Five-Seven MRD MkIII Threaded Barrel?

8466 Views 57 Replies 12 Participants Last post by VariousCheeses, 2 mo ago

shadowsk72

Discussion Starter · 9 mo ago

Hi, does anyone know if the threaded barrels currently offered for the MkII will work in the MKIII? Specifically I was looking at the EFK Fire Dragon and Jarvis barrels. I emailed EFK last week and have not heard back. Still waiting to hear back from Jarvis as well. Thanks

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Buffman

· #2 · 9 mo ago

As far as I'm aware yes they will.

Reactions: 1

Trevbond

· #3 · 9 mo ago

Not sure I’d go with efk. Their chamber neck is significantly shallower than the stock barrel. Same headspace. This causes the fired case to expand outwards more and leads to more case neck separation.

shadowsk72

Discussion Starter · #4 · 9 mo ago

Trevbond said:
Not sure I’d go with efk. Their chamber neck is significantly shallower than the stock barrel. Same headspace. This causes the fired case to expand outwards more and leads to more case neck separation.

Thanks for the info! I'll give the Jarvis a try. I've used them in the past and was satisfied.

Buffman

· #5 · 9 mo ago

I've never had an issue with case neck separation using my EFK barrel. Just saying.

Reactions: 1

romeo_alpha01

· #6 · 9 mo ago

B&T sells a threaded barrel for use with their suppressors (sold separately). They are in fact just Jarvis barrels with a M10x1 thread pitch.

Trevbond

· #7 · 9 mo ago

Buffman said:
I've never had an issue with case neck separation using my EFK barrel. Just saying.

Have you noticed what I’m referring to? Just shining a light down each chamber looks significantly different or looking at a fired case neck. I’m not talking thousandths of an inch. Atleast hundredths or maybe more.

Here’s an aside rant/complaint… this community sucks. FN 5.7, that is. This was my first and only gun. Inherited it from my grandfather. The ammo is too damn expensive. So I’ve learned to reload it or attempt to. Which has been quite frustrating. I can’t find anything that shoots accurately enough for my liking. Sure I can make **** go fast but that’s not what’s important to me.

On the quest for accuracy I purchased a red dot and got the mount from fivesevenreddot. The pin he supplies are weak af. It mushroomed out and I spent an entire day trying to get it out. Ended up having to drill it out and ruined the fn rear dovetail. Fivesevereddot doesn’t respond at all to my emails. Of course the parts aren’t in stock so I end up purchasing a slide from someone on this forum. I recently learned that dude is selling something that had a “destruct order” but didn’t mention that. Still not sure what that means but it might have something to do with my frame cracking. Or maybe that’s just FNs gun. Or maybe my reloads, idk but I wasn’t loading anything crazy. Where my gun is cracking is not beefed up in the mk3. It was from mk1 to mk2 but mines mk2.

I also removed the mag safety, polished the sear and trigger and put in a lighter trigger spring. The only part of this adventure that actually turned out well. I can say that paying $500+ to have this gun accurized seems like a rip. Sure you’re messing with an important part of the gun but if you keep your angles intelligent and drop test the **** out of it you can figure it out. And if not, buy a new sear. They cost less than 20 rounds. The stock trigger sucks but can be made better.

I also purchased the efk barrel in this quest. I have not noticed an increase in accuracy. It does shoot a little faster but that’s no surprise since it’s longer.

And then there’s the issue of case neck separations. I have not noticed this in once fired brass but it happens all the time in multi shot cases. Which is obviously another ding on the cost effectiveness of shooting this round. It also happens more in the efk barrel than stock and I believe it’s for the aforementioned reason.

The case neck separation also happens more often when shooting off a pistol rest than off hand. This I’m perplexed by and can’t explain. And when shooting rapidly. I can explain that. The round is hotter(figuratively and physically).

I’ve tried a multitude of reloading techniques over thousands of rounds such as different dies, neck mandrels, OAL lengths, crimps, glue, polishing the neck, trim lengths, different neck inner diameters, using a scale to .01 grains, dry neck lube, different bullets, and I’m sure things I’m not remembering at the moment. The only thing I haven’t tried is neck turning and annealing but that seems like a recipe for failure in this round.

If cases can’t be shot more than twice reliably, this round is not shootable in my eyes.

