There's something to this ball powder...

[CJR]

Nobade,

For PPCB in the 30/06, the NRA recommended (Cast Bullet Manual) two (2) WW760 loads;

1. 160 gr. 301618, BHN 17, 53 Gr. WW760, no fiber filler, 2816 fps (muzzle), 2834 fps (15 ft.), 46620 c.u.p.

2. 195 gr. 301620, BHN 19, 49 gr. WW760, no fiber filler, 2515 fps(muzzle), 2530 fps (15 ft.), 44350 c.u.p.


The pressures listed were obtained from tests at H.P White Laboratory, Bel Air, MD.

Best regards,

CJR

[Nrut]

Do all ball/spherical powders have a progressive burn rate?

I am thinking H335 and BL-C(2) for using in the 35 Whelen as Hodgdon has loading data for those two powders in that caliber..
Thanks

[CJR]

Nrut,

Excellent question! Prior to ball powders, burn rates were controlled by using different geometrical shaped grains which have different surface areas to burn. With ball shaped granules; a ball is a ball, is a..... , and the surface area is relatively constant. So in order to change powder burn rates with ball powders they use different deterrent chemical coatings. So, theoretically speaking, depending on what chemicals are used to coat the ball granules, you could achieve any burn rate you wanted, i.e. digressive, neutral, progressive.

I found it was simple to identify progressive powders in reloading manuals. Look for the powder with the lower PEAK pressure and the highest velocity. When you find it, chances are it's a progressive powder. As I mentioned sometime back, one of the Lyman manuals had, for one caliber, the measured pressure and velocity of a digressive powder load and a progressive powder load. Though the velocities were close, the pressure was lower with the progressive powder. Likewise, it wasn't that long ago that Hornady was hyping their progressive powder loads,i.e. 200-300 fps higher velocities at the same SAMMI pressure levels that's dictated for standard calibers. Marketing at its finest!

There are some NRA articles on the development of ball powders.

Best regards,

CJR

[303Guy]

I see BL-C(2) consistently produces higher velocity with lower pressure than the other powders. Not so in the 30-06 but close. That would be my first choice I should think. It's the same in the 303 Brit but it's not available in my parts

[Nrut]

Thanks CJR and 3030Guy,
Both Hodgdon and Accurate Powders manuals have pressure data and come to think of it I usually default to the powder that that gives the highest velocity for the lowest pressure..
I also tend to try powders that give compressed loads if they are in the velocity range that I am after..

[Nobade]

Nobade,

For PPCB in the 30/06, the NRA recommended (Cast Bullet Manual) two (2) WW760 loads;

1. 160 gr. 301618, BHN 17, 53 Gr. WW760, no fiber filler, 2816 fps (muzzle), 2834 fps (15 ft.), 46620 c.u.p.

2. 195 gr. 301620, BHN 19, 49 gr. WW760, no fiber filler, 2515 fps(muzzle), 2530 fps (15 ft.), 44350 c.u.p.


The pressures listed were obtained from tests at H.P White Laboratory, Bel Air, MD.

Best regards,

CJR

Thanks for the loads - I just picked up a bottle of 760 today to play with, so I'll see what I get.

[geargnasher]

Nobade, check out MJ's "paper patch challenge" thread, I just shot and chrony'd some groups with Winchester Supreme 780 and 160-grain PPCBs. At 99% loading density in the LC '06 brass the charge was 59 grains and velocity on the high side of 2650 with my 22" barrel. So far I'm really liking this powder, it does the same thing RX22 does but without needing compacting buffer to protect the boolit base for accuracy, and it gets a shade more than 200 more fps with what appears to be about the same pressure.

Gear

[303Guy]

I tried a lighter boolit in my pig gun with W748 and the boolit base was undamaged. Velocity wasn't the highest judging by boolit impact damage. I repeated the test with wheat bran filler and the impact damage was notably more and there was indication of higher pressure on the primer plus boolit base deformation and trailing edge 'feathering'.

The charge was 34.8gr W748 under a 194gr boolit. (I didn't reduce the charge for the wheat bran test).



