confusing ballistics .357 rifle vs pistol

[1sailor]

I'm buying a Ruger .357 carbine and while looking at the velocity comparisions on the Hodgdon website it seems a little confusing to me. In comparing the same loads, rifle vs pistol, I'm seeing some where the exact same load is shown producing less velocity through the carbine then through a pistol. Also, it appears that there is only a noteworthy difference between them when shooting lighter bullets. Even then, with only a couple of exceptions the spread is really not what I would have expected. I have read several articles and comments by owners that the .357 really comes into it's own when fired from a rifle but that's not at all what I'm seeing at Hodgdon's site. Anyone here reload for a carbine and maybe have some input on this. Kind of looks like the biggest difference is just better bullet placement with the carbine and even then perhaps only over 50 yards or so.

 

[colt_saa]

I bet you are reading the pistol vs. rifle loading data sections for this data. You need to see what the test barrels were for the measurements in each section. Remember,you are looking a different data taken by different technicians on different days with different test barrels.

All else being equal, the same load when fired from a longer barrel will achieve more velocity.
Slower powders do better in longer barrels. There is point when a very fast powder in a long barrel has diminishing results, but this is the exception and not the rule.

The following measurements of Factory ammunition were all taken under the same condition on a single day

Remington 125 JHP
3 1/2" S&W 27 - 1315 FPS
8" Python - 1599 FPS
20" 1982 - 2192 FPS

Hornady 158 XTP-HP
3 1/2" S&W 27 - 1219 FPS
8" Python - 1383 FPS
20" 1982 - 1744 FPS

Winchster 180 Black Talon
3 1/2" S&W 27 - 1085 FPS
8" Python - 1170 FPS
20" 1982 - 1532 FPS

 

[Fishinfool]

Without looking at the H site, I am guessing they may be loads using fast powder. I know for a fact that heavy loads of slow powder like 296, that give a 158 grain jacketed bullet about 1300 to 1400 in a revolver will do more like 1800 fps in my Marlin lever action.

Same with various slow powder loads in .44 mag.

Larry

 

[Rule3]

You must not be comparing apples to apples.

Take the king of magnum powders H110 and a acommon 158 gr XTP

From a 10" test barrel (pistol) who has that? they get 1591 fps

From a 18" rifle barrel they get 1757fps

Same powder charge.

 

[1sailor]

Not sying there is NO difference. Only that the differences seem to be less than many have indicated. With the same load of H110 behind a 158gr XTP you have 166 FPS increase in the 18.5" carbine as compared to their 10" test barrel (I do agree that a 10" test barrel is far removed from real world firearms). While that is an increase it's also about the most wxtreme increase until you get into the lightweight bullets. If you go with anything much faster than H110 the numbers start becoming a lot closer together. So I guess the main factor here seems to be that in order to gain any real increase you have to limit yourself to slow powders. That same bullet with titegroup shows a marked loss in velocity from the carbine. Just too fast of a powder I guess.

 

[ironhead7544]

A solid 10 inch barrel will give about 300 fps more velocity than a 4 inch barreled revolver with 158 gr full loads in 357 Magnum.

Check some other manuals.

 

[Rule3]

Not sying there is NO difference. Only that the differences seem to be less than many have indicated. With the same load of H110 behind a 158gr XTP you have 166 FPS increase in the 18.5" carbine as compared to their 10" test barrel (I do agree that a 10" test barrel is far removed from real world firearms). While that is an increase it's also about the most wxtreme increase until you get into the lightweight bullets. If you go with anything much faster than H110 the numbers start becoming a lot closer together. So I guess the main factor here seems to be that in order to gain any real increase you have to limit yourself to slow powders. That same bullet with titegroup shows a marked loss in velocity from the carbine. Just too fast of a powder I guess.

You pretty much answered your own question. For true magnum loads the SLOWER powders are what produce the pressure and velocity. Thats why they are Magnum powders. 2400 will be about the same and easier to work with, you can download it more and it uses regular primers.

If you chronograph that H110 load out of a real pistol of 4 or 6" compared to the carbine there is way more velocity spread. Several hundred fps is a lot.

Whatever is fastest in a short barrel will be fastest in a long one.

 

[IraIII]

Do a search for "Ballistics by the inch". That will take you to a site where they test loads in barrels by firing, then cutting an inch off. In any situation there is always an exception, when the powder and resultant gases are no longer expanding any further travel in a barrel with the friction will slow the bullet down. How long of a barrel would be different for each different load.

 

[Neumann]

Without looking at the H site, I am guessing they may be loads using fast powder. I know for a fact that heavy loads of slow powder like 296, that give a 158 grain jacketed bullet about 1300 to 1400 in a revolver will do more like 1800 fps in my Marlin lever action.

Same with various slow powder loads in .44 mag.

Larry

This! The same is true for 2400 powder. A fast powder might burn completely in less than 10" of barrel. Beyond that, the gas would cool adiabatically, reducing the pressure and possibly slowing the bullet due to friction.

There is little or no muzzle flash from a hot 2400 load in a 20" barrel, but the velocity is roughly 300 fps faster than through a 4" barrel.

