ARMS 18 mount on M305

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Hi Guys,


Looking for help/advice from those who have succesfully mounted an ARMS 18 mount to an M305. I'm running into an issue where the mount sits to the left and on a angle (looking at it from the back you can see it leaning downward to the left).

I'm guessing it's a mount to receiver fit issue, anybody ran into themselves and can recommend a solution?


Thanks
Eric
 
There is a post I did about it in the stickies somewhere...
When you installed it did you use the C-clip that came with the mount?
If so, remove it, discard it and try again.
Hope that helps
 
I copied and saved this awhile ago from you :)

Installing An ARMS18 Mount by M14Doctor

I find it odd that so many folks have issues getting ARMS 18 style mounts to align correctly.

Here's my tips:

* Get rid of the horse shoe washer on the inside of the retaing bolt. This lil bugger is what offsets the front of the mount... I ditch it everytime.

* The rear screw that attaches to the stripper clip guide key. This has an adjustable pad that is key to alignment.

* Remove the screw and use a slot screw driver to adjust. First step is to back it out so it doesn't make contact upon "test fit" install. Same goes for the front pad.

**on my promag version this rear adjustable pad was installed backwards from the package. The slotted face should face up, away from the receiver.

* Snug fit the side bolt and set a 3/4 or 1" dowel on the mount. Observe position.

* Then slowly bring rear pad to just touch the clip guide key.

* Install rear screw to just snug, then fully tighten side bolt

* Check alignment and level.

* These can now be adjusted by removing rear screw and lessening or increasing the tension of the rear pad. Reinstall screw and fully tighten.

* Finally adjust front pad until it just touches receiver.

Seems to work every time for me, and I install an awful lot of the ARMS18 style mounts.
 
Yeah, that's it..... Confuses a lot of people this m14doc/45acpking thing LOL
Same guy :D this username is what I started with on cgn and the "m14doctor" thing was my former dealer account.

Anyhow, good to see that info gettin used :rockOn:
 
helpful advice... no go

The mount is still offset to the left, even when loose fitting it, and won't stand straight (is angled downwards to the left when seen from the rear)

I see a m14.ca mount in my future...
 
Well... It's the best we can do for ya from our keyboards :D
Bummer she's giving you grief
The odd time I have had the same issue and I solved it by polishing the long horizontal key that mates to the receiver below the side bolt
I've had this issue on both norcs/polys and M1A's
Because the arms is steel, these surfaces , key and keyway, sometimes need massaging. I only work the mount, not the receiver.
We're not reshaping so much as polishing and deburring.

Another issue could be the vertical key and keyway above the side bolt may not be aligning correclty. I have seen this on a handful of chinese receivers. This is generally a bad one and a receiver machining mistake. Unfortunately..... This would mean an m14.ca mount might be your only solution.
 
Glad this thread showed up. I loaded up a bunch of sweet loads and took them to the range on Sunday. I should mention this is the first time I've put a scope on the ARMS18, (it's an older Tasco 2-7 I'm hoping works as 2X is okay for deer where I hunt, but 7 should do for target).

I dialed the scope down to 2X to shoot @ 25 yards and could clearly see the front sight, significantly to the right of center. I was not even on paper at 25 unless shooting at the left edge of the paper. I dialed that bastard about 160 clicks left and got it to about 1 inch right @ 100 yards. Problem was, "ON" @ 25 yards was about 10" high @ 100 yards.

I tore the mount down last night, wondering why I don't stick to bolt actions, but followed the instructions and I think I have it sitting pretty well now.

I recommend that anyone using this mount take a good hard look at it with some straight edges before even thinking of mounting the scope.

Thanks 45ACPKING and Chalkriver for posting.
 
final update on this one - got an M14.ca mount, beautifully made, I love it

but... I soon discovered that while the ARMS looked to stand crooked (and it likely did to some degree), the M14.ca kept about the same point of aim as the ARMS. Seems barrel itself isn't centered in receiver or something also these lines. Even tried different scope with different rings.

In the words of my ancestors: calisse de ########!!!!!

Looks like it's back to irons on this one... or selling it outright :mad:

my faith in Norinco has been somewhat shaken... just got a CQA that had a crooked front sight (was obvious so sent for return), coupled with this... I'd rate the norcs as a "meh" overall. I still love my norc 1911 though :redface:
 
How far off is it? So far that you can't adjust the scope to align POA with POI?
Does the gun shoot nice groups? If it does maybe consider some windage adjustable rings to get things lined up.....
 
I had a similar problem on one of my Norcs.

The one rifle I had selected to keep the original barrel length, with the smoothest action etc. had a receiver left-side surface that was not true to the barrel bore. The mount was ever so slightly to the left, to the point that aiming at one target at 50 yards I was hitting the next target to the right. I fought with it and tried what I could and rather than take a grinder to the mount I bought and installed an M14.ca mount.

There is a mention of some receivers being thicker on the left forward corner buried in one of the stickies.
 
45ACPKING said:
Well... It's the best we can do for ya from our keyboards :D
Bummer she's giving you grief
The odd time I have had the same issue and I solved it by polishing the long horizontal key that mates to the receiver below the side bolt
I've had this issue on both norcs/polys and M1A's
Because the arms is steel, these surfaces , key and keyway, sometimes need massaging. I only work the mount, not the receiver.
We're not reshaping so much as polishing and deburring.

Another issue could be the vertical key and keyway above the side bolt may not be aligning correclty. I have seen this on a handful of chinese receivers. This is generally a bad one and a receiver machining mistake. Unfortunately..... This would mean an m14.ca mount might be your only solution.
Click to expand...

As stated above, and taken into account that 45ACPKING has forgotten more about the M14 then I'll ever know. It is a simple process. I seem to do a lot of them now for the boys. It involves a Dremel and lapping compound and polishing away some FINISH (only mount!) in key areas to fit it to the receiver and lapping the rail into the receiver. It is a very simple process, just time consuming.

Warning: do not do this if you are not confident with a Dremel and do not understand the receivers geometry. I try EVERYTHING else before I resort to this method; C clip, pressure pad, stripper clip guide, and proper torque before letting the owner know the progress and options and letting them decide what they want.
 
Can-down said:
How far off is it? So far that you can't adjust the scope to align POA with POI?
Does the gun shoot nice groups? If it does maybe consider some windage adjustable rings to get things lined up.....
Click to expand...

it's too far to be adjusted with scope alone. I did think about windage adjustable rings... but at that point I'll probably keep it as an irons only.

As far as grouping, hard to say, shot it very little and never for groups, but with the irons it does shoot to point of aim
 
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