Hello, this seems to be the place for AR newbies.  I'm not new to guns - hunting and pistol but have never owned an AR.  This seems to be a prime time to step up.  I ordered a "BCM Recce KMR-A 16" Barrel, 5.56 NATO, Dark Bronze, 30 Rounds (Optic Not Included)"; I spent the time I could afford looking at reviews, spoke to a few people, then purchased online.  I hate having to buy this way, but stock was dwindling as I watched.

I'm sure my questions are answered somewhere in the depths of the forum, but I can't find any direct answers.  So I thought I'd just ask my questions.  Please feel free to answer any questions I didn't ask, but should have, as well.

1. This is a KeyMod rather than M-LOK handguard.  I think that's probably fine, but should I swap it out initially, or not worry about it.
1.5 I understand that KeyMod and M-LOK are designs for attaching accessories.  Do you have to buy specific accessories that work with them?  That is, do I have to look for a KeyMod Scope or iron sight or light, or do those things have some standard fitting that then attaches to a mount that is specific to KeyMod or M-LOK?
2. Should I add iron sights?  I've read that (a) you won't need them for HD (b) you'd never want to be without them
3. Does a rifle like this typically come with a case, or just in a box?
4. At some point I want to swap out the upper for a 6.5 Grendel upper for hunting.  I assume (in general) AR-15 is AR-15, so I can just pick a 6.5 Grendel upper from anyone reputable and it should work?  And I don't need an armorer to do this?
5. Is there anything obvious I should add to this rifle?  I know you can spend what you want, but for today what I really want is a good HD weapon.
6. Other than the obvious "take it out and shoot a lot" is there anything I should do initially with the rifle (cleaning/lubricating/etc.)?
7. Is there anything about this particular make/model/etc. that I should know or be aware of?

Thanks in advance!

1. Keymod and MLOK are hole patterns. If you want to put on an attachment, you can do it two ways: 1) buy a Keymod-to-picatinny rail. Mount the rail. Then put any attachment that takes picatinny, which is almost universal. 2) buy a direct-mounting Keymod attachment. Mount it directly to the handguard.

Option 2 is preferable, since it’s lighter and cuts out the middleman. Given that MLOK is more popular, you’ll find that direct-mounting may be hard to find. It may be wise to have at least one or two 3” pic rails to start out.

2. Generally, if you’re using a magnified scope, no irons. If you’re using a red dot, get irons. Irons are great because they’ll always be there, never need batteries, etc. I think they are worth it, as a fail safe against anything going wrong with any optic, for any reason, ever.

3. Can’t say for sure, but a cheap soft case will suffice for a long while. It’s hard to crank out $100-300 on a nice case when you could buy something much more important.

4. To change the caliber, you just pop off the upper receiver and replace it with the different one. The AR lower is very versatile, so as long as you have the right mags, bolt, and barrel, most variant calibers will run on a standard lower with no issues.

5. For HD, the answer is usually: optic, light, sling, ammo. A quality budget red dot is ~$100 from several manufacturers. A Streamlight is about $100. A decent sling goes from $30-75. Several spare mags and ammo to go with it (and the rifle zeroed).

6. When you pull it out of the box, it’s a good idea to clean it from tip to butt, checking everything to verify they are correct and in spec. If you find something wonky, you can contact the manufacturer and resolve it ASAP. You’ll also need to zero it, so take the first couple hundred rounds to verify function, break it in, and get your sights dialed in.

7. Nothing really. ARs are adult legos- just plug and play. You can replace bits, upgrade things, swap details. They are pretty robust, and your rifle will probably outlast your grandkids.

Thank you for the response!  So if I want to add backup iron sights, a scope, and light, would the best alternative simply be to purchase a few Picatinny rail sections to attach to the KeyMod and forget using keymod stuff at this point?  Do those accessories typically come with Picatinny mounts, or is that something you add to them?  Finally, in purchasing additional mags is there a reason to purchase metal vs. polymer, small capacity vs. large?  Is this all just purely personal preference?

Lefty answered pretty much everything, but just to elaborate on some of your immediate needs/wants for HD, and also coming from someone else who isn't as experienced or knowledgable, I'd say get a light, some iron sights, and a sling to start. Do yourself a favor and get quality stuff. Not only do you want to make sure you don't buy stuff that could possibly crap out at the worst possible time, but you'll ultimately end up saving yourself money over time; buy once, cry one.

Iron sights are going to be $150-$200 for decent ones. Magpul MBOS Pro's or Troy Battle sights are well thought of. If you don't want or need flip up sights there's many reputable options out there. I like having the option for them to be up or down so I went with flips.

As Lefty mention, Streamlight makes decent lights for not a bad price. You can buy a 1" tubed light and a keymod mount for around $100. I personally like Inforce WML's. They have a built in Picatinny mount so you'd either have to get a small piece of pic rail to go with your keymod rail, or mount it at 12 o'clock on top of the rail near the muzzle and put your front sight behind it.

As far as slings go Magpul and Blue Force are some common go-to brands. I have the Magpul MS4 because I like the option of two point or single point. Single point isn't a very popular method for a lot of people, and with a 16" barrel it probably won't be for you.

