Powder Charge vs. Diameter

[Bullzye]

I am loading for .44mag, but I guess the answer would cover any caliber...

I am loading Dardas' cast 200gn RNFP's and 240gn SWC's. I am trying bullets sized larger, (going from .430" up to .432") to see if that will solve my keyholing issues from a Marlin lever. Also for a Ruger SBH that leads the barrel like nobody's business with my cast stuff so far.

Should I keep the powder charges the same as listed data for the bullet weight?

The loading manuals list the cast bullet diameters for the .44's I'm loading at .430", would bumping the bullets up to .432" have an effect on the powder charge?

I'm thinking about the fatter bullet sealing better and pressure levels, or with the smaller bullet I guess the pressure was slipping past the bullet? (sorry, thinking out loud there...)

I don't load the high end of anything, I usually use mid range load data.

I'll be using 2400 and Titegroup or Win 231 powders.... and just for plinking/target shooting out to 100yds.

Thanks for any advice!

[Larry Gibson]

I'll be using 2400 and Titegroup or Win 231 powders.... and just for plinking/target shooting out to 100yds.

Use the Titegroup or 231 for those loads. Start low and work up using the Marlin with pistol data. Keep the velocities under 1150 fps out of the rifle and you'll probably find pretty good accuracy with either powder. When you have that accuracy load for the rifle then just use it in the BH, you'll find it probably will shoot very well in the revolver also. Such a load will serve your "plinking/target shooting" requirement quite well.

Are you using your own lube? if so What?

If using the hard wax lube (that usually is the leading problem with commercial cast bullets) that comes on most commercial bullets try tumle lubing them in LLA as per the instructions. Many times that solves the leading problems with such loads as you're interested in. I will also wash off the hard wax lube (soak in Coleman fuel for 30-45 minutes in coffee can then swirl around a bit and dump out) and relube them with Javelina or Bac and load them to magnum levels (1350 - 1450 fps) for use out of my revolvers.

Many PB'd cast bullets, especially heavily BB'd ones, will not shoot well at all above 1400 fps out of a rifle so the top end revolver loads are too much for using such cast bullets in rifles because of the higher velocities with those loads in rifles.

Larry Gibson

[fecmech]

I would second Larry's velocity recommendations. Also with both a 215 gr and 250 gr bullets that I use in a .44, somewhere around 7 grs of 231 should put you in the ballpark. That runs about 900 fps out of my Ruger SBH and that should be around 1100 fps in your rifle and for me is very accurate.

[fredj338]

Going to a slightly larger bullet isn't going to affect pressures much as long as yo uare not already shooting max loads. Dardas makes a hard bullet if I recall. If theya re undersized for your guns, they will lead. have you gaged the cyl throats of your RBH or slugged the rilfe? Shooting larger bullets through an undersized cyl is pointless, you end up w/ a smaller bullet entering the bore.

[Bullzye]

Are you using your own lube? if so What?

Larry Gibson

Thanks all for the help. As far as lube, I'm using a light coating of Liquid Xlox and dusting those with powdered mica. They look and feel pretty slippery.

[cajun shooter]

I did not hear you say that you slugged the barrel or measured the cylinder throats. This is the only way to get on track with any revolver. You may have a undersized cylinder and over sized barrel which has occurred in the past. It's all only guessing until the measurements are taken. A lead bullet that is of the proper alloy and used with a softer lube such as BAC should give you a good bullet if .001-.002 over the bore size. This will allow the base to fill into the bore and seal the base against the hot gases.
If you are using hard commercial bullets and lube then that is the perfect way to end up with leading and unstable bullets.
Larry also gave you good advise.

[44man]

I don't put a lot of stock in a perfect throat fit but a boolit must be at least groove size and a little larger is better.
The Marlin suffers from the wrong twist. There is even a gun writer in Handloader this month that has tried to get Marlin to change for years as have I with no luck. They actually sent me the Greenhill formula showing I am wrong! :killingpc
Next, the SBH will do better starting at 240 gr boolits, the 200 can be problematic. Then a store bought semi wad cutter has it's own problems. Wrong alloys and no alignment at the forcing cone.
Next is the lube. The boolit is too slippery combined with LLA that will lead a bore fast. I can NOT use the stuff in any of my guns. The snot can't be fixed! Some love it and I don't argue but it does not work for me.
Strange things happen with boolit size. I use water dropped WW boolits and Felix lube. I made two molds for my 330 gr boolit and found the second one drops at .429"-.430". My throats are .4324" and the groove is .430". Yet I have shot under 1" at 100 yards with my SBH, no leading at all.
I scratch my head over it, it should not work but it does as have many, many .430" boolits. I do shoot up to .432" but have never found a difference, all will shoot.
I take no stock in expanding a boolit in the gun to obturate either. In 57 years, I have never found any accuracy from that.
I have shown these before. Must be over 500 shots since I cleaned the gun. This with the boolit that is TOO SMALL at 200 yards and I shot the steel at 100 yards off hand, less then 1". My friend shoots 1/2" groups at 50 yards with this boolit from a new SBH Hunter and shoots his deer in the neck. :holysheep
I can not shoot a Keith like this.

[MtGun44]

"Looks and feels pretty slippery"

Well, no offense, but our fingers can't tell much that relates to what happens
inside the barrel. Much experience shows marginal lube capability with Alox alone,
mica may or may not make much difference.

Try LBT soft blue or NRA 50-50. Start with a known good lube and get the load working.

THEN experiment with lubes, you will then know if the new lube is any good or not.

Bill

[Larry Gibson]

+1 on; "Try LBT soft blue or NRA 50-50. Start with a known good lube and get the load working.", especially for use in a rifle.

One other question; are the "Darda's" bullets hard cast with a bevel base?

Larry Gibson

[Frank]

44man:

I scratch my head over it, it should not work but it does as have many, many .430" boolits. I do shoot up to .432" but have never found a difference, all will shoot.

That saves people from needing a bigger bullet or mold. But we often hear, It must fill the throat. Make the bullet bigger, or get .432, it works great. I tried a BTB that was .432 PB shot at high velocity and that was the worse leading I ever had. Ever!! We hear Fit is king. But what is the right fit? It is not such a big deal, Fit. There is room for deviation.

[Bullzye]

"Looks and feels pretty slippery"

Well, no offense, but our fingers can't tell much that relates to what happens
inside the barrel. Much experience shows marginal lube capability with Alox alone,
mica may or may not make much difference.

Try LBT soft blue or NRA 50-50. Start with a known good lube and get the load working.

THEN experiment with lubes, you will then know if the new lube is any good or not.

Bill

No offense taken... I have not shot them yet so what I meant was, comparing a plain bullet to the ones I coated with the Xlox & mica, (first time I used either one) I liked the way they looked and felt. You can feel the added lube sliding them against each other, so it's gonna have an effect.

Whether it's a good effect or not is to be seen. I will follow up.


**Larry Gibson: The Dardas are hardcast bevel base.

**cajun shooter: No I haven't slugged either one. I just thought I'd try a few of the bigger ones and see if they fly straighter and ck. on how the barrels look regarding the leading.

Thanks again all! This info will go to good use.

[runfiverun]

marlins generally like bigger and harder.

[Larry Gibson]

Bumping the bullet to .320 should have negligeable effect on the powder charge. Especially since with a hardcast BB'd bullet you will need to reduce the velocity so it falls in the 900 - 1150 fps range for best accuracy, probably in the 1000 - 1050 fps range with either bullet.

A tumbling of LLA probably will prevent any leading from the hardwax lube that most commercial cast bullets are lubed with.

Larry Gibson