 

[rwsmith]

My formula for a test barrel

The shortest pistol barrels in general use are 2" long. The longest are (generally) 8 3/4" long. There are carbines with 16" barrels. What does a 10" barrel relate to? Nothing except a few pistols that few people own.

Why not make the test barrels like........5", and extrapolate for a longer/shorter barrel that's off by a few inches instead of 6" or more?

Do the manufacturers want to supply data to customers that relates to nothing in the real world? Perhaps by making it 'mysterious' and difficult to cipher they can make whatever claims they want and nobody can dispute it unless they are running a 10" test barrel. Maybe they are concentrating on data for the Thompson/Center crowd.

 

[1sailor]

IraIII, thanks for the tip regarding the "Ballistics by the Inch" site. Very revealing. Especially when looking at test results with real life firearms rather then "test barrels".

 

[Rule3]

Some manuals actually use real guns for their tests so the results are more likely to be real world.

 

[MarkDozier]

i have just worked up a load for the hornady 158 gr. XTP. My 1894 makes an average of 1727 fps. 14 grains of 296.
have not chornd the pistol but it shoots good.

 

[muddocktor]

I did some actual testing of this around the first of March and posted my results over at the 1911 forums. I was actually testing results between jacketed bullets and Hi-Tek coated lead bullets, but did the testing in a Model 27 (vented 6 1/2" barrel) and my old Rossi 92SRC carbine (non-vented 20" barrel). My loads were with 16.3 grains of 296 and the bullets used were Zero 158 grain JSP for jacketed bullets and Bayou 158 grain coated SWC bullets. I found that the coated SWC bullets averaged 83 fps faster in the pistol than the jacketed bullets and 66 fps faster in the rifle than the jacketed bullets. The coated lead bullets averaged 528 fps faster in the rifle compared to the pistol and the jacketed bullets averaged 550 fps faster in the rifle than the pistol.

The coated SWC bullets averaged 1234 fps out of my pistol and 1762 fps out of the carbine.

I imagine that if you were loading with a much faster powder such as Unique, you wouldn't see as big a velocity difference, but with your true magnum class powders you are going to see a decided difference in velocity when going from a pistol to a rifle with the same load.

 

[alwslate]

When I look at load data on the Hodgdon website or in their manual I
only look at their stated velocities to see how the different powders
compare. Their test barrel velocities for handgun rounds have no
relevance to the real world where revolvers are used.

 

[1sailor]

I agree that their test barrels have little relavence to real life. However it should still consistantly show differences in velocity with the same loads in longer barrels. I'm guessing that they use long test barrels to inhance the appearance of their powders. At least on paper.

 

[scooter123]

I agree that their test barrels have little relavence to real life. However it should still consistantly show differences in velocity with the same loads in longer barrels. I'm guessing that they use long test barrels to inhance the appearance of their powders. At least on paper.

People do tend to purchase powders based on the velocities they see in the reloading guides, so powder manufacturers do Hype their data by using longer than normal barrels. In addition I sort of suspect that they use the "fastest" barrel they can find, because I've seen some handgun data I can only match using a rifle.

Vihtatvouri claims 1050 fps from one particular recipe I use for 38 special with a 7.7 inch barrel and out of my 6 inch Dan Wesson that load only yields 800 fps. That barrel has to be lined with ball bearings or something like that to get that much gain out of a measly 1.7 inches. BTW, same load produces 1150 fps from my 20 inch Winchester.

As for your initial query, I can tell you that Hodgdon's Handgun data is VERY inflated and I suspect their rifle data was flat out made up. As for why, I run a 14.8 grain load of H110 in my Winchester and Rossi rifles and it averages 1615 fps. from a 20 inch barrel. Out of a 6 inch Dan Wesson revolver that same exact load only produces 1200 fps. BTW, this particular load has proven to be the most accurate load I've worked up for my Winchester and the initial data set came from Hornady.

 

[Engineer1911]

From back in the 1980 to 1995 time frame, I used IMR-4227 in 357 and 44 mag loads for lever action rifles. I bought 1# as an experiment for higher velocity when I first got my chronograph. My Marlin 44 mag got higher velocity, but the accuracy did not improve.

 

[Mcwsky09]

Several hundred fps is a lot.

Feet Per Second to Miles Per Hour | Kyle's Converter

Every 150fps of additional velocity is an extra 102 miles per hour.

So 1200 fps vs 1350 fps may not sound like a lot - but it is 102 mph difference. Sure 1200 fps is already 818 mph and 1350 is 920 mph but it is also about 135 additional foot/pounds of energy, using a 158 grain projectile, which is about 25% increase despite only a 12% increase in velocity since energy involves multiplying mass and velocity.

ENERGY CALCULATOR

 

[old&slow]

My data shows about a 400 fps. gain using the same load out of a 3" GP100 -vs- a 16" Rossi carbine.

158 gr cast loaded with 2400:
1243 fps out of the 3" ,, 1677 fps out of the 16"

158 gr cast loaded with WC820:
1116 with the 3" ,, 1561 fps. with the 16".

158 Speer JHP loaded with W296:
1183 in the 3",, 1645 fps. in the 16"

Those 3 are the only comparison data I have..