Topic: A question for Dutch Bill about "primer" charges or duplex loads.

Retrieved: 12/20/2014
Last Post: 11/14/2007

SASS has put me in a quandary. They won't allow duplex loads, and by that I mean 45-70 with 5% to 7% SR4759 under the compressed black powder charge. Lyman does list this load and I've been shooting it and have had very encouraging results.

SASS does allow all manner of black powder and smokeless (almost forgot how to spell that) loads for long range side match shooting. I'm not concerned about main match stuff here. That's simply ring close steel and have fun. I'm wanting your take on the idea of putting some 777 under the bp much like I do the SR4759. I'll work out the ratios and I have the equipment and experience to do so without chasing the high pressure gremlin. This load would be SASS legal by their own rules.

Dutch Bill
November 07, 2007

You could try the duplexing with black powder and 777 but I don't think you will see the benefits that you see with the 5% to 7% of SR4759 in your normal duplex load.

While the 777 is based on a mixture of charcoal and a dintitro it still behaves more like a black powder than a smokeless powder.

John Boy
November 07, 2007

Dick, if you want to juice up the velocity, instead of FFg, go to Swiss 1.5 and crimp the case. I've packed 75gr of Swiss into a 45-70 case with a 551gr bullet and got 1214 fps that easily reached 1000yds. Better yet, use Swiss FFFg and it will 'rock'. Ain't no CAS LR Match that shoots 1000yds.

Dick Dastardly
November 08, 2007

Here's the thing.

I shoot several 1000 yard matches each year and some SASS side matches that are shorter. I don't want to fool around with several loads. The gun is a fine original Remington Rolling Block action completely reworked to 45-70 (it was .43 Spanish). I enjoy shooting it but don't use it a lot. Nothing like my SASS main match guns.

Then, waiting in the wings, I have a fine Winchester 38-55 "Legendary Frontiersman" that I bought on the cheap since Winchester made too many of these "collectible" guns. It works great out to 300 yards. So, if I do need a gun for shorter distances, the 38-55 does it.

I finally got my hands on some 777 and will start working up loads through the winter. I will report.

w44wcf
November 09, 2007

Hodgdon shows 60 grs. FFG 777 giving 1,161 f.p.s with a 485 gr. bullet... unfortunately not much different than b.p.

http://www.hodgdon.com/data/muzzleloading/granular/t7cartridge.php

If you used a bullet that would have a longer bore riding section which would protrude less into the powder space, higher velocity could be achieved.

John Boy's suggestion of using Swiss FFFG would definitely be a positive step in the right direction.

Ranch 13
November 12, 2007

DD, I use 2 loads in my sharps, either 68 grs of Goex cartridge with a 530 gr bullet or 68 grs of Goex 2f express with the same bullet. Never have anyproblems with hitting targets from 200-1000 yds with either one.

One thing to be cautious of there's a whole bunch of places besides Sass that don't like duplex loads.

If it's cleanliness a person is after, then go with 5744 and the like.

How's come you want to use duplex loads anyways?

John Boy
November 12, 2007

Dick, thinking the topic over again... speed isn't every thing that is going to provide consistent good groups/hits out to 1000yds or any distance.

I looked back over my spreadsheet for the last trip to Ridgeway: My best recipe was 70gr Cartridge with a Postell 535gr bullet - rang Homer at 1000: 7 out of 10 shots with 5 in a row. This load only clocks at 1140 fps.

And I know I've told you before: the original 500gr Big lube using 57gr H777 - the 5 shot 7" x 2.25" group at 600yds with El Cheapo.

The deal is: ...To develop the recipe that is going to put a bullet 'to sleep' the best' at the distance you are shooting and then pray hard, that you have read the wind and the mirage correctly.

Dick Dastardly
November 12, 2007

Extreme consistency is what I want. That and enough speed that I can get to 1000 yards before I run out of ladder. I'm getting 1350 fps now and would like to stay above 1250 fps.

I'm hoping that during the winter I can work up a duplex load with 777 and FFFg bp that will do what I want. The 777 would be the spark plug and the double push would use the entire barrel.

Duplex loads have a dual impulse. Some of the powder is thrown ahead and burns late. Heat and pressure is high and the push, if loaded right, continues down the entire tube. That's where the payoff comes.

