Curious what the newer version looks like. There are a number of ways I could mod either the feed tray or the receiver above the BE. Last I checked the feed tray was north of $500. Or I could replicate Mark's device. If you get a chance, could you post a comparable pic to those I posted?

That would be great if you could take a photo of it for me.  Since Mark isn't making it, and I enjoy making my own parts.. this would be helpful.

With all the different MCRs.. I'm curious if there's a list compiled of the differences between the generations.

This is what the updated (granted they are not all that new at this point) feed tray looks like.  The way its shaped the feed tray bullet channel cutout doesnt expose any of the aluminum receiver like the older feed tray did that was cut much higher.  The feed tray is as low as the top of the steel barrel receiver extension.  You can see the green paint from M855 that has scraped off on the feed tray and barrel extension in the pic from the bullet being forced down that "rampway".

The feed trays are expensive so I would factor that into your purchasing cost if you buy an older unit with the older aluminum alloy feed tray.  It the unit you are looking at purchasing has the aluminum alloy feed tray you are going to want to replace it anyway as they wear out pretty quick anyway.

Attached File

Pics from a bunch of angles including one with a cartridge in the feed tray showing how the insert interacts with the bullet to force/guide it down into the barrel.

Attached File

The bullet guide appears to be nylon or some kind of plastic?

yup, they are some sort of polymer

Prefect for a 3d printer then.  Got one coming in.  ??

I have a 3D printer but I'd probably put a chunk of Delrin in the mill. I have a couple of other ideas as well.

Is anyone doing anything different for the bolt catch other than the supplied part?
The KNS pins are b/o everywhere. I'd rather not drive the roll pin out more than once.

For testing purposes it would be good to use a 3d printer.
I have to do everything by hand now that I don't have access to a Bridgeport. I miss that thing.

I have a solution for the bolt catch... Very simple. I've always been a fan of the Magpul BAD. (I even machined one for myself before it was released) .  
Any case take a Phase 5 extended bolt release and cut the top off and install. Simple and easy. I also added some JB weld to the openings to add more rigidity. I shaved it down lower than I needed to but it still is rigid.



Adding photos of my MCR steel feed tray for historical reference. This was purchased in 2017

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Well I installed a MG34 spring, took out the little piece of metal in back of the buffer tube and ran my MCR.
On a 90rd run, it had an issue stripping one round out and required me to pull the charging handle back a few times to strip the round from the belt, into the chamber. I had lubbed about 80% of the belt but the section I didn't lube was the place where I got my issue.

For magazine fed my friend had a issue of light primer strikes. No idea what is causing it to happen to him. I did a 20rd magazine run with my ammo and it ran..

What ammo are you using?
As I posted on the first page, I've had my Shrike since around 2006 and never once lubed any links/ammo and I've run many thousands of rounds but I only shoot brass cased ammo.  Mine has the very early modified 249 SAW feed tray.  I have a couple friends with the same experience.
In addition I find that non-domestic brass cased ammo is a little fatter or rougher going into links.  Even brass cased Wolf Gold is this way.  
I also only use used links.  If I take a Wolf Gold and insert it into links I can feel that it isn't as smooth as LC M193 or M855...both of which are much easier to insert.  
Not saying it won't work though.  I just have to use the Ares supplied spring and an H2 buffer and it will run Wolf Gold just fine.  But if I run M855 / M193, I can run a 308 Tubb flat spring and hydraulic buffer and get a slower cyclic rate (in the 600's which is amazingly slow for Shrike / MCR).
I also only hand link ammo as well.  If you use a linker, you won't feel when a specific link requires more force due to a damaged link.

