Liberty Mystic Question - 5.45x39

[EagleKeeper]

Hello, I've been a long time lurker here, love the wealth of knowledge. But I have a question I haven't seen answered here yet. If this is in the wrong section I apologize, but I was wondering about the possibility of running 5.45x39 (7N6, standard russian milsurp) from a 16" AR-15 through a Liberty Mystic. The product page says the can is rated for 5.56 from a 16" barrel, and since 5.45 runs at lower pressures (plus has less energy) I would assume it would be good to go, but I definitely don't want to assume anything when it comes to a $1K suppressor. Thanks for any help.

[lafsnguy]

I would imagine it would be good but I would just call liberty and get the answer straight from them.

[JohnInNH]

EK,

Heat is something you want to keep in check. The rate of fire is the issue. Wait till Liberty gives you an official answer. But overheating is what you have to be careful of with the 223 as well. It's not a Torch (Liberty 5.56 silencer)

I just shot 10 rounds of 308 lead gas check subs using my Mystic GAD I love this thing.

210 gr lead RN with a gas check over 8.5 gr of TrailBoss gives me 1001 FPS in my 24" 1:11.25 M700 The Mystic sounds sweet!

[kernelkrink]

One thing to be aware of, the 5.45 round is known to need a little bit of travel beyond the muzzle before it "settles down" and flies straight. The very long bullet tends to yaw a bit, so if the baffle holes are pretty tight, you may get strikes. It is fairly common to see elongated holes in the target @ 25 yards and then get nice accurate round ones out beyond 50 or 75.

[EagleKeeper]

Thanks for all the replies, I really appreciate it. I got an answer back from Liberty which kind of surprised me, they said the 5.45 (and 7.62x39) are too high of a pressure round to recommend firing through the Mystic. Now I'm no gunsmith, but from what I have read the 5.45x39 has about a 20% lower chamber pressure than 5.56x45. I don't know what this means at the muzzle, but I just can't see a 53 gr bullet @ 2900 fps having a higher pressure than a 62 gr bullet @ 3100 fps. But like I said I'll leave it up to the experts.

EK,

Heat is something you want to keep in check. The rate of fire is the issue. Wait till Liberty gives you an official answer. But overheating is what you have to be careful of with the 223 as well. It's not a Torch (Liberty 5.56 silencer)

I just shot 10 rounds of 308 lead gas check subs using my Mystic GAD I love this thing.

210 gr lead RN with a gas check over 8.5 gr of TrailBoss gives me 1001 FPS in my 24" 1:11.25 M700 The Mystic sounds sweet!

Thanks for the info. I figured heat would be a major issue, since they advocated using a 16" barrel for the 5.56/.223. I found out first hand how much an issue heat is this weekend, when I fired 200 rounds through a full auto M-16 with suppressor. It was unbelievable how hot it got. Of course now I have to get one.

One thing to be aware of, the 5.45 round is known to need a little bit of travel beyond the muzzle before it "settles down" and flies straight. The very long bullet tends to yaw a bit, so if the baffle holes are pretty tight, you may get strikes. It is fairly common to see elongated holes in the target @ 25 yards and then get nice accurate round ones out beyond 50 or 75.

I don't foresee this to be a problem, since the Mystic is designed for 9mm rounds, I can't imagine the 5.45mm getting that far out of whack. Still something to keep in mind tho, I will have to test my AR with some close up paper punching to be sure it is flying true.

[rockman96]

One thing to be aware of, the 5.45 round is known to need a little bit of travel beyond the muzzle before it "settles down" and flies straight. The very long bullet tends to yaw a bit, so if the baffle holes are pretty tight, you may get strikes. It is fairly common to see elongated holes in the target @ 25 yards and then get nice accurate round ones out beyond 50 or 75.

I don't foresee this to be a problem, since the Mystic is designed for 9mm rounds, I can't imagine the 5.45mm getting that far out of whack. Still something to keep in mind tho, I will have to test my AR with some close up paper punching to be sure it is flying true.

It's not a problem. I've shot a fair amount of 5.45 through a .30 can....762SD to be exact. Maybe through a 5.56 can it would be, I don't know.

[BigDave@SMDW,LLC]

Hello All,

I figured I would weigh in on this finally.

The reasons we dont rate it for this round are varied. The main ones are that we know very little about this round, and the bullet stability is another large concern. This silencer was primarily designed for 9mm pistol and carbine use as well as 22LR, we upped the rating to include 223 after we did some testing with it. It would be catastrophic to have a rifle round yaw into the baffles of the Mystic. To put it nicely, it would gut it like a fish... We cant keep adding full power factor rifle rounds to the list, it will eventually bit us in the rear. This application begs for a 30 cal rifle can. I think another poster already stated he had great luck with this combination.

Would it handle the pressure.... most likely. We just cant keep upping the ante though. There is a youtube video of a guy voiding his warranty by shooting his Mystic on a 7" AR pistol. (We all know him) I will be honest with you, I was shocked to watch it. But you know what? It held it... I would have thought it would have exploded for sure... The math says it will, but apparently the math is on the conservative side.

Sorry about not adding the rating. We just cant do it.