Compared to stick powder.

[geargnasher]

Big difference there, and not just grain size. With the ball powder I would think you could eliminate the filler completely unless your load is running less than about 90% of case capacity. I'm wondering if you could get some H414/Win760 and see what that gets you as far as case capacity.

I'll look later tonight and see what .303 capacity is and see if I can scrounge up some load data for cast boolits of that weight.

Gear

[303Guy]

That load is 75.6% density and was without filler. With filler (wheat bran) the efficiency goes up quite a bit but with feathering. I can get H414 and I dare say it might be the powder for my longer barrelled guns. Right now money is tight so I shall be concentrating on using what I have, especially with the pig gun. It's such a handy little carbine and so easy for me to carry around with my elbow-itus. So I need (or want) a load with a bit of velocity to increase its versatility with its short barrel. Hence the pursuit of spherical powders in the Varget burn-rate range. So far I've found W748 to meter rather well. Each time I weigh a measure load it comes out at 34.8gr and that's without the vibrator I affixed to the measure for consistency with stick powders (a trick that works well).

[geargnasher]

I was checking the capacities and such before bed, looks like typical loads in the .303 with W760 are about 5-7 more grains than the W748, so if you're at 75% with nearly 35 grains of W748 you'd be at 82.5% on the conservative side with an equivalent load of 760.

I forget how long your pig gun is, but whether it's half a meter or a meter it will probably still blow lots of unburned powder out the muzzle, that's sort of the nature of the beast with ball powders. Also, I've seen data from several different reports that show muzzle velocity to be 50 fps or more several feet in front of the muzzle compared to muzzle exit velocity when using ball powders, like they give a little boost from the muzzle blast after the boolit is free from the confines of the bore.

In any event, I'll bet you'll get higher velocity (if that is your goal) with the heavy boolits and W760 than with W748, even though the barrel is shorter, although the 748 should work just fine for you. I'm assuming that hunting velocity with the best accuracy possible and good funtionality is the goal here, and I think you're on the right track with the ball powders.

One other thing you might try with the W748 is a half-grain of Dacron (polyester fiberfill). If you have any old stuffed toys, an old pillow, torn-up jacket, or know anyone who sews you probably have a lifetime supply of the stuff. The Dacron works better than wool or cotton IME, and won't start a grass fire like some of the natural fiber fillers can. I've had really good luck combining Dacron, 60-80% loading density with slow ball powder, and plain-based cast GG boolits because it seems to be the right combination of gentle launch (the powder), consistent burn (the Dacron), and undamaged boolit bases (combination of the slow, soft powder and the fiber cushion behind the boolit base that also seems to help greatly to reduce or eliminate gas-cutting of the base).

I wish there was some way I could ship you the half-pound of H414 I have here from an odd lot so you could try, but I don't know of any economical way to do it. If you do, it's yours for the shipping.

Gear

[303Guy]

Thank you kindly, Gear. Unfortunately powders cannot be shipped easily in my parts. Dealers can't ship it locally for internet purchases either.

I haven't found any visible sign of unburned or partially burned powder. If I use wheat bran I do find it in the catch cloth. I've also found partially burned stick powder when the load was too low. I'll make a plan for a better catch, just to see. I was surprised at the apparent difference in velocity with the addition of wheat bran.

I do have a torn jacket which I kept for the Dacron and I have used it but not under the 194gr boolit. That was with the card tests.

The pig gun barrel is 370mm/14.5 inches from the breach face. I might get a chance to chronograph it today.

[303Guy]

How low can one go with W748 under a 194gr boolit in the 303 Brit? The Brit has the the same case volume to base of neck as the 308 Win.

[geargnasher]

The only real-world personal experience I can share on that is taking a .30-30 load that starts at 32 grains and reducing it to 22 grains and working up. It was really dirty until about 25 grains. Keep in mind I used Dacron to keep the powder located against the coals and there might be some risk of SEE if you reduce the load too far. 25% reduction below starting loads is pretty drastic for any rifle powder, but I got away with it with that powder. Always be super-careful when reducing ball powder loads much below minimum recommended loads.

