Ruger Blackhawk 45 Auto Loads

By Jerrick Linde 

The Ruger only load, a somewhat mysterious term to those that are not familiar with Rugers or handloading.  To understand this term we need to look at a short history of Ruger firearms, mainly the Blackhawk line of revolvers.   

Blackhawk Historical Review

In 1955, Ruger introduced the Blackhawk revolver chambered in 357 Magnum.  This revolver had the classic styling of the Colt Peacemaker with modern improvements such as coil springs, adjustable sites, and a frame mounted firing pin.  These improvements over the traditional Colt Single Action made the Blackhawk a reliable and tough gun that appealed too many.    

The original Blackhawk had not even been out a year when Bill Ruger heard rumors of a new 44 caliber cartridge.  Ruger wasted no time in chambering his Blackhawk to the new most powerful handgun cartridge around, the 44 Magnum.  However, to do this he had to come up with an all new design.  The original Blackhawk .357 was too small to handle the size and power of the new 44 Magnum round.   So Ruger took the easy route and enlarged the existing Blackhawk design to handle the new cartridge.   

The Blackhawk 44 Magnum was an immediate success.  However, it did have its problems such as being too light to fully control the recoil of the 44 Magnum.  Many shooters complained that the recoil was too much so Ruger remedied this situation with the release of the Super Blackhawk.   

To create the Super Blackhawk, Ruger used the larger 44 Magnum framed Blackhawk and added on weight by switching the grip frame from aluminum to steel, adding a set of protective ears for the rear site, and equipped it with a non-fluted cylinder.  With these changes in place the Super Blackhawk handled the recoil of the 44 Magnum much better than the standard Blackhawk.  Sadly this meant that the original Blackhawk 44 Magnum would be discontinued at a later date as well as the original 357 Blackhawk, which was replaced by a model that had the same smaller frame size but incorporated the protective site ears introduced on the Super. 

In 1973 Ruger introduced the New Model Blackhawk and Super Blackhawk revolvers.  With the new models came the change to a transfer bar safety system and the elimination of all small framed Blackhawks. From this time forward until 2005 all Blackhawks regardless of caliber would be built on the larger 44 Magnum frame of the Super Blackhawk. In 2005 for a anniversary run of .357 Flattop Blackhawks, and uses this smaller frame size in the Ruger New Vaquero revolver.

From the mid sixties on Ruger increased the versatility of the Blackhawk and New Model Blackhawks by offering them as convertible models.  These models came from the factory with an extra cylinder chambered in a different cartridge of the same caliber as the main cylinder.  One of the convertible models that Ruger offers is the 45 Colt Blackhawk with a spare cylinder in 45 Auto.   

Terminology History

It did not take long for shooting enthusiasts to realize that the New Model Blackhawk was an overbuilt gun for some of the calibers it was offered in.  After all it was the same gun as the Super Blackhawk but with a few cosmetic differences.  Handloaders quickly took advantage of this strength by uploading certain cartridges to a much higher pressure.  By simply increasing the operating pressures of some older cartridges over what original guns could safely handle a large performance increase could be achieved while maintaining safety in the Blackhawk. 

Handloaders and handloading data publishers realized they needed a way to identify loads that were loaded to significantly higher pressures in old cartridge cases so they would not find their way into the wrong gun.  The term universally accepted was Ruger only load.  Since Ruger was one of the only companies building modern, very strong guns in calibers that were traditionally chambered only in older weaker designs, it was a Ruger only load because it would only be safe to fire it in a Ruger.

Typically a Ruger only load is one in which a low pressure cartridge is loaded to a much higher operating pressure that is still within the safety limits of the Ruger New Model Blackhawk.  These loads would be very dangerous to fire in the original firearm that they were intended for so care must be taken that this does not happen.  The 45 Colt Ruger only loads are probably the most well known.  There are also Ruger only .38-40 loads, .44-40 loads, and .32-20 loads.  Most of these cartridges were black powder cartridges and operate at very low pressures compared to most modern cartridges.  When carefully loaded to higher pressures these rounds get a large performance increase.   

The 45 Auto is not nearly as old as the 45 Colt or some of the other more common Ruger only loaded cartridges but it is very similar. Since it is chambered in the Ruger New Model Blackhawk and has a relatively low operating pressure, it is a candidate for Ruger only loading.   

Ok, why in the world would I want to load a Ruger only 45 Auto load?  Well for a few reasons. 

    1. 45 Auto brass is very plentiful and is less expensive than 45 Colt brass.
    2. The 45 Auto even with higher pressure loadings uses less powder than the larger 45 Colt.
    3. The 45 Auto with Ruger only loads would be a far more versatile cartridge.
    4. The best part, it will be fun working up some new loads.

I mainly want to save a buck or two but also have some fun.  I also realize that even with hot loads the 45 Auto will never be able to match the Ruger only 45 Colt loads the Blackhawk is also capable of firing.  However, a Ruger only 45 Auto load should provide a worthwhile increase in performance as well as making it a great understudy for the Ruger only 45 Colt loads.   Here is where I begin my search for the Ruger only 45 Auto load. 