Thanks for understanding,
David

[EagleKeeper]

Awesome, thanks for the reply Big Dave. I appreciate the direct level of customer interaction on a message board, that is something great. I do completely understand the slippery slope you are straddling, it is a 9mm can first and foremost, anything else is just icing on the cake. And I know the unfortunate (and unjustified) reputation that 5.45x39 has for instability. As a longtime 5.45 shooter I can tell you that is due to the monkeys at Century Arms using .224" (5.56x45) diameter barrels in their early Tantals, and unfortunately that reputation has kept up with the round ever since. Also the relative obscurity of the round makes testing for you difficult, I know I would not want to endorse something I made without extensive testing first and I appreciate that same mindset from a manufacturer.

I have the utmost confidence in my Adams Arms 5.45x39 Piston upper, and will be punching some paper from 1 to 25 yards, in addition to the standard 50 and 100 yards (where this platform is beautifully accurate) this weekend just for grins, as I know the 1/8 twist barrel stabilizes these rounds. But thanks again for the awesome support and quick answers you have provided, if you ever need a test bed for 5.45 I will be more than happy to lend my AR! Thanks.

[EagleKeeper]

Just for fun, here's a pic of my system (because you know what they say, threads are worthless without pics!).


Palmetto State Lower
Adams Arms 5.45x39 Piston Upper
Magpul MOE FDE Furniture
Aimpoint Comp M2 (4MOA dot)
YHM Flip up BUIS
Badger Tactical Charging Handle

[JohnInNH]

Dave I ran the 7" numbers just for you!

Barrel Length Muzzle Pressure Ft lbs of energy 5.56/BLK & difference
--------BLK ----------- 5.56 ---- Ft/lbs 5.56/BLK ------ delta
16" ---- 4,851 PSI ---- 11,434 psi ---1118/1370 ------- 252 ft lbs
14" ----5,672 PSI ----- 13,235 PSI -- 1040/1306 ------ 266 ft lbs
10.5" - 7, 917 PSI ---- 17,921 PSI --- 867/1163 ------- 296 ft lbs less energy than a BLK and 10,000 PSI more
7" ---- -8,952 PSI -----26,447 PSI --- 624/953 -------- 329 ft lbs MP of 26,447 PSI!! in a Mystic.. Dave you de man!


I just added this 7" line... Look at those MP#s!!!! Anyone who puts a mystic on a 7" 5.56 NATO barrel and SHOOTS IT is CRAZY!!!

That's some proof test!

[EagleKeeper]

Dave I ran the 7" numbers just for you!

Barrel Length Muzzle Pressure Ft lbs of energy 5.56/BLK & difference
--------BLK ----------- 5.56 ---- Ft/lbs 5.56/BLK ------ delta
16" ---- 4,851 PSI ---- 11,434 psi ---1118/1370 ------- 252 ft lbs
14" ----5,672 PSI ----- 13,235 PSI -- 1040/1306 ------ 266 ft lbs
10.5" - 7, 917 PSI ---- 17,921 PSI --- 867/1163 ------- 296 ft lbs less energy than a BLK and 10,000 PSI more
7" ---- -8,952 PSI -----26,447 PSI --- 624/953 -------- 329 ft lbs MP of 26,447 PSI!! in a Mystic.. Dave you de man!


I just added this 7" line... Look at those MP#s!!!! Anyone who puts a mystic on a 7" 5.56 NATO barrel and SHOOTS IT is CRAZY!!!

That's some proof test!

Wow! That is insane, over double the pressure and it still survived. Nice job on that safety factor, I am impressed.

As a side note, what program are you using to do this analysis? These sort of things intrigue me. Thanks.

[JohnInNH]

QUICKLOAD

[peytont]

Is titanium more likely to bulge or burst? I'm shocked by those numbers as well! Can't believe it didn't blow.

[EagleKeeper]

I must say, I'm glad Liberty decided to add this round to the incredible list of calibers the Mystic is rated for.

[BLAKE2131]

I want to say theyll rate it down to Krink bbl length but im not 100% let me check with Dave

[BLAKE2131]

The mystic will take 5.45 down to a 8" bbl but itll cook the paint off if shot too fast

[EagleKeeper]

The mystic will take 5.45 down to a 8" bbl but itll cook the paint off if shot too fast

Wow awesome. I'm kind of ticked I bought a Cyclone already (4 months pending...) since I originally recieved a negative on the 5.45x39. But hey I'll be buying another can soon. Thanks for the response. Do you know what min length its rated for 7.62x39? I've got a M92 PAP that could use a little quieting down.

[BigDave@SMDW,LLC]

We have tested on 16" barrels so far and all is well with that on the 7.62 x 39. This round will get a better gas seal then the 5.45 so be careful with it on the Mystic. I have not done all the math to support this round yet as we have been working on the concentricity issues that we see with the AK platform...

16" barrels for now though are good to go.

David

[EagleKeeper]

We have tested on 16" barrels so far and all is well with that on the 7.62 x 39. This round will get a better gas seal then the 5.45 so be careful with it on the Mystic. I have not done all the math to support this round yet as we have been working on the concentricity issues that we see with the AK platform...

16" barrels for now though are good to go.

David

Awesome, thanks for the response. I was definitely worried about concentricity of my stock AK threads, which is why I'm thinking the mystic might be a little better fit for this .311-.312 projectile vs my .308 Cyclone. I would be testing it real close with a dowel rod before attaching. Thanks for the speedy response!