Author Topic: .428 with .429 bore  (Read 3213 times)

Offline William R. Foster

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Re: .428 with .429 bore
« Reply #25 on: November 29, 2018, 11:32:31 pm »
Excellent. Thank you. Now a follow up question. If my math is correct starline states their walls are 0.0065, now you add that to .430 with the addition of the wall on the opposite side and im at 0.443. How exactly is that going to work? Honestly playing with all the 44wcf sized bullets the math doesnt add up. I figure im just tired and doing the math wrong, but figured id check.

Offline William R. Foster

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Re: .428 with .429 bore
« Reply #26 on: November 29, 2018, 11:39:06 pm »
Gah. Nevermind. Im an idiot. I was thinking about the charge hole of the cylinder. Not the throat. Tired thinkin is not good thinkin.

Offline Cholla Hill Tirador

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Re: .428 with .429 bore
« Reply #27 on: November 30, 2018, 03:15:20 am »
 Shoot first and if things don't work out, try something else.

Online Coffinmaker

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Re: .428 with .429 bore
« Reply #28 on: November 30, 2018, 10:12:27 am »
SO.  Contrary to popular belief, Old Dogs can learn new stuff.  Rather than continue my belief about the possibility of cast lead bullets expanding upon firing, I went researching.

It is true that cast lead bullets can expand upon firing.  CAVIAT:  This phenomenon requires the lead alloy be carefully for Brinnell Hardness to the pressure level of the cartridge.  If one is shooting common commercial cast lead bullets the probability of those bullets obdurating at the pressure levels we shoot at is ....... Nil.  If one is shooting Bevel Base bullets the probability of obturation is ..... zip.  Likewise, shooting gas check bullets .... Nada.  Expansion after passing thru cylinder throats ..... only with dead soft bullets.

Shooting undersize bullets and expecting the bullets to "bump up" is a fools errand.  Also, at no point in research could I find any reference to indicate unlimited obturation.  The ONLY effective method for best performance is to shoot bullets sized correctly to the bore (Groove Diameter).

Those knowledge laden folks that toss the "fact" that lead bullets will "Bump Up" are only partly correct and only for an absurdly small number of CAS shooters.

Offline Cholla Hill Tirador

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Re: .428 with .429 bore
« Reply #29 on: November 30, 2018, 12:25:07 pm »
SO.  Contrary to popular belief, Old Dogs can learn new stuff.  Rather than continue my belief about the possibility of cast lead bullets expanding upon firing, I went researching.

It is true that cast lead bullets can expand upon firing.  CAVIAT: This phenomenon requires the lead alloy be carefully for Brinnell Hardness to the pressure level of the cartridge.  If one is shooting common commercial cast lead bullets the probability of those bullets obdurating at the pressure levels we shoot at is ....... Nil.  If one is shooting Bevel Base bullets the probability of obturation is ..... zip.  Likewise, shooting gas check bullets .... Nada.  Expansion after passing thru cylinder throats ..... only with dead soft bullets.

Shooting undersize bullets and expecting the bullets to "bump up" is a fools errand.  Also, at no point in research could I find any reference to indicate unlimited obturation.  The ONLY effective method for best performance is to shoot bullets sized correctly to the bore (Groove Diameter).

Those knowledge laden folks that toss the "fact" that lead bullets will "Bump Up" are only partly correct and only for an absurdly small number of CAS shooters.

  Your text in red has already been addressed in a previous post. I researched the formula I mentioned and it is 1422 x Bhn of the bullet = the pressure required to begin obturation. That explains why the nearly pure lead bullets of ~6-7 Bhn used in cartridges 140+ years ago worked in (slightly) oversize barrels.

  I don't why a bevel base bullet wouldn't obturate, maybe not a much as a flat base bullet due to the smaller surface area of the bullet, but the forces of physics would still be at work.

  Sorry friend, like it or not, cast bullets can and do bump up, under the prescribed conditions. I don't recall anyone saying anything about "unlimited obturation". You can place a lead ball on an anvil and beat it with a hammer and it will only "obturate" so far. I'm not sure when/where/ and why that came into the discussion.

  Of course the best course of action is to size the bullet properly. I personally size for throat diameter, or even a thousandth or two over. Sizing to groove diameter works well only if and when the cylinder throats diameters are close to the diameter of the barrels grooves. This has been demonstrated repeatedly with Ruger SA's whose cylinder throats are very typically of less diameter than the grooves of the barrel. This makes for horrid accuracy and is why 'smith's offer the services of opening cylinder throats. I had a New Vaquero in 45 Colt with this very issue. At the other end of the spectrum are Colt SA's in 45 Colt flavor. Their throats are likewise notorious for being grossly oversized. The last 3rd Generation 45 Colt I owned had cylinder throats as large as .457". THAT is the very situation in which one must use a soft bullet that will bump up to fill the throats.

 You are exactly correct regarding CAS shooters who need a projectile capable of hitting a large target at short range. Few concern themselves with accuracy, but you must remember that there are those of us at the opposite end of the spectrum who enjoy shooting revolvers at longer ranges, and to do so effectively the bullets must behave properly.

 If you care to research the subject further, Dave Scoville, Brian Pearce, Mike Ventrino and the Cast Boolit website are great sources of information and learning.

 CHT

 

Offline Roscoe

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Re: .428 with .429 bore
« Reply #30 on: December 08, 2018, 11:07:10 am »
Hey all, i have decided to get chancey and go with a 44WCF revolver and Rifle combo. That being said ill obviously be reloading. The info i have found for the Cimarron Frontier is that its a .429 bore. I cant find any info on the bore size of the Short Rifle they sell. Regardless .429 has been near impossible to find online for a bullet, with .428 being the closest. Will .428 be okay for both revolver and rifle until i get to where i cast my own? Any potential problems? Thanks.


It is .430 bullets you need for a .429 bore, since you want to ensure a good bore seal on firing. My Uberti 1875 Remington Outlaw is the same, and its throats are too large for the .428 bullets I tried. I wound up with RCBS Cowboy dies (which are not carbide and require lubing cases). I had to get the expander plug for 44 Russian, Special, Magnum at .430. The chambers required that I trim brass to 1.290 or less and seat to a COL of 1.582. These passed both the cartridge gauge and the pistol chambers, so a rifle should accept them based on being in spec with the gauge. The bullets I use are the same profile and hardness that I use for 44 Special, and which others might use in 44 Russian. The bullets have to be flat nose in order to be shared for the rifle ammo.

Note that I do not size new brass, because the 44-40 dies would size it too small, expecting .428 bullets. The virgin Starline brass fits both the case gauge and the gun chambers, while taking on more of a necked shape after firing. The gun is remarkably accurate with these loads, so something is working.