DOES BARREL LENGTH MATTER??

[74man]

I am going to load 38 special (158 Gr. LRN & 158 Gr. SWC, using Unique Powder) for my two stubby and I want to know if the barrel length matters on the reload data? I have load data that say's 7 inch barrel but I can't find any load data for a 2" barrel 38 stubby. I have lead 38 Round Nose data, 38 lead Semi Wad Cutter data but they both use 7 inch barrels, so is there a difference in load data or can I use that data and shoot them from a 2" barrel stubby? If someone has 38 special load data for 2" barrel stubby's and want to share with me, it would be greatly appreciated. I want to use Unique powder and have already primed them using CCI small pistol primers. I also have CFE pistol powder, H-110, W-296, Lil Gun, WSF that I have for reloading other calibers. I have also ordered some BERRY'S 125 Gr. RNFP bullets, thank you, 74man

 

[The Glockodile]

Only as a function of sight radius, I would suppose.

 

[AJC1]

The load data is exactly the same, the listed velosity will not match. If the test barrel is longer it will have higher velocity than you will get in a test. Load limits are based on peak chamber pressure that is basically identical for all weapons of the same type. Revolvers will be different in where that peak occurred than semi pistols based on the cylinder gap.

 

[mkl]

Barrel length will make a difference in velocity, but will have no practical effect on pressure. So yes, you can use the data in your books based on a longer barrel, but do not expect to get the velocity the loading book lists,

Unique is a great powder; I use it in almost all of my .38 Special loads.

 

[.308 Norma]

I have lead 38 Round Nose data, 38 lead Semi Wad Cutter data but they both use 7 inch barrels, so is there a difference in load data or can I use that data and shoot them from a 2" barrel stubby?

Yeah, you can use the same load data. Of course you're going to get lower bullet velocities from your 2" snubby compared to bullet velocities from 7 inch barrels. But you probably already knew that.

 

[nofendertom]

What kind of loads---light plinking, medium or heavy SD loads ?

 

[denton]

It's hard to get much muzzle velocity out of snubby with 158 grain bullets. You might do better with 125 or even 110.

 

[25-20 WCF]

Anyone interested in actual data?
http://www.ballisticsbytheinch.com/38special.html




.

 

[Charlie98]

Actually, one of the most accurate loads I ever came up with was Unique under a Hornady swaged 158grn SWC... shot out of a 3" J-frame.

As others mentioned... barrel length does not really matter, in the end your pistol will tell you whether or not it likes it, regardless of barrel length. Unique is a reasonable powder for shorty .38's, including light target rounds or nearly full-power SD loads.

 

[Soonerpesek]

Anyone interested in actual data?

Anyone interested in reading the entire OP.....?

 

[Engineer1911]

Just to be clear, length DOES matter.

 

[AJC1]

Just to be clear, length DOES matter.

I get tired of hearing it from her, now you want to chime in....

 

[Engineer1911]

Sorry, Shorty.

 

[Slamfire]

I have not chronographed Unique in one of my 38 snubbies. I have shot literally thousands, if not tens of thousands of 158 LRN or LSWC with 3.5 grs Bullseye in snubbies, four and six inch 38 Specials. This load is an excellent, accurate load, and I believe a standard pressure load based on velocity comparisons.

To have an idea of what charge to use for Unique, just compare the Bullseye load in the four and two inch revolvers. The Unique load should drop as much.


S&W M64-5 Georgia Department Corrections four inch barrel


158 LRN 3.5 grs Bullseye mixed cases Fed 100
20-May-20 T = 72 °F

Ave Vel = 739.1
Std Dev = 22.3
ES = 60.4
High = 760.6
Low = 700.2
Number rds = 6


158 LRN 3.5 grs Bullseye lot 919 11-29-05 Brass mixed cases WSP
10-Jun-20 T = 85 °F

Ave Vel = 757.7
Std Dev = 22.6
ES = 60.06
High = 798.1
Low = 738.1
N = 6

158 JSP RMR 4.0 grs Bullseye lot 919 11-29-05 Brass mixed cases WSP
10-Jun-20 T = 87 °F

Ave Vel = 729.7
Std Dev = 17.32
ES = 73.82
High = 748.8
Low = 675
N = 18

158 LRN 4.5 grs Unique lot UN 364 3/9/1992 Brass mixed cases WSP
10-Jun-20 T = 85 °F

Ave Vel = 794.7
Std Dev = 29.9
ES = 143.7
High = 851.7
Low = 708
N = 24

Federal Factory 158 gr Nyclad +P
20-May-20 T = 72 °F

Ave Vel = 851.2
Std Dev = 21.3
ES = 67.79
High = 883.7
Low = 815.9
N = 12

Federal Factory 158 gr LSWC +P factory
20-May-20 T = 72 °F

Ave Vel = 849.9
Std Dev = 36.04
ES = 105.5
High = 895.2
Low = 789.6
N = 9

Taurus M85 B2UL 2" Barrel
158 LSWC 3.5 grs Bullseye thrown, Mixed Brass WSP
11-Dec-04 T = 54 F

Ave Vel = 686.3
Std Dev =13.63
ES 58.48
High 718.8
Low 660.3
N = 30

shot little high and centered

158 LRN Master Factory Ammo
30-Dec-04 T = 56 F


Ave Vel = 698.2
Std Dev = 20.56
ES 105.8
High 753.5
Low 647.6
N = 32

I do not recommend using 2400, W296, H110 in the 38 Special, especially in a snubbie. I have no idea what the other powders are . These magnum level powders are inappropriate in a 38 Special and even if you kept the pressures down, the fireball out the barrel would be horrible.

