Cylinder bores too small?

[Dusty Miller]

If my bullet size is .429 and my cylinder bores range from .424 to .427, are things a bit tight given that the case also takes up some space?  I'm thinking that I should use a smaller sizing die.

[jd45]

As I understand it, first you want to slug your barrel with a soft lead slug(they make kits for this purpose), & measure it with a micrometer to find out what your barrel's groove diameter is. Next step is to ream out your chamber's freebores to .001" over groove diameter, if they're under. If you are over groove dia. by 3 or 4 thou, which isn't your case, a person might have to consider a new cylinder....someone with more experience might want to weigh in on this , too. jd45

[jd45]

In reference to your "case taking up space" comment, I don't think the case comes into play in the freebore of the chambers. jd45.

[Iowegan]

Dusty, Case length is not critical in a revolver like it is in a rifle. In a 44 mag or 357 mag, I like to use the magnum cases even in light loads. Mostly to prevent fouling in that last 1/10" of chamber. I doubt that it has much to do with accuracy.

JD45 is right on with his recommendations. If your throat is larger than the bore, you'll get fouling. If the throat is smaller than the bore, you'll lose accuracy. I like to see the throats reamed to within .0005" of bore diameter.

A smaller sizing die would just make matters worse. The cartridge would "flop" around in the chamber and would expand to the chambers diameter when fired.

The only true "fix" is to have your throats reamed to a uniform and correct diameter. That said, some guns shoot just fine with tight throats so don't spend the money unless you are getting poor accuracy or excessive lead fouling.

[ricciardelli]

Woah...hold on a second!

The guy said his cyliner bore is ranging from 0.424 to 0.427.

He didn't say a darn thing about case length, throat diameter, or barrel diameter!

Read his question...

CYLINDER BORE...

Now, if his cylinder bore is 0.424, there there isn't any way that he is going to fit a 0.429 bullet and case into that chamber easily...period!

Now, I'll make two assumptions...

The first is that he is talking about a .44 caliber cartridge. and will also assume he is talking about a .44 Magnum.  The case diameter of a .44 Magnum is 0.457!

He can use a stinking .30 caliber sizing die on his .44 cases, but if he gets the bullet to seat, the case diameter where the bullet sets is still going to be 0.457.....and it ain't gonna go easy into a 0.424 cylinder!

[jd45]

There may be some confusion here as to what Dusty means by "cylinder bores". Dusty, did you mean the part of the chamber forward of the case mouth was .424 to .427? Or were you referring to the diameter of the hole where you insert the cartridge into the chamber at the back end of the cylinder? I kinda think the former. And, again, I don't think the case enters the freebore or throat of the chamber....but correct me if I'm wrong. jd45.

[Dusty Miller]

Right you are jd45.  I'm refering to the forward end of the cylinder.  And, no, the case does not extend to the end of the cylinder bore and the taper of the bullet itself allows the tip of the bullet to come flush with the front of the cylinder.

[Dusty Miller]

Well, I got to think'n that maybe I'd better check that out and when I did the cylinder measured 1.75" and the case (minus the rim) measured 1.63, so the tip of the bullet is not flush with the end of the cylinder.  I tried to push one of the bullets thru the cylinder (from front to back) and where the taper reaches .249" it does come to a stop.

[jd45]

Dusty, what you said last tells me the throats or freebores
 of the chambers in your cylinder are too tight & need opening up, as stated before. It seems, especially with a jacketed bullet, this condition has the potential of creating unsafe pressures. Your gun may be a strong gun, but, if not corrected, it could still cause trouble. Might wanta talk to a gunsmith about it. jd45.
P. S....I think you meant .429", didn't you?

[Lancel]

Dusty:
I bet you're talking about a .44-40 cylinder with a .44 special/magnum barrel.  Do you have a S&W Model 544?

Larry

[Dusty Miller]

The gun is a Colt Anaconda, I shudda sed that right up front, sorry guys.

[unspellable]

Last night I measured the chamber throats onb three of my 44's.  They are oversized.  Just how much oversize is tolerable?

(Doesn't say much for quality control.)

[Black Jaque Janaviac]

Unspellable,

My understanding is that slight oversize cylinder throats is tolerable, or at least better than undersized.  Undersized throats will swage the bullet down too small for the rest of the barrel.  Then you get gas blow-by.

I suppose there's a limit to how much oversize they can be too - that's why they reduce the chamber throats to begin with.  I dunno what happens then - most commonly the problem is undersized throats.

[Dusty Miller]

Today I dropped that Anaconda off at the gunsmith to get those cylinder bores squared away.  It'll cost $80 max and I figure that's fair.  I figure that if I tried to do it myself and screwed it up then it'd cost me at LEAST $80 to replace the cylinder.

[unspellable]

I guess the question on oversized ones is, how big is too big?  At what point do things begin to suffer?  I have always heard that the optimum throat diameter is 0.001 inch larger than the barrel groove diameter.

[tominboise]

Not a .44 but on my .45 Colt Bisley, the bore measures .451", so I shoot .452" bullets.  I reamed the throats to .4526" (they were .449" from the factory.)

Tom