info on pressure 45 colt

[Texas Jack Black]

I was at the range today and happened to witness a double charge of Unique shot out of a revolver .The shooter thought it was a little stout and we pulled the remaining bullets .and weighed them .The load was 14 grains of Unique with a 255 Keith SWC in 45 colt. Could anyone tell me why the gun did not blow? This load must of been well over 30,000.


T J B

 

[B.Roberts]

I'd be interested in what quickload would guesstimate the pressure of that load at. I would not expect a 30,000cup load to kablooey any modern colt sized sa. However, I would expect the gun to be damaged in short order. Just a guess on my part.

 

[Dale53]

Texas Jack Black;
Much depends on WHAT revolver it was shot out of.

Ruger Blackhawks, as an example, will easily take 30,000 PSI (not that I would recommend that charge).

Handloader #246 has a fine article by Brian Pearce on the RCBS 45-270-SAA bullet that rates single action revolvers into three strength classes:
1- 14,000 psi
2 - 20,000 psi
3 - 32,000 psi

Unique is often used with 10.0 grs in "20,000 psi" revolvers with a 250-280 gr bullet. However, I would never use as much as 14.0 grs in one of my guns (or yours, for that matter).

Heavier loads than 10.0 would be better served by appropriate charges of slower burning powders (my choice is H110/296 or WC 820).

While not recommended AT ALL, I am not surprised that the 14.0 gr charge failed to destroy the revolver (particularly if it is a Black Hawk .45 Colt). The Blackhawk is a 32,000 psi gun by Brian's rating.

On the other hand, just because someone "got away with it" does NOT mean it is suitable.

It's kind of like the "misguided" soul who drives a 100 mph through traffic on an interstate and gets away with it (once). It doesn't mean it's a good idea :roll:

Dale53

 

[Bucks Owin]

FWIW, I've shot 11 grs UNQ behind a 255 gr lead bullet for right at 1100 fps. Hodgdon data shows 11.5 grs with a 260 gr JSP going 1116 fps at 28.8K CUP. I don't shoot much UNQ anymore, I much prefer HS6 for that velocity neighborhood.....(And W296 for highest velocities)

14 grs UNQ is certainly too hot, but like Dale, I'm not surprised that a .45 Ruger handled that charge without incident...

 

[Texas Jack Black]

Much to my surprise this was a COLT SAA 3rd Gen This is why I am so baffled I checked and weighed the remaining 10 rounds all were 14 grains of Unique. :shock: :shock:

T J B

 

[Rclark]

Checking in with Linebaugh.... If this was a Ruger Blackhawk, 60,000 CUP was the pressure that 'blew up' a Blackhawk in .45 Colt. That is why around ~30,000 is used as a maximum 'safe' pressure... which of course is double the SAMMI pressure of 14,000. This was in CUP measurement instead of PSI, but for this discussion is 'roughly' the same.

Now if we use that same 'logic' to a Ruger New Vaquero, we know that around 20,000psi is safe in these revolvers. So one could speculate that around 40,000psi would blow it up. Haven't seen/heard the test done though ... just speculating.


Here is the article....

http://www.customsixguns.com/writings/dissolving_the_myth.htm

Does that help show why the gun didn't blow? Assuming this was a Ruger as posting here.....

 

[Texas Jack Black]

Checking in with Linebaugh.... If this was a Ruger Blackhawk, 60,000 CUP was the pressure that 'blew up' a Blackhawk in .45 Colt. That is why around ~30,000 is used as a maximum 'safe' pressure... which of course is double the SAMMI pressure of 14,000. This was in CUP measurement instead of PSI, but for this discussion is 'roughly' the same.

Now if we use that same 'logic' to a Ruger New Vaquero, we know that around 20,000psi is safe in these revolvers. So one could speculate that around 40,000psi would blow it up. Haven't seen/heard the test done though ... just speculating.


Here is the article....

http://www.customsixguns.com/writings/dissolving_the_myth.htm

Does that help show why the gun didn't blow? Assuming this was a Ruger as posting here.....

This was a COLT SAA :shock:

 

[SargeMO]

FWIW, I've shot 11 grs UNQ behind a 255 gr lead bullet for right at 1100 fps. Hodgdon data shows 11.5 grs with a 260 gr JSP going 1116 fps at 28.8K CUP. I don't shoot much UNQ anymore, I much prefer HS6 for that velocity neighborhood.....(And W296 for highest velocities)

14 grs UNQ is certainly too hot, but like Dale, I'm not surprised that a .45 Ruger handled that charge without incident...

+1 on all of that.

 

[Rclark]

How did I miss that :shock: . Yikes! I usually read the whole thread before I comment :roll: .

 

[Texas Jack Black]

The load was supposed to be 7 grains of Unique he loaded 14 gr he fired 3 rounds before stopping .
I also shoot Colts but limit my max load to 9 grains of Unique I knew there was a problem as soon as I heard and saw the gun roll.
I want to find out what the pressure of that load was .It seems that these New Colts are stronger than most think . I would not want a load over 9 gr.of Unique in my Colts.
Luck was with him today. The Colt went back to my loading room and was cleaned and checked out .I have now fired some loads through it at my indoor range and It is working great.


T J B

 

[un-ique]

QuickLoad show just a hair below 40K psi. This could easily vary by 10% or more depending upon a number of factors.

 

[Dale53]

I would say someone was EXCEEDINGLY lucky! Pretty much like firing three proof loads (at the minimum). Let's hope it didn't permanently stress (read: weaken) that revolver...

Dale53

 

[Texas Jack Black]

WOW ! I was sitting next to him . I would have thought that gun would have now been declared a parts gun.


T J B :shock:

 

[Jimbo357mag]

Two words 'Careless' and 'Lucky' 8) 8)

...Jimbo

 

[Bucks Owin]

Interesting pressure curve. Quickload is a cool program, wish I had it.. 8)