Get a GOOD smith for iron sights,
And use the full length 'Peep' type that come back to the back of the receiver instead of those 'Miss Everything' sights they like to mount on the barrel way forward of the receiver.
A GOOD SMITH will have the proper jigs to secure the reciever/barrel and make VERTICAL drill holes for mounting.
Personally, I prefer the military M-24 type mounts, but that front mount has to be silver-soldered on the barrel, and that will take a REAL GUN SMITH to do properly.
(The factory custom shop will do it CORRECTLY, but it's not real cheap...)
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As for mag capacity,
You MUST remember the mag should NOT extend past the bottom of the rifle in 'Tactical' rifles.
Many 'Police' and 'Military' specifications don't even have detachable mags, internal mags only.
Pin-Point rifles are intended to fire ONE Cold Bore shot to end a problem or close an 'Issue'...
The mag doesn't protrude out of the stock so it doesn't get hung up on anything, or interfere with what might be 'Less Than Optimum' rest when you are trying to get a sight picture...
Something you might want to consider for your 'Tactical' rifle before you start buying extra parts...
SOLID FLOOR PLATES make for a MUCH MORE RIGID receiver/action mount than something with a big hole in it.
The first thing I do when I get 'Tactical' rifles in is take the aluminum floor plate/trigger guard off and install a STEEL trigger guard and floor plate.
Detachable magazine is up to the particular end user,
Military wants 4 shot or 5 shot detachable mags,
'Bench' shooters usually want internal mags with solid floor plates,
Police departments are mixed up all over the place.
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The second thing you should consider,
Torque Wrench for the floor plate to action screws.
The rifle will NEVER shoot really well if you don't have the same TORQUE on the screws and don't have the action bowed in the rifle stock.
Torque wrench for optics mounts is advisable, but you don't remove your optics every time you clean,
You DO remove the action from the stock every time you clean... (or at least you should)
and you SHOULD release the tension from the mounting screws when the rifle is in storage,
And that will require a torque wrench to properly tighten up the screws before each use...
If you remove/change optics, you should also re-torque those mounts when you reattach to keep proper zero.
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The THIRD thing you should consider before the rest is proper optics mount for the top of the receiver.
Most optics mounts are TWO PIECES of crap aluminum.
Pass right by those.
The next type (and next step up in cost) are the full length mounts that bridge the action opening... But made of ALUMINUM.... Pass on those also.
Find yourself a STEEL mount that is a FULL BRIDGE over the opening in the receiver.
(Badger, Ken Ferrel, ect.)
Aluminum expands and contract TWICE the rate of steel,
And it does it 3 times as fast!
So, as the day gets warmer, the sun comes out or goes behind a cloud, your optics mount is moving around like worms in a skillet on top the receiver....
And if you are LUCKY, it's just the MOUNT, and the attachment screws aren't trying to BOW THE RECEIVER as the aluminum moves around!
Now, since you have STEEL that is expanding and contracting at the same rate as the action/receiver,
Consider having a GUN SMITH put the bridge on for you.
Factory Remingtons come with #6 Screws to attach the optics mounts.
You should really have #8 or #10 Screws doing the job,
OR,
If you intend to use #6 screws, at least put an EXTRA SCREW in each end to secure the mount better.
(military rifles are, Army #8 screws, Marines #10 Screws)
'Joe Average' doesn't have a head mill or the correct Jig to add perpendicular holes and thread them in an action, so a well equipped gun smith is the logical choice.
The steel bridge mount, with proper connections, will STRENGTHEN and STABILIZE the action, keeping the rifle receiver from bowing or twisting as much when you discharge a round.
Bedding the optics rail mount to the receiver is always a good idea.
Bedding keeps ANY movement from making the mount move around, and it helps distribute the screw force (clamping load) out over more of the receiver/mount.
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Rings are a personal choice, just keep in mind you want TWO screws on each side of the optic on EACH MOUNT (4 screws total) to spread out the clamping force load and keep your screws from backing out with expansion/contraction and use/abuse.
Personally I wouldn't put a high end optic in a set of rings that weren't lapped or reamed for 'True'.
Most rings will clamp down at odd angles and try to twist the tube, which again, causes zero to shift when the tube expands/contracts with temprature.
It only takes a few minutes to hand lap in a set of rings, and for the sake of consistency and just plain old peace of mind, I do it.
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Next, consider a good tune on the trigger.
You are NOT looking for a 'hair Trigger', you DO NOT want the rifle to go off when you take the safety off,
You DO NOT want the rifle to go off when you bump it on something,
You DO NOT want the rifle going off with every slight touch of the trigger, this causes unexpected discharges...
You want AT LEAST 3 or 4 pounds on any FIELD RIFLE, and 'Tactical' rifles are field rifles by definition....
Remington rifle are VERY tuneable for both Creep up to release,
Release tension,
And overtravel.
Personally, I don't like 'Creep', but all military and police want some 'Creep' or 'Take Up' in the triggers.
Release you want to be at 3 to 4 pounds MINIMUM.
If you go below 3 pounds, you are ASKING for problems.
Over travel...
This is a hot potato...
Personally, I think over travel stops just yank the receiver when you hit them...
Just like yanking the trigger does.
I take the over travel stops out of my guns and my shooting improved.
Some people like a specific over travel amount, but that is personal taste, and people will argue for HOURS over it!
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Once all that is done, and you have broken in the barrel properly...
Consider things like magazine capacity and color changes!
