[gundrted]

Hello

Just got off the phone Sig and they confirmed I have two routes form my MCX SBR (both are back ordered). I already have mil-spec SBR (form processing) lower I'll be using. The MCX lower will remain non-AFT regulated.

1. AR Conversion Kit. This includes a full w/hand guard 9in 300blk upper, folding stock and stock adaptor. $1305.60 (think that was the price)
2. SBR Parts only. 9in 300blk Caliber exchange kit, stock adaptor and suppressor width rifle length hard gauge. $900 ($600+$100?+$200)

Both options are f-ing expensive with or without the 20% warranty reg discount.

My first thought was to swap the barrels between the 9in and 16in. Then move the upper and stock different lowers. This is the cheapest, but the most work. Getting an AR conversion kit nets me two working ARs.

So here are my questions.

Do people really do this?
How easy is it to, really, swap the barrels?
Does having the hand guard cover the suppressor really protect it or does it just look amazing?
Can or would you want to shoot a 9in barrel with a rifle length hand guard?
Is a assembled upper and folding stock worth around $400?
Aside for the pain to my checking account are there other advantages/disadvantages here?

 

[kansascity45]

Interesting options, but it's all academic at this point.

SIG has been promising delivery in a month or so - and selling 'pre-orders' on these 300Blk kits & parts all year. They told me this week that some 're-engineering' was necessary - and couldn't say if any will ship this year...

Cheers

 

[gundrted]

I guess this is more a though exercise more than anything, but I'm good with putting my name on the list.

To complicate matter .... If I go with a full upper kit, it doesn't need to an MCX (I guess). that make the options a lot wider ..... ugh .... first world problems.

 

[mikedeanellis]

I have the MCX carbine patrol model, 16" barrel and long handguard. 556 nato.

My plan, far future is to buy the shorter barrel, sig silencer, and shorter handguard. 300 blackout.


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[Adiboo]

FYI to all:

I spoke with a rep from SIG CS today and asked if the MCX 9" .300 BLK complete upper assembly AR conversion kit comes with the folding stock as the OP claims and it DOES NOT.

I made the call today after reading this thread because I have this same item on order. I was pretty sure that a stock was not included in the "kit" but had to comfirm.

 

[kansascity45]

Right, SIG's MCX caliber conversion kit's present spec doesn't include a butt stock, and I don't know why it would. Since, they're doing some MCX 're-engineering' process, we can't be sure exactly what these 300blk kits will include though.

I'm told they fully intend to produce these kits, but they're not saying what they're re-engineering, or when 300s will be produced - in either complete rifles or conversion kits.

Based only on a few posts here, we can only guess they've found some excessive receiver wear running 300 at very high round counts.

So, here's where I think we are - Starting last year, a very large number of us MCX owners 'pre-ordered' SIG's MCX 300 kits. We've now been waiting patiently for a LONG time, but IMO we're not in a good place right now.

We've pointed out the broad disconnect with SIG's presenting MCX as a modular platform that's 'specifically designed for 300blk'. And, their continuing marketing of their 300 conversion kits with no delivery schedule in sight!

Our concerns have need thoroughly expressed, and I'm told SIG's 'powers that be' are currently considering this matter.

We can appreciate QA/QC required delays, and if they're unable to give us an actual delivery schedule - we've suggested a couple consideration options that seem reasonable. These considerations are kit price reductions based on shipping delay time from 'pre-order', or webstore coupons - if an owner chooses to cancel their 300 order...

Hope to learn more soon...

Cheers

 

[gundrted]

FYI to all:

I spoke with a rep from SIG CS today and asked if the MCX 9" .300 BLK complete upper assembly AR conversion kit comes with the folding stock as the OP claims and it DOES NOT.

I made the call today after reading this thread because I have this same item on order. I was pretty sure that a stock was not included in the "kit" but had to comfirm.

Interesting, because the rep I spoke with said the AR upgrade kit came with everything. Perhaps I'll call back next week and confirm.

Parts aside ... any one have thoughts on:
Does having the hand guard cover the suppressor really protect it or does it just look amazing? Keep in mind I didn't go for Sig can. I'm getting the SilencerCo Hybrid.
Can or would you want to shoot a 9in barrel with a rifle length hand guard?

