.357 3" or 4" barrel velocity
- Thread starter snubbyfan
- Start date
Don't worry about it one bit.
BBI (ballistics by the inch) can give you a very rough idea, but, individual chambers can vary by enormous amounts & individual rounds can also.
Its not unheard of to see 6 rounds out of the same gun vary by 100 fps - or more - using the same ammunition in each cylinder.
Anyhow - the old, old, old rule of thumb (from back int he days when a chronograph would set you back as much as a house - meaning, there was really no way for Joe Sixpack to verify anything)was - 50 fps loss or gain for every inch.
BBI (ballistics by the inch) can give you a very rough idea, but, individual chambers can vary by enormous amounts & individual rounds can also.
Its not unheard of to see 6 rounds out of the same gun vary by 100 fps - or more - using the same ammunition in each cylinder.
Anyhow - the old, old, old rule of thumb (from back int he days when a chronograph would set you back as much as a house - meaning, there was really no way for Joe Sixpack to verify anything)was - 50 fps loss or gain for every inch.
There is a huge difference between individual guns. If you study the BBI site you'll note that their 4" S&W shot faster than the 6" Colt they tested. And by a considerable amount. They have data in 2 columns. In one column all data is from the same test barrel as it is cut shorter. This data will show speeds slightly slower than from real guns. BUT since it is all from the same barrel the relative difference is MUCH, MUCH more accurate than the data from real guns.
Across the spectrum of loads tested you see 150-250 fps less speed from 3" compared to 4". As barrel length increases the differences get smaller. Once you get into rifle barrel lengths you often see 10 fps per inch differences, but with handguns barrel length is extremely important.
Magnum revolvers need barrel length to be effective. The load data you see listed in most ballistics charts is from 8" test barrels. A 4" barrel is already 1/2 the length of the barrel used to get data and will be significantly less. This surprises many people. But no one would be surprised to see that a 300 mag from a 12" barrel was significantly less than from a 24" test barrel.
Everything is a compromise, but 125 gr 357 mag fired from a 3" barrel will give you just about the same speed as 124 gr +P fired from a 4" 9mm. 357's fired from 2"-2.5" barrels are significantly slower than 9mm and 4" guns don't beat 9mm by much.
Across the spectrum of loads tested you see 150-250 fps less speed from 3" compared to 4". As barrel length increases the differences get smaller. Once you get into rifle barrel lengths you often see 10 fps per inch differences, but with handguns barrel length is extremely important.
Magnum revolvers need barrel length to be effective. The load data you see listed in most ballistics charts is from 8" test barrels. A 4" barrel is already 1/2 the length of the barrel used to get data and will be significantly less. This surprises many people. But no one would be surprised to see that a 300 mag from a 12" barrel was significantly less than from a 24" test barrel.
Everything is a compromise, but 125 gr 357 mag fired from a 3" barrel will give you just about the same speed as 124 gr +P fired from a 4" 9mm. 357's fired from 2"-2.5" barrels are significantly slower than 9mm and 4" guns don't beat 9mm by much.
Jim Watson
New member
What is it FOR?
That is still a pretty big gun and all a 3" barrel will do is clear a seat cushion when worn holstered and seated.
For shooting the 4" has longer sight radius and better balance.
That is still a pretty big gun and all a 3" barrel will do is clear a seat cushion when worn holstered and seated.
For shooting the 4" has longer sight radius and better balance.
TruthTellers
New member
Sometimes a longer barrel on a revolver doesn't necessarily mean greater velocity. A lot of that depends on how wide the gap is between the barrel and cylinder.
If this is for concealed carry, the 3 inch is fine. If it's for anything thing else, go with the 4 inch. Personally, I think 5 inch barrel revolvers, especially those .357 and under, are the best, but the 5 inch GP's are hard to find.
EDIT:
If this is for concealed carry, the 3 inch is fine. If it's for anything thing else, go with the 4 inch. Personally, I think 5 inch barrel revolvers, especially those .357 and under, are the best, but the 5 inch GP's are hard to find.
EDIT:
Get the 4 inch then.
riverrat38
New member
The Buffalo Bore website shows velocity from real guns.
One 357MGN example shows about 50 FPS difference between 3 and 4 inch barrels.
Here is a guy that really likes the 3 inch snub version.
https://www.youtube.com/watch?v=Nn2XX81_kPU
Best,
Rick
One 357MGN example shows about 50 FPS difference between 3 and 4 inch barrels.
Here is a guy that really likes the 3 inch snub version.
https://www.youtube.com/watch?v=Nn2XX81_kPU
Best,
Rick
Lots of testing done here.
I have a 3" bbl Smith 686+, and a 4" 686. And I have done a lot of real world chronographing with the two side-by-side with the same ammo.
Full throttle ammo using lighter bullets (125gn w/Power Pistol) or slower powders (158gn w/2400), the difference is about 90-95 f/s. Slightly "de-tuned" ammo using heavier bullets and intermediate speed powders (158gn w/HS-6), the difference drops to about 70 f/s. Faster propellants realize less difference: 125gn w/AA2 - 20f/s; 158gn w/AA5 = 40f/s.
Also of note: I have a 8-3/8" bbl 686 too, and have run the same tests. Usually, there is no velocity gain to speak of - but a few f/s over the 4". I strongly suspect the barrel/cylinder gap produces rapidly diminishing returns. I don't have a 6" 686, but I suppose that's probably the longest barrel that does much good in all but novelty applications (super light bullets w/super slow powders - that sort of thing).
I have a 3" bbl Smith 686+, and a 4" 686. And I have done a lot of real world chronographing with the two side-by-side with the same ammo.
Full throttle ammo using lighter bullets (125gn w/Power Pistol) or slower powders (158gn w/2400), the difference is about 90-95 f/s. Slightly "de-tuned" ammo using heavier bullets and intermediate speed powders (158gn w/HS-6), the difference drops to about 70 f/s. Faster propellants realize less difference: 125gn w/AA2 - 20f/s; 158gn w/AA5 = 40f/s.
Also of note: I have a 8-3/8" bbl 686 too, and have run the same tests. Usually, there is no velocity gain to speak of - but a few f/s over the 4". I strongly suspect the barrel/cylinder gap produces rapidly diminishing returns. I don't have a 6" 686, but I suppose that's probably the longest barrel that does much good in all but novelty applications (super light bullets w/super slow powders - that sort of thing).
I carry my 3" 686 in the cooler months (when I can layer up and conceal).
My 3" conceals much better than the 4". Not so much because of the barrel length; but because the 3" is a round butt, and the 4" is a square butt (all 686's currently in production are round butts). My 3" is a 7-shot; which also makes it more suitable for carry (IMO). And it's a great target shooter too. Now my 4" 686 is my favorite gun of my entire collection - it's an awesome piece. But the 3" is the more versatile gun. So if I could only have one or the other . . .
