45 Colt vs 45 Win Mag pressures & velocity in Contender?

[EdK]

Looking at the Loadbooks USA comprehensive Contender reloading manual there is quite a bit of data on these two rounds. There is some data developed exclusively for the T/C on each round however much of it from the component manufacturers serves a dual purpose: Ruger revolvers in the 45 Colt and Wildey/Grizzly pisols in the 45 Win Mag.

One thing is clear: The 45 Win Mag in virtually all instances whips the 45 Colt. Now the 45 Win Mag is a much more modern cartridge loaded to a relatively high (for a handgun) SAAMI pressure limit (40,000 PSI). On the other hand the 45 Colt is ancient and is loaded to a wide variety of pressures depending upon the firearm. I do understand that the publishers of this data are already going out on a limb so to speak when publishing "Ruger-only" data knowing that someone could possibly fire it out of an heirloom 1st generation Colt SAA.

That said, is there really any reason why the 45 Colt cannot be loaded to match the 45 Win Mag in the Contender Only? And by that I am eliminating the Ruger revolver because even though I am not an authority I have read the writings of those who are generally respected among the sixgun community (e.g. John Linebaugh) who limit stock Rugers to around 30-32,000 PSI.

The only two significant variables I know of limiting pressure in the TC are (1) the amount of metal surrounding the chamber and (2) frame backthrust. Given a Contender in good working condition and either round chambered in a full diameter barrel what would be a reason why one could be loaded to significantly outperform the other? Actually, with the Colt case being longer it would seem to hold a slight edge...

Before anyone asks: No, I have not exceeded published data yet and probably would not without pressure testing. Even if it is never pursued I'd like to know the answer.  At any rate liability is all that comes to my mind as in what would happen when a 40000 PSI 45 colt round gets into an old revolver  :eek:

Ed

[skb2706]

Not being familiar with either my only guess would be that the brass or cross section of the case for the LC may be significantly thinner than the WM. As brass is also a determining factor in the max pressure level regardless of gun..........

[jlevach]

Would be my best advice given how pressure is handles in the R/C
Given factory new brass and the way the contender handles presure(based on the size of the case head and backthrust) I would say you can probably just about equal loads to each other in either caliber the 45 LC has the added advantage of being able to a much better roll crimp than the Win mag with its taper crimp thus at least theoreticly allowing a longer burn of the powder. I would say in identical barrels (10" bull 's) th two cartridges would be able to equal one another with carefull loading
Just my honest opinion after loading the 45 LC in everything from Win 94's to ruger blackhawks S&W n-Frames and contenders for well on 20 years.
Be carefull your milage may vary.
Jim L

[Lone Star]

Bob Hagel tested both cartridges in 10" Contendersabout 25 years ago and found that he could exceed velocities with the .45 LC by around 50-100 fps or so in his barrels.  This makes sense due to the larger case capacity of th e.45LC.  Brass strength was not an issue - he tested both cases for hardness and thickness and found the .45LC from Federal to be as strong or stronger than .44 Magnum cases.

Note that the .45WM is not loaded to 40,000 psi; it is 40,000 cup, a reasonable difference.  40,000 psi is 10% higher pressure than the max SAAMI pressure for a .44 Magnim.

[EdK]

Note that the .45WM is not loaded to 40,000 psi; it is 40,000 cup, a reasonable difference.  40,000 psi is 10% higher pressure than the max SAAMI pressure for a .44 Magnim.

Thank you for the observation and correction. I should know better than to throw those figures around casually as I'm well aware that CUP and PSI are not interchangeable. However even though the relationship is not linear, Piezo-derived PSI figures for a given cartridge always run higher than the cup figure for same so at least my error was in the conservative direction (e.g 40,000 CUP=40,000+X PSI).

So being a stickler for precision, we click on the Leverguns link for SAAMI pressures to confirm your 40,000 cup and yes you are correct. Then looking at 45 Colt (Ruger) we see 25,000 cup.

So 45 Win Mag pressure = 45 Colt (Ruger) pressure + 60%!!! Little wonder why the 45 Colt takes a whipping in comparison. But to the original point: in the Contender Only why should it have to?


Thanks for the dialogue thus far... Ed  

[MnMike]

(Caution, I am a lover of the unloved .45 WM)

Why bother? Get a .45 WM barrel.
- It is accurate
- Easy to load
- It packs a punch
- Doesn't kick too bad
- Used barrels can be cheap (check Eds)

JMHO

mike

[wheelgun]

(Caution, I am a lover of the unloved .45 WM)

Why bother? Get a .45 WM barrel.
- It is accurate
- Easy to load
- It packs a punch
- Doesn't kick too bad
- Used barrels can be cheap (check Eds)

JMHO

mike

I agree I bought my 45wm 14" in 2000 and love it.Very accurate with Blue Dot powder over 185gr-230gr bullets. :grin:
I have shot 45 acp in mine many times and they shoot well.They head space on rim and extractor ( i guess) too short to reach end of chamber.