Gear

[Nobade]

Today I shot the 30-06 with some of the 53gr. WW760 loads behind Ranch Dog 170 bullets, sized to .303 and patched back to .309 and lubed with Rooster Jacket. No filler. It worked fairly well, only had 4 wild fliers out of 40 rounds fired. Shooting at 300M I was seeing approx. 2 foot groups. Not terribly accurate, but it seems to be a good start and gratifying that I could fire that many shots with no leading and the bore is still super clean. What I did discover is this powder really needs magnum primers. I loaded some with Wolf LR and some with Federal 215s, the Fed primed ones lit off instantly and hit higher than the Wolf primed ones, which sometimes had perceptable hang fires.

Now I need to start trying to find out the source of the fliers. My guess is bullets with voids in them. I didn't weigh each bullet, next time I will and see if that helps. And maybe open up my sizer to .304 to get a .310 bullet to fit the throat tighter... the search goes on.

[geargnasher]

Yes, Nobade, I had a range session today with the Supreme 780 and '06 that was giving me odd flyers every three or four rounds, dropping one four inches low from the group with annoying regularity. I suspect base voids as well, I didn't weigh these boolits because I was in the more elementary stages of load development, but I was culling a lot of them due to visible base voids, no telling how many had a bad void right under the surface near the edge of the base.

I'm going to some more development using card wads under the boolit bases, and also change back to Felix lube as a patch lube, all these were done with 45/45/10 tumble lube and I don't think it's up to the task of going over 2650 fps.

Gear

[Nobade]

I think my next step is to try some #311466 from my new NOE mould and see if the shorter nose is a help. As for lube, the Rooster Jacket seems to be working very well, no sign of leading or really anything in the bore but a little dust.

[303Guy]

Are ball powders position sensitive? I repeated the H748 test, this time with Dacron filler. Boolit impact damage was only slightly less then with wheat bran but a lot less than with no filler. The gun was fired straight down so the powder was away from the flash hole.

[geargnasher]

My experience says yes, very much position sensitive when loaded to fairly low density. I discovered this shooting turtles from a high bank with my .30-30 years ago, when pointed down, even slighly down, with my light charges of 748 I would occasionally get a barely-perceptable hangfire, and slight vertical stringing seemed to be the rule. I switched to 2400, same thing, then switched to Unique and the problem went away. I'm sure Dacron would have made it a non-issue with either the 748 or the 2400 based on later experiments I've done.

Gear

[CJR]

Nobade,

I'm a little surprised with the group size you got at 300M. Your load is close to the NRA load I cited for a 160 gr. bullet. These NRA recommended PPCB loads should be capable of 1MOA or less. Some questions/comments:
1. Is your PP in contact with the chamber's forcing cone? PPCB seem to shoot better when against the chamber forcing cone.
2. Have you miked your the OD of your PPCB, after some time, to see if the paper is increasing in OD?
3. Weighing your CB for long range is a good idea.
4. I use magnum primers in my W748 and W760 loads.
5. There are many CB form designs that are accurate up to some range and then become unstable/inaccurate after that. Many, many years ago the NRA identified some available CB designs that had these problems. Shortly thereafter, the mould makers stopped making these bullet forms. Though your CB design form may be fine at lower velocities/pressures, when you drive it close to 50,000 psi, the bullet will be severely obturated (depending on its hardness) to the bore and in some cases the form of the bullet will be changed slightly (i.e. nose set back, etc.). The bullet's dynamics/stability will then change just enough (i.e. spacing changes between CG/CP) to affect long range accuracy. Only more testing will tell you exactly what your hi-vel CB form/load will do at long range.
6. From what I've read, if you get vertical stringing that typically indicates the powder charge is not quite right. The recommended solution is to do some "incremental ladder testing" at long range until you find the "sweet spot" (i.e. where a range of powder charges cause no vertical stringing). An example would be; you find a powder range of say 49.5 to 51.5 grs where these loads all impact at the same location at 300M. Any loads lower or above this powder charge range would vertical string on target.

Best regards,

CJR