Softening a Norc M4 - Pics of brakes used on last page

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Mystic Precision

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A few months, I jumped into an AR with the then new Norc M4. Given the asking price, it was a no brainer.

Was thrilled with how it functioned and shot so blinged it up. Put up a post on the surgery needed to get the orig parts off - not so much fun. But at least I know the material used was superb.

I have been shooting ARMSCOR 62gr FMJ over 22gr of WCC 735, CCI 450 in Fed brass. Combo runs great and is a moderate load so brass should last as long as I don't loose them.

What surprised me was how much it kicked... Was all that internal mass smashing around.

With the new YHM flip sight gas block, I started to reduce the size of the port to get less gas into the receiver. It takes a very small hole to make things run. This rifle was WAY overgassed.

Slowed the parts enough that I was able to change the direction of the ejected case - from going forward to going backwards. Then it just stopped if the port was reduced more.

So now to slow the bolt carrier, and buffer with the goal to get them to just stop before they hit the back of the buffer tube.

With some great advice, I decided to find a 9mm buffer and a heavier spring. I also added a 'twang buster' . Just a hunk of plastic that sits on the back of the spring. My thought it might be a softer smack if the carrier hit it.

After a few months of waiting, I got back to the range and fired some rds.

WOW, it is so much softer and gives the impression of shooting a 10/22 with speedie ammo.

There were some new shooters there and they tried it. All were holding the rifle pretty loosely and most had a failure to eject/feed. The carrier wasn't cycling completely.

When I shot it with a firm grip, it functioned 100% so I have pretty much hit the limit of how soft I can make this rig (recoil pad and sprung stock would be the last items but I am not sure they are worth the fuss).

I can now just feel the carrier bump into the back of the tube but it isn't going very fast. Kind of a shuck shuck feeling. Loving it.

There is one more tweak I might do to stop the buffer/carrier completely before it hits but I think I am getting into a condition where it becomes unreliable.

We shall see.

I continue to very impressed with this Norc. When I am not making it fail to function, it runs without fuss or much lube - only a smear of synthetic grease on it now. haven't cleaned it and nearing 600rds without a bobble.

Trigger tuned up nicely for a crisp light single stage pull.

All the US bling parts have stayed on and working great.

Having way too much fun....

Jerry
 
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Goal was to spend as little money as possible.

The light carrier might not be ideal if I decide to go with a heavier bullet ?????

JP, and others, also make gas blocks that will restrict the case flow. More and more will come out as silencers get used more often. But again, pricey and not so easy to get sometimes.

All methods used are simple and can be accomplished by anyone.

Jerry
 
recoil

The first thing you said that peaked my interest was the use of 62gr.bullets,Im assuming you are using Sierra boat tail match(blitzking???),anyhow the heavier bullet increases recoil as you probably already know,the difference between a boat tail and a non boattailed round can make a small noticable increase in felt recoil especially in a semi auto(gas pressure,delay, seating depth and OAL) which again you already likely know from your reputation. One of the easiest ways I have found on semiauto's to reduce recoil and have no effect on reliability is to increase mass of the firearm. It doesnt take much wieght to change the "feel".depending on the type of stock you run you can use steel shot in a battery compartment,or add to the pistol grip void and even Cast a lead weight to mount inside your free float tube(try an ounce in one position and then the others one at a time)The different positions will have different effects depending on many variables BCG,buffer weight,spring tension, barrel weight and length especcially with a moderate load of 748,try Vita Voiri. But im likely preaching to the quior here as I understand your a extreme long distance bolt guy,you finally got to lazy to operate the bolt didn't you? me too.
 
Body armor or a level 4 set of SAPI plates on your body! Takes up all that recoil. :eek:

Nah, I'm just :nest: and yanking your chain! Keep having fun with that rifle. Sure is different from the Precision Rifle game, eh? :D

Cheers,
Barney
 
S&J will have our KA-1222A units in stock in early January, makes an AR feel like a .22 and it is compact and lightweight (only 62g)

Jonah11-24-08001.jpg



Might also want to put a heavier buffer in it. If the buffer is hitting the back of the tube it will feel like the gun is kicking a lot harder than it should.
 
I would try the spikes tactical T2 buffer with the tungsten powder fill, and a dlask (pws) copy break....best thing I ever added to mine :D
 
Fenix.NZ said:
you wanna reduce the recoil of your AR ? .. buy an M14 , shoot it for a few days, then go back to the AR :D problem solved
Click to expand...

