|
Forum Rules | Firearms Safety | Firearms Photos | Links | Library | Lost Password | Email Changes |
Register | FAQ | Calendar | Today's Posts | Search |
|
Thread Tools | Search this Thread |
May 16, 2018, 08:47 PM | #1 |
member
Join Date: June 12, 2000
Location: Texas and Oklahoma area
Posts: 8,462
|
NSWC Crane Determines Midlength ARs Run Better
http://soldiersystems.net/2018/05/14...d-performance/
Synopsis: Midlengths pick up an average of 32-40fps on velocity Midlength cyclic rate about 60rpm lower Midlength had 2800 MRBF at 160F, 1993.8 MRBF at ambient temp, and 562.5 MRBF at -60F. Crane is planning to put 34,000 rounds of M855A1 through each upper. At 12,000, they still haven’t noted a degradation in accuracy in the midlengths (twice the barrel life M4A1 averages). |
May 16, 2018, 11:02 PM | #2 |
Senior Member
Join Date: August 25, 2008
Location: In the valley above the plain
Posts: 13,424
|
Interesting.
While my own preference is for mid-length gas on barrels shorter than 18", I can't say that I've done enough testing to really show any difference other than a 'smoother' recoil impulse than carbine gas.
__________________
Don't even try it. It's even worse than the internet would lead you to believe. |
May 17, 2018, 07:45 AM | #3 |
Senior Member
Join Date: June 10, 2005
Location: SW Florida
Posts: 2,747
|
Great. I recently bought a mid upper, thought it was fugly, was gonna sell it this afternoon. Now you've got me wondering if I should hang onto it.
__________________
God's creatures big and small, eat them one, eat them all. Last edited by kymasabe; May 17, 2018 at 06:15 PM. |
May 17, 2018, 08:49 AM | #4 |
member
Join Date: June 12, 2000
Location: Texas and Oklahoma area
Posts: 8,462
|
The part I find curious is I can’t think of any reason the gas system would have an effect on barrel life, especially such a dramatic one (twice the average and still going). Something about that seems off to me.
|
May 17, 2018, 01:49 PM | #5 |
Senior Member
Join Date: August 25, 2008
Location: In the valley above the plain
Posts: 13,424
|
I think the barrel life claims are questionable, as well.
My assumption is just that it's a good lot of barrels, and/or a manifestation of a good lot of ammunition.
__________________
Don't even try it. It's even worse than the internet would lead you to believe. |
May 17, 2018, 02:57 PM | #6 |
Senior Member
Join Date: June 22, 2017
Posts: 1,011
|
It would be nice to have the actual report from the Navy instead of just the reporter's take on its findings.
|
May 18, 2018, 06:55 AM | #7 |
member
Join Date: June 12, 2000
Location: Texas and Oklahoma area
Posts: 8,462
|
That’s from last week’s 2018 NDIA conference in Indianapolis. They take forever to publish the conference materials; but they’ll publish most of the presentation materials eventually. I think they are up to March 2018 right now.
If you actually attend the conference, you get copies of the presentations plus you get access to a lot of info that never makes it to the DTIC.mil website. |
May 18, 2018, 12:21 PM | #8 |
Senior Member
Join Date: April 10, 2015
Location: ga
Posts: 321
|
Would increased Barrel life come from decreased gas port erosion? Would a mid length have less gas port erosion?
|
May 18, 2018, 01:40 PM | #9 |
Senior Member
Join Date: July 24, 2012
Location: Parker, CO
Posts: 4,594
|
I was wondering the same...
Gas port errosion would play a factor is barrel life and accuracy long term. A midlength should see less errosion than carbine length. Now my question is... Are the rifles 16in barreled or 14.5in barreled with midlength? |
May 18, 2018, 02:22 PM | #10 |
Senior Member
Join Date: November 4, 2013
Location: Western slope of Colorado
Posts: 3,679
|
The article says 14.5”
|
May 18, 2018, 02:40 PM | #11 |
Senior Member
Join Date: July 24, 2012
Location: Parker, CO
Posts: 4,594
|
Thanks for clarifying... I didn't have time to read the article earlier.
|
May 18, 2018, 02:55 PM | #12 |
Senior Member
Join Date: June 10, 2005
Location: SW Florida
Posts: 2,747
|
Sorry, posted (and deleted) response.
__________________
God's creatures big and small, eat them one, eat them all. Last edited by kymasabe; May 19, 2018 at 09:08 AM. |
May 18, 2018, 11:22 PM | #13 |
Senior Member
Join Date: August 25, 2008
Location: In the valley above the plain
Posts: 13,424
|
Edit: Disregard.
__________________
Don't even try it. It's even worse than the internet would lead you to believe. |
July 4, 2018, 01:45 PM | #14 |
member
Join Date: June 12, 2000
Location: Texas and Oklahoma area
Posts: 8,462
|
Link to NDIA presentation: https://partner-mco-archive.s3.amazo...1527866983.pdf
ETA: Looks like that is a link from a conference attendee who posted it on the web and not a DTIC.mil link. Last edited by Bartholomew Roberts; July 4, 2018 at 01:51 PM. |
|
|