Sorry if this hurt your eyes reading but maybe it will help guide some from the misguided adventure and they might choose another gun or caliber to bang their head against. I was looking for 1 inch accuracy at 20 yards off a rest and I’ve failed. I know this is possible. But I don’t know if it’s possible in 5.7 with an FN. and I’m talking consistent groups.

Save the go elsewhere comments. I will. I just need to be in a state that I can legally buy a gun. Until then I’m stuck gluing my frame back together and continuing the quest. If I figured it out I’ll share and not give the whole I know that answer but I’m not telling you… just buy my stuff.

even that last comment gives me a twinge of regret saying because there is essentially only one aftermarket parts reseller for this gun and what if I get on his bad side. No more parts! So yea I’m annoyed by this community for these reasons.

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Reactions: 1

JChura

· #8 · 9 mo ago (Edited)

Trevbond said:
Here’s an aside rant/complaint… this community sucks. FN 5.7, that is.....

Sorry if this hurt your eyes reading but maybe it will help guide some from the misguided adventure and they might choose another gun or caliber to bang their head against. I was looking for 1 inch accuracy at 20 yards off a rest and I’ve failed. I know this is possible. But I don’t know if it’s possible in 5.7 with an FN. and I’m talking consistent groups.

Save the go elsewhere comments. I will. I just need to be in a state that I can legally buy a gun. Until then I’m stuck gluing my frame back together and continuing the quest. If I figured it out I’ll share and not give the whole I know that answer but I’m not telling you… just buy my stuff.

even that last comment gives me a twinge of regret saying because there is essentially only one aftermarket parts reseller for this gun and what if I get on his bad side. No more parts! So yea I’m annoyed by this community for these reasons.

Tough journey. Similarly have a MKII. Stock, except for trigger work by Eden Perfection. He was a pleasure to deal with. Fortunately, live in a free state, have not have the same accuracy issues. Was considering going the red dot route but what after market support there is seems to just offered by a whole lot of amateurs at best, downright cranks at worst, so held off. Not hesitant to get on any of those cranks "no soup for you" list nor am I interested in being a beta tester for hot pulled factory ammo that are not tested per CIP specs. Would never do business with them. Had tried to point out the glaring problems with one in particular.

Sorry to say, but apart from my experience with Eden, is no real legitimate ( as in professional who will return messages and timely complete orders without problems) after market support for the 57 that I have found.

This forum seems to be predominately a place for cranks to shill for business. Made some longer posts myself pointing out the decades long pattern of repeated extravagant claims made by one.

Matt is an asset, but his steadfast support for one vendor in particular, despite red flag after red flag, is a head scratcher.

Hope you find some kind of solution to your not so fun journey and stick around. You sound like a knowledgeable person, make no crank claims, don't try to sell anything, and share some pretty insightful info. In short, the kind of poster with useful info to share, and to learn from.

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Trevbond

· #9 · 9 mo ago

JChura said:
Tough journey. Similarly have a MKII. Stock, except for trigger work by Eden Perfection. He was a pleasure to deal with. Fortunately, live in a free state, have not have the same accuracy issues. Was considering going the red dot route but what after market support there is seems to just offered by a whole lot of amateurs at best, downright cranks at worst, so held off. Not hesitant to get on any of those cranks "no soup for you" list nor am I interested in being a beta tester for hot pulled factory ammo that are not tested per CIP specs. Would never do business with them. Had tried to point out the glaring problems with one in particular.

Sorry to say, but apart from my experience with Eden, is no real legitimate ( as in professional who will return messages and timely complete orders without problems) after market support for the 57 that I have found.

This forum seems to be predominately a place for cranks to shill for business. Made some longer posts myself pointing out the decades long pattern of repeated extravagant claims made by one.

Matt is an asset, but his steadfast support for one vendor in particular, despite red flag after red flag, is a head scratcher.

Hope you find some kind of solution to your not so fun journey and stick around. You sound like a knowledgeable person, make no crank claims, don't try to sell anything, and share some pretty insightful info. In short, the kind of poster with useful info to share, and to learn from.

First off thanks for the kind words.

Second, I do share some hesitation on what you are referring to. There’s too much smoke for there not to be a fire. And behind that smoke too much bombastic, know all rhetoric. Unfortunately I think the community is just too small for there to be much quality.