Been there and actually, my full figured M305 was a softer shooter then this Norc. certainly no worse.

As was said, it is the impact of the bolt carrier and buffer against the back of the tube that is the problem.

when I stopped the bolt from cycling, recoil was peanuts so its not the load that is the issue. which is why I have gone to lengths to try and 'stop' the carrier/buffer from slamming.

Hungry, I actually started shooing this rifle with my padded shooters vest. It kicked stupidly hard for a 223 and I have shot a TON of 223. Going bang, bang, bang as fast as I pull the trigger is a hoot and we are hoping to get some targets up so we can do some CQB fun stuff.

Clays, bowling pins, golf balls and other targets of opportunity are such a pleasant change from the rigour of match practise.

shooting the rifle today, you can feel and hear the back and forth of the carrier/buffer. Kind of fun... like working the slide on a pump SG without the effort.

yes, it is that slow.

AND.... I got it to stop running. This is not a bad thing. I have run this rifle with little to no cleaning AND little to no lube. Then several steps to limit the forces to let it cycle. It has soldiered on very very well given my attempts to make it stop.

Now, after at least 600rds, the lube is not enough and with so little slide speed, it is just hanging up. BUT it still functions almost 75% of the time. I bet if I went with a heavier load, it would run 100% again.... but that would defeat the fun of a shuck..shuck semi auto.

I took out the carrier to see how badly the fouling was. It really wasn't all that dirty with no burnt on carbon. A quick wipe with the finger took off the dirty grease and there was clean metal underneath.

I think this syn grease is mixing with the fouling and keeping it from caking to the metal (?????).

To keep the test going, I am just going to wipe off the dirty grease with a towel WITHOUT taking the bolt and carrier apart. Relube and see what happens.

I am hoping that it keeps going. Certainly not the way to set up an AR as a working rifle but with so many claims these things are cantankerous beasts, I am running it as 'poorly' as possible to see if my rifle is so.

So far, I have nothing to complain about. The thing keeps going until I really do stuff that I shouldn't.

As I said above, when I stopped the gas from cycling the BC, the recoil was mild. I don't see how a muzzle brake will help the real issue which is the overspeed of the BG?

then I didn't want it any louder then it already is.

As to adding weight, I am not interested in a heavy battle rig. That reduces its affectiveness to move and gun. the 12lbs M305 I had was a pussycat to shoot but what a pain to lug around.

Jerry
 
kingarmory said:
S&J will have our KA-1222A units in stock in early January, makes an AR feel like a .22 and it is compact and lightweight (only 62g)

Jonah11-24-08001.jpg



Might also want to put a heavier buffer in it. If the buffer is hitting the back of the tube it will feel like the gun is kicking a lot harder than it should.
Click to expand...

I put in a 9mm buffer which is around double the weight of the factory one. Then I put in a heavier buffer spring. It has all worked very nicely.

Not to come across as a d!ck but the unit you show will do little to act as a muzzle brake. The exit port is WAAAAYYYY too big (at least how it looks in the pic). What you have is a fancy ported flash hider.

I really liked the concept of a shock absorbing buffer. It would do a similar job to what I have done but if the gun is still overgassed, the parts will still slam into the rear of the buffer tube ie too much inertia.

reducing the amount and pressure of the gas through the gas block is the best solution to this platform. I am so surprised there aren't adjustable gas blocks with a knob with various settings like the XCR.

would be very straight forward to make.

Jerry
 
"...how much it kicked..." I'd bet it has more to do with the muzzle blast and noise being so close to your head. That wee stock won't help either.
 
Valid point but I am double plugged and have shot the rifle at various levels of 'gas'. In its orig format, it kicks way more then any 223 has a right to. Feels like a SG with 1 1/8oz standard load.

Left with a sore shoulder after only 30ish rds.

With no gas, it just goes bang and that's about it. My load is quite light.

Pity, no one is closer to try. It is kind of fun to hear and feel it move back and forth.

recoil pads are lacking in the AR world. I have a magpul stock now and the extended pad is not all that wonderful as recoil pads goes. Most other stocks only have slip on plastic covers to help.

The idea is that these rifle don't kick. Well, mine doesn't anymore...

Jerry
 
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