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schambers
20 January 2016, 09:24
Gents,

I need suggestions for a 7.5" rail! Working on another 300blk upper and rough math is telling me that a 7.5 is the longest I will be able to go (will be able to get exact dimensions if the mailman drops off some parts today). The rail I'm currently looking at is an SLR ION but I would like to see if there is something out there that I'm missing

Build info:
The build is being specced' around a Griffin RSTA. I wanted to build the most compact overall package that will give me good accuracy, heat mitigation, low gas blowback, able to fire with/ without the suppressor, yada yada yada. If the maths work out, I should end up with the equivalent of a 15" - 16" barrel when the suppressor is attached.

Barrel: 10.3" BA Premium, Hansen Profile
BCG: LANTAC EBCG
Charging Handle: Griffin SNACH
Muzzle Device: Griffin OTB Suppressor Mount, flash hider variant
Suppressor: Griffin RSTA


My biggest concern at this point is how the Hansen Profile will react with a reflex suppressor. Since there will be some space between the Muzzle device/ suppressor assembly, will there be weird harmonics? Will that air space retain heat or help dissipate heat? Just airing come concerns on the build. The Hansen profile may be thick enough to not even make any measurable difference.

Pics for reference:
http://www.weaponevolution.com/forum/attachment.php?attachmentid=356&d=1453338637
http://www.weaponevolution.com/forum/attachment.php?attachmentid=357&d=1453338647

Looks like I have 7.6" between the receiver and the edge of the mount. Also have about 1mm space between the barrel and mount.

RiverRat
20 January 2016, 18:50
Midwest Industries Gen 3 MLOK (also available in KeyMod).
366

BCM KMR-ALPHA 7" KeyMod only.
367

All pics from manufacturers' sites.

Dstrbdmedic167
20 January 2016, 18:57
Another option and one of my personal favs. Is the 7" Fortis Rev 2 it Measures 7.3".

Pic from fortis site

http://uploads.tapatalk-cdn.com/20160121/124caa848825413c31fcd6041457a05b.jpg

Brahmzy
20 January 2016, 19:03
I just got an NSR7 for my 8.5 300BLK. A little old school, but until SMOS brings out there new rails...

BoilerUp
20 January 2016, 19:05
If you go with a Seekins MCSR or Aero Precision Enhanced handguard you can go longer and partially shroud the can.

Something like this: http://aeroprecisionusa.com/m4e1-sd-105-barrel-complete-upper-receiver.html

DutyUse
21 January 2016, 04:23
Another vote for the NSR 7 at 7 1/4".

http://images.tapatalk-cdn.com/16/01/21/0cdf29724f7886764da965b5b341cf83.jpg

jdhill
21 January 2016, 19:31
I'm on the hunt for a Mega wedge lock carbine length for my 8.3 build

UWone77
21 January 2016, 19:37
Geissele MK4 or MK8 ... I've got a MK8 7" waiting for a 4.5" 9mm build.

SwissyJim
21 January 2016, 20:16
SLR Rifleworks (http://slrrifleworks.com/index.php?route=product/category&path=66_106)makes some pretty good handguards, and a number of them either 7, 7¼ or 7½" in length

schambers
28 January 2016, 16:37
Yeah. An SLR 7.5 seems like it will be the best fit. Was hoping something new would have come out of SHOT

Sak007
17 February 2016, 02:51
I have a Bravo Company KMR7 on a 8.5 barrel .
657
658

Jerry R
17 February 2016, 07:24
I'm running a KMR 7" on an 8.5" also. I really like the dimensions of the KMR.

http://i70.photobucket.com/albums/i106/pdogkilr/Firearms/AR-15/223%20Wylde%20Pistol/IMG_0848%20Arisaka%20Finger%20Stop%20Size%201024_z psgv7r0ra1.jpg~original

Sak007
18 February 2016, 05:49
I'm running a KMR 7" on an 8.5" also. I really like the dimensions of the KMR.

http://i70.photobucket.com/albums/i106/pdogkilr/Firearms/AR-15/223%20Wylde%20Pistol/IMG_0848%20Arisaka%20Finger%20Stop%20Size%201024_z psgv7r0ra1.jpg~originalI hate posting photos with all of your guys quality photos . I'm gonna go buy a Polaroid and scan the polaroids in and give it that artsy retro look .

schambers
17 March 2016, 15:24
Finally got the upper and the basic rifle together. Going to start experimenting with a loadout, and I need to settle on a MRO mount. Final pics when the entire thing comes together.

There is a lot more space between the end of the reflex mount and the handguard than I though there would be. Probably around 1/4"

http://www.weaponevolution.com/forum/attachment.php?attachmentid=853&d=1458253094

http://www.weaponevolution.com/forum/attachment.php?attachmentid=852&d=1458253085

Highlights:
LANTAC BCG
Griffon SNACH
JP Silent Capture Spring
Geissele Trigger

UWone77
7 June 2016, 19:32
schambers, how is this working out for you?

I'm looking at several piece meal 9mm upper builds and can't decide on a rail combo.

schambers
10 June 2016, 19:08
Still waiting on the RISTA to come out of NFA jail so I haven't tried it suppressed yet.

Over than that the setup seems to be working out well enough. The griffin charging handle and Lantac big make gas a non-issue and the silent capture spring works as advertised. I've only put about 200 rounds through it though, so not a whole bunch of data yet.

The only problem I have is that there is that slight tuning fork sound coming from the flash hider. I'm curious to know how it will sound when it's inside of the suppressor.

I can live with it now but it may be irritating to me after and while and force me to switch to a muzzle brake

jdhill
19 July 2016, 17:36
1453

1450

1451

Mega Wedge Lock carbine length on an 8.3" bbl...

UWone77
19 July 2016, 22:16
1453

1450

1451

Mega Wedge Lock carbine length on an 8.3" bbl...

Nice find on the sights!

jdhill
20 July 2016, 06:09
Nice find on the sights!

I've had these for a few years (found the front in the bargain bin at Rainier Arms) ... I'd actually prefer the actual HK height ones (a little lower)

Aragorn
23 January 2017, 08:36
Necropost... but I'm in the same boat and figured I'd just come back here instead of making a new thread.

I'm using the exact same barrel. BA 8.3" Hanson .300

My catch is I'm looking for something with 3 full usable M-lok slots at the 3/6/9 positions, which seems to put me with the Mega Wedge Lock, an 8" SLR, or the 2A rails. I'm kinda leaning towards the 2A because it's the lightest and least expensive, but I'm not so sure after watching the install video and seeing that the rail is secured to the nut with 4 finger tight set screws that don't even thread into the barrel nut. Anyone have any experience with this? Also leaning away from the 8" SLR because that would overhang the muzzle device, and I'd prefer to have that area free in case HPA passes.

fledge
23 January 2017, 12:45
SLR has 7.5" rails with that configuration. Their ION version adds even more.

The 2a attachments aren't "finger tight." They tighten with hex key. I was skeptical of it at first too but after installing three of them, I've not had a single issue of movement or rotation. Just take your time securing them so that the rail is centered. They bite into the barrel nut grooves, pushing the rail into the receiver.

Aragorn
23 January 2017, 13:30
SLR has 7.5" rails with that configuration. Their ION version adds even more.

The 2a attachments aren't "finger tight." They tighten with hex key. I was skeptical of it at first too but after installing three of them, I've not had a single issue of movement or rotation. Just take your time securing them so that the rail is centered. They bite into the barrel nut grooves, pushing the rail into the receiver.

Ah good to know. The install video showed him putting almost no pressure on the hex key during install. Since you've had good luck with them, I'll probably go that way.

Joelski
23 January 2017, 13:39
Turn the shoulder down to 8", rethread and get an SMR Mk 4. Problem solved! [:)]