You have found a load that is accurate? I’ve read damn near the entire fn and 57 forum and I can’t find any load data that takes much consideration into accuracy. It’s all about speed and pushing the loads until pressure signs appear.
Most discussions around load data center on sd, accuracy and pictures of groups, but with 5.7 it’s more pictures of primer cratering and neck movement.

If so please share the details. Not just OAL, trim length, bullet, and powder but also how do you size the neck? Is there something you find is an important factor to get really good consistent accuracy?

shadowsk72

Discussion Starter · #10 · 9 mo ago

So I heard back from Jarvis today. This was his response-

"We did confirm with FN that the barrels are the same. The only issue we are aware of is with the GSL direct thread suppressor, which bumps the front end of the slide when attached to the barrel.

Regards,

Andrew Jarvis"

I asked was there any suppressor he could recommend at this time. Will post back

JChura

· #11 · 9 mo ago

Trevbond said:
....

If so please share the details. Not just OAL, trim length, bullet, and powder but also how do you size the neck? Is there something you find is an important factor to get really good consistent accuracy?

Don’t reload myself, but much respect to those that seriously do, especially this cartridge.

My MKII is more accurate than I am. Have it sighted in for 195. Sight setting works well with 198 which is my go to. Groups consistent. Got into the platform just as things were starting to get rough in 2020. Timing was spot on perfect because I was able to load up on FN ammo" at the "cheap" $25-30 level just before it spiked to crazy levels fast. Hopefully PSA delivers on its ammo, prices fall.... Ammo cost is a defintely a consideration, especially so for being an only firearm.

Most of the data loading is, like you mention, about maxing velocity rather than much on accuracy. A lot of the mystique about the round is based on velocity so there is that understandable tendency to see just how fast you can go before…..
Not much, but hopefully could lead you to useful info....

People on the following forum seem knowledgeable and might be a good info source to get both general and specific loading info for max accuracy :
Reloading 5.7X28

Very small blip of info here--lower velocity was said to be accurate:
5.7x28mm Load Data: Favorite Handloads - Shooting Times

Did see a second report that slower was accurate (R57 though was test gun).
An Official Journal Of The NRA | Tip: Handloading the 5.7x28 mm Cartridge

Lot of general load data here, also a link to an article:
Cartridges of the Month | Metallic Load 5.7x28 FN / 5.7x28mm FN Handload Data,Metallic Load .40 Smith & Wesson / .40 S&W HandloadsShotgun Load

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Buffman

· #12 · 9 mo ago

JChura said:
Matt is an asset, but his steadfast support for one vendor in particular, despite red flag after red flag, is a head scratcher.

I always try to remain impartial as possible. I want my viewers to have as much information as possible so that you can cut through any typical company marketing. I've been critical of said vendor plenty of times over the past. Given that any video/content I produce, at a high level, is an attempt at sale/support of a vendor, I hope my reputation shows I'm not a one sided shill, and that I'm here to help get more more support from all manufacturers alike for the 5.7 community.

In my tests at accuracy, I've found the 40gr vmax to be one of the more accurate bullets used in 5.7, along with the Gold Dot, but those were done in an 8". If I get a chance I'll try a group size with the Rock this weekend.

Reactions: 3

jaflowers

· #13 · 9 mo ago

Trevbond said:
First off thanks for the kind words.

Second, I do share some hesitation on what you are referring to. There’s too much smoke for there not to be a fire. And behind that smoke too much bombastic, know all rhetoric. Unfortunately I think the community is just too small for there to be much quality.

You have found a load that is accurate? I’ve read damn near the entire fn and 57 forum and I can’t find any load data that takes much consideration into accuracy. It’s all about speed and pushing the loads until pressure signs appear.
Most discussions around load data center on sd, accuracy and pictures of groups, but with 5.7 it’s more pictures of primer cratering and neck movement.

If so please share the details. Not just OAL, trim length, bullet, and powder but also how do you size the neck? Is there something you find is an important factor to get really good consistent accuracy?

I load all my various 5.7 loads for accuracy with the only exception being my light plinking load, it's for short range only and for training. Even my high speed SD loads were picked for accuracy, not for their pure speed.....although they aren't slow by any means. Outside of some pulled SS195 bullets, I've found the 32 to 36 grain bullets work best for my accuracy....32 for pistol and 36 for PS90/single shot rifle.

