Dacron fillers ??

[1johnlb]

I am about to begin useing dacron filler for the first time and am curious of how the filler will effect my previously worked up loads. Will they increase pressure if done right? Will I need to work up new data for my rifles? After reading the very well discribed process these are questions still going through my head. If I understood it right dacron has very little effect on the pressures compared to others like COW.

Thanks for your help Gents.

[leadman]

In my experience the dacron filler will raise pressure some. Some things that could influence how much is case capacity, weight of filler and whether the case is bottlenecked or straight walled.
I would reduce the powder charge a little and work back up. Depending on the powder/cartridge you may not need the filler.

Some more info on what you are shooting would help.

[1johnlb]

2400 , imr4227, imr4895, imr4064 [ unique, reddot, titegroup I know don't need a filler ]

303b,308w,30/06,7.5x55,7.5x54,7.62x54r,8x57,8x56r,6.5x55

314299,311299 these are my two newest molds that have been highly suggested here. I am currently working on 314299 in my no4mk2 with 4227 [best load 17.8] and imr 4064[ best load 27.0]. I haven't even taken the 311299 out the bag yet, also waiting on a mold from N.O.E. for my k31.

[BruceB]

2400 , imr4227, imr4895, imr4064 [ unique, reddot, titegroup I know don't need a filler ]

This statement ASSUMES too much.

I have loaded tens of thousands of rounds using very-moderate amounts of dacron.

Side-by-side tests of loads which were IDENTICAL except for the presence of small amounts of dacron in some, and NO dacron in the comparison loads, showed that even the faster powders like 2400 are sensitive to some degree.

WITH a low-density dacron tuft, loads typically had slightly-higher velocities, and lower extreme spreads and standard deviations.

Sometimes the grouping was somewhat improved, and sometimes it was not.

Cartridges included in this result were both straight-case and bottle-necked.

The dacron should never be packed-in like a dense wad. For example, even in the .416 Rigby which holds 120 grains of powder, my dacron tuft with a 55-grain powder charge (well-under 50% of capacity) weighs only about ONE GRAIN.

"Low-density tuft" are the important words in using dacron for a filler material.

[Larry Gibson]

Yes the Dacron filler will raise the pressure. Does so for 2 reasons; 1st it positions the powder and promotes more uniform ignition and efficient burning. 2nd sticking the Dacron filler in the case reduces case capacity.

How much it will raise the psi and whether or not the load needs to be adjusted depends on the load. Too many variables to guestimate.

Suggest you read the sticky on proper use of fillers if you haven't. There are times to use a filler and times not to. 1johlb's blamket statement does indeed "assume too much".

Knowing more about what you are contemplating using the filler in and the loads you have would be helpful?

Larry Gibson

[1johnlb]

Thanks Again
Yes, I read the tread, it was very informative and very helpful. It answered most but It just didn't answer these questions very well. leadman asked me for more info on what I was working with and I know that left alot of open territory. I wasn't looking for a specific PSI reading just general discussion of it's effect on pressure. I understand that different case profiles, cals, and many other variables can factor different things. Excuse me if I am not always clear, I'm not the best typiest. But I am of above average intellegents. And I am greatful for all you gentelmens time and help.

Just to clear things up. I am currently working up loads for 314299 with 2 parts coww and 1 part foundry type, in my no4 mk2 , with a bedded receiver and barrel, in full military dress.

without dacron and 4227 17.8 grs is my sweet spot, but still has some vertical stringing

with imr 4064 and no dacron my sweet spot is 27.0 gr. and some stringing


the 4227 load shoots about 2" at 80 yds [ 80 yds until I get the corn out the feild]


the 4064 load shoots about 1.25 at 80 yds

both with vertical stringing. By my understanding both of these loads are in need of a case filler. My question is , is my sweet spot most likely to change because of increase pressure and for most of my other loads like and simular to these in my other cals. For the most part my question has already been answered but any other points that you point out will be respectfully concidered. I guess my best bet is to just get out there and do it. I have always been one that learned best with hands on.

THANKS AGAIN

[Larry Gibson]

Vertical stringing can be from the bedding in a No4 MkII (was a common problem with SMLEs). However, if it doesn't vertically string with quality jacketed then the Dacron filler may very well be of benefit.



Suggest a 1/2 - 3/4 gr Dacron filler with the loads mentioned.

Drop the 4227 load to 16 gr and work back up to 17.8 gr.


Drop the 4064 load to 24 gr and work back up to 27 gr.

Larry Gibson

[john hayslip]

Ross Seyfried wrote in a Rifle article that in his experience small amounts of dacron may cause chamber ringing. He said never use less than 8 or 9 grains. I ringed a 32-30 chamber using a cork wad. The wad was about midships of the case, the same place the ring was, and the bullet was breech seated.I've switched to florist foam on straight, or nearly straight cases. It seems to burn completely without fouling and no indications of pressure increases.

[bangerjim]

I use Dacron all the time. Just load 'em, stuff 'em, and shoot 'em. Don't get lost in the weeds. Have fun!

banger

[jr86]

I like using Dacron in m14s and m1 garlands. Helps it cycle more reliably with reduced loads of 4064 and 4895.

I don't like adding an extra step if I don't have to though so I don't use it in my bolt guns.

[1Shirt]

I agree with Bruce and Larry nearly always, and this is no exception. That said, I use dac fill with most loads of 2400 and slower powders, and have had excellent success with same including in 375 H&H. Had never used 4227, but was able to snag an 8 pounder and two one pounders of it recently, and 2400 is scarce in this area, so will be testing 4227. Big factor is to keep the Dacron fluffy, and not at all compressed. I do not use cut squares, as it is fairly easy to compress them. I pull the fibers and just lightly push them down the neck and onto the power with no compression.
1Shirt!

[303Guy]

I found in my records that I was using 22gr H4227 under a 214gr boolit with Dacron in my 1896 LE I. A close up photo of the primer shows very mild pressure and there is no base damage to the boolit (which was a plain base).

[1johnlb]

Was that a paper patched?

The sweet spot for my #4 mk2 was 17.8 and I had another at about 21grs but not as good of group just faster. Thats the reason I was staying at 17.8. I am probably going work with 4064 first, because weight of boolits, faster fps, and planning on shooting it 200 meters.

[303Guy]

Yes that was paper patched. The base was fully exposed. I never range tested that load, only test fired it to check for base damage which is was the objective.