Does sizing actually matter at all?

[Wardo1974]

I was reading through a 1940's vintage reloading manual written by Philip Sharpe, the Complete Guide to Handloading.

In it, he talks about sizing bullets, and he cited an experiment whereby bullets were loaded and fired as much as .006-.008 overbore. His conclusion was that they shot fine with zero accuracy or pressure problems, and that as long as bullets are sized at least .001-002 larger than the bore, then they are fine to use.

Given this, why bother with slugging your bore looking for that exact .001-.002 overbore measurement? I recently loaded some .45-70 rounds into my 1886 Browning, which I'd previously slugged to be about .458. The boolits I loaded came out at .463-.464. I loaded and fired them, and noticed absolutely nothing but tight groups (better than the .460's I'd been using!)

So I'm asking, why not simply use a boolit several thou larger than bore diameter and forget about slugging for the "perfect" bullet size? If it's too large, the act of firing it swages it down to the right size anyway, doesn't it?

[17nut]

I was reading through a 1940's vintage reloading manual written by Philip Sharpe, the Complete Guide to Handloading.

In it, he talks about sizing bullets, and he cited an experiment whereby bullets were loaded and fired as much as .006-.008 overbore. His conclusion was that they shot fine with zero accuracy or pressure problems, and that as long as bullets are sized at least .001-002 larger than the bore, then they are fine to use.

Given this, why bother with slugging your bore looking for that exact .001-.002 overbore measurement? I recently loaded some .45-70 rounds into my 1886 Browning, which I'd previously slugged to be about .458. The boolits I loaded came out at .463-.464. I loaded and fired them, and noticed absolutely nothing but tight groups (better than the .460's I'd been using!)

So I'm asking, why not simply use a boolit several thou larger than bore diameter and forget about slugging for the "perfect" bullet size? If it's too large, the act of firing it swages it down to the right size anyway, doesn't it?

If you dont slug then what is bore + a couple of thousands?

As long as the bullet is to large gas cutting/leading is avoided and that is the main thing.

[dragon813gt]

I don't slug my barrels. I have enough sizing dies to try different sizes. I don't shot military surplus rifles so the bores are consistent. I'm not a fan of pounding anything through a barrel. I know it works for many but I've found it unnecessary.

[Dusty Bannister]

For me, the slugging of the barrel is easier than doing a chamber cast. One gives you the minimum necessary for not leading, the other gives you the maximum safe diameter of bullet/case mouth thickness that can be used. But then you need to also measure the case mouth thickness of various makers to stay below the max figure and also allow for clearance. Keeping it simple seems a good idea.

[Maven]

"So I'm asking, why not simply use a boolit several thou larger than bore diameter and forget about slugging for the "perfect" bullet size? If it's too large, the act of firing it swages it down to the right size anyway, doesn't it?" ...Wardo1974

The answer is "It depends...." I've tried sizing to various diameters in both rifles and revolvers and found that size really does matter, although it would be quicker to avoid that chore. However, I do try several different plain based CB's in my .30-06 with light powder charges and am pleased with their accuracy. One of them, a Lee 30-150-TL (group buy here years ago), drops from the mould @ .317" (base), but that doesn't seem to handicap it. Gas checked CB's, OTOH seem to do better when sized to fit the rifle.

[DougGuy]

That was the 1940s, Ruger hadn't yet invented the Blackhawk revolver, Colt's were still in the first generation, 1911s would gladly chamber a .453" boolit.

I think it's safe to say that rifle chambers and revolver cylinder throats were quite generous in that period of manufacture. Look at the Colt SAA cylinders vs. groove diameter, and the S&W model 1917, both being sized so a .452" boolit would fall rattling through the throats. I wonder what size factory ammo was for just the .45 Colt cartridge in those days? The .45 Schofield called for a .454" boolit.

In the time that article was written and even many years later, sizing was an unnessary step. Nowdays, you can't even get .45 ACP loaded with a .452" boolit to go fully into a chamber, or a .45 Colt loaded with a .452" boolit to fully chamber in a modern cylinder unless throat resizing has been performed.

So much for the term "match grade."

[mdi]

Sizing bullets to barrels is kinda like buying britches. You can go to the store and try on a bunch of different sizes and perhaps eventually you'll find a pair that fits, or you could measure your waist and know what size to buy...

[runfiverun]

you might know what size to buy but the Chinese measure in metric.

when you shoot an oversized boolit your squeezing it down.
this makes it longer.
the rifling is displacing more metal.
that extra metal can only go 2 directions and the boolit is going one of them.
which leaves the back or steering end of the boolit to be damaged or for those little ribbons of lead to be pushed to.
I like square bases on my boolits I make them that way, I like to keep them that way until they leave the muzzle.
distorting them right at the start of the hole is not on my list of how to do things.

