuming a 15 bhn or more. The fastest consistent group I got was 2400 fps. The groups were okay up to 2600, but nothing to be happy about.

You can read it here. This is the first ladder round session I did and have since made a barrel cooler. After several ladder steps I would change targets and consistently shots 1, 2 and 3 on target and 4 drifting as the barrel got much hotter. Shooting the gun back in with less rounds when much better.

Shooting the 30.06 Cast bullet, ladder rounds

So it took a long time, but I finally got around to it. The groups are not going to be super tight. I was using a lead sled, but on a fold up plastic table in a farm field. It was still pretty easy…

archeryrob1.wordpress.com

This was very interesting. The fliers (for the GOOD loads) were due to barrel heating up? You are sure of that? I know it was always the ;ast shot, but any chance that could ave been shooter fatigue? How thick is the barrel? Hot warm did it FEEL?

Jim G

 

[DMW1116]

I shoot 135 and 165 grain coated bullets from my 30-30. I’d keep an eye on pressure instead of velocity. The 135s gave some rough leading being pushed with 2400 powder. Changing to W231 and H335 solved the problem.

The 165s are MBC White Tail 4 sized for Marlin barrels. I’ve pushed them a little north of 1,600 fps but the pressure is low. Accuracy wasn’t great but there wasn’t any leading.

 

[JimGnitecki]

I shoot 135 and 165 grain coated bullets from my 30-30. I’d keep an eye on pressure instead of velocity. The 135s gave some rough leading being pushed with 2400 powder. Changing to W231 and H335 solved the problem.

The 165s are MBC White Tail 4 sized for Marlin barrels. I’ve pushed them a little north of 1,600 fps but the pressure is low. Accuracy wasn’t great but there wasn’t any leading.

Thank-you for the added data!

Jim G

 

[DMW1116]

I like to keep the pressure down around a 38 Special +P, which is to say under 20,000 psi according to reduced load data posted here. Sizing helps a lot. I’ve never had leading from the MBC bullets. The 135s are 0.3095”, thus smaller than the 165 @ 0.3115”. I have also gotten sub-MOA groups from the 165s, but not quite there from the 135s. The X-ring is about 1.5”. I expect the 165s will grow but I’ve only shot test groups so can’t say how much.

 

[Charlie98]

I’d keep an eye on pressure instead of velocity.

which is to say under 20,000 psi

The Pedersoli is good to 28000PSI, so I think Jim is OK. Max load with a cast 405grn bullet would be 32grn AA5744, for a little over 1700fps. If the bullets were seated longer (that's how I do it in my Pedersoli...) you could probably work up even higher, with appropriate caution. I would say, even though the Pedersoli is a good replica, feeding it a steady diet of max pressure loads isn't going to do it any favors.

Today, we have thick clouds, no visible sunshine, and it's snowing!

That's why I moved to Texas...

When I disastrously fired those 30 405g conventionally lubed commercially cast bullets, they left long streaks of lead all along the barrel!

There could be a number of reasons for the leading there... not the least of which is lube, bullet diameter, flame cutting, or bullet hardness. There was obviously a problem... but simply going to powder coating may be a bandaid, not a cure, if you see what I mean.

If you are really going for max velocity, I'm going to suggest you switch off AA5744, and go with one of the 4198's. You will pick up about 100fps with the same pressures, and have better case fill. I know you have availability problems... but I'm just throwing that out there. AA5744 is a great powder, no doubt, but it has it's limits, which is why I dropped it in favor of IMR4198.

 

[JimGnitecki]

Charlie98: I am open to changing powders, but in the interests of changing oine thing at a time, I think first I want to change bullets and find one that can group well with my specific rifle, before changing powders. Right now, the problem is not insufficient velocity, but rather finding a bullet that this rifle likes.

Jim G

 

[kcofohio]

To the OP, I acknowledge that you already received very good advice above. I just thought I would throw this in the mix.

I tested out 2 different bullets out of a 357 magnum rifle. A 170 gr. Keith style SWC. And Lee's 158 gr. SWC gas-checked. Alloy mixture of 95-3-2 at about 12 Bhn for both. Using Hi-Tech and sized to .358".

I used Lyman's load data with 2400, though the 158 gr. data was for a RN. Starting out at low-mid range, I worked up to the max load data. Chronograph was about 15 ft. in front of the muzzle. Rifle twist rate is 16:1. If I had a faster twist, I'd probably go with a harder alloy mixture to prevent stripping on the rifling.

At max of 15.5 gr. with the 158-c gr., of 5 shots, the average was 1846 fps.
The max for the 170 gr. SWC is 13.5 gr. Of the 5 shots, the average was 1678.
I still need to get out to the 50m and 100M for some accuracy test.

I didn't see any sign of fouling to the naked eye. Now a time before when I had just started coating, I didn't get the process down correctly, and had lined the barrel up with Hi-tech fouling. It wasn't too hard to clean.

 

[JimGnitecki]

Thank-you, Kcofohio.

Jim G

 

[Targa]

The fastest I have ran cast bullets are just over 2300 fps in my 30-30. They are sized correctly for the barrel, gas checked and powder coated with a BHN around 18. They are very accurate with no noticeable leading.

 

[JimGnitecki]

A number of you guys have mentioned using gas checks even with powder coated bullets. So the powder coating alone is not sufficient? Or, is it sufficient only if you have a high BNH?

Jim G