Loading Data Selection

So where do we get load data for Ruger only 45 Auto loads?  Unfortunately you won&rsquot find it listed in any loading manual or in any online data.  Does that mean you should quit right now?  No, because there is a source of data that we should be able to safely use to load the 45 Auto to a higher pressure.  This data comes in the form of 45 Super data and 460 Rowland.  Both of these cartridges are related to the 45 Auto but operate at higher pressures.   The 45 Super is dimensionally identical to the 45 Auto, except it is slightly heavier and constructed to handle the extra pressure.  The 460 Rowland is also dimensionally similar to the 45 ACP but is slightly longer to prevent it from being chambered into a standard 45 Auto gun. Even though the 460 case is longer the rounds are loaded to the same over all length (OAL) as the 45 Auto so that the round will function correctly through properly modified and chambered firearms.  Thus the 460 Rowland has very close to the exact same interior volume as the 45 Auto.  

Establishing Pressure Parameters

Now that the reloading data has been selected, I need to establish a safe maximum working pressure.  This is very easy to deduce because the New Model Blackhawk 45 Auto cylinder can safely chamber and fire 45 Super ammo, which operates at 28,000 Cup.  The Blackhawk revolver is also capable of safely firing the 460 Rowland round or 45 Magnum by having the Ruger 45 Auto cylinder rechambered by a competent gunsmith to either caliber.  Both the 460 Rowland and 45 Magnum cartridges hit pressures of up to 40,000 Cup.  From this it appears a safe maximum pressure range is between 28,000 Cup to 40,000 Cup.  To me, the 40,000 Cup upper limit might just be a bit too much.  In order to add an extra margin of safety I decided to put the upper limit at around 35,000 Cup.   

For load data I went to Hodgdon’s online site and looked at data for the 45 Auto, 45 Super and 460 Rowland.  For these three cartridges I am mainly looking at Longshot powder.  At the time of this writing Longshot was the only powder Hodgdon had data listed for use in the 460 Rowland.  You can find this data at  Below you will find Hodgdons data for Longshot powder in these three cartridges.     I have highlighted loads that fall within the pressure range in the tables that should be considered maximum for Ruger only 45 Auto loads. 

45 Auto Hodgdon Longshot data

Bullet Start load Velocity (in feet per second) Pressure (in Cup) Max load Velocity (in feet per second) Pressure

(in Cup)

185 HDY JSWC 7.2 919 11,300 8.2 1,044 17,000
200 Spr JHP 7 918 13,300 7.8 1,013 16,900
230 HDY FMJ 6.3 848 14,100 6.8 908 17,200

45 Super Hodgdon Longshot data

Bullet Start Load Velocity (in feet per second) Pressure (in Cup) Max load Velocity (in feet per second) Pressure (in Cup)
185 HDY JSWC 7.2 919 11,300 8.4 1,120 20,100
200 Spr JHP 7 918 13,300 8.1 1053 20,100
230 HDY FMJ 6.3 848 14,100 7.3 959 19,800

460 Rowland Hodgdon Longshot data

Bullet Start load Velocity (in feet per second) Pressure (in Cup) Max load Velocity (in feet per second) Pressure (in Cup)
185 HDY JSWC 12 1,413 34,700 13.5 1,503 38,800
200 GR. SPR JHP 12 1,372 34,300 13.8 1,456 39,400
230 HDY XTP 10 1,207 32,200 12 1,336 39,200

By reviewing the tables you can see Hodgdon’s data using Longshot is very similar for the 45 Auto and 45 Super.  The 460 Rowland with its much higher operating pressure is vastly different and appears to be the data that I want to use as my baseline.  The starting loads for the Rowland will do exactly what I want for my Ruger only 45 Auto loads.   

Load Preparation

With the rapidly rising cost of reloading components I was only able to test two different jacketed bullets for my first batch of loads.  I used two different Montana Gold bullets: the 451” 200 grain flat point bullet and the 230 grain full metal jacket.  I tried to avoid any hollow point bullets for this test because most 45 Auto hollow point bullets are not designed for the velocities I hope to achieve.   

I loaded the bullets into once fired PMC 45 Auto cases using Hodgdon’s Longshot powder and used Winchester large pistol primers.  These are the exact same primers I use for hot 45 Colt loads as well as 44 Magnum loads.  For the powder charge I decided to work up to the max load established earlier.  For the 200 grain bullet I decided 1,300 fps would be nice goal to try and achieve.  Looking over the 460 data it appears 12 grains of Longshot should be able to get me there and still be easily within the safety margins of the firearm.  So 12 grains of powder is what I decided to work up to and call max for now with the 200 grain bullets.  I did the same process with the 230 grain bullet and decided 1,200 fps was a good goal.  Once again it appears the start charge for the Roland will work out very well as a load to work up to in achieving this goal.  For the cartridge OAL I went with what Hodgdon recommended for the 460 Rowland rounds, 1.270” for the 230 grain bullet and 1.225” for the 200 grain bullet.   

