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9mm AR-pistol or 9mm AR-PCC?

7.62x39Lover7.62x39Lover Member Posts: 3,939 ✭✭✭
edited September 2019 in Ask the Experts
Hi Guys!

For a 9mm pistol cartridge, what length barrel is perfect in terms of taking advantage of all the powder? Is a 16 inch barrel on a PCC actually too long for a 9mm cartridge? What barrel length is optimal to get all of the power / velocity out of a 9mm pistol cartridge?

Comments

  • NeoBlackdogNeoBlackdog Member Posts: 17,234 ✭✭✭✭
    edited November -1
    I think it was Toad67 that posted this site a month or so back
    http://www.ballisticsbytheinch.com/9luger.html

    Looks like a 17" barrel is going to get you the best velocity with most of the loads listed.
  • MobuckMobuck Member Posts: 14,124 ✭✭✭✭
    edited November -1
    I'm in the process of assembling an AR 10.5" 9mm "pistol". Actually it's already been assembled, test fired for suitability, dis-assembled, and re-assembled using a dedicated 9mm style upper. I have a bid on a dedicated 9mm Glock mag lower to finish the project.
    The reason for all the fiddling: I wanted to see if/how it was going to feel and fit my specific criteria for use using mostly parts on hand before spending the additional $$. My intent is to build a SD firearm for my work vehicle that has more range than a CCW handgun, is easily suppressed with a more compact suppressor vs 5.56, and is shorter OAL w/suppressor than a typical 16" barrel carbine is w/o.
    Now, to the question of barrel length. I have both a Ruger PC9 and Marlin Camp 9 with 16" barrels and have shot both out to 100 yards. What I found with those is that the longer barrel extracts all the available power from 147 grain ammo. Based on my casual research on the diff between 16" and 10.5"(my choice for pistol barrel length), very little velocity is lost/gained between the two lengths when using 147 grain factory ammo.

    The reason I'm only looking at 147 grain ammo---only a handful of factory ammo choices will stay sub-sonic from the 10.5" barrel and the 147 carries it's velocity better at longer ranges. A 147 from a 10.5" barrel will have almost as much velocity @ 100 yards as the same from a 3.5" has @ 10 yards.
  • mark christianmark christian Member Posts: 24,443 ✭✭✭✭
    edited November -1
    I prefer the 8" barrel and generally fire 147gr. If OAL length is a consideration then something like the Glock 19 fitted with a Micro-Roni stock set makes for a very compact package; far smaller than any conventional 9mm carbine.
    E0UGmPA.jpg
    frymT3Sh.jpg
    9mm carbines are easily suppressed and are generally subsonic with the 147gr bullets. I know that a suppressor is on your wish list, so keep in mind that once you screw on the "can", the OAL of an 8" barrel carbine is now more or less identical to what it would be with a 16" barrel.
    0YVMVTN.jpg

    I apologize for the poor quality photos which I took with my phone.
  • mark christianmark christian Member Posts: 24,443 ✭✭✭✭
    edited November -1
    Mark are there any new suppressors offered that also behave as rifled bbl extensions for enhanced accuracy or is that limited by technological limitations and legal constraints???
    I can't say that I've seen anything like that.

    If I recall some of Hiram Maxim's early cans were rifles and the bore diameter matched to that of the firearm platforms bbl. Obviously using a .30 cal can on a .22 diameter bbl makes this a non issue.
    Lots of folks own one .30 caliber can and shoot .223 through it. The issue is that the .30 cal is bigger, longer and heavier, which makes a .223 caliber rifle more awkward.

    I also remember early cans being set up for the addition of front sigjts - offering a greater sight radius extension and improved accuracy - but that feature seems to be lacking or have disappeared over the last 30 years...
    Getting the front and rear sights regulated is problematic, especially if you want to remove the suppressor. Most folks only own one can per caliber and switch it between several pistols so the sighting issue would be difficult to overcome.

    On pistol carbine family designs with silencers has there been an issue with poorly trained individuals grasping the can while shooting to stabilize the gun - I assume the fine threads commonly encountered in the industry are incapable of supporting such a load without breaking...
    Shoot 20 centerfire rounds through a suppressor and then grab it with you bare hands and you won't do it again! In TV shows and in the movies, they never show you the kind of scorching heat a suppressor retains after firing. The old SIONICS suppressors for the MAC-10 series had a heat resistant cover and there are after market companies which currently make covers which will slide over suppressors.

    Also I cannot recall seeing and flash suppressor or recoil reduce or blast deflection baffles incorporated in cans since some developmental patent experiments prior to 1935.
    Flash hiders for suppressors are still offered by a few manufacturers, but a suppressor is an extremely effective flash hider by itself. Adding a flash hider makes the OAL of a suppressor even longer, something which most shooters want to avoid.

    Is there any issue with certain bullet weights or purposely designed subsonic ammo failing to allow the action to cycle correctly on pistols or smg's with heavier bolts or weighty internals???
    Yes, that is a problem. There are ammo companies which load suppressor specific ammunition which is sub sonic and will function without (many) issues. Otherwise shooting sub sonic ammo is like shooting .22 rimfire ammo: you have to try a few (or several) loads to find out what works and what won't.

