more reactive filler experiments

[Nobade]

I have discussed the idea of reactive filler (or ablative filler if you prefer) in the paper patching room, but not here yet. Basically the idea is if you are shooting a cartridge that takes an almost full case of powder, adding a little very slow burning ball powder to it to make a 100% density compressed load can be beneficial sometimes. Usually I use WC860 for this since it adds very little energy to the load. So far I haven't had any problems doing this, but it does need to be used with discretion if you wish to employ it.

Today I got the most dramatic example of what it can do that I have seen so far. Previously I had loaded some 30 Badger ammo with 8.0gr. 10B101 and the RCBS plain base cowboy boolit. This load works well with gaschecked boolits but I wanted to try it with a plain base one. Well, it was awful. About 8 MOA with no predictability at all. So just to see what would happen, I pulled the boolits and added .5cc WC857 on top of the original charge. That was enough powder to make the seating depth correct to fit my chamber. Today I shot some, not expecting much. Wow, what a change! At 50 yards it was just one hole. At 100 yards it showed 1/2 inch of vertical and about 2 inches horizontal due to wind effects. The velocity went from 1400 fps to 1700 fps, so 857 is a lot more energetic than 860 and certainly added a significant amount of energy. I couldn't believe what I was seeing, but fired 30 rounds with all the same results.

So, an interesting development. Soft lead boolits, plain base, going way faster than you are supposed to be able to fire plain base designs, with very good accuracy. I have done this before using cream 'o' wheat for filler, but usually with mediocre accuracy and problems like caking up in the fired cases. These stayed clean, no extra fouling anywhere, and no pressure signs at all. This has been an interesting technique to pursue, and is allowing me to do things that I previously wasn't able to do.

-Nobade

[303Guy]

Great feedback, thank you. So now my question is, how do I translate that to my Brit? Or is that kicker charge territory? I did have a look at what powders were available and specifically for some WC860 but at the time I couldn't remember 'WC860'. :???: At least I remembered to go there.

[leftiye]

BaBore put some .30 badger loads up on a thread about 32-20 (I think it was). Said the cases were about the same capacity. Am I in the right world? Anyhow, his charges used were a bit hotter than I was daring to use in a 32-20. How do you think these backwards duplex charges would work in a 32-20? The 32-20 is a quite problematic cartridge to load. Generally, the guns won't take modern pressures, and when they do, the brass gives up. I'm wondering if this approach might not (at least in rifles) give a bit more velocity at moderate pressures.

[Nobade]

Great feedback, thank you. So now my question is, how do I translate that to my Brit? Or is that kicker charge territory? I did have a look at what powders were available and specifically for some WC860 but at the time I couldn't remember 'WC860'. :???: At least I remembered to go there.

In your 303 Brit, I could see this being useful if you were using a fairly fast rifle powder, like IMR3031 or 4198, and still wanted to have a full case. A little WC860 on top of the main charge would allow you to have something to stop the PP boolit against so it wouldn't get pushed back into the case but not overpressure. I do the same thing with my 416 Taylor - a full charge of 3031 is about a 90% fill, so a little slow ball powder on top gives me a compressed load and protects the base of the boolit for better accuracy.

-Nobade

[Nobade]

BaBore put some .30 badger loads up on a thread about 32-20 (I think it was). Said the cases were about the same capacity. Am I in the right world? Anyhow, his charges used were a bit hotter than I was daring to use in a 32-20. How do you think these backwards duplex charges would work in a 32-20? The 32-20 is a quite problematic cartridge to load. Generally, the guns won't take modern pressures, and when they do, the brass gives up. I'm wondering if this approach might not (at least in rifles) give a bit more velocity at moderate pressures.


I'd be careful with this. The Badger and the 32-20 are very close in case capacity, but the Badger cases (38 spl) are quite a bit stronger. I am firing these in a Ruger #1 rifle, so I have no worries about the brass or the gun as far as pressure problems. I suppose it would work in the 32-20, but since I have no way to test the actual pressure generated or see what the curve looks like, I would be hesitant to give any kind of recommendation for doing this in anything designed for low pressure limits. A Marlin 1894 likely would be fine but a 32-20 handgun is another matter, especially old S&Ws that weren't proofed for smokeless powder. If you do end up trying this, do let us know what happens. Me, I'm sticking to black powder in my 32-20s.

-Nobade

[Canuck Bob]

Why slow ball powder? Would slow stick powder work the same?

[leftiye]

Much stick powder ignites more easily than ball powder does. Should work if the powder is slow enough.

[truckjohn]

Sounds quite interesting.... Makes me wonder if there's any way to use this to "Fill up" cases normally loaded with "Moderate speed" rifle powders...

Say - for example - the classic 30-06 load with a 168 grain bullet over 46g IMR 4895... Could you top it off with some 50BMG powder or 20mm vulcan powder to fill up the small amount of case capacity?

The other question I have....

Does it add muzzle blast and flash from the slow burning powder igniting as it exits the barrel? That's one of the things I try to avoid with many hunting loads - as I don't like to see the scope go "Red" when I pull the trigger...

[Bjornb]

This is very interesting and sounds like it could be tried in HV loads where cases are frequently loaded to about 85-90% with powders like various 4350s etc. Pressures are commonly only in the 30s so adding milsurp powders like WC867 could provide both extra energy and a filler to keep the bullet seated correctly in the throat. Thanks for the tip.

[Nobade]

Sounds quite interesting.... Makes me wonder if there's any way to use this to "Fill up" cases normally loaded with "Moderate speed" rifle powders...

Say - for example - the classic 30-06 load with a 168 grain bullet over 46g IMR 4895... Could you top it off with some 50BMG powder or 20mm vulcan powder to fill up the small amount of case capacity?

The other question I have....

Does it add muzzle blast and flash from the slow burning powder igniting as it exits the barrel? That's one of the things I try to avoid with many hunting loads - as I don't like to see the scope go "Red" when I pull the trigger...

Yep, that's the idea. As long as your main powder charge isn't going to get you anywhere close to maximum pressure and there's not TOO much room left, this seems to work quite well. As for flash, I haven't fired any of these in the dark so couldn't comment on that. The added powder is usually quite small, so doesn't seem to change the recoil much.

-Nobade

[rbuck351]

You can fill the case with the slow powder (WC860,H5010) then replace it a few grs at a time with your faster powder (4895 or such) until you get the velocity you want or pressure signs.

[leftiye]

Could be dangerous at some point in the progression (hangfire or double pressure spike, maybe SEE). I wouldn't start at the bottom and work up. Rather back off a load with an easy to ignite powder to moderate (starting load) pressure, and add slower powder.

[truckjohn]

Yeah, I mean, you gotta exercise some sense....

Just because loading 10% "Super Slow Stuff" works fine on top of a charge of moderate powder doesn't mean that you can start off with 10-grains of Bullseye and cap it off with 65 grains of surplus 20mm Vulcan powder in a 7-mag....

[geargnasher]

A dose of Winchester 780 on top of a low-midrange charge of Reloder 7 in the .30-30 gets well into the Leverevolution velocity range, makes a neat fireball, and groups very well. That's the only load I've tried yet since Nobade started sharing the idea last year.

Gear