A sight is going to be very dependant on personal preference and "mission". How big is your house? Is it an apartment, house, mansion, ranch..? How far are the shots you'd potentially need to take? Do you like/prefer red dots or magnified optics? What type of reticle do you like? You'll most likely have to experiment a bit. Do you have friends or ranges that rent guns with various optics you could try out? I myself prefer red dots. I went with the Trijicon MRO HD because I feel the donut of death reticle is the fastest you can get for CQB distances but is cluttered and distracting for distance shots. With the HD you can alternate between the two.

As far as what you may need to know about your rifle, you picked a really good one and you should have zero issues with it or ever need to upgrade it for a "better" one.

Iron sights and any type of optic will purely be picatinny, which is what you have running along the top of your upper receiver and handguard. Some accessories might come with section of pic rail, but the vast majority do not.

Most likely the only keymod accessories you will need to worry about (for now anyways) would be a vertical foregrip, forward sling mount, and flashlight mount. If those are things you even want.

With magazines, you can't really go wrong with PMAGS. They're very cheap, plentiful, and totally reliable. 30 rounders are the norm. You might prefer lower capacity mags if the length of them impede your shooting position. You might want higher capacity ones if you want to reload less? I think alot of people don't feel that you really need more than 30 rounders though

So if I want to add backup iron sights, a scope, and light, would the best alternative simply be to purchase a few Picatinny rail sections to attach to the KeyMod and forget using keymod stuff at this point?

Depends on what you want. The irons and optic will go on top, so nothing changes. The specific light you chose will dictate how it’s mounted, so you may or may not need a pic rail. Same story for other accessories.

I’d focus on sights first... picking a light is a whole other set of questions. Magpul has good ploymer backup irons at ~$80 for the set, or you’re looking at ~$150-200 for metal.

Example of polymer
Example of metal

Then adding a red dot sight... China has produced some great budget options in the $100-200 range, that can take a ton of casual abuse, stay on for years at a time, etc. Specific models: Sig MSR and Romeo 5, Primary Arms Advanced Micro Dot, Vortex Crossfire and SPARC AR II, Holosun (many options). If you’re a casual human doing casual human things, these optics are the default.

If you want a bit more quality, the +$300 range includes Trijicon MRO, Aimpoint PRO and ACO. Then blastproof wartime stuff at $700 with Aimpoint T2, CompM5, etc.

Do those accessories typically come with Picatinny mounts, or is that something you add to them?

Attachments will be built to accept a particular mounting pattern. MLOK beat Keymod as the industry standard, so you’re usually going to see Picatinny or MLOK options as the default. Keymod is cheaper, but less abundant. Any attachment will have at least one mounting option, like this light kit built for Pic rails:

Attached File


Finally, in purchasing additional mags is there a reason to purchase metal vs. polymer, small capacity vs. large?  Is this all just purely personal preference?

Both are good if they come from a good manufacturer (Brownells/Okay/Surefeed for metal, Magpul/Lancer for polymer). Many small details make people preference one over the other, but soldiers have been using both interchangeably in combat for the last decade. So get a couple of each and pick your favorite. 30 rounders are standard, everyone has a handful of them. 20 round short mags are good for benches and hunting, but may be harder to find/ more $$$. Army standard is 7 mags per person, so that’s a good number to start. Mags are disposable and will fail with a few years of hard abuse, so most gun dudes end up with a bucketful. Or pallet. Or warehouse.

Poor advice, bud. He said specifically that he is new to the ar15. He needs sights, a sling, illumination, and ammo. Aftermarket triggers fall way behind everything else mentioned.

ETA: Basically I’m saying, don’t fill his head up with ideas. You start talking about trigger upgrades, and he is going to think that is what he needs, when really  he just doesn’t.

Add "sights" first.  I started out with iron sights and added a red dot later.  Since adding the red dot I really haven't used the irons.  Then buy a bulk order of M193 ammo and some extra magazines and learn to shoot it.  Add a light and sling when budget permits.  I agree with the previous comment that a decent soft case will get you, your rifle, loaded magazines and extra ammo to the range and back.  Later you might want to add an additional range bag to haul more stuff.  Check out MidwayUSA for some affordable options.

I just joined the forum today and find it to be so helpful. If you don't mind me expanding on this thread, I am close to being in the same position as the OP. I am in the selection process and am trying to figure out whether KeyMod or M-Lok is the way to go. I understand the Army has selected M-Lok so I'm sure that will increase its' popularity. Any feedback that will help me with this selection is appreciated.
Thanks!

M-lok is superior in almost every way to keymod. You do have to ask yourself a couple of questions though. How much shit are you really going to be hanging off of your rifle. If it’s just a light and a grip of some kind, you can probably get away with keymod.

Why even bother with keymod? Well, the thing is, guys are dumping perfectly good keymod rails left and right to upgrade to an m-lok equivalent. That gives a guy an opportunity to scoop up some really good deals on perfectly serviceable rails that utilize a less favorable accessory mounting system. There are still plenty of keymod mounting solutions out there currently that will fit most users needs.

Keymod looks like ass though, so go get you an m-lok rail and don’t look back. How’s that for a time waster?

Either will work fine for 99% of end users, but MLOK has won the war and you will see less and less Keymod stuff being made and even less development into new stuff for the system.

To sum it up, go with MLOK.

This.

If you only need a light, and you want the cheapest... good keymod handguards can be had for CHEAP. If you’re building the upper, I mean.

If you want flexibility, and you’re buying factory... MLOK. It’ll be more available for a longer time.