296 in Short Barreled 357

[cooper]

Has anyone loaded Winchester 296 in a short-barreled 357 Magnum?  I have a S&W Model 66 with a 3" barrel.

Any comments?  I imagine it would have a huge flash, and be extremely loud.   I use 296 in my 6" 44 Mag, and love it, but wonder if the ballistics are still good in the shorter barrels.  

Can anyone recommend any powder that gives you a high velocity (with 158 gr. bullets, both cast and jacketed), with minimal muzzle flash?

[Questor]

No practical experience, but I did read an article on it recently and it seemed that faster powders are a better choice if highest velocity is desired.

[Reed1911]

In a 3" barrel you are just going to have to accept the flash, the faster powders will reduce it, but it will always be rather significant with full loads. I'd go to something in the AA#9 or HS-7 range for the powder. H110 and W296 are just too slow to be efficent in a 3" barrel.

[PaulS]

The test results that I have read and the test printouts that I have seen show that the highest pressure occurs in the first couple of inches of the barrel even with the slowest burning powders. Even with the slowest burning powders it is all burned within an inch of the chamber. If you have a barrel that is longer than 2 inches your 270 is burning all the powder in the case. That muzzle flash is because of the super heated gasses that are escaping before they have time to cool. Do you lose velocity with a shorter barrel? YES! the hot gasses continue to push against that bullet as long as the pressure generated is higher than the drag on the bullet in the barrel. Can you get some velocity back by using faster burning powders? NOT according to the studies that the NRA, Hodgdon powder company and a few others have published throughoout the years. If you could, then they would be listed as such in the manuals. Do you lose muzzle flash with faster powders? YES! the pressure drops off faster and with that pressure the temperature drops too! That pressure drop is also what keeps you from getting more velocity with the fast powder than you get with the sloiwer burning powders. The best powder for any load depends completely on the weight of the bullet and the available space for powder. You can only use so much powder until peak pressure goes over what is safe so you can't put 40 grains of Bullseye in a 270 with a 4 inch barrel and get good velocity before it turns into a hand grenade. By the same token you can't get enough of H450 into a 38 special case to get the pressure high enough to push a bullet fast enough to make it worth doing.
The powders that give the highest velocity will always give the highest velocity - regardless of the length of your barrel!

[Reed1911]

mmmm...yes and no, mainly yes except for certain calibers in certain guns, but that is a very small argument point. My response was pointed to efficiency, not merely speed. There is no reason to use 5g more powder to double the muzzle blast and only increase the speed by 20FPS. Faster powders in shorter barrels will almost always be more efficient.

[PaulS]

Reed1911,

I don't know how you measure efficiency but I am willing to bet that if it is on velocity per grain of powder the fastest powders are the most efficient regardless of barrel length. The problem is that the diference in velocity is 200 FPS from the fastest to slowest burning powders. The difference in a max load of 296 or H110 and the next fastest powder is a 40% drop in powder with 35 fps drop in velocity using AA5. The next 40 fps drop in velocity is using H. Universal with a further 25% decrease in powder charge. Another 30 fps drop in velocity with a half grain drop in powder charge with the fastest powder (in this manual) 231.
from 1217 fps down to 986 fps and from 15.5 grains to 6.8 grains. So yes, the most "efficient" powder is the fastest powder. If you are only putting holes in paper you can make it even more efficient by dropping the charge down to 5.5 grains of the fastest powder.
I measure efficiency a bit differently - What powder will give me the most accurate rounds that will most effectively kill what I am shooting at. With the 357 being a marginal cartridge with which to hunt I need all the velocity I can get in an accurate load. I use H110 (W296) because it does the job well on both counts.

[j two dogs]

Yes I've tried it. And yes I don't have any eye brows left. I tried it in my Ruger sp 101 with 3 incher. I've settled on titegroup the nitrocellulose based powder burns efficiently with very little muzzle flash.

[Bullseye]

Heck, I will not load 296 in a 10" Contender Barrel, or any caliber that it is suited for.  The muzzle blast just does nothing for me, and the shorter the barrel the worse it gets.  I know the 296 gives more velocity than the other powders and accuracy is always better in my guns, but if I want to cook hot dogs I will use a grill, not the muzzle flash off my gun loaded with 296.

[Jerry Lester]

The test results that I have read and the test printouts that I have seen show that the highest pressure occurs in the first couple of inches of the barrel even with the slowest burning powders. Even with the slowest burning powders it is all burned within an inch of the chamber. If you have a barrel that is longer than 2 inches your 270 is burning all the powder in the case. That muzzle flash is because of the super heated gasses that are escaping before they have time to cool. Do you lose velocity with a shorter barrel? YES! the hot gasses continue to push against that bullet as long as the pressure generated is higher than the drag on the bullet in the barrel. Can you get some velocity back by using faster burning powders? NOT according to the studies that the NRA, Hodgdon powder company and a few others have published throughoout the years. If you could, then they would be listed as such in the manuals. Do you lose muzzle flash with faster powders? YES! the pressure drops off faster and with that pressure the temperature drops too! That pressure drop is also what keeps you from getting more velocity with the fast powder than you get with the sloiwer burning powders. The best powder for any load depends completely on the weight of the bullet and the available space for powder. You can only use so much powder until peak pressure goes over what is safe so you can't put 40 grains of Bullseye in a 270 with a 4 inch barrel and get good velocity before it turns into a hand grenade. By the same token you can't get enough of H450 into a 38 special case to get the pressure high enough to push a bullet fast enough to make it worth doing.
The powders that give the highest velocity will always give the highest velocity - regardless of the length of your barrel!

I've actually experimented in depth on this subject, and yes, in this case as well as in most, this is true. In small bore bottle neck cases though, it often works a lot different. It's way to involved for me to "single finger" type it here, but here is one case of it...

I was loading AA-2015 with 40g Balistic Tips about 12-14 years ago in a Browning A-Boly II Varmint(it's what started my little study). I actually ended up loading in 1 tenth increments to watch the velocities. After I reached my maximum velocity, it started falling off with each additional tenth. The only conclusion I could come to was that unburned powder was compressing against the base of the bullet, adding weight, and friction, therefore reducing my velocity.

I set up a backstop made of various materials untill I found a combo that would catch the powder exiting the barrel, and just as I thought, the amount of powder leaving the barrel was higher in direct relation to increases in my charge weights. I tested it over, and over, and came up with exactly the same results.

This alone proves to me that all the powder is not burned up in the first few inches with some combinations. I've since found quite a few similar situations using slow powders in various other bottle neck rounds.