 

[kansascity45]

Interesting, because the rep I spoke with said the AR upgrade kit came with everything. Perhaps I'll call back next week and confirm.

Parts aside ... any one have thoughts on:
Does having the hand guard cover the suppressor really protect it or does it just look amazing? Keep in mind I didn't go for Sig can. I'm getting the SilencerCo Hybrid.
Can or would you want to shoot a 9in barrel with a rifle length hand guard?

Sure, those MCX/MPX suppressor width handguard options will be great if they stay cool enough to actually use. Obviously, the can needs to fit inside the handguard too.

Their looks are a personal preference, but having the ability to move your support hand out on a piston SBR - that's also suppressed will be a VERY popular option.

Perhaps one day, this MCX setup will be available .. we're just not there right now...

Cheers

 

[gundrted]

I found these comments below

https://www.ar15.com/forums/t_3_118/696233_.html&page=1

Well a bit for looks, and some justification for it.
You're able to run a longer sight radius with irons.
More hand guard to grab a hold of.

But again, suppressors are HOT -
Sustained fire will leave you with a hot can.

Removing the can under the hand guard is going to be a pain in the *** if it's not a thread on.

Also you this thread needs to be moved to the suppressor section.

 

[kansascity45]

Yeah, agree with those comments. My interest is better support hand control. You see, the closer your rifle support hand is held into your body, the weaker your grip on the rifle.

Say there's a late night bang - the sound of your front door being kicked-in. You're walking through a doorway with rifle at high ready - a bad guy grabs at your weapon.

Using the muzzle of your rifle as club to knock this guy's head off is your immediate response. There's NO time for changing grips or a backswing - you'll need all the power you can muster at that instant!!

Your striking-force is much greater with that support hand further out on the barrel.

So, training with your support hand as far forward as practical is solid technique. And SIG516's 7" handguard just isn't long enough.

This scenario isn't a fiction. Our SOCOM instructor broke his rifle's vertical hand grip on 'the biggest Iraqi he'd ever seen's sternum' going through a doorway in Fallujah. Oh - He doesn't suggest using those vertical hand grips either...

As for running suppressors underneath a hand guard - there have been several tests on this setup with no significant problems. Of course, these suppressors can run very hot, so the handquard will heat-up, but it's really no different that the gas valve on SIG's ARs. Depending on the handguard's materials - continuous mag dumps may cause some discoloration of the handguard though...

Cheers

 

[gundrted]

Thanks for all the comments.

I ordered, back ordered, the MCX AR Upgrade Kit in 9in 300blk today.

I spoke with two different reps (just to be safe) and the the AR Upgrade Kit INCLUDES: MCX Upper 9in 300blk, stock adaptor and folding stock. I'm not sure what other people have ordered but the AR Upgrade Kit includes all 3 items. Buying just the SBR parts I wanted would be cheaper, but I felt the work disassembling/reassembling rifles into different configs just wasn't worth it. This way I end up with two rifles using the same uppers. I could always steal parts from one to keep the other working.

I decided not to get the suppressor width rifle length hand guard. It was back ordered, like everything less, but I figured I could always get that once I try the stock guard. By the time I get the Kit there may even be aftermarket options.

As for lead times on the back ordered items there was no firm date. The rep did say that most of the production is going to complete units and not 'parts'. He said they are having a hard time keep up with volume of orders as a whole and not just the MCX line.

Again ... Thank for all the input.

 

[kansascity45]

OK, gotcha - You're talking about an MCX AR Upgrade Kit, and I'm thinking MCX Caliber Conversion Kit.

Yeah, we've heard of, but haven't seen any AR Upgrades Kits to run MCX uppers on standard AR lowers. The folding stock adapters are available, but no MCX uppers.

That $1,306 upgrade kit price you mention is just $143 less than what I paid for my complete MCX rifle. And for perspective, these 9" 300blk caliber conversion kits we're pre-ordering are $480 for the barrel, handguard and bolt.

No one knows when SIG with ship MCX in 300blk rifles or kits. So, if you want to have an MCX to shoot this year - it's gonna be a 5.56...

Cheers

 

[mig1nc]

FWIW Lipseys listed the upgrade kits with stocks too.

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[230Ag]

yep. I talked to SIG on Monday and they claim that the 9" 300 BLK barrel swap kits will ship in 2 months, but it seems like they have been saying that for a while.