Does filler = smaller groups ?

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Been playing around with my 458 Winchester and this is what I've developed so far with a 5 shot group. Each shot was spaced apart a timed 2 minutes. Clear conditions with no wind. Of the bench.

Load 1. Speer 400gr. with 26.0 gr SR4759 @ 50 yds = .204"
Load 2. Speer 400gr. with 30.0 gr SR4759 @ 50 yds = .359"

There is a space between the bullet and powder charge of an average .790 inches. When the rifle is is horizontal the charge will be spread out over the length of the case. When the primer ignites the powder will burn ( so I think) in a line and since there is no compaction may be irregular each time.

What if a person covered the powder with a thin piece of paper and topped the remaining space with a filler allowing for a slight compression by the bullet. Since these loads are almost half the charge of a full magnum load, I cant see there being a problem or SO I THINK. Is .790" to much space to fill

Wouldnt a compressed powder charge be more effective than one that's spread across the bottom of a case?
 
Only you can answer this question, that many of us have pondered over for a very long time.
With me, the verdict is still out. Sometimes it works best with filler, sometimes without works best. There are also many types of filler to try, as well as many other suitable powders.
I don't see how you could hope to improve on the groups you mention.
 
dacron pillow stuffing is the usual material. It is complety consumed.

I have tried it but could not see any difference. It just made me feel better, i guess.

Like h4831 said, how much better can it get?
 
I don't like the idea of fillers even for light loads, but if it were my .458 and I were determined to fill 'er up I might be inclined to insert a .410 shotgun wad over a paper card on the powder and then seat the bullet - lot of messing around though. As mentioned, if they're shooting well and they seem to be, who needs subMOA on a practice load anyway?
 
I've never tried light loads in my 458WM but with low velocity loads in the 45-70, I've had some noticibly improved results using a filler. With light or low velocity cast bullet loads using 2400 or IMR 4227 for example, I found accuracy improvements using a filler. I started with shredded cotton ball material but found a round foam backer rod product called Stopdraft by Tago, cut to the required length, to be more or less ideal.

Another option I'm leaning more towards lately is using Trail Boss powder. As bulky as it is, a filler becomes a non issue.
 
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sbtennex said:
I don't like the idea of fillers even for light loads, but if it were my .458 and I were determined to fill 'er up I might be inclined to insert a .410 shotgun wad over a paper card on the powder and then seat the bullet - lot of messing around though. As mentioned, if they're shooting well and they seem to be, who needs subMOA on a practice load anyway?
Click to expand...

Use caution when using any sort of filler, especially DO NOT leave any airspace between an overpowder wad of any kind and the bullet as a ringed chamber will be the result, destroying the barrel.

SR 4759 was designed as a smokeless replacement to be used in large volume black powder cartridges and I have found it works very well without a filler, in .45-70, .45-90 and .44-40. An older Lyman loading manual will have loads for the old cartridges as well as reduced velocity loads for (then) new high velocity cartridges. Some of the old Lyman manuals also listed loads for both cast and jacketed bullets.

Various fillers have been tried over the years; cotton batten, kapok over the powder, cream of wheat to fill the case to the base of the bullet, etc. Just be aware that using any sort of filler can be dangerous if one is careless.

As well, many older rifles in which one is tempted to use a filler have softer steel than modern rifles and will be damaged/ruined easier through misadventure from careless loading.
 
I've never liked the idea of a filler, and don't use it. Despite that I have managed decent accuracy with reduced loads in a variety of cartridges including the .458, but when I load reduced loads they are for small game hunting with a powerful rifle, not for match accuracy. What are your loads for? Are you looking for match accuracy, minute of squirrel, minute of grouse or minute of rabbit? If your groups range between a quarter and a third of an inch at 100 yards, or even 50 yards I don't think you will see much improvement with the use of a filler. As much as I like 4759, I use Unique far more often, resulting in even more airspace in my cases and I use magnum primers which may produce better ignition when the powder it not held against the flash hole.

Another option you could try is a very slow powder that will match the velocity you are after but will fill the case. For example, I have a .30/30 load with a 195 gr bullet backed by 30 grs of Winchester 760. The load is mild, yet fills the case nicely. If you have some very slow powder like R-25, Retumbo, or such like, you will probably be able to work up a reduced load with a full case of powder.
 
Opcx6 said:
Use caution when using any sort of filler, especially DO NOT leave any airspace between an overpowder wad of any kind and the bullet as a ringed chamber will be the result, destroying the barrel.

SR 4759 was designed as a smokeless replacement to be used in large volume black powder cartridges and I have found it works very well without a filler, in .45-70, .45-90 and .44-40. An older Lyman loading manual will have loads for the old cartridges as well as reduced velocity loads for (then) new high velocity cartridges. Some of the old Lyman manuals also listed loads for both cast and jacketed bullets.

Various fillers have been tried over the years; cotton batten, kapok over the powder, cream of wheat to fill the case to the base of the bullet, etc. Just be aware that using any sort of filler can be dangerous if one is careless.

