158gr a no no out of pistols?

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RogaDanar
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158gr a no no out of pistols?

Post by RogaDanar » Sun Jul 01, 2012 8:43 pm

http://www.ar15.com/forums/