Author Topic: Bore diameter?  (Read 2782 times)

Offline BOOMSTICK BRUCE

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Bore diameter?
« on: December 06, 2016, 05:14:01 PM »
What is the average chamber diameter of a .460, 454 and 45 colt? I'm getting ready to bore the conversion cylinder out on my avenging angel Walker to chamber 460 and 454 cases but need to know what bit size I need.
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Offline prof marvel

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Re: Bore diameter?
« Reply #1 on: December 06, 2016, 11:22:54 PM »
My Dear Bruce -
In the bad old days Clymer Reamers had all the dimensions on their website, but alas, no more.

I was able to find the dimensions for .45 Colt for you:

.45 colt cartridge dims


.45 colt chamber dims


from this you can see the chamber web is .487" whilst the cartridge web is .480"
so you see the chamber needs to be "slightly" larger than the brass for clearance.

note also the very slight chamber taper from web ( .487" ) to the neck ( .480") but you can probably get by without the taper.

these dimensions are rather accurate so you should not rely on a drill bit, but you should use more precise reamers.
For a straight walled cartridge, you ought to  get a smaller "straight roughing reamer" and the final straight  "finish reamer"
for a reasonable price off ebay.

hth
prof marvel
« Last Edit: December 06, 2016, 11:25:26 PM by prof marvel »

Offline mazo kid

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Re: Bore diameter?
« Reply #2 on: December 08, 2016, 09:48:48 AM »
Bruce.....to what purpose are you wanting to do this? You are limited as to COL by the length of the cylinder as it is. Maybe it is to be able to load heavier boolits in the 460 and 454 cases? You would still need to trim the longer cases to 45 Colt length.

Offline mazo kid

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Re: Bore diameter?
« Reply #3 on: December 08, 2016, 09:53:34 AM »
Oh, and the 454 boolits would be OK, but the 460 ones would have to "squish" down a bunch, raising pressures a lot.

Offline prof marvel

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Re: Bore diameter?
« Reply #4 on: December 08, 2016, 12:50:42 PM »
I "think" Bruce is looking into the straight-walled cases in the ".45 Colt brass family" that include the .45 Schofield, the .45 Colt, the .454 Casull and the 460 S&W  in order to ream the cylinder for a ".45 Express BP Cartridge" experiment.

here's more poop
https://en.wikipedia.org/wiki/.460_S%26W_Magnum

a .45 colt finish reamer runs ~ $85 from brownels

ooooooohhhhh this thread discusses rechambering a cylinder and has links to the SAAMI specs for both cartridge & chamber!
note that the Casull & .460 chamber dims are "tighter"
http://rugerforum.net/ruger-single-action/36699-reaming-cylinder-45-colt-not-45-colt-reamer.html

here's the important stuff:
snip-----------------------------------------------
JTknives, You are right ... the 45 Colt chamber dimensions haven't changed since the cartridge was invented in the 1870's. The origional 45 Colts used .454~455" bullets so the chamber had to be large enough in diameter to accommodate the larger bullets plus the thickness of the case. Now that industry standards for 45 cal bore diameters are .451", jacketed 45 cal bullets are now .451" and lead bullets are .452". That means there is about .003" of excess chamber diameter at the mouth and even more at the case head because the origional chambers had a slight taper. This doesn't seem to bother accuracy much but cases will last longer if they don't swell up as much.

Yes, it does get a bit confusing .... there are actually two forcing cones ... one in the barrel mouth that everyone knows about and another inside the chamber. The cone inside the chamber is a transition from case diameter to bullet diameter (.4805 to .4525" in a 45 Colt chamber). This cone is vital if you shoot ammo with shorter cases ... such as a 45 Schofield in a 45 Colt or a 45 Colt in a 454 Cas.