As well, many older rifles in which one is tempted to use a filler have softer steel than modern rifles and will be damaged/ruined easier through misadventure from careless loading.
Click to expand...

Agreed, which is one of the reasons why I'm now working with Trail Boss for some of those light loads. With some of the light load powder charges I mentioned previously that I've used in the 45-70, I got from my old copy of Lymans 1st Edition Cast Bullet Handbook. Use of a filler wasn't mentioned but in trying them they did seem to give me more consistent accuracy results. I never was too fond of over powder wads or cards. I've tried a few different filler mediums but the best I came across was the foam backer rod cut to length. Initially when I heard about it and first tried it I was somewhat skeptical as I was unsure what would actually 'happen' to the filler. The only noticeable result, looking off to the side of the barrel when the round is fired, appeared to be like a puff of dust. I never noticed any residue in the barrel at all.
 
Been playing around with my 458 Winchester and this is what I've developed so far with a 5 shot group. Each shot was spaced apart a timed 2 minutes. Clear conditions with no wind. Of the bench.

Load 1. Speer 400gr. with 26.0 gr SR4759 @ 50 yds = .204"
Load 2. Speer 400gr. with 30.0 gr SR4759 @ 50 yds = .359"
Click to expand...

I checked my book and it lists SR4759 as a red load "Caution" and 30g is the max charge listed at 1445fps (Speer book) 458 WIN MAG

Besides Accuracy what are you looking for? low charge weight ? lower cost? Plinking load at low velocity?

My old lyman book list IMR 3031 as the Accuracy Powder to use at 2337 fps A lot higher velocity app 800fps higher and the case is a lot fuller.

if looking for a plinking load have you considered Cast bullets ?
300g cast to app 1500 to1900 fps
400g- 480g cast to app 1200 to 1800 fps
 
most accurate loads should fill the case 80%to90%, if you want the very best pressure, velocity, and accurcy ;get apowley computer,andpsi calculator and use them
 
Johnn Peterson said:
Agreed, which is one of the reasons why I'm now working with Trail Boss for some of those light loads. With some of the light load powder charges I mentioned previously that I've used in the 45-70, I got from my old copy of Lymans 1st Edition Cast Bullet Handbook. Use of a filler wasn't mentioned but in trying them they did seem to give me more consistent accuracy results. I never was too fond of over powder wads or cards. I've tried a few different filler mediums but the best I came across was the foam backer rod cut to length. Initially when I heard about it and first tried it I was somewhat skeptical as I was unsure what would actually 'happen' to the filler. The only noticeable result, looking off to the side of the barrel when the round is fired, appeared to be like a puff of dust. I never noticed any residue in the barrel at all.
Click to expand...

The foam backer rod filler sounds interesting, what diameter is it? If it is close to the inside diameter of the case it should work fine, the ideal length would take up all airspace between powder and bullet without compression.

My pet .45-70 target load (short range) is 457483 385gr or 457193 420gr cast fairly soft sized .458 over 20.0grs SR 4759 with no filler. This is the most accurate load in my 1886 Winchester and at approx. 1000 fps it is soft on recoil with the rifle butt. It is most accurate uncrimped and single loaded with thebullet seated to engage the rifling, an old benchrest trick.
 
I use Dacron quilt batting. You do not need a card wad.
Caution though, as one of the loads listed in the first post is a max load, you should be aware of two things.
One, the weight of the filler should be added to your projectile weight, meaning back off and re-work up your load.
The other is that fillers tend to make the powder burn more cleanly, and more completely in my experience (45-70) and possibly get more pressure as a result. Again meaning you should back off and re-work the load.
 
Opcx6 said:
The foam backer rod filler sounds interesting, what diameter is it? If it is close to the inside diameter of the case it should work fine, the ideal length would take up all airspace between powder and bullet without compression.

My pet .45-70 target load (short range) is 457483 385gr or 457193 420gr cast fairly soft sized .458 over 20.0grs SR 4759 with no filler. This is the most accurate load in my 1886 Winchester and at approx. 1000 fps it is soft on recoil with the rifle butt. It is most accurate uncrimped and single loaded with thebullet seated to engage the rifling, an old benchrest trick.
Click to expand...

The original stuff I was able to get hold of was 5/8" diameter so it was a bit of a process. After figuring what length I needed, I also went to the trouble of cutting out a wedge shaped slice that would make it easier to fit the brass.

Some of the info on what I was using, the process to make it fit and load info I passed on to H4831. As luck would have it, he found a very similar product 1/2" in diameter that worked even better. Cutting to length and a slight rolling between thumb & index finger to compress a little for fit was all that was required. I've used it with positive results in light loads with IMR 4227, 2400 and Unique.
 
WOW thank you for the info. Maybe I will leave it alone.
My 100yd groups are averaged at .920" Should be able to pick off a few gophers with that.
 
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