I'm shooting American Eagle, but not sure what my friend was shooting when he had a problem.  All of the ammo is brass, no steel. The links I used are 1 time used, each link was hand loaded, I don't have a loader.. but might buy one later.
The 90rds on the belt I loaded, I had 10 rounds of unlubed and the rest lube. I happen to put the unlubed links in the middle of the run to see if it stops. Note that I had huge stoppage issue the previous time I went shooting with the unlubed links. The lubed section I lubed the links with Johnson wax.. it was so smooth going in, I recall the unlubed was definitely more harder to push in, which is expected. Possibly your used links allowed ammo to strip out easily.  I'll just lube my links for now to ensure I don't have stripping issues.

I think my main issue is the light primer strikes my friend had using his magazine. I'm wondering if those were caused by bolt bounce. I was thinking to change to a Kynshot hydraulic buffer, but I found a post about it saying that one guy didn't have success with it.  Maybe I'll replace my Spike's ST-T2 with the ST-T3. I have one lying around so I can't imaging it couldn't hurt anything to try it out.

My links aren't 'loose' if that is what you are thinking.  I can take once fired links from various sources and they all run fine with no lube unless they have been bent or something.   I've even tried some brand new links one time and it made no difference.  The couple guys I know don't bother to lube their links either.
My Kynshot works but only with M855.  I wouldn't try a Kynshot unless your setup was well broken in and after you have had success with an H2.  
I wouldn't use a Spike's buffer since they use tungsten powder. The powder doesn't have as much of a dead blow hammer affect as the solid weights of a typical H2.  

I have never went heavier than an H2 and after I don't know maybe 15K or so rounds I had the lug on the carrier shear off on me.  This was around 2007 or 2008.  I met with Geof of Ares and he said it was possibly a bad head treat and swapped it out for me.  He did caution me on using heavy buffers with any piston AR since you are putting more stress on the op rod and the impact lug on the carrier while a standard AR the worst that will happen is it just won't cycle if you go too heavy.

I have never had much success with the Kynshot buffers in my Shrike.

I started off with the regular 5.56 Kynshot buffer and would get both short stroke issue as well as failure to strip rounds from the links.    I ended up cutting the piston down and rewelding the piston to the "head" of the buffer to decrease its stroke as well as the pressure required to compress the buffer completely so the gun could reliably scoop up the next round in the tray. This seemed to eliminate the short stroke issue but I still had issues with rounds being stripped from the links completely.

I also bought the 9MM Kynshot, 308 Tubbs flat wire spring, and installed an A5 tube.  With this setup I still had similar failure to strip rounds but not as bad as the 5.56 Kynshot probably due to the 9mm buffer weighing more.

I have also played with a Colt Hydraulic in an A2 stock and it slowed the rate down and stripped rounds from the links but lived a short life as the pin holding the buffer together cracked in a couple hundred rounds due to the sharp piston recoil of the Shrike.

My take is that the Kynshot buffers have a couple issues.

1. They don't have enough mass in the right place to reliably strip rounds from the links.   The place where the spring engages the buffer is that disk on the front of the piston and when the buffer and carrier comes forward and hits the link that energy/mass on a normal buffer that would be used to strip the round from the link is instead absorbed by the rear body of the buffer collapsing/compressing on the piston.

The Shrikes design weakness is that they have very little over-travel on the bolt carrier group to get a running start at the round in the link and the distance and angle into the barrel is a pretty sharp transition. So you really need a sharp impact on the cartridge to dislodge it from the link and force it down and into the barrel. Due to the design  of the kyshot buffer where the buffer spring only directly controls that little disk on the end of the piston,  the buffer absorbs some of that impact energy on the forward feed stroke as most of the buffer mass is on the end of the little collapsing piston rod.

2. They absorb too much rearward stroke so you get no "bounce" of the buffer+carrier off the rear of the receiver buffer tube which helps with stripping rounds from links and they can also cause the gun to short stroke as well exacerbating the limited bolt over-travel issue inherent in all Shrikes.

