Velocity Loss in a 3inch Barrel? Please Answer! - XDTalk Forums - Your HS2000/SA-XD Information Source!

washington101 · 05-31-2006, 10:50 AM

Hey guys,
Has anyone measured the velocity of some ammo from their XDsc in 9mm? I am wondering what kind of velocity loss there is in a 3inch barrel. thanks.

I was thinking that if a 3inch barrel doesnt allow enough velocity to built up then there is no use for it. It's just a small gun with no punch.

Hooz · 05-31-2006, 11:00 AM

Click right here and prepare to be enlightened.

washington101 · 05-31-2006, 11:10 AM

Thanks Hooz, but do you have data on velocity loss in the SA XDsc 9mm? My estimates say there should be about 137fps loss from a 4inch to a 3inch. With some ammo that velocity puts the round in "ineffective" territory.

Hooz · 05-31-2006, 11:23 AM

I have an XD-9SC and an XD-40 w/9mm conversion barrel, but I don't have a chronograph to test your theory. Even if I did, the sheer volume of variables from load-to-load (case, primer, powder, bullets, etc) and manufacturer-to-manufacturer would be too great to quantify in a few hundred rounds of shooting over a chronograph.

In the article I linked above there was, at most, a 90FPS drop in muzzle velocity when dropping from a 5” barrel to 4.25” barrel. I read in a print magazine long ago that you can expect a 50-100FPS drop per inch of barrel length in most handgun calibers.

So what I guess I am saying is that your question depends entirely on what load you plan to shoot, and what you consider “ineffective” (Which is a whole other can of worms).

I don’t think there is a real, easy answer to your original question.

**PackerfanXD** · 05-31-2006, 02:27 PM

I am of the opinion that less barrel would mean less drag or friction and shouldn't adversely velosity. My Father-in-law has a chronograph though I haven't tested the sub yet. Here is the results from my service firing WWB 115 grain ball ammo:

Average Velostity- 1165 ft/second

Extreme Spread- 67 (1193- 1126)

Energy Range- 347 ftlbs

This is an average of ten shots. I'll test the sub this weekend.

CyberOtaku · 05-31-2006, 03:23 PM

Quote:

Originally Posted by XpackerfanD

I am of the opinion that less barrel would mean less drag or friction and shouldn't adversely velosity.

The increased drag is going to be irrelevant compared to the decreased gas pressure. The shorter the barrell, the less time the bullet has to accellerate and the less pressure can build up behind it. I believe more powder tends to go unburned in a shorter barrell.

**jalley** · 05-31-2006, 03:26 PM

Quote:

Originally Posted by CyberOtaku

Quote:

Originally Posted by XpackerfanD

I am of the opinion that less barrel would mean less drag or friction and shouldn't adversely velosity.

The increased drag is going to be irrelevant compared to the decreased gas pressure. The shorter the barrell, the less time the bullet has to accellerate and the less pressure can build up behind it. I believe more powder tends to go unburned in a shorter barrell.

You are correct

mullanman · 05-31-2006, 03:42 PM

i usually get chrono readings of 20-30 fps slower per inch of barrel loss.

Every gun is a little different as well as every barrel.

**PackerfanXD** · 05-31-2006, 04:42 PM

Quote:

Originally Posted by CyberOtaku

Quote:

Originally Posted by XpackerfanD

I am of the opinion that less barrel would mean less drag or friction and shouldn't adversely velosity.

The increased drag is going to be irrelevant compared to the decreased gas pressure. The shorter the barrell, the less time the bullet has to accellerate and the less pressure can build up behind it. I believe more powder tends to go unburned in a shorter barrell.

Ahhh.

I'll still chrono the sub this weekend and see what the difference is between my service and sub.

washington101 · 05-31-2006, 06:04 PM

the R9 is another 3inch pistol. When I looked at the data from it I saw that 115gr. bullets were travelling 147fps slower in a 3inch barrel as opposed to a 4inch barrel.
This seems to be the case for most ammo. At least 100fps loss in that one inch of barrel. I would be very interested to see your results from your chrono tests this weekend. I think that is a great idea!