    Has anyone handled or tested out the shotgun suppressors on 12 gauge or 20 gauge guns???
    I've seen them, but haven't fired one.

    I know internal baffle design and architecture has advanced - but what about inserted sound absorbing materials development???
    That is more or less at a standstill. The use of "filler" like metal wool placed inside the tube is a thing of the past. The ATF has ruled that a suppressor wipe is a controlled part and the entire suppressor must be returned to the manufacturer for a worn out wipe to replaced. That more or less put an end to consumer interest in suppressors which use wipes.

    Are cans always comparable with say polygonal rifling or progressive gain twist rifling or can interfere patterns develop and occur that negativity affect performance or function???
    Not that I am aware of.

    With electronic ignition of careless ammo like the Daisy VVL or H&K G11 or even the Remington etronix cartridges / munitions is sound further reduced as there is no primer pop - only action noise and mechanical sounds???
    Mechanical sound from a firearm is actually louder than most people think. The bolt cycling on a Ruger 10-22 is about 110 db, while the firing sound suppressed is not that much more. Although I still have a Voere VEC-91 (and a single box of ammo) hidden way in one of my safes, electronic primed ammo has more or less been forgotten.

    I found the nagant gas seal target revolver with a maxim designed silencer to be the quietest I ever experienced and in a revolver the number of moving interlocking parts was much less of a concern - it being the only revolver I am aware of that can successfully incorporate a can...
    I've never fired a suppressed Nagant

    I wonder if any early precursor or experimental trial pieces had any success in the 1850 to 1886 time frame - I confess I know almost nothing about this frame of reference..
    it would be a fertile field for scholarly research.

    Mike
  • rufesnowrufesnow Member Posts: 241
    edited November -1
    I prefer the 8" barrel and generally fire 147gr. If OAL length is a consideration then something like the Glock 19 fitted with a Micro-Roni stock set makes for a very compact package; far smaller than any conventional 9mm carbine.
    E0UGmPA.jpg
    frymT3Sh.jpg
    9mm carbines are easily suppressed and are generally subsonic with the 147gr bullets. I know that a suppressor is on your wish list, so keep in mind that once you screw on the "can", the OAL of an 8" barrel carbine is now more or less identical to what it would be with a 16" barrel.
    0YVMVTN.jpg

    I apologize for the poor quality photos which I took with my phone.



    QUESTION! Saw a guy selling something similar, to your "MICRO-RONI"at a gun show. I told him it was Verboten, and the feds were going to haul him off to he gray bar hotel. If they caught him selling it to everybody, who wanted to turn their G 17 into a PDW. He told me that it was legal and I was full of beans. (Only beans wasn't the word, he actually used). Whats the straight skinny on these type of accessories. That convert G 17's into PDW?
  • mark christianmark christian Member Posts: 24,443 ✭✭✭✭
    edited November -1
    There are two versions of the "Roni". Mine is a registered short barreled rifle. The unrestricted version looks similar but has a folding "arm brace" instead of a butt stock, an an angled front grip in place the forward vertical grip. The two versions look very much alike, but there is a world of difference between them when it comes to the law.
  • MobuckMobuck Member Posts: 14,124 ✭✭✭✭
    edited November -1
    I think Mark did quite well answering the questions so I have little to add.
    The fine threads on the muzzle are surprisingly strong so it would require a barrel bending force to strip those threads. It might be possible to damage the threading of an a softer metal such as aluminum.
    After doing some early/late shooting while hunting, I haven't noticed ANY muzzle flash from our suppressed rifles.
    While generally repeatable in mounting, the connection between suppressor and host is not consistent enough to allow mounting a front sight on the can body.
    While it may be acceptable to use something like wire pulling lube inside a can to increase the effectiveness under specific circumstances, it's much too messy and creates cleaning issues that would make it unacceptable for general use. I tried the "wet can" method ONCE and said "Never again" long before I got all the mess cleaned up.
    As Mark said, you'll likely only grab the hot can once and learn from the initial experience. We seldom shoot more than 4-5 times while hunting so heat isn't an issue but we usually wrap stretch camo tape on the can anyway.
    Another tidbit that wasn't mentioned: Suppressing the muzzle blast doesn't change the sound of super sonic bullet crack.
  • MobuckMobuck Member Posts: 14,124 ✭✭✭✭
    edited November -1
    "How does diameter and length of a silencer or suppressor affect performance or is it more based on the internal baffle design architecture..."

    I have an engineering background and have designed my own "Form 1" suppressors. I can honestly say that it takes a lot of baffle wizardry to overcome internal volume in suppressor design. A big, cheap, simple can is often as effective as an exotic, expensive design with a smaller size. The problem is that big cans don't handle well, are often heavy, can change POI significantly and "cheap" materials don't stand up to the heat/stress inside a can as well as inconel, titanium, stellite, and such.
    The successful suppressor manufacturers spend a lot of time and money looking for the magical design that does a great job while being as light/small as possible. I don't begrudge them the prices they ask(well, most of the time anyway).
    PS
    My statement above is part of the impetus for my 9mm AR pistol build. I can Form 1 ($200 stamp fee plus a few $$ in parts)an adequate suppressor capable of handling a 10.5" 9mm but a can capable of handling a 10.5" .223 and doing a decent job of suppressing it costs $400-700 plus $200.
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