Testing the loads

My launching platform of choice for the load workup is a convertible Ruger New Model Blackhawk chambered in 45 Colt with a spare 45 Auto cylinder and 5.5 inch barrel.  To assist in the testing of these loads I used my Pact Model 1 XP chronograph to get some useful and comparable data at a distance of around 12 feet to make sure the muzzle blast would not affect the readings.  As far as muzzle blast there was a lot of it.  You will definitely want to wear ear muffs or plugs while working up any similar loads.   

For the data gathering, I fired 5 shot strings of each load for an accurate comparison.  Before firing any loads over the chronograph I first fired them off hand at 10 yards at a paper target to get an idea of where the bullets would hit.  I was surprised that all loads tested hit to the point of aim and would have made one large group if they were all fired at the same target.  I was also surprised at the accuracy of all loads fired.  One hole groups were the norm with all loads tested. 



One thing that I was very surprised about during the testing of these loads was the recoil.  I wasn&rsquot really sure what to expect when I fired the first rounds through the gun.  I did know from past experience with this gun and Ruger only 45 Colt loads that it could get brutal, so I made sure to wear my padded Uncle Mikes shooting gloves just in case.  With the gloves on the recoil seemed very mild even with the top loads.  The top 200 grain bullet loads did seem to be a bit snappier than the top 230 grain loads though.  In the end, the recoil actually seemed far milder than the recoil in the same gun with Ruger only 45 Colt loads.  This is most likely caused by the lighter bullets that I used for the Ruger only 45 Auto loads compared to what I usually use in Ruger only 45 Colt loads.  Another factor that contributes to less recoil  is that these loads use almost half the amount of powder weight wise as what a Ruger only 45 Colt load uses.  In the end it comes down to shooting anywhere from 35-65 grains less weight out the barrel with each shot compared to a Ruger only 45 Colt load.  That is enough to make a noticeable difference in felt recoil.   

When it came time to eject each fired case I was very pleased that they all easily fell from the chamber with little or no help from the ejector rod.  Every round fired also still had a nicely rounded primer.  All in all the brass and gun exhibited no signs of high or excessive pressure during the entire test.


As far as the velocity goals I am happy to say that they were achieved within the max loads that I settled on earlier.  One thing that I was very happy to see was that the loads I assembled using 45 ACP cases and 460 Rowland load data came within 20 fps of Hodgdon’s published 460 Rowland data with both bullet weights tested.  This indicates that the 460 Rowland loads in the 45 ACP case are operating at very similar pressures as what Hodgdon published for the 460 Rowland.  So these rounds should easily fall within the safety margins of the Blackhawk.  The table below shows chronograph data recorded from the test.  To conserve space I am only going to show the top load for each bullet tested as well as a standard 45 ACP load that was used as a base line for the test. 

Ruger only 45 Auto loads

Load 45 Auto

Standard load

45 Auto using Rowland data 45 Auto using Rowland data
Bullet 230 Rainer plated 200 gr Flat point 230 gr FMJ
Powder charge 5.8 grs Win 231 12 grs Longshot 10 grs Longshot
Velocity for shot #1 864.6 1378 1192
Velocity for shot #2 913.9 1383 1176
Velocity for shot #3 902.9 1413 1194
Velocity for shot #4 878.6 1394 1227
Velocity for shot #5 901.3 1392 1169
Average Velocity 888.66 fps 1,392 fps 1,191 fps
Standard deviation 26.79 fps 13.4 fps 22.4 fps

Need more data?

Want some loads using other powders?  For that you will need to look at other powder manufacturers load data for the 460 Rowland and adapt it to the 45 Auto case.  Just start low and work up.  A chronograph is an invaluable tool while doing this.  For this test I chose to start with Hodgdon’s Longshot powder because it has listed loads with pressure data for the 45 Auto, 45 Super and 460 Rowland.  This made it easy to establish some safe loads to start with.  Having a pound of Longshot donated to me for this test by John Knutson also helped me make the decision of what powder to start with.  Thanks again John.  In the future I will likely try out some other manufacturer’s data.  It seems to me that a good cast bullet would be ideal for these Ruger only 45 Auto loads and would make these loads a great understudy to the Ruger only 45 Colt loads.  In fact with these loads and a Ruger New model Blackhawk, the 45 Auto can easily be used as a hunting cartridge to take nearly any game animal in North America or as protection against wild animals. 

Safety Warning

Warning, these loads are safe only in Ruger New Model Blackhawk revolvers.  More specifically these loads were safe in my gun.  Do not use these loads or attempt to load the 45 Auto in the manner that I described with any other firearm chambered for the 45 Auto.  They are not as strong as the Ruger New Model Blackhawk.  The only other firearms these loads may be safe in would be a Freedom Arms model 83 with a spare 45 Auto cylinder, and large framed original Ruger Blackhawks with a 45 Auto cylinder. 


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