.45 Colt and.45 Casull cylinder throat diameters??

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Mus408

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The cylinder throats on my .45 Colt Ruger Bisley measure .451 and the throats on my
.454 Alaskan measure out at .455 diameter.

Shooting mild 850 FPS to Ruger type loads using my hard cast lead .452 diameter bullets,I get no leading in my Bisley or any of my other .45 Colt revolvers or rifles in the barrel.

Looking through my Lyman 49th loading book and my Speer book they recommend .451 diameter
bullets for the .454 Casull and of course .452 for Colt .45

When I shoot any of my hard cast bullets through my Alaskan I get leading,like I have mentioned before,in the area of the bore starting right after the forcing cone exit.

When shooting jacketed bullets in the Alaskan the bore is clean with no signs of heavy copper build up.

What is the correct throat size of the .454 Casull and why do the loading manuals specify .451 diameter bullets.

Some have said it could be a tightness in the bore where the barrel is screwed in the frame on the Alaskan. The short barreled Alaskan frame looks to be machined as one piece.
Is the barrel an insert that is pressed or screwed in and how would they grab the barrel insert to screw it in?
 

sasu

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My 454 Super Redhawk has 0.454" throats as measured with pin gauges.

I believe that is the reason for rather bland accuracy results as I cannot find ready made bullets with that diameter. All store bought bullets are 0.451"-0.452".

It has been suggested that the large 454 Casull throats in Rugers are done on purpose to limit chamber pressures in this high pressure caliber. The pressure peak is reached right about the time the bullet starts moving so the throat diameter probably has a measurable effect on the pressure peak level.

The Super Redhawk barrel is inserted in the frame, torqued in place and then the protruding part is just cut off and then the muzzle is crowned. That is how the process was explained somewhere.
 

Mus408

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So with lead bullets at any power level you would see leading due to the extra cylinder throat clearance giving blow by of hot gases?
My 315 gr. hard cast bullets do have gas checks but you still get the lead I assume due to the gases going on past the gas check.

The revolver shoots well for what it was designed for...high powered rounds within close distance.
 

Mus408

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Talked with Oregon Trail Laser Cast bullets today and they are sending me a free test pack of .452 and .454 bullets to try. Their testing shows the .454 cast bullet seems to work better in .454 Casull.
 

Snyd

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I took a cylinder from a SRH 454 and put in in my 4" Redhawk. I cannot push a .454 boolit through them. A .452 is a push fit. The chambers are also tighter than the 45 Colt cylinder that came out of RH. Fired 45 Colt cases will not go in the 454 Cylinder.

I don't buy the .454 throats for pressure reasons. The 6 shot 454 Cylinder is made from special 465 Carpenter steel. It was proof tested to 92,000psi.

http://www.modernapplicationsnews.com/articles/m0401stainless.htm
 

Mus408

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I don't by it either as in over sized throats to relieve pressure....maybe sloppy tolerances.
Do other brand .454 Casull revolvers have +.454 size throats?
 

Snyd

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Mus408 said:
I don't by it either as in over sized throats to relieve pressure....maybe sloppy tolerances.
Do other brand .454 Casull revolvers have +.454 size throats?

Question. How did you measure the 454 throats?
 

Mus408

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Snyd said:
Mus408 said:
I don't by it either as in over sized throats to relieve pressure....maybe sloppy tolerances.
Do other brand .454 Casull revolvers have +.454 size throats?

Question. How did you measure the 454 throats?

Hole gauge and micrometer.
 

Mus408

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Got my sample .454 bullets in from Oregon Trail and loaded up some to test tomorrow.

The .454 bullet will just slide in the throat of the Alaskan...not fall in like a .452

Will see if any leading develops after shooting these.

These are .45 Colt rounds consisting of the 255 gr. .454 diameter Laser Cast bullet over 9.5 gr. of
Unique. Typical easy plinking rounds I intend to use.
 
Joined
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Some current SAAMI diameters for the .45 Colt chamber . . .

Immediately adjacent to rim counterbore 0.4870" (+0.004")
0.200" deep from breech face 0.4862" (+0.004")
1.2949" deep from breech face (start of short taper to throat) 0.4800" (+0.004")
Throat (cylindrical) 0.4520" (+0.0075")

Cases are 0.480" cylindrical. (-0.006")

For the .454 Casull . . .

Immediately adjacent to rim counterbore 0.480" (+0.004")
0.200" deep from breech face 0.4797" (+0.004")
1.4070" deep from breech face (start of short taper to throat) 0.4775" (+0.004")
Throat (cylindrical) 0.4525" (+0.004")

Cases are 0.4775" cylindrical. (-0.006")

Just FYI.

Note that the classic check of throats is to slip a 0.451" jacketed bullet into the throat from the front and if it will slip thru the throat with little to no "push" it's pretty darn good. Most throat reamers are 0.4525" diameter.

:mrgreen:
 

sasu

Single-Sixer
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Mar 29, 2007
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We need "negative" reamers that take throats from 0.4540"-0.4560" down to SAAMI nominal 0.4525". I would pay $50 for such a reamer, maybe even $75.
 

Mus408

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Why can't Ruger just make the damn thing right to begin with??
A call to them tomorrow to explain themselves!!

Maybe they can fit a beefy .45 Colt only cylinder to it!
 

cas6969

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It's my experience that all Ruger 454 throats are slightly large, I assumed it was an extra safety margin to keep the pressure down.
 

Mus408

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That's what I have heard also. Do the other .454 revolver makers do the same?
 
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