Can we discuss the use of Dacron ?

Will

Well-Known Member
I am going to start loading some 45-70's for my new GBL. I read a lot of people have success using IMR 3031 and Dacron. I happen to have a lot of this powder on hand.
I also have 4198, varget, 2400, and H335.
I have read a lot on Dacron but the ideas seem to be spread out.
How much should I use?

What should I not do?

I don't wanna be one of the guys talking about a ringed chamber.
 

Brad

Benevolent Overlord and site owner
Staff member
This isn't real helpful but use just enough.
You DO NOT want a wad of Dacron tamped over the powder. It isn't a wad, it merely needs to hold powder to the rear of the case on firing.
Use a fluffy tuft and get it into the case. Make sure it isn't tamped down. The bullet seating should push it down the rest of the way.
The Dacron needs to hold the powder in place lightly but must also be in contact with the base of the bullet.

It will increase pressure and velocity a bit. With 2400 in my 45-70 I saw increases of 50-100 fps. Vertical was reduce a little at 100 yards. I don't use Dacron much as it adds an extra step.

For a 45-70 a tuft the size of a large marble, loosely packed, is plenty. Maybe a wad 1/2-3/4 inch in diameter? Worst case if you use too much is a blast of white Dacron out of the muzzle.

My nderstanding is that most chamber ringing has been attributed to having a wad of Dacron over the powder wth loose space between the Dacron and bullet base. This makes the bullet behave as an obstruction leading to the chamber ringing.

Like anything in shooting, no guarantees.
 

KHornet

Well-Known Member
Brad's advice is very good, and about the same as I would have given. That said, I use dac for all rifle loads with burning rates of 2400 and slower that do not fill 1/2 the case. Small tufs with no packing, just enough to hold the powder on the bottom of the case. By half the case, I mean 1/2 of powder charge to the mouth of the case. I have noticed a very small amount of increase in pressure , but there is some. Like brad, I load 2400 for my 45-70, as it is economical, and shoots better in my rifle than any other powder I have tried. Some of the older Lyman manuals recommended Dac fill for 45-70, but it is not in the more recent issues. Good luck, and let us know how you do.
 

sundog

Active Member
Years ago I was at the club one day when another member was shooting a Ruger #1 and hand loading his cast bullets as he went. He even packed a kapok 'wad' down HARD over the powder charge with a tool he had made just for that purpose. Swore it made the best accuracy he had ever had. I had scoped his target earlier, and it didn't look that way to me, but hey, who am I to judge someone else's technique. I simply said my adios and departed before he pulled the trigger again.
 

Ian

Notorious member
Dacron batting sheets have a natural "loft" to them, or "relaxed volume". Cut a small square out with scissors and let it sit for a few minutes and you can see what volume it wants to occupy. I generally put about twice the amount of Dacron as it would occupy relaxed to put some spring against the powder and keep the column back against the primer where I want it. THE most important part with Dacron is to make certain that it is lofted within the case to occupy all the open space between powder and bullet, plus some compression. No tamping it down against the powder and leaving a big open space between Dacron and bullet base.

In the instance of bottle-neck rifle cartridges, I poke my Dacron bits down inside with a small Allen wrench or similar device that snags some fibers going in, that way I can sort of drag the fibers down to the powder yet not push the whole wad down inside. With a little finesse, it's easy to get the Dacron fluffed up within the airspace evenly, leaving extra up in the neck for the bullet to push down. I can't over-emphasize that when I say "compression" and mention pushing down the excess Dacron when seating a bullet I mean VERY SLIGHT compression. Don't get the idea that it's as dense as a stuffed toy when I'm done, only about twice normal loft or less, basically just enough to fill the space and put a little hold-down pressure on the powder. That's all it takes to get the benefit and be safe.

One other thing, Dacron does tend to boost pressures a little bit (or more depending on the situation), so always always always reduce known-good loads before trying them with Dacron.
 