[jlevach]

BUT these pressure were designed for Colt SAA type guns and those of equal strength. Whe the ruger blackhawk and the T/C contender came on the scene(as well as some custom 5 shot Sa revolvers) those pressure standards went out the window. You can now fint +p ans +P+ loads for the stronger 45 long colt chambered guns in various loadxing manuals which bring it up to almost any straight walled pistol cartridge and suppior to many. It keeps up with the 41 & 44 magnums easily as well as the 45 super and the 45 win mag. Major advantage to the long volt over the win mag is the crimp you can use on the case and avaiability of better bullets being avaiable able to take advantage of a good roll crimp instead of the winmags taper crimp. Other than this difference there is really no real advantage to either round. JMHO
Jim L

[EdK]

BUT these pressure were designed for Colt SAA type guns and those of equal strength.

Actually 25,000 CUP is "Ruger Only" territory. Colt SAA limits are way below this level. Hence the original question of why is the 45 colt limited to approx 25000CUP/30000PSI in the Contender Only if the Contender is factory-rated for the 45 caliber Win Mag @ 40,000 CUP?

Thanks to the discussion thus far I think I have my answer though: The 45 Colt's probably good for the same pressures as the Win Mag in the Contender Only except nobody's ever going to publish any load data to that effect.  

[Lone Star]

...and the reason they will not is because by convention, hot .45LC loads have been listed for the Ruger Blackhawk and the Contender.  The BH is limited to around 32,000 cup - tests above this limit have resulted in bulged or blown cylinders.  The Contender is not constrained to this level, but the chance for a miss-communication is too great to list 40,000 load data in the major manuals.

http://64.233.179.104/search?q=cache:oOZjS-cTftsJ:sixgunner.com/old_model/linebaugh/dissolving.htm++%22case+head+thrust%22++linebaugh&hl=en&lr=lang_en

[jlevach]

THIS: If the same barrel steel can handle the 45 win mag as well as the 45 colt and we already know the brass for both calibers is of equal strength then why would'nt the contender barrel be able to withstand the same pressures in both cartridges. Answer of course it can and with the roll crimp vs the taper crimp the 45 long colt is better able to give your more power with basicly the same loads. Will anybody ever publish this information in a loading manual? NO absoultly not the legal issues  would be killer since most folks just will not own up to their own mistakes. Its always somebody elses fault. As long as this mindset is in fashion all loading and firearms companys will have no choice but to cover their ass in any way they can. Its just a fact of life. This post is for information purpose only and any advice is taken at your own risk. JMHO
Jim L
Contender collecter/shooter 20 years
reloader  for 28 years

[Lone Star]

The strength issue with Contenders is the frame, not the barrel, just as the strength issue in .45 revolvers is the cylinder, not the barrel.  Early Contender frames stretched when exposed to high case head thrust - I know, I did it - but the barrel will not fail (unless it is the octagonal .45LC, the steel is less than 0.08" thick at the flats and I'll not load mine hot for that reason.)  It is case head thrust which matters in Contenders, and radial pressure (hoop stress) which matters in revolvers.

The .45LC has a greater case capacity so it can exceed .45WM velocities noticeably at equal pressures.  I use .454 cases cut to .45LC length and load the bullets out to 1.77" to maximize power further.  Power is comfortably over listed .45WM loads.  The Oehler M43 says the pressure is at .45WM levels.  The loads are IMO safe for me to use, but I'll not share them with others.

Contender shooter for 31 years....  

[jlevach]

frames react to pressure (backthrust is one reason you can load 223 up to higher pressures than say 44 mag in the same T/C frame) since the case size for the 45WM anf the 45 LC is esentually the same they should be able to operate at the same pressure levels(as you have proved with your own loads excedding the 45 WM loads using 45 colt brass) And of course we are talking bull barrels not the older octogon ones. these days i stick mostly to lower pressure loads. With the carpel tunnel i just don'r like or need the recoil of the T/C with heavy loads. Personally I'll stick to the 22, 32 H&R, 38 spec, 357 max(not bad in the 9" barrel with the KBI muzzle break, 45 colt(cowboy loads) 410, 9mm, 223,30-30(surprisingly light recoil in my 14" barrel) and leave the 44 mag to my Super Redhawk
Which handles the 44 magnum recoil easily with its huge size and weight.
I'll stick to 357 in my N frame revolvers.
Jim L

[EdK]

Well, it looks af is at least a couple of forum members have reasonably proven that the limits on published TC load data are there primarily for Ruger revolver users. It certainly makes sense that the Contender would be stressed similarly regardless of 45 Colt or 45 Win Mag.

Interesting that it is suggested that the 45 Colt can beat the 45 Win Mag in the Contender.

Thanks again for the posts. I don't really know where this is taking me... I've always been interested in getting some pressure measuring equipment. On the other hand I don't know that I was originally ever looking to load to 45 Win Mag velocities - let alone exceed them. The differences in data was so great I was mainly looking to understand it.