[beagle]

For many years, with Lyman's (and other manufacturer's) tendency to produce moulds which cast undersize bullets, slugging the bore was a necessity to insure that we cast a bullet that was big enough to fit the bore. In those days, not so much to insure bore fit but to insure that bullets were big enough. Now, with custom makers producing moulds which cast bullets closer to desired diameter and larger, slugging is sometimes necessary to produce a ready to load cast projectile that is large enough to fit the bore and at the same time small enough to load in a cartridge and still chamber freely. No matter how large the bullet is, if it will chamber and fire, the pressure will swage it down to fit the barrel. The old thinking of Sharpe's day was to have a bullet that perfectly fit the barrel and even today, we can't say that's wrong as the groups shot by Harry Pope and many of the old timers using breech seating still stand today as outstanding, if not in some case, records. The unknown is what makes casters strive for perfection and attracts shooters to the game./beagle

[mdi]

Hmmm. A while back on a forum, I quoted Sharpe on the .006"-.008" oversize bullets and was quickly "corrected" (flamed) as that would cause a "dangerous rise in pressure"...

[Wayne Smith]

... Which is why many say that the throat measure is the important one, not the bore. It has been said here many times, if you can chamber it, shoot it. Lead squeezes nicely.

[nicholst55]

Elmer Keith used to regularly shoot nominal .458" diameter boolits through .45 Colt SAAs. He blew more than one of them up, too.

[dubber123]

Elmer Keith used to regularly shoot nominal .458" diameter boolits through .45 Colt SAAs. He blew more than one of them up, too.

I'm guessing ole Elmer had them stuffed about as full of powder as possible too though

[ohiomadman]

Hmmm. A while back on a forum, I quoted Sharpe on the .006"-.008" oversize bullets and was quickly "corrected" (flamed) as that would cause a "dangerous rise in pressure"...

.006-.008 is nothing. I once accidently shot a couple of .358 boolits down a .308 barrel. No Kabooms, just sounded kinda funny.

[Victor N TN]

I've grown rather fond of my ugly face, hands and fingers. I think I'll stick with .001" over size and let that be the end of it for me. I have enough scars and wrinkles. I don't need to be purposely making any new ones.

[Boogieman]

Elmer wrote about sizing 300 gr. 49/90 bullets down to use in a 45 Colt over 35gr. of 3f black powder.

[lotech]

I've accumulated many sizing dies over the years, so slugging a bore is not necessary. A cast bullet a few thousandths over hurts nothing and is often beneficial for accuracy, but there are limits. In rifles, I shoot more .308 and .30-06 than anything else and have found, generally, that either a .310" or .311" works best in most guns. I'll usually find that accuracy diminishes, at least slightly, with a bullet sized to .312". Going the other direction, a .309" bullet may also contribute to a decline in accuracy.

Some moulds cast just right and sizing is not needed. It's easier though to apply lube with a lubrisizer using a die large enough so that no sizing occurs; only lube is applied.

[Wardo1974]

At this time, I would like to point out that I was using pure lead boolits when I tried this out. Obviously they would swage down to the size of the barrel a lot easier than an alloy might, and it is thus incorrect to assume that this works for everything as a rule of thumb.

[bedbugbilly]

Isn't another factor is if you want to shoot a larger boolit - say .006 - .008 oversize of the bore - whether or not if you can get it stuffed into the case mouth and whether it will chamber?

I have a 45 Colt (uberti cattleman) that has extremely generous size chambers. The throats are about .454 though and I can easily chamber a 454-190 255 gr. RNFP boolit that falls from the mold at .4545 to .455 - and the bore slugs out at .452. I don't load near max and it works just fine and is accurate.

But . . . I have a GEW98 8mm Mauser - 1905 Danzig - that the bore measures out to .323. I have a NOE 130 ish grain FN mold that was a group buy a while back. It's a .325 and if I load them in brass and try to chamber them, they are too tight. Size them to .323 and they work just fine. I have an extra Lee .323 push through sizer that I'm going to gently open up to .324 to see if that will work . . . but again . . . is it not dependent on if they will chamber as well?

[Wardo1974]

Isn't another factor is if you want to shoot a larger boolit - say .006 - .008 oversize of the bore - whether or not if you can get it stuffed into the case mouth and whether it will chamber?

I have a 45 Colt (uberti cattleman) that has extremely generous size chambers. The throats are about .454 though and I can easily chamber a 454-190 255 gr. RNFP boolit that falls from the mold at .4545 to .455 - and the bore slugs out at .452. I don't load near max and it works just fine and is accurate.

But . . . I have a GEW98 8mm Mauser - 1905 Danzig - that the bore measures out to .323. I have a NOE 130 ish grain FN mold that was a group buy a while back. It's a .325 and if I load them in brass and try to chamber them, they are too tight. Size them to .323 and they work just fine. I have an extra Lee .323 push through sizer that I'm going to gently open up to .324 to see if that will work . . . but again . . . is it not dependent on if they will chamber as well?

When I asked my question, I overlooked this part, basically because...I can't shoot it if it doesn't chamber. I'd have to think that yeah, if you have to jam them in there, it isn't going to work, or if it does, in that instance just might produce pressure issues.

Those big boolits in my 1886 dropped in neat as you please, so I had no worries at all. My main thought on it was, I wanted to know what the greybeards on the forum here thought about shooting a boolit that big.