How do I know if I need to resize my .44 slugs?

[chutestrate]

My slugs are dropping from my mold at .430. I drop them into my cylinder and cannot push them through. Do I want to size them down to .429?

The revolver is a Taurus Raging Bull.

[Outpost75]

Open the cylinder. Drop six naked, as-cast bullets into the chambers from the rear and try to push them through and out of the cylinder, through the ball seats using the eraser end of a pencil with hand pressure only. If they go through easy with no resistance and fall out the end of the cylinder, they are too small. If they go through with firm hand pressure they are perfect.
If you cannot push through by hand they need to be sized.

Ignore the groove diameter of your barrel. Cylinder throats are all that matters.

[MBTcustom]

Open the cylinder. Drop six naked, as-cast bullets into the chambers from the rear and try to push them through and out of the cylinder, through the ball seats using the eraser end of a pencil with hand pressure only. If they go through easy with no resistance and fall out the end of the cylinder, they are too small. If they go through with firm hand pressure they are perfect.
If you cannot push through by hand they need to be sized.

Ignore the groove diameter of your barrel. Cylinder throats are all that matters.

I absolutely agree, unless of course the throats are smaller than the groove diameter of the barrel, in which case you've got other issues and you need to have a smith ream your throats.
Assuming the cylinder throats are the same size as your groove diameter or larger, the above reply is gospel.

[bedbugbilly]

+1 ^ ^ ^

[44man]

You MUST know groove to groove first. That might be .430" so using a .429" boolit will do you no good at all. If the groove is .429" and so are the throats, shoot that size. It does no good to shoot over throat either.
Actually as long as a boolit is at groove or a tad over it can be a loose fit through the throats. Throats are best if .0015" over groove. Make boolits .0005" under throats.
I have shot thousands of bullets/boolits at .430" through .4324" throats with a .430" groove with accuracy that baffles. I do also shoot .432" boolits and darned if I can tell the difference.

[mdi]

"Push through" isn't a dimension. "Hand pressure"? What is that in PSI? If you wanna get the right size slugs (aka cast lead boolits), measure. Get a micrometer and measure the diameter of your bullets. Slug the cylinder throats and measure with a micrometer (must be larger than groove diameter of the bbl.). Slug the barrel and measure with micrometers. With facts (real measurements) you can determine needed bullet diameter. All else is a WAG...

A good place to start is bullet diameter the same as throat diameter (my .44s have .430" and .431" throats so I size to .431" and no leading).

If all this seems to be too much work/trouble, just get a Lewis Lead Remover and shoot any diameter bullet...:bigsmyl2:

[Larry Gibson]

You MUST know groove to groove first. That might be .430" so using a .429" boolit will do you no good at all. If the groove is .429" and so are the throats, shoot that size. It does no good to shoot over throat either.
Actually as long as a boolit is at groove or a tad over it can be a loose fit through the throats. Throats are best if .0015" over groove. Make boolits .0005" under throats.
I have shot thousands of bullets/boolits at .430" through .4324" throats with a .430" groove with accuracy that baffles. I do also shoot .432" boolits and darned if I can tell the difference.

I concur. I've also found shooting bullets .002 - .003"+ over groove diameter is also usually detrimental to accuracy. I've shot numerous revolvers of .44 and .45 calibers with bullets sized to groove or not more than .002 over that were more accurate than when bullets were sized to throat at .003 -.005 over groove. I've found that decent accuracy with such miss-matched groove/throat diameters is more a function of alloy hardness than fit to the throats.

Larry Gibson

[44man]

I concur. I've also found shooting bullets .002 - .003"+ over groove diameter is also usually detrimental to accuracy. I've shot numerous revolvers of .44 and .45 calibers with bullets sized to groove or not more than .002 over that were more accurate than when bullets were sized to throat at .003 -.005 over groove. I've found that decent accuracy with such miss-matched groove/throat diameters is more a function of alloy hardness than fit to the throats.

Larry Gibson
Thanks my friend. It is not a butt clench thing. I truly wish some would relax more.

[Larry Gibson]

Thanks my friend. It is not a butt clench thing. I truly wish some would relax more.

Me too. I've found that sometimes "fit" is not the "king" many think it always is but sometimes is the court jester:drinks:

Larry Gibson

[Jtarm]

Agree on measuring everything.