We can finaly get some concrete data.

05-31-2006, 10:50 AM	#1
washington101 XDTalk Newbie Join Date: Mar 2006 Posts: 20	Velocity Loss in a 3inch Barrel? Please Answer! Hey guys, Has anyone measured the velocity of some ammo from their XDsc in 9mm? I am wondering what kind of velocity loss there is in a 3inch barrel. thanks. I was thinking that if a 3inch barrel doesnt allow enough velocity to built up then there is no use for it. It's just a small gun with no punch.

05-31-2006, 11:00 AM	#2
Hooz XDTalk 2K Member Join Date: Feb 2006 Location: Hilliard, OH Posts: 2,141	Click right here and prepare to be enlightened. __________________ XD-9 Tactical Member: IDPA, USPSA, ASSA, NRA, GOA

05-31-2006, 11:23 AM	#4
Hooz XDTalk 2K Member Join Date: Feb 2006 Location: Hilliard, OH Posts: 2,141	I have an XD-9SC and an XD-40 w/9mm conversion barrel, but I don't have a chronograph to test your theory. Even if I did, the sheer volume of variables from load-to-load (case, primer, powder, bullets, etc) and manufacturer-to-manufacturer would be too great to quantify in a few hundred rounds of shooting over a chronograph. In the article I linked above there was, at most, a 90FPS drop in muzzle velocity when dropping from a 5” barrel to 4.25” barrel. I read in a print magazine long ago that you can expect a 50-100FPS drop per inch of barrel length in most handgun calibers. So what I guess I am saying is that your question depends entirely on what load you plan to shoot, and what you consider “ineffective” (Which is a whole other can of worms). I don’t think there is a real, easy answer to your original question. __________________ XD-9 Tactical Member: IDPA, USPSA, ASSA, NRA, GOA

05-31-2006, 02:27 PM	#5
PackerfanXD XDTalk 5K Member Join Date: Feb 2006 Location: Ground zero of the invasion Posts: 7,402 Blog Entries: 1	I am of the opinion that less barrel would mean less drag or friction and shouldn't adversely velosity. My Father-in-law has a chronograph though I haven't tested the sub yet. Here is the results from my service firing WWB 115 grain ball ammo: Average Velostity- 1165 ft/second Extreme Spread- 67 (1193- 1126) Energy Range- 347 ftlbs This is an average of ten shots. I'll test the sub this weekend. __________________ I am currently traveling space and time. I will be returning last week. The wealthiest nation in the world with the mightiest army man has ever assembled could not stop them. http://www.break.com/usercontent/200...00-358890.html

05-31-2006, 03:42 PM	#8
mullanman XDTalk 1K Member Join Date: Dec 2003 Location: New Mexico Posts: 1,911	i usually get chrono readings of 20-30 fps slower per inch of barrel loss. Every gun is a little different as well as every barrel. __________________ USPSA L2683

05-31-2006, 11:10 AM	#3
washington101 XDTalk Newbie Join Date: Mar 2006 Posts: 20	Thanks Hooz, but do you have data on velocity loss in the SA XDsc 9mm? My estimates say there should be about 137fps loss from a 4inch to a 3inch. With some ammo that velocity puts the round in "ineffective" territory.

05-31-2006, 06:04 PM	#10
washington101 XDTalk Newbie Join Date: Mar 2006 Posts: 20	the R9 is another 3inch pistol. When I looked at the data from it I saw that 115gr. bullets were travelling 147fps slower in a 3inch barrel as opposed to a 4inch barrel. This seems to be the case for most ammo. At least 100fps loss in that one inch of barrel. I would be very interested to see your results from your chrono tests this weekend. I think that is a great idea! We can finaly get some concrete data.

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