Here's my recommendation: If you plan to shoot lead bullets, use the 454 Cass chamber reamer but control the depth to 1.290". Use a .4525" throat reamer. If you plan to shoot exclusively jacketed bullets, the .460 S&W reamer can be used, however the chamber will likely be too tight for lead .452" bullets. Don't worry about the angle of the internal cone ... either will work just fine. "

http://www.saami.org/PubResources/CC_Drawings/Pistol/45%20Colt.pdf
http://www.saami.org/PubResources/CC_Drawings/Pistol/454%20Casull.pdf
http://www.saami.org/PubResources/CC_Drawings/Pistol/460%20SandW%20Magnum.pdf
endsnip-----------------------------------------------

4D will rent you a reamer for ~ $33 plus "stuff"
https://www.4-dproducts.com/displayitem.php?rowid=263&tname=rental

and you can frequently find good stuff on fleabay:
http://www.ebay.com/itm/231982727944?ssPageName=STRK%3AMEBIDX%3AIT&fromMakeTrack=true
http://www.ebay.com/itm/NEW-SURPLUS-MOHAWK-USA-485-CARBIDE-TIPPED-STRAIGHT-SHANK-REAMER-/331478215702?hash=item4d2da42c16:g:CIMAAOSweW5U3Pr6

searching for specific diameters is tedious, but fruitful


ooooohhhhhhh
here is a cheap one that gets you REALLY close - 31/64:
http://www.ebay.com/itm/Lavallee-Ide-31-64-0-4844-12-303-mm-4-Flute-Straight-Chucking-Reamer-8-Loa-/232157181652?hash=item360da576d4:g:rmoAAOSwGtRXw5gs

hope this helps
prof marvel
« Last Edit: December 08, 2016, 01:11:49 PM by prof marvel »

Offline mazo kid

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Re: Bore diameter?
« Reply #5 on: December 11, 2016, 10:46:49 AM »
I "think" Bruce is looking into the straight-walled cases in the ".45 Colt brass family" that include the .45 Schofield, the .45 Colt, the .454 Casull and the 460 S&W  in order to ream the cylinder for a ".45 Express BP Cartridge" experiment.

I understand, but my point is that I don't see much velocity change over the 45 Colt case. Yes, the case of the 460 is slightly bigger, bullet is bigger, but not much increase in powder capacity. As I said, by reaming the chambers to 460 size, you are weakening the chamber wall and increasing pressures by using a larger, heavier bullet. But, I could be wrong....


Offline mazo kid

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Re: Bore diameter?
« Reply #6 on: December 11, 2016, 12:28:31 PM »
Guess I was just talking off the top of my head....did some reading and find the 460 cartridge uses .454" bullets. So, if Bruce wants to experiment with an "Express" load, he would use a lighter than normal bullet?

Offline BOOMSTICK BRUCE

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Re: Bore diameter?
« Reply #7 on: December 23, 2016, 05:40:39 PM »
So the thought here is .460 cases loaded with 60 grns of trip 7 with a 250 keido out of my Walker. Give the converted Walker back the punch is supposed to have instead of watered down .45 colt loads... Converting a Walker to .45 colt basically powers it down by 25%...
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Offline 45 Dragoon

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Re: Bore diameter?
« Reply #8 on: December 23, 2016, 06:27:55 PM »
I don't know Bruce, a 250gr lead slug moving 1014 fps is pretty decent! That's out of a 7 1/4" test bbl.  So, a Walker length bbl. would add a snick to that. That's from a top load with CFE pistol with 1000 psi to spare.  (You can shoot those in a Dragoon too  .  .  .  lol !!!)


Mike
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Offline AntiqueSledMan

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Re: Bore diameter?
« Reply #9 on: December 30, 2016, 05:57:07 AM »
I think Bruce wants a .45BPM. I even thought about doing that one.
The thing that really scares me with that one is the fact that Factory
Loaded Ammo would blow it to smithereens. Not that Bruce or any
other Black Powder shooter would intentionally load it with a Factory
Load, there are a lot of "Ignorant People" out there.

Offline ssb73q

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Re: Bore diameter?
« Reply #10 on: December 30, 2016, 06:35:39 AM »
I don't know Bruce, a 250gr lead slug moving 1014 fps is pretty decent! That's out of a 7 1/4" test bbl.  So, a Walker length bbl. would add a snick to that. That's from a top load with CFE pistol with 1000 psi to spare.  (You can shoot those in a Dragoon too  .  .  .  lol !!!)


Mike
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Follow me on Instagram @ goonsgunworks

Hi Mike, I understand that modern .45 Colt brass can be loaded up to .44 Magnum energies with lower pressures. Of course you need a beefed up revolver to use those loadings, like the big Rugers.

Regards,
Richard
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