Jerry R
6 June 2011, 17:05
A small group of friends got together last month to do some shooting – some serious stuff, and some fun stuff. We had bolt guns in .223 Remington, and AR Variants in 5.56 and 6.8. We also mounted scopes and zeroed a couple of .308 rifles. An SSG and an M1A National Match.
All NFA Rules were observed. We wanted to do some load testing to see how much velocity loss is incurred as you chop the barrel. We also wanted to do some carbine scenario work with pistol transitions. Thursday was a travel day and we shot Friday and Saturday.
Mods - if the video is not appropriate to the thread, let me know and I will edit the post.
Be patient with the video, a "Jungle Walk" starts at about 2:40
The first day was spent doing the chronograph work. We had several barrel lengths and several loadings in 5.56 and 6.8.
We were in the central pan-handle of Florida – altitude 167 feet above sea level, sunny, calm, mid 80’s and shooting under a pair of 12x12 pop-ups.
Several interesting things came to light during this phase of the shoot. First off, we were very careful about logging the details of each round used, so if you see something you think is not correct – the data is exactly as it came off the chronographs. We used PACT timers with Chrono-Mod, PACT Skyscreens spaced at 24 inches, placed ten feet from the end of the shooting bench. We were shooting at 100 yards. We probably should have changed targets for each loading, but we didn’t. The 6.8 target ended up with one ragged hole about three inches in diameter. This was with three different barrel lengths shooting seventeen different loads with six different shooters.
The graphics below represent a summary of most of the work. Notes and comments at the bottom will help explain the data. I tried to minimize the variations for this first test. I was not looking for a “best” load, I wanted a “standard” load for barrel length comparison. I stuck with one powder (H322) and one charge weight (28.0 is below maximum for any of the bullet weights loaded). All rounds were loaded to the cannelure and crimped with a Lee Factory Crimp Die. Experimentation will come later. That is not what we were after on this trip – velocity variations was what we were looking for; that is why the loadings were “standardized”.
If there is data we should add, that we missed, data you question, let us know what you think.
http://i70.photobucket.com/albums/i106/pdogkilr/Firearms/Page-1.jpg
http://i70.photobucket.com/albums/i106/pdogkilr/Firearms/Page-2.jpg
http://i70.photobucket.com/albums/i106/pdogkilr/Firearms/Page-3.jpg
GriffonSec rockin' his 8.5" 6.8 Build
http://i70.photobucket.com/albums/i106/pdogkilr/Firearms/2011%20Spring%20Shoot%20in%20Florida/IMG_1609300PPISized1024.jpg
http://www.youtube.com/watch?v=dDU-nXBr62g
All NFA Rules were observed. We wanted to do some load testing to see how much velocity loss is incurred as you chop the barrel. We also wanted to do some carbine scenario work with pistol transitions. Thursday was a travel day and we shot Friday and Saturday.
Mods - if the video is not appropriate to the thread, let me know and I will edit the post.
Be patient with the video, a "Jungle Walk" starts at about 2:40
The first day was spent doing the chronograph work. We had several barrel lengths and several loadings in 5.56 and 6.8.
We were in the central pan-handle of Florida – altitude 167 feet above sea level, sunny, calm, mid 80’s and shooting under a pair of 12x12 pop-ups.
Several interesting things came to light during this phase of the shoot. First off, we were very careful about logging the details of each round used, so if you see something you think is not correct – the data is exactly as it came off the chronographs. We used PACT timers with Chrono-Mod, PACT Skyscreens spaced at 24 inches, placed ten feet from the end of the shooting bench. We were shooting at 100 yards. We probably should have changed targets for each loading, but we didn’t. The 6.8 target ended up with one ragged hole about three inches in diameter. This was with three different barrel lengths shooting seventeen different loads with six different shooters.
The graphics below represent a summary of most of the work. Notes and comments at the bottom will help explain the data. I tried to minimize the variations for this first test. I was not looking for a “best” load, I wanted a “standard” load for barrel length comparison. I stuck with one powder (H322) and one charge weight (28.0 is below maximum for any of the bullet weights loaded). All rounds were loaded to the cannelure and crimped with a Lee Factory Crimp Die. Experimentation will come later. That is not what we were after on this trip – velocity variations was what we were looking for; that is why the loadings were “standardized”.
If there is data we should add, that we missed, data you question, let us know what you think.
http://i70.photobucket.com/albums/i106/pdogkilr/Firearms/Page-1.jpg
http://i70.photobucket.com/albums/i106/pdogkilr/Firearms/Page-2.jpg
http://i70.photobucket.com/albums/i106/pdogkilr/Firearms/Page-3.jpg
GriffonSec rockin' his 8.5" 6.8 Build
http://i70.photobucket.com/albums/i106/pdogkilr/Firearms/2011%20Spring%20Shoot%20in%20Florida/IMG_1609300PPISized1024.jpg
http://www.youtube.com/watch?v=dDU-nXBr62g