To slug or not to slug

[pcolapaddler]

I've read conflicting opinions on the need to slug a revolver barrel.

Advocates cite improvements in accuracy and other benefits. They also mention slugging the cylinders as well.

I'm new to casting. So far I have only made a few ingots from range scrap.

I can see the benefit of slugging I guess. But if I understand correctly, the soft lead plug is inserted from breech and pushed out through the muzzle. It would seem that this is a bit difficult with a revolver. Or am I missing something?

What would be the benefit of doing this with the cylinders?

I am working with .38 special / .357 magnum.

Thanks

[reed1911]

On a revolver you will have to put the slug in from the muzzle end. What you hope for is that the barrel and chambers of the cylinder are all the same size, but it very rarely works out that way. So, if you slug your barrel and it runs .3570" and you slug your cylinder and it runs .3580 you are in a good place. If the cylinder throats are smaller than your bore, you will want to hone them out or cut them to all be at bore size or slightly larger. If the bore is smaller than the throats, not a problem so long as all your chambers are the same size. If they are not the same size or nearly so, you may want to have them opened up. You may not, I would slug it all and then start shooting, sometimes you don't need to do anything but take it to the range and burn up powder.

[mart]

There is much to be gained and nothing lost by knowing the critical dimensions of your revolver. As Ron noted the best orientation is to have the cylinder mouths slightly over groove diameter. The other way around doesn't shoot cast well. Use a brass rod or hardwood dowel to tap a soft bullet from the muzzle to the breech of your revolver. A good micrometer is preferred for measuring the slug, though a good quality dial caliper can be used. I always have a few sizes of lead round balls around and use those for slugging the bore.

[C.F.Plinker]

Remember to oil the slug and the barrel well. It may be hard to get started since you are sizing the slug down to barrel dimensions. Once it is all in the barrel, the slug will move fairly easily. As you get it down toward the point that the barrel is screwed into the frame try to see if it is harder to move. If so, you may have a choke point there. Once it is out clean off the oil and measure it. If you have a Smith and Wesson which has 5 grooves this can be tricky because each land is opposite a groove. There are several threads on how to do this however.

Now take the slug that you just measured and see if it will go through each cylinder with almost no pressure except that which is necessary to line the slug up with the cylinder throat. If it does, then your cylinder throats are the same size or slightly larger than the tightest spot in your barrel. If not get more slugs (one for each cylinder hole) and slug the cylinder. After measuring each one, you will know how much the cylinders will need to be honed out. Personally, I would size some boolits for .001 to .002 larger than the barrel slug and see if you get any leading before deciding on getting the cylinder throats opened up. As always, listen to Dr. Gun because he will tell you what he wants.

[tazman]

Some times you can get lucky with the cylinder and try a couple of jacketed bullets or sized boolits in the cylinder throats and find a tight fit. Often you can find out if the throats are the same size this way.
Not an option for the barrel.
I have a couple of S&W revolvers that have small throats and smaller barrels but shoot just fine with the ammo I make for the "normal" sized guns.

[Hickok]

In .357, just size to .358" to start out and see how it goes. If you check anything, slug the cylinder throats.

I have always had good luck sizing to .358" for .38's and .357 magnums.

In .44's and .45's I always check the diameter of the cylinder throats, as they can vary widely.

[Jtarm]

IDK where you're getting you're information, but I have never seen anyone argue against slugging a revolver bore. Unless you think when people say throats are the critical dimension, they mean you shouldn't slug the bore. You need to do both. Even if your boolits fit the throats, if groove diameter is larger than the throats, your bollits aren't going to shoot well.

Laziness is the only reason I can think of not to do it.

[rintinglen]

Put me down in the lazy catalog if you must, but before I squander an hour of my time pounding lead into holes, I shoot the gun. I've been around the block enough times to know what to expect from a "new" (at least to me) gun. Unless the gun fails to meet my expectations, I don't bother with slugging the bore or the chamber throats. Now if leading is a problem, or if I don't get the accuracy I expect, then I'll start nosing about, but if everything is ok, I'll just load, shoot, and repeat.

[tazman]

Put me down in the lazy catalog if you must, but before I squander an hour of my time pounding lead into holes, I shoot the gun. I've been around the block enough times to know what to expect from a "new" (at least to me) gun. Unless the gun fails to meet my expectations, I don't bother with slugging the bore or the chamber throats. Now if leading is a problem, or if I don't get the accuracy I expect, then I'll start nosing about, but if everything is ok, I'll just load, shoot, and repeat.

I agree. The only reason I checked 2 of my revolvers was curiosity, not from needing to correct problems.

[pcolapaddler]

Thanks. I appreciate the responses.