Reactions: 2

JChura

· #14 · 9 mo ago

Buffman said:
....
I hope my reputation shows I'm not a one sided shill, and that I'm here to help get more more support from all manufacturers alike for the 5.7 community.

No dig meant Matt—hence the “head scratcher” reference (did not nor do I mean to say you are a shill of anyone). Find your videos/input to be a tremendous asset. Did see your torture test video where you tried, but could not replicate that claim the R57 was not drop safe. You are, and I mean it in the most complimentary way, Matt “Mr. 57” Buffman.

Have noticed past comments where you are asked you recommendations on defense loads. Where the head scratching comments originate from. Respect the fact these are your own opinions which no doubt are based on some extensive testing over many years. Me, I guess we just might have an honest disagreement which I think might stem from different perspectives.

My approach is very much a consumer one. Can I make a simple purchase of ammo/services, receive it timely with no drama and delay, and can be assured it was tested to be in compliance with max CIP barrel pressure, and is safe. Where I see constant puffery, etc., ---that’s a no go vendor for me, and I would not recommend.

Performance v consumer perspective I think—not a question of shilling at all.

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Buffman

· #15 · 9 mo ago

JChura said:
No dig meant Matt—hence the “head scratcher” reference (did not nor do I mean to say you are a shill of anyone). Find your videos/input to be a tremendous asset. Did see your torture test video where you tried, but could not replicate that claim the R57 was not drop safe. You are, and I mean it in the most complimentary way, Matt “Mr. 57” Buffman.

Have noticed past comments where you are asked you recommendations on defense loads. Where the head scratching comments originate from. Respect the fact these are your own opinions which no doubt are based on some extensive testing over many years. Me, I guess we just might have an honest disagreement which I think might stem from different perspectives.

My approach is very much a consumer one. Can I make a simple purchase of ammo/services, receive it timely with no drama and delay, and can be assured it was tested to be in compliance with max CIP barrel pressure, and is safe. Where I see constant puffery, etc., ---that’s a no go vendor for me, and I would not recommend.

Performance v consumer perspective I think—not a question of shilling at all.

From a consumer perspective I do not disagree. I do get frustrated at times when bullet weights change, but retain the same model designation, or those weights aren't listed on the box, nor are stated velocities obtainable. I will agree that all chronograph's suck, and in general even the big guys throw numbers on boxes that sometimes don't happen. I certainly would welcome an operating pressure listed on their site for each round and the method at which it was obtained

Reactions: 1

JWolf

· #16 · 9 mo ago

4

It will work just fine with the EFK 6.0 and 7.0 barrels. The 5.4 will not work due the the threads being about 2mm too deep. The new angled profile of the new MRD cover with hit your muzzle device. EFK is aware of this and is adjusting the thread depth.

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JChura

· #17 · 9 mo ago

JWolf said:
.... I have a detailed video ............................... In fact any MKII compatible barrel OEM and EFK will also work just fine in the MKIII MRD.

So you were wrong-yet again? Ever going to give details on the multiple engineering degrees you claimed to have earned--as in what degrees, and from where?

JChura

· #18 · 9 mo ago

x

Nambo

· #19 · 9 mo ago

JChura said:
So you were wrong-yet again? Ever going to give details on the multiple engineering degrees you claimed to have earned--as in what degrees, and from where?

why are you so hostile? It’s beginning to get to the point where it’s more toxic than anything else. It’s not just with jwolf either.

JChura

· #20 · 9 mo ago

Nambo said:
why are you so hostile? It’s beginning to get to the point where it’s more toxic than anything else. It’s not just with jwolf either.

Pointing out repeated errors by a self-claimed “expert” is “hostile”? Maybe I’m wrong, but I don’t believe the purpose of the forum is to be a “safe space.” Nor do I see it is a "hostile" or “toxic” micro-aggression to point out when an “expert” consistently posts objectively incorrect information. If I hurt or challenged your feelings in some way, I do apologize though. Objective facts are tough things to face sometimes, and are often difficult to reconcile with emotions.

Perhaps your concern might be better focused on others who might rely to their determinant on chronically wrong “expert” advice? That would certainly be hostile, hopefully only to the wallet, and not worse…..

No sure what specifically your “not just” comment refers to. Never my intent to wrongly micro-aggress. If you have a specific "not just" example, I will certainly re-review what I had posted, acknowledge any error, and apologize if I was wrong. I do try my imperfect best to take ownership and responsibility.

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