For a revolver, I'd take it a step further: drive a slug from the frame side to just past the forcing cone (but fully into the grooves) and not past the end of the frame. A little awkward, but doable. Then drive it back out from the muzzle end.

This slug should match the one you drive all the way through.

If the full-length slug is smaller, you may have some thread choke, I.e. the barrel got squeezed too tight when screwed into the frame. You can also detect it by paying attention while slugging the bore. Use slow, consistent taps and feel for a sudden increase in resistance.

Choke is easily fixed by fire-lapping, but don't do it unless the chamber throats are already good. If they're undersized, they'll just swage the soft lap boolits to below grove diameter and let them rattle down the barrel.

The boolits don't have to fill the throats completely. If they're soft enough and/or the load generates enough pressure, the base will expand on firing & seal the throat.
Hollow base boolits exist for that very purpose.

I'd be worried if my sized boolits took much pushing to get them through the chamber throats. I like them to stick just enough to exit with a little shaking or very light push. I always figured too tight of a fit would cause pressure to spike.

[chutestrate]

Ok, so I'll measure which I was anticipating on doing anyway. But what about this scenario. I measure get a barrel measurement by driving a slug all the way through, I measure the throat up to the lands and grooves. The diameter is .429, and my slugs currently are measuring .430. If they are not able to be pushed through the cylinder with a little bit of pressure will that be ok? I don't want to find out the hard way. I know lead is soft and all that, but this is a new step for me.

I guess I need to tap slugs through the cylinder as well to get their measurements.

[DougGuy]

Ok, so I'll measure which I was anticipating on doing anyway. But what about this scenario. I measure get a barrel measurement by driving a slug all the way through, I measure the throat up to the lands and grooves. The diameter is .429, and my slugs currently are measuring .430. If they are not able to be pushed through the cylinder with a little bit of pressure will that be ok? I don't want to find out the hard way. I know lead is soft and all that, but this is a new step for me.

I guess I need to tap slugs through the cylinder as well to get their measurements.

That certainly works.

What is best is if the cylinder throats are at least the same size as the groove diameter, or up to .001" ~ .002" over. Regardless of what anything measures, if you can drive a soft lead ball through the bore, and then slide it into and through the cylinder throats with little or no pressure, that tells you the throats are at least a tad bigger than the groove diameter of the bore, and IF you size your boolits so that they are a light drag fit through the cylinder throats, then they are at least being presented to the forcing cone at or slightly larger than groove diameter which is mathematically about perfect. Without a caliper or micrometer or pin gage or nothing. Just that right there. Slug the bore, and push the slug into the cylinder throats.

You DO want the boolits to go through the throats with a light drag fit if possible. This way there is no interference in chambering a loaded round where the boolit is forced into the chamfer or the throat. It is likely pressure will increase with a boolit larger than cylinder throats. Since resistance is less when fitment is correct, pressure will be less as well.

Edit: Size to fit the throats, not the groove diameter.

[chutestrate]

Ahhhh, your way makes more sense. I appreciate all of the information.

[chutestrate]

I haven't slugged the barrel yet, darn honey do's. Just for kicks I took some other cast slugs I had and dropped them in the cylinders. They measured .429 from Hunter's Supply. None of them dropped through nor could they be pushed through with pressure. So I am wondering....if my .430 slugs cannot be pushed through and the .429 slugs cannot be pushed through should I just size them to .429, and call it a day?

[DougGuy]

I would consider sending the cylinder and having the throats reamed if you can't push a .429" through it.

I have two .44 caliber reamers, one is .4315" the other is .4325" normally if a cylinder doesn't have any throats larger than .4315" I would choose to size them all to .4315" and let the shooter size to .431" and all would be good.

Many if not most Ruger .44 cylinders have uneven throats, it's just a fact of life that results from them using a Hitachi machine that reams 3 throats at a time and running it with worn reamers. As they wear they cut smaller and smaller throats. Then when one gets replaced, the throats it cuts are often considerably larger than the others in the same cylinder so it's plenty common for a cylinder to have one pair of throats that is larger than .432" and the rest are smaller.

For these cylinders the only way to correct them is to use the larger .4325" reamer and size all to the largest throat(s) then size the boolits .432" to fit those.