I've loaded and shot cast SWC and WC bullets from the gun. They were purchased from a couple of LGS here in my neck of the woods. I didn't notice that they were any less accurate than anything else that I have used. My greatest concern is not to do damage to myself or my equipment / firearms.

Can I use a bullet that I cast from pretty soft alloy - like flashing lead - as a slug? Or if I need something else, where can I find a suitable slug?

Thanks

[Jtarm]

Flashing lead should be perfect.

I dunno why it would take anyone an hour, but OK.

[bangerjim]

My 38/357's all shoot .358's perfectly. Slugging AFTER shooting them just proved I was good to go!

On new guns I now shoot 1st, check for inaccuracies, and then check with a slug. No need of wasting time messing around with it if not needed. If a gun shoots well (to my expectations) with what I size to, I could care less what the slugged size is.

"Sometimes you read and follow the text book...sometimes you use the book as a shim under the table leg!"

[Hickok]

IDK where you're getting you're information

Laziness is the only reason I can think of not to do it.My info comes from over 40 years of shooting revolvers and casting boolits for them. I don't like pounding a lead slug down a perfectly good bore from the muzzle end unless it is needed. The S&W barrels have a 5 groove rifling that is very difficult to get an accurate measurement. (If the OP has a Smith)

Like RinTinglen, I have been around the block a few times and this ain't my first rodeo.

[bedbugbilly]

Put me down as "lazy" as well. I try them out first.. . ruinationglen says it pretty well. I have quite a few 38s as some 357s. All they get is cast. I have maybe checked two of my revolvers - my Ruger 357 NV (which we all know Rugers can have tight throats) and the Uberti 45 Colt Cattleman that I got this past summer. I did just as tazman says . . . pulled the cylinders and checked the throats with sized cast boolit.

I only have two semi-autos - both 9mm. But again, I try 'em first and see the results. If a problem, then I'd probably slug the bore but I just haven't had one in either so . . . I guess I'm lazy on those as well

[Dan Cash]

If you plan to live your casting life with Lee moulds, don't worry about it, just take your chances. Since slugging the bore and chamber throats on your revolver is so easy, you would be foolish to spend the money on a quality custom mould, eg. Accurate, NOE etc., without knowing the required dimensions.

[mdi]

Just like I like to know what the tire sizes are on my vehicles (and my wife's shoe size), I like to know as much as I can about my guns. Unless one is on the lazy side, and some may fear driving a slug down a barrel, there is no down side to barrel slugging (takes less than 10 minutes). Some mentioned a variation in groove diameter from muzzle to breech end, but I have not had a problem noticing difference in force needed to drive a slug through. If you start a slug into the muzzle and it get looser farther down, that means the latter part is larger in diameter, and conversely, if it gets tighter, the grove diameter is smaller. When finding a problem like this,other methods of slugging the barrel can be used (slugging the first 1/2" of the muzzle). Many Rugers (single action revolvers) have been correctly diagnosed with restrictions at the barrel/frame juncture by barrel slugging. 90% of my centerfire guns, both handguns and rifles have been slugged, and measurements recorded for future use (I cast bullets for almost all my guns and correct dimensions are needed).

For revolvers, since good shooting needs a cylinder throat larger than groove diameter, the easiest way to determine is barrel slugging and measuring the cylinder throats, either slugging or plug/pin gauges. But then, it's your time, your guns, and your frustration/satisfaction. I like messing with my guns so no time I spend in my shop is wasted. ;)

[tzzler44]

One thing I would add to this discussion is I've found it's much better to GREASE the slug instead of oiling

[Larry Gibson]

I don't "slug" a revolver barrel unless absolutely necessary and find most often its not. I do use pin gauges to find the bore diameter of the barrel. Unless the barrel is something really exotic I simply add .009 to the bore dimension and call it good to know. That is most often .000 - .001 over the actual groove diameter I found many years ago. Thus I use the bore + the .009 dimension for the minimum bullet diameter and have yet to find that wrong.

Revolver throats in many makes are tapered. Thus if the start of the throat is not over .002 larger than the throat mouth (most aren't that much larger) I use prefer the larger diameter to size the bullets.

If the throat mouth is larger than .002 than the barrel groove diameter I do not use a larger diameter bullet as I have found no improvement in accuracy and actually have found a decrease in accuracy if the bullet is more than .003 than the groove. In such cases I've found a harder alloyed cast bullet not larger than .002 over groove diameter most often shoot best. My experience with such is with numerous Colt New service and SSA's in 45 Colt and S&W M1917s in 45 ACP with groove diameters of .451 - .452 and cylinder throats of .454 - .457.


Larry Gibson