If the duplex load simply causes an explosion before the bullet gets moving it simply raises pressures, produces recoil and makes an inconsistent burn and resulting velocity.

Wish me luck.

Dutch Bill
November 12, 2007

If I can be of any help here.

When Hodgdon first came out with the 777 I was asked to take a real close look at it based on the claims that were being made for it. Mainly to see how it compared to the Swiss made bp.

In ballistic strength in my patched ball rifles the 777 was almost as fast as the Swiss bp.

Compared to Pyrodex the 777 burns hotter. Heats up the barrel almost as fast as the Swiss bp does.

The ascorbic acid based subs are cool burning and usually a good bit slower than a rifle burn rate bp and really weak compared to Swiss bp.

The hotter burning 777 can present a problem when you start pushing the charges above a certain point. It begins to form what the ml boys were calling a crud ring just ahead of where the patched ball or slug sat on the charge. Another deal where the gas temperature gets high enough to melt and fuse the potassium carbonate created by powder combustion.

So as you begin to increase the proportion of 777 to bp watch for any hard fouling to form. I suppose this would form just ahead of the chamber in a cartridge gun.

I have no idea how good a blow tube would work on it. When I began to see the crud ring form in the patched ball rifles it was tough to rmove. The normal fouling left by 777 is highly soluble in water and readily soluble in water. Once it begins to fuse to keep the highly soluble part but begin to loose the readily soluble part. This may be a thing with bullet lube performance in the cartridge gun though. You might be able to compensate a bit for any fused fouling with the bullet lube selection or how much the bullet carries.

I can tell you that the 777 makes some awesome blank charges in the ml rifles. Cracked like a 30-30 out back.

Ranch 13
November 12, 2007

From what chrono work I've done with the bp cartridges, I'm not sure duplexing is going to make anything more consistant than the 5fps or so that seems to be the norm.

In the results for the 1 mile shoot held at Kenny Wasserburgers last fall one of the things they posted was the chronograph readings of everybody's loads. One shooter was loading 75 grs of goex 3f express in a 45-70 and was coming within 78 fps of 45-110's loaded to the hilt with swiss.

Don't know what your using for a sight, but both the ladder on my barrel and the tang sight have plenty of room to shoot clear over 1000 yd targets shooting 65 grs of plainol 2f, and the cartridge and express loads I mentioned earlier will lob 530 gr bullets well past the 1000 yd target and still have room to go up.

Lars
November 13, 2007

Shooting extensively 777 FFg in three four old BP cartridges, at or near Hodgdon-recommended charges and bullet weights, I have never had a hard crud ring in front of the chamber, or anywhere else in the bore. MAYBE there was one in cases -- where it would be in analogy with results you note on muzzle loaders, but, I doubt it because brass cleaned up nicely in nothing more than hot water. Never saw it in C&B revolvers, even with heavier loads recommended for Ruger Old Armies.

Never tried loading 777 FFg in charges above what Hodgdon lists, or in muzzle loaders. Got performance very close that that with Swiss FFg in same cartridges. When I want to go above Swiss FFg velocities, I use slow burning nitro powders.

Ranch 13
November 13, 2007

DD sometimes barrel length can make a lot of difference also.

At Kenny W's Creedmore shoot it takes 45-70's and the like almost 5 seconds to get to the 1000yd target, and the big stuff is only about a second less, or so it seems.

The light was shining just right, so that my binoculars (20x70's) I could see the bullets coming into the 1000 and 900 yd targets. I could call the hit before we heard it. It was also pretty interesting to watch those bullets coming in for a landing.

Ranch 13
November 13, 2007

Yup those old slow lead slugs do a bunch more damage than the unwashed think. My 750 yd fuel oil tank, those 530 gr bullets will penetrate the near side and leave a very good likeness of themselves in the far side. Even shooting the steel targets at 1000 yds those bullets make a huge splash, and recovered whole bullets are ones that missed the target.

Cohagen
November 14, 2007

All of us getting into long range struggle at first. Duplex loads kind make it easier to get veloscity only, not necessarily consistant accuracy. Stay true to the Holy Balck, Bullet shape, lube, and compression factors, barrel twist to bullet used, F size of powder, are paramont to the long range game.

Lots of variables to work with to get that one super pet load...

Starter dabs of the modern fad stuff - forget about it.