4"-8" Wadcutter Velocity?

J

justinr1

New member
Guys, as some of you know, I am about to receive a Python 8" in .38 spl only. I've already decided that this gun will be fed lead only. As I remember, it used be that the velocity of a wadcutter would be measured out of a 6" barrel. Now, most of what I see is listed out of a 4". I'm planning on experimenting with every commercial 148 wadcutter I can get my hand on. My question is this, will I still see a significant increase in velocity out of a 8", or is the powder completey optimized for a 4"?

justinr1
 
there's quite a lot of wadcutterism on this page -the wadcutter article and the one about ruger double actions. I've generally gottne about 740=50 with factory loads from 6" smiths and rugers and the 2.8 grain load seems very close
http://www.milesfortis.com
then go to the "guests" page.
 
Ok, I should have re-worded by statement. I don't necessarily want to see a MAJOR increase in velocity, just not less. Saying that, I would not cry if I got an extra 50 fps out of it.

Let's face it, I really need to get a chronograph this year. I don't plan on re-loading, but knowing my performance out of factory can't be a BAD idea. Maybe I can ANSWER some questions instead of ASKING all the time!

justinr1
 
With wadcutters I would expect a slight increase in velocity. A bigger increase in velocity would be seen with Magnum loads. I think an 8 inch barrel would be the ideal length for maximum velocity with most Magnum revolver calibers and still be a convenient sized handgun. I always wanted a Ruger GP-100 with an eight inch barrel just to see what it could do.
 
I get maybe 20 feet per second more from a 6" gp than from a four using these loads using bullseye and unique.
 
Velocity vis a vis Barrel Length

As a general rule, as the barrel lenght increase, velocity will increase around 40 fps per inch of additional lenght.

Naturally, there is a point of diminishing return, but I don't know what it is... probably greater than a revolver/pistol would reasonalby have.

So, going from 4" to 8" will improve arpimd 160 fps.

FWIW

Chuck
 
Hmmm...... Funny you'd ask that particular question.

When it recently occured to me that I had .38's in 2, 3, 4, 5 & 6" lengths, the light bulb suddenly got a little brighter. :rolleyes:

As soon as I get a combination of good weather and some spare time, I'm gonna sit down and chrono my 148 HBWC load (2.8 Bulleye) in all five guns just to see for myself just how much difference an inch of barrel length really does make. ;)

The guns I'll be using are:

1) S&W M-36 (1 7/8")
2) Ruger SP-101 (3 1/4") * (.357 Mag)
3) S&W Combat Masterpiece (4")
4) S&W 38/44 Heavy Duty (5")
5) S&W .38 Masterpiece (6")

I also want to compare group size for all the various barrel lengths simultaneously while chronographing and will be shooting from 25 yards with iron sights. 10 rounds fired each gun for average velocity and extreme spread.

Any other suggestions?

Stay tuned sports fans! :eek:
 
While shooting all those guns would be a great way to spend a day, I am doubtful that you could draw concrete conclusions to the barrel length question. When using multiple guns you must consider that each gun will have different chamber dimensions, different headspace, different barrel-cylinder gaps and different internal barrel dimensions and surface irregularities. The best way to determine the effects of barrel length on velocity would be to start with a long barrel, recrown it, shoot it, shorten the barrel, recrown it and repeat the process.

So, Justinr1, when can we expect you to sacrifice your Python in the name of ballistic science?
 
>>I get maybe 20 feet per second more from a 6" gp than from a
>>four using these loads using bullseye and unique.

Even considering different guns (thus ballistics), that 20 fps is more in line of what I expected (sometimes too pessimistic, I know.)

>>So, Justinr1, when can we expect you to sacrifice your Python
>>in the name of ballistic science?

Ballistic science will have to wait. I'm going to have to follow my own advice and get a chronograph before I purchase another gun. In fact, I'm going to research one while I wait on my Python. Please stop me from spending more money on this hobby!!! I obviously can't stop myself if I'm spending a grand on a Python. Oh well, I think the money is well spent. Pretty sick, huh?

:p :o :rolleyes: ;) :) :D
 
re: to CRSam

Wheelgun610.......nice set of 9mm guns.

Sam
Click to expand...

9mm??? :confused:

No 9's in that list...... or anywhere in my inventory for that matter

Granted my proposed test method/criteria won't be as scientific as using one gun and cutting/recrowning the barrel, but I think it will give usable comparison info for the average person, (myself included) :cool:

But if anyone wants to donate a long barreled revolver..... :eek::D
 
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Of course barrel length isn't the only factor in velocities. What I find with my wadcutter guns though is that there is a small but consistent gain in velocity with faster burning powders-like unique and bullseye. You could put a bullet between thumb and fore-finger and thump it across t he sky screens fast enough to make up the difference. I've also found a somewhat more pronounced gain with 3" Chief's specials over th 2" version. The Six inch barrel begins to show a bigger gain over the 4" when you got to the slower burning powders like 2400 or 296. For instance, some 125 grain factory and hand loads I've used will do about 1450 from the 4" and 1540 or there about from the six. Likewise, I worked up a load using 2400 and a cast 158 that did 1460 from a 4" gp and 1520 from an 8 3/8" Model 27.

Chronographs are interesting things. They also let you know if your loads are providing good consistency.
 
4"-8" Wadcutter Velocity

Chonograph the load in 8 3/8 barrel and deduct 33 feet per second for each shorter inch.
 
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