3. The kynshot buffers also are not great at controlling bolt bounce as they have very little dead blow hammer effect compared to traditional sliding steel (or preferably) tungsten weights.  Similar to the issue above, the only dead blow effect Kynshots have is the body of the buffer collapsing forward on the piston as the carrier slams home.   I have a sliding anti-bounce weight inside my Shrike carrier to help with bolt bounce and without that installed all of the kynshot buffers I have will all experience bolt bounce with a dead downed hammer.

I personally both stretch and lube my links in order to ensure I don't get stoppages as I do like to shoot both US ammo as well as brass case foreign ammo (Wolf Gold, PPU) out of my gun and I also run a reduced power recoil spring to slow the ROF.  I just have a pile of "shrike" links that have been pre-stretched over the years and hit them with silicone lube spray before linking them.

My personal setup that I have used for years is the MGI rate reducing buffer and a Springco Red enhanced spring.   However, I have considered repairing the Colt Hydraulic with a better quality steel pin and also cutting it down to A5 spec (as the back end is just an open tube with extra oil in it) and trying it out again to see how it goes.

The challenge with trying to follow somebody else's buffer spring recipe is that there are so many variations on Shrikes over the years that different combination of barrels, gas port, gas regulators, feed trays, etc.  all make folks guns behave differently.  One gun may run great with a particular setup and another one will struggle.   About the only setup that is close to a guarantee to run is the factory Ares spring, an H2/H3 buffer, and US made M855 belted into at least once fired links, but the cyclic rate is really high in that config which in turns help provide reliable feeding of rounds.  Once you delve out of that prescribed combo all bets are off and its up to the owner to find what config their specific gun/barrel combo likes.

Thank you for the pics, that is certainly a lot of extra machine work for the addition of the little bit of ramp above the BE.

I agree with all your points but as I mentioned before, this configuration should only be attempted if your Shrike / MCR is already running 100% and you want to slow it down...and even then it may not work for you...just as you stated.  

I wish the Shrike / MCR did have more carrier travel.  Even if it were a little bit like what Surefire did with their OBC.  

There is just not much you can do in regards to tuning it to run slower without suffering reliability issues.  

I think what I have is about the slowest I have seen posted anywhere.  You can see in my video I'm getting 561 / 568 RPM with the Kynshot RB5007 / A5 / 308 Tubb spring / M855.
It is barely working for me in this configuration.  The action must be clean and lubed to run but as you can see in my video below, it does work.  As mentioned, I don't stretch or lube links.  I think if I did do that, it would continue to run more fouled.
Or I could switch to the Ares supplied spring and still run the RB5007.

I commend you on adding weight to your carrier.  I would think that would greatly help if you're having bolt bounce issues.  
After having one carrier break on me and considering the price, I don't want to modify a carrier and then not have Ares/Fightlite support it if I had it modified.  My recommendations are not permanent modifications that can easily be reverted if not successful.   BTW, I haven't had any bolt bounce (light primer hits) with this configuration... only failures to strip rounds when dirty....but again, I don't stretch or lube links.  

What broke on the carrier?
No kidding on the price of an carrier. I had to buy a F/A carrier. I was tempted to weld some metal on to my S/A carrier for the price they were charging!

I posted all the details on the first page of this thread....
https://www.ar15.com/forums/armory/-/23-500374/#i5133044

On that post I mentioned how I never went heavier than an H2 (4.5 oz) and the carrier broke and now I'm running a 5.9 oz hydraulic but I believe that the hydraulic cushions some of the initial recoil impulse that I think will prevent breaking another carrier...although I see people posting running 6.8 oz MGI buffers in their Shrike/MCR's these days.
The links on my site below you may also find interesting:
http://www.c3junkie.com/?page_id=977
http://www.c3junkie.com/?page_id=325

Damn. I should be all over this thread. I run our LARB MOD3 buffers in the Shrike/MCR and I’ve heavily modified the feed ramp...

Feeding issue fix for the Shrike/MCR...
Pictures

Wow, that is some major modifications.

Wow. Tagged for updates.

Well, that’s what it took to fix the MCR feeding issues. And it worked like gang busters.