 

[jmr40]

I'm probably not saying anything that hasn't already been said, just coming from another perspective. The load data you're looking at is from a 7" barrel which is typical for revolver load data. The load listed is fine to use in any barrel length. It will be OK in a 2" barrel or a 10" barrel.

Where it gets confusing is the expected velocity from a 7" barrel will be very different from a 2" barrel. And even a little different from a barrel longer than 7"

 

[buck460XVR]

This should give you some idea if barrel length matters.......http://www.ballisticsbytheinch.com/38special.html

 

[mdi]

Well Buck beat me to it . The chart doesn't show LSWCs but the velocity drops per barrel length are clearly shown. http://www.ballisticsbytheinch.com/38special.html. I'm using he same bullet for some loads in my 2" 38 as my 4" 357 Magnum, a 125 gr JHP. But I know the velocities I get from my snubbies aren't reaching the expansion threshold. My loads clock around 725 fps.

BTW the chart above is for a soft, swaged bullet and the data will differ from a cast bullet...

 

[Highland Lofts]

I read somewhere you get about 50 per second more velocity for every extra inch of barrel length. So size does matter for more velocity.

 

[GeoDudeFlorida]

I am going to load 38 special (158 Gr. LRN & 158 Gr. SWC, using Unique Powder) for my two stubby and I want to know if the barrel length matters on the reload data? I have load data that say's 7 inch barrel but I can't find any load data for a 2" barrel 38 stubby. I have lead 38 Round Nose data, 38 lead Semi Wad Cutter data but they both use 7 inch barrels, so is there a difference in load data or can I use that data and shoot them from a 2" barrel stubby? If someone has 38 special load data for 2" barrel stubby's and want to share with me, it would be greatly appreciated. I want to use Unique powder and have already primed them using CCI small pistol primers. I also have CFE pistol powder, H-110, W-296, Lil Gun, WSF that I have for reloading other calibers. I have also ordered some BERRY'S 125 Gr. RNFP bullets, thank you, 74man

A couple of things having to do with barrel length will make a difference: how much still expanding gas gets blown out the barrel and how much time the bullet has in the barrel to accelerate before friction and the lack of expanding gas cause it to begin to decelerate.

Powder burns in the chamber but the gases created by the burning powder continue expanding until the powder and heat of burn are fully consumed. That's where the decision about slow powders vs. fast powders come into the equation. Unique, HS-6, Accurate No.5 and Universal are probably the slowest powders I'd suggest for a short barrel. A faster powder will burn different, not necessarily better, but it will also result in a different recoil impulse - a quick, sharp poke as opposed to a long, slow push. A punch versus a shove. In a short barrel, the slower powders don't have time to shove so recoil like a fast powder and expend themselves on the air around the muzzle. More heat, more noise, not necessarily more recoil, but plenty of wasted energy to be sure. That's why shorter barrels get lower velocities, too. At least, it's one of the reasons.

Speer has loading data for it's SB type Gold Dots and that will give you some clues as to which powders don't really benefit from longer barrels.

 

[P Flados]

For target practice or informal shooting, Unique or WSF are probably both reasonable choices. I would prefer the lighter bullet if it shoots good. If it were my gun, I would actually want to go with a powder a good bit faster than either of these as faster powders will produce less noise/blast from a snubbie when loaded to the same velocity.

I have Quickload and it is a good tool for evaluating which powder will give you best velocity for your barrel length.

Your magnum pistol powders came out on top, but I would not use them for 38 Sp. They are really designed for rounds that run a lot higher in pressure.

For more serious work, the 158 SWC sounds like your best choice. You may want to push the load closer to book max. Book max based on the on-line Alliant guide is 4.7 gr Unique. Quickload uses muzzle to breech for barrel length so I plugged in 3.7 inches, the Speer 158 SWC, the 1.44" OAL (0.365 seating depth) and 4.7 gr Unique. Assuming a 30 to 40 fps loss for cylinder gap and the predicted velocity comes in real close to 790 fps.

For this application slower powders will give more velocity. Ignoring the magnum powders, ranking yours by slowest goes: CFE Pistol, WSF and then Unique. However, I doubt that there would be 20 fps difference between the bunch and I am not sure what kind of load data you would be able to find.

 

[Archie]

As already mentioned, barrel length will normally increase muzzle velocity. Since you stated you have revolvers with two inch barrels, that's what you get. (I have several two inch .38 Specials and don't really feel inadequate.)
Barrel length really makes NO difference in type or amount of powder to use. Contrary to the opinions of some, short barreled revolvers (or pistols, rifles or shotguns) do not require faster powders than longer barreled arms of the same type. The faster burning powders allow (require) smaller amounts of powder as the pressure raises quicker. You probably will not notice. Do not be concerned over data for a certain barrel length. Do be concerned over data for different bullet weights and to a limited extent, date for a different construction of bullet (very uncommon in .38 Special).

Good fortune!

 

[Bcwitt]

Lighter bullets & faster powders usually workout a bit better in snubbies.