WC860 and PP boolits

[Nobade]

I just finished shooting a variety of rifles using a duplexed load of WC860 and PP boolits. 30-30, 32 spl., 308, 358, 375 Taylor, and 45-70. I still need to try the 30-06 but that can wait until another time.

In every case, this duplex load has worked very well. Lil' Dandy rotor #3 of IMR4227, or about 4 grains with enough 860 to make a tightly compressed load. Clean burning in everything, and very accurate. At least as good as the rifle is capable of using its best loads. Velocities were never terribly high, but certainly enough to be interesting. The 45-70 is barely faster than with black powder, but the 30 cals are well over 2000 fps. The 375 around 1900, and the 358 about the same.

It looks like if you want cheap shooting and good performance, this is a very useful powder as long as it is duplex loaded. Of course you should be aware of what you are doing, and don't duplex it in anything where it has a chance of working correctly - large case/small bore magnums, 25-06, 6.5x55, etc. In those rounds it will develop significant pressure by itself. But in cartridges where it normally would be useless, it can be made quite functional with a "kicker" charge.

I have some WC857 on the way (someday), and am going to do some similar tests with it when it arrives. I expect better power and hopefully the same easy load workup and gentleness to PP boolits. We shall see...

-Nobade

[303Guy]

Most interesting! Have you done a comparison with only tightly compressed WC860?
Can one use shotgun powder as the kicker? OK, there is a big difference there as the very fast powder could theoretically shift the main charge and boolit forward before full ignition begins so I'd rather someone else tests it ..... [smilie=1:

[Nobade]

I've done that before, years ago. Used Red Dot. It works but I wouldn't recommend it. Too easy to mess up.

-Nobade

[303Guy]

Thanks. OK then, can I do a similar thing with W780 and a filler? Sorry, just had to ask. Hey, it might be feasible.[smilie=1:

[303Guy]

Well, I tried it. I like it. I loaded 3grs H4227 under 30gr W780 and filled up the case with wheat germ which needed a little compression to get the rest in then compressed to base of neck so effectively, two neck lengths compressed down to base of neck. The powder would have taken about 77% of case volume. The wheat germ weighed 8.4grs and the boolit 208grs. Pressure indications suggest a moderate pressure and zero unburned powder - that being in the 15½ inch barrelled pig gun.

[Nobade]

Yep, it works. This may be a very useful way to solve paper patch accuracy issues coming from hitting the boolit too fast and having gas leak past the patch. Of course WW780 isn't $5/lb, but the concept is the same.

I had always kept away from using a case full of super slow ball powder when 1/3rd case of fast powder might give the same velocity. The ball was cheaper but by the time you used so much more of it, it wasn't. Now that the slow balls are the only surplus powder on the market and we are now experimenting with this paper patching I see that this is going to be the way to go, where it wasn't when we were shooting naked boolits a few years ago.

-Nobade

[Any Cal.]

Nobade, what are the accuracy issues w/ the fast powder? How do they manifest themselves?

[Nobade]

Shots don't go where they are pointed?

Seriously, what I and others have found is that PP boolit needs to get a gentle start down the bore for the best accuracy. It is possible to get very good accuracy using faster powders if you keep the pressures down in the realm of normal boolit loads, but as soon as you start pushing things up to normal jacketed levels, pressure and velocity wise, things get more difficult and very small details start to really matter. One of the things very slow powder - slower than you might think would be good to use - does is essentially become its own filler. The boolit is clear of the throat and on its way down the bore before the pressure builds to its maximum, and the hot gas gets to it. The more I mess with this kind of shooting, the more I find myself gravitating toward very slow for the application powders. Pretty much it needs to be safe with a full, compressed case load to get the best accuracy from PP boolits.

I know there are plenty of exceptions out there, and I have a few rifles that fall into this category. But by and large the best results come from full loads of slow burning ball powders. At least things get easier going that route.

-Nobade

[pdawg_shooter]

I have always gotten the best results by using a powder that gives 100%+ load density. One of my best loads in a 06 is using H4831sc under a 311041 sized .302 and patched back up to .310. This load shoots better than any jacketed load I have tried in this rifle. For me, slower is better.

[303Guy]

pdawg_shooter, what velocity does that '06 give you and what is the boolit weight if I may ask.

I have a problem with one of my rifles with the slower is better philosophy because the barrel is too short for very slow powders so the kicker charge is of interest in that regard but the test I did produced pressures that I don't want to increase much. The recovered boolit has trailing edge feathering so either the alloy is too soft for that charge or the launch pressure is too high. The expansion and lack of penetration in rubber grinds and weight loss (all signs of high velocity) suggests too high pressure.

[Nobade]

Well, 780 is quite a bit faster than WC860. You may be on the ragged edge of wanting to duplex load that powder. Do you have anything available to you that is slower?

Right now in the US, the only military surplus (cheap) powder available is the really slow stuff made for 50 cal and 20MM cannon. This is a good way to get it to work in smaller cartridges, I don't know that I would want to duplex load anything faster.

-Nobade

[pdawg_shooter]

pdawg_shooter, what velocity does that '06 give you and what is the boolit weight if I may ask.

I have a problem with one of my rifles with the slower is better philosophy because the barrel is too short for very slow powders so the kicker charge is of interest in that regard but the test I did produced pressures that I don't want to increase much. The recovered boolit has trailing edge feathering so either the alloy is too soft for that charge or the launch pressure is too high. The expansion and lack of penetration in rubber grinds and weight loss (all signs of high velocity) suggests too high pressure.

The bullet is 174gr with my alloy and the velocity averages 2667 for 10 rounds.

[303Guy]

Thanks pdawg. I have a theory that the 30-06 is just about the optimum is not perfect cast boolit and possibly paper patch cartridge. Given that the throat design is ideal too. It seems to me that the case capacity is just right. With fast powders there is enough case capacity for the powder to expand into without over pressure for the gentle launch and enough capacity to hold enough pressure to drive the boolit to a healthy velocity. It seems the capacity is also enough to suite slow powders that fill the case. Just my theory but how often does one hear of good results with the 30-06 and how often poor results?

I can get just about any powder I want in my parts and they're in stock right now. I see H1000 in stock as well as some H5010 and LeverEvolution.

[wmitty]

I just ordered 8 lbs each of 857 and 860 and 24 lbs of 870 thinking that this might be the way to go with paper patching. I tried some AA 8700 in the '06 with the 314407 modified group buy mould this last week and was pleasantly surprised with the resulting groups. I will try sizing the plain based version down and pp'ing it next with the slow powders.

The g.g. version clocked 2265 fps with 64.5 grains of 8700 from a 24" Rem 700. I started trying a kicker of 700 x with the following results:

1 gr 700 X / 64.0 8700 - 2293 fps

2 gr 700 X/ 63.0 8700 - 2331 fps

3 gr 700 X/ 62.0 8700 - missing

3.6 gr 700 X/ 61.0 8700 - 2389 fps

I was using my ancient Oehler M 12 which I hadn't used in years... You would crack up laughing if you saw how it works. Anyway, I missed collecting the data for the 3.0 gr load 'cause the sun was dropping fast and I was trying to hurry. I was also trying to mike case expansion at the same time as I was chronographing; the 2 gr and 3 gr loads showed .0009" expansion on the pressure ring, but I missed miking the 3.6 gr loading before firing it.

I'll try the paper patched plain bases and see what velocities/ group sizes I come up with.

db