iamkris

January 19, 2008, 05:57 PM

I went to the range today to finally play with some Christmas toys I got...sighted in the Millett DMS-1 1x-4x illum reticle scope on my Para FAL, played with my new Shooting Chrony and tested some handloads.

What a great time, I thought, to find out actual velocity readings with exactly the same loads, shot from a 16.25" bbl FAL back-to-back with a 21" StG58A FAL. I've heard lots of people say that you should expect 50+ fps per inch of barrel velocity loss...I wanted to see what two back to back rifles actually would yield.

It was very cold at the range (-2 deg F) so I only shot 5 rounds for each load in each rifle. Also, the overall velocities for all loads were lower than I expected...I'm assuming that is a temperature effect. These readings are averages of 5 shots each read from the Chrony.

Load #1: 41 gr IMR4895, 150 gr surplus FMJ, 2.80" OAL

DSA 16.25" Para FAL 2311 fps

DSA 21" StG58A FAL 2449 fps

Load #2: 42 gr IMR4895, 150 gr surplus FMJ, 2.80" OAL

DSA 16.25" Para FAL 2379 fps

DSA 21" StG58A FAL 2501 fps

Load #3: 43 gr IMR4895, 150 gr surplus FMJ, 2.80" OAL

DSA 16.25" Para FAL 2453 fps

DSA 21" StG58A FAL 2598 fps

Load #4: 44 gr IMR4895, 150 gr surplus FMJ, 2.80" OAL

DSA 16.25" Para FAL 2501 fps

DSA 21" StG58A FAL 2643 fps

Now this isn't apples to apples since it isn't the same rifle, same barrel and only difference being the length. For the statisticians out there, the sample size is rather small as well, both in number of rounds fired as well as number of firearms. Other factors, like bore size, wear, chamber size, etc, can influence velocities.

That said, with these two rifles, you can see that the delta is in the 120-140 fps for 5 inches of barrel. That puts the velocity loss at 25-30 fps per inch of barrel.

You can make your own judgements if that matters to you. Here's the rifles

http://i2.tinypic.com/6pk4zg7.jpg

http://i13.tinypic.com/4ullpva.jpg

What a great time, I thought, to find out actual velocity readings with exactly the same loads, shot from a 16.25" bbl FAL back-to-back with a 21" StG58A FAL. I've heard lots of people say that you should expect 50+ fps per inch of barrel velocity loss...I wanted to see what two back to back rifles actually would yield.

It was very cold at the range (-2 deg F) so I only shot 5 rounds for each load in each rifle. Also, the overall velocities for all loads were lower than I expected...I'm assuming that is a temperature effect. These readings are averages of 5 shots each read from the Chrony.

Load #1: 41 gr IMR4895, 150 gr surplus FMJ, 2.80" OAL

DSA 16.25" Para FAL 2311 fps

DSA 21" StG58A FAL 2449 fps

Load #2: 42 gr IMR4895, 150 gr surplus FMJ, 2.80" OAL

DSA 16.25" Para FAL 2379 fps

DSA 21" StG58A FAL 2501 fps

Load #3: 43 gr IMR4895, 150 gr surplus FMJ, 2.80" OAL

DSA 16.25" Para FAL 2453 fps

DSA 21" StG58A FAL 2598 fps

Load #4: 44 gr IMR4895, 150 gr surplus FMJ, 2.80" OAL

DSA 16.25" Para FAL 2501 fps

DSA 21" StG58A FAL 2643 fps

Now this isn't apples to apples since it isn't the same rifle, same barrel and only difference being the length. For the statisticians out there, the sample size is rather small as well, both in number of rounds fired as well as number of firearms. Other factors, like bore size, wear, chamber size, etc, can influence velocities.

That said, with these two rifles, you can see that the delta is in the 120-140 fps for 5 inches of barrel. That puts the velocity loss at 25-30 fps per inch of barrel.

You can make your own judgements if that matters to you. Here's the rifles

http://i2.tinypic.com/6pk4zg7.jpg

http://i13.tinypic.com/4ullpva.jpg