Brad

Benevolent Overlord and site owner
Staff member
I tried some Dacron in a rifle shooting healthy loads with cast and found that adding Dacron was about the same as adding 1/2 gr more powder. Thanks fiver for that suggestion.
I frequently have a few strand of Dacron sticking out from between bullet and case after seating the bullet. I just ignore it.

Ian, neat idea comparing space taken up by fluffed Dacron and the space left in the case.
 

JWFilips

Well-Known Member
If it is to be: It is a Dacron "Fluff" weighed in at about 1 to 1.3 grains each..... Gently worked into the case neck & body with tweezers so it fluffs in the case body over the powder and into the base of the neck....It is never a "wad" It is never tight! ( Sorry if "Larry's" voice came through:rolleyes:)
It is just that I had to shoot many hundred low weight H4895 Rounds in my old JP Sauer Mauser to see If it would ever shoot again! That is a lot of Dacron Fuffs!
Still one of the most accurate loads for it
 

KHornet

Well-Known Member
My tufts (pulled apart, weigh just a bit over 1/2 grain for use in my 30 cals. Have never seen any Dacron out in front of the bench when shooting. Have seen others who use a lot more than me, have the stuff floating in the air after a shot. Obviously IMO to much!
 

Brad

Benevolent Overlord and site owner
Staff member
I have never smelled it but I have had someone to remain nameless tell me I was using too much. Some people don't like the snow like effect one gets with lots of Dacron.
 

Brad

Benevolent Overlord and site owner
Staff member
I can smell a person shooting cast using 50/50 Alox lube. Yuck.
 

Will

Well-Known Member
I'll post some results after this recent 16" of snow here in Ky melts off thanks for the help
 
9

9.3X62AL

Guest
I won't use Dacron in ANY load, ever again. I have a flatband Winchester 94 that was once chambered in 25-35 WCF--it now campaigns on in 38-55 M&B thanks to Jesse Ocumpah in Oregon (JES Reboring). Dacron usage--and it was done properly--ringed the 25-35 chamber right at the neck/shoulder junction. On balance, the non-existent-to-incremental accuracy increase isn't worth the demonstrated risk to me.
 

Josh

Well-Known Member
I won't use Dacron in ANY load, ever again. I have a flatband Winchester 94 that was once chambered in 25-35 WCF--it now campaigns on in 38-55 M&B thanks to Jesse Ocumpah in Oregon (JES Reboring). Dacron usage--and it was done properly--ringed the 25-35 chamber right at the neck/shoulder junction. On balance, the non-existent-to-incremental accuracy increase isn't worth the demonstrated risk to me.
This is the problem with Dacron, duplexing, or filler. Those that use it and never have issues try to explain how it is done. Those who do it then screw something up rarely admit they *may* have screwed up and then demonize the practice. It surely isn't for everyone, but it does have it's place.

Dacron in the 30-30 case really isn't necessary, but when using cases of larger size (308 and up) it can serve a valuable purpose with reduced charges of slow powder. Ringing a chamber using dacron may be because the fast powder was too fast?

Who knows... anyone have a junker rifle to test this in?
 

Ian

Notorious member
Evidently the steep taper and large bore/case ratio of the 25-35 is unsuitable for billowy fillers. Typically, Dacron is used in straight-walled BP calibers when using reduced charges of dense, fast smokeless powder, sort of the opposite situation. I use Dacron from time to time in my reduced loads for .30-30, but generally it isn't necessary as Josh pointed out. I have in the past used a lot of Dacron in .308 Win and '06 with no problems at all, as well as a whole bunch of straight-walled or nearly straight cartridges.

Any time we go outside of the normal loading practices there is some bit of risk, but there's risk to just going outside.....and often great reward.
 

JWFilips

Well-Known Member
Will,
Dacron is unnecessary with 2400 powder It is primarily used in the slow rifle powders with lighter loads. 3031 H4895 etc
Jim