Procrastinating on paper work... so I made a 357 mag and 9mm barrel graph from BBTI

One of my problems is that one way I procrastinate is to do something lower priority I feel like doing instead of the actual thing I should prioritize… So last night, instead of doing what I was supposed to do, I ended up making a graph using some data from BBTI for 357 magnum and 9mm barrel length.

I was curious to see at what point the rate of increase in velocity significantly slowed for typical 357 magnum ammo in regards to barrel length… and also did 9mm because “why not.” I think the data is from a TC Contender barrel, however since chamber length is included in the barrel length but it doesn’t have a cylinder gap, I’m hoping the numbers would be close enough to make some generalizations for a revolver.

I thought I’d post the graphs up in case other’s might be curious of similar or related things:

357 Magnum Barrel Length data from BBTI:

9mm Barrel Length data from BBTI:


@Scotty >>> can you tell what purpose you will the this data for ?

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It was more just to visualize the idea of the curve of barrel length vs velocity (and energy) in shorter barrels, and at what point the increase in barrel length slows. For example, going from 2" to 3" has a larger % increase than 5" to 6".

I guess it’s just to add to my reasoning if I pick up another 357 in the future. I’ve been eyeing the S&W 60, Kimber K6, Ruger SP-101, and the S&W R8 iterations. Or maybe to talk me out of them… I’m happy with my 2.75" 66-8 (although it’s still pretty large), and told myself at 5" I’d rather have another 44.

I figured the 9mm graph might talk me out of a LTT Centurion purchase, too, since I am happy with my M9.

Pretty much it’s just mental jibber jabber since I won’t be making any firearms purchases for awhile.

@Scotty >> is this for defense ?

I think it’s to justify buying a Marlin 1894 and a Ruger PC carbine. Scotty, consider yourself justified :+1::laughing:
And yeah, 2 to 3 inch is a 50 percent increase, whereas 5 to 6…isn’t :thinking:

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But, 6 inches is where the .357 is just starting to stretch its legs, so to speak.

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@mattm >> is that the 45 Colt 1894 ?

Not the one relevant to this post.
Visited these guys decades ago. They wanted me as a programmer for their coordinate measuring machine…2 month gig. Told them if I’m a temp, so are my programs :sunglasses:…hang on, brain fart, thinking of Winchester. Hard to believe all the gun manufacturers this stupid state lost.

That would be one reason… Again, just wanted to see what the graph looked like. More about just visualizing on some thoughts. Thought some might find the curves interesting. I’ll probably pickup a snub nose within the next few years, though.

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I definitely find curves interesting. :hugs:

You could substitute torque/horsepower and rpm and hit the car forums as well with your graphs.Multi tasking as it were. The bean counters would love that.

Interestingly enough, I should ask my friend what graphs and curves he assesses in making his 1,500-2,000 HP race cars. Good catch! I don’t understand anything about those programs for tuning though.

@mattm >> I have the Marlin 45 Colt. Very long story short. Get the 44 mag.
Don’t get me wrong. I also have a 45 real Colt 45 single action army and will never sell them but if you haven’t loaded for the colt I’ll tell you what to expect. Aside from that the Marlin 45 Colt can be loaded pretty hot. It’s the same Receiver for the 44 mag. ( tricks & tips ) let me know.

@Scotty >> the air Wait revolvers even in 38 special plus P are very snappy ( 23 oz ). My first choice is the Smith & Wesson model 442. Good to carry a lot and shoot a little. Try them before you buy them.

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Yes, but for example, from their data from the Fed Hydra-Shok 158gr, 5" to 6" is a 20% increase in length, but only a 6% increase in velocity and 12% increase in energy. 2" to 3" is a 50% increase in length, and a 22% increase in velocity and 51% increase in energy. And to add to that, 5" to 8" is a 60% increase in length, but only a 14% increase in velocity and a 29% increase in energy.

Therefore (since it is a curve and not linear), there is a point at which barrel length for increased velocity has relatively significant diminishing returns, which could be a factor in choosing compromises in weight and size for carry… which also changes with bullet weights.

I was looking for 2-5" differences, but since it wasn’t much more work to include lengths out to 18" I figured I’d include them in the graph. Also graphs sometimes suggest other info that wasn’t related to the original purpose. For example, I found the energy numbers of the 140gr interesting. I also thought it was interesting that the 110gr Corbon followed the 158gr curve (I think it is a practice ammo). I also found it interesting that the 9mm shorter barrels velocity increase was significnalty less steep. Although it would be logical that it would be.

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I think the aireweights are even lighter… at least that’s what they post on their specs (11.7oz PD version and 14.7 on the other). A few years ago I rented an airweight and shot 38 sp +P (can’t remember the grain) and decided that I needed more time with that weight class of revolvers before I would carry it… also with aftermarket grip options.

I don’t remember having any issues with a stock, steel, 5 shot (Taurus) I shot a few decades ago, but I’m pretty sure it was only 38 sp target ammo. I do remember that the ratchets on the star extractor were showing a lot of wear, even though the owner kept his firearms well maintained.

I considered the Model 36 at 19.5oz. I told myself I would wait until a 90’s snub nose Colt DS made it’s way to the used rack, but never followed up. I guess I’m afraid that it would become a safe queen, or would have repair issues if I shot it a lot.

I’m even considering the Taurus 856, but with so many posts on the internet of crane spring and screw issues, and the used one I saw at my local FFL had significant pitting speckled all over a SS version, I hesitated.

Then I figured if I was going for the steel snubs, I might as well get the magnum versions for increased ammo selection.

@Scotty >> 14.7 Oz is correct. Thinking of charter arms.

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