Precision Rifle Gear ARCA rail for AI AICS old thumb hole chassis
- Thread starter NavyshooterM40
- Start date
It looks to me that you just need to measure the flat area in front of mag well and get the appropriate length rail. Mounting is the issue you’ll need to address. Since I’ve never had the good fortune of owning an AIAW I can’t say what you have to to mount the rail. If I were to guess, and that’s exactly what this is, I’d say it would involve tapping the chassis to mount it.
Just ordered a short Sawtooth. RRS said they no longer make one for the old AI AICS.
Thanks for the help
Thanks for the help
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Given I had a stock one like yours, I put a long Sawtooth one on and it sticks out about 3" on the end, no issues. Works great; both fit and finish, like it came from the factory.
Also, as a nice plus, it has recesses in the plate to accommodate the parts that stick out a bit on the bottom of the AICS legacy chassis. Obviously, once you put on the long one, you will not have access to pop in and pop out a Parker-Hale or Versapod variant. Any adapters you did manage to pop in with this rail (bi-directional versapod spigot, BT65, etc.) would require taking the rail off to access the spigot release button for said adapter (some people are using adapter rods to mount things like magnetospeed, bulletseeker chronos, etc.)
Matt did some really thoughtful and solid engineering. Give Matt at SawtoothRifles.com a call, if you did not already, as he is pretty fast on filling backorders (was for me, at least). Going to get the short one to work with the Badger IMUNS variants on the ends of others.
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No tapping or special machining needed with the Sawtooth Dependabilt rail. Everything comes in the kit as a bolt-on option. All hardware included with no mickey mousing about.
Meant to post these pictures of the SawtoothRifles.com long ARCA rail for legacy AI chassis earlier but holiday preparations took precedence. Hope this helps...
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Right but I'm also running the bottom rail on that imuns. I assume you are not
With respect to IMUNS (Badger Ordnance Integrated Mount Universal Night Sight), there are four total variant AICS versions: the IMUNS (Badger Ordnance part number 310-10; https://www.milehighshooting.com/badger-ordnance-310-10-imuns/ or https://www.brownells.com/optics-mo...-bases/imuns-night-sight-mount-prod44442.aspx) and the IMUNS-C ('covert' version with Badger Ordnance part number 310-30; https://www.badgerordnance.com/imun...ert-for-ai-covert-rifles-1-5-bore-310-30.html). The last two variants are discontinued by the manufacturer as of this post but new old stock still exists in the wild (shown below for reference).
The currently available variants, the IMUNS and IMUNS-C, will both work in legacy AICS square tubular chassis with the longer ARCA Sawtooth rail options (https://www.sawtoothrifles.com/product/dovetail-rail-accuracy-international-at/). Without the associated bottom retaining plates in place (see below), both currently manufactured IMUNS variants have smooth bottoms for longer Sawtooth ARCA rail emplacement. The exception is on the IMUNS (not the IMUNS-C) in the area where the spigot release button would stick down and protrude; maybe some members have either removed or kept the tab in place with no issue.
The IMUNS unit below has a slight smaller diameter barrel channel (1.25") than the IMUNS-C (shown further below). Shown with and without the retention plate with sling swivel with side views for how the long Sawtooth ARCA rail would clear, or not clear, the spigot release tab:
The IMUNS-C below has a slightly larger diameter barrel channel (1.50") than the IMUNS with a removable picatinny rail that adds additional rigidity once screwed in place: However, this picatinny rail would obviously need to be removed for longer Sawtooth ARCA rail emplacement:
It is not clear whether or not the extra rigidity lost by not having anything more than the crossblock retention roll pin in place to hold the IMUNS units in the front of the legacy AI chassis is an issue. That is, it would most likely be dependent on how tight tolerances are for the IMUNS body (for either variant) is to the inside muzzle end of the square tube legacy AI chassis. This matter does not seem to be an issue with the original shorter flush-mounted blocks that were in place that came from the factory (see my previous post above with pics). However, given the point of the IMUNS unit is to support NV equipment and the like (with its rigid alignment to the optic it, presumably, is in front of), these retention base plate omissions (swivel on the IMUNS and picatinny on the IMUNS-C) could present a shifting migration/optical alignment issue for whatever equipment is attached to it above.
The discontinued variants are the Badger Ordnance Embedded Front Rifle Mount (EFRM):
(https://www.brownells.com/optics-mo...ases/embedded-front-rail-mount-prod44615.aspx)
and the Light Rifle-Embedded Front Rifle Mount (LR-EFR):
(https://www.scopelist.com/badger-or...unt-for-mounting-clip-on-style-nv-sights.aspx)
The currently available variants, the IMUNS and IMUNS-C, will both work in legacy AICS square tubular chassis with the longer ARCA Sawtooth rail options (https://www.sawtoothrifles.com/product/dovetail-rail-accuracy-international-at/). Without the associated bottom retaining plates in place (see below), both currently manufactured IMUNS variants have smooth bottoms for longer Sawtooth ARCA rail emplacement. The exception is on the IMUNS (not the IMUNS-C) in the area where the spigot release button would stick down and protrude; maybe some members have either removed or kept the tab in place with no issue.
The IMUNS unit below has a slight smaller diameter barrel channel (1.25") than the IMUNS-C (shown further below). Shown with and without the retention plate with sling swivel with side views for how the long Sawtooth ARCA rail would clear, or not clear, the spigot release tab:
The IMUNS-C below has a slightly larger diameter barrel channel (1.50") than the IMUNS with a removable picatinny rail that adds additional rigidity once screwed in place: However, this picatinny rail would obviously need to be removed for longer Sawtooth ARCA rail emplacement:
It is not clear whether or not the extra rigidity lost by not having anything more than the crossblock retention roll pin in place to hold the IMUNS units in the front of the legacy AI chassis is an issue. That is, it would most likely be dependent on how tight tolerances are for the IMUNS body (for either variant) is to the inside muzzle end of the square tube legacy AI chassis. This matter does not seem to be an issue with the original shorter flush-mounted blocks that were in place that came from the factory (see my previous post above with pics). However, given the point of the IMUNS unit is to support NV equipment and the like (with its rigid alignment to the optic it, presumably, is in front of), these retention base plate omissions (swivel on the IMUNS and picatinny on the IMUNS-C) could present a shifting migration/optical alignment issue for whatever equipment is attached to it above.
The discontinued variants are the Badger Ordnance Embedded Front Rifle Mount (EFRM):
(https://www.brownells.com/optics-mo...ases/embedded-front-rail-mount-prod44615.aspx)
and the Light Rifle-Embedded Front Rifle Mount (LR-EFR):
(https://www.scopelist.com/badger-or...unt-for-mounting-clip-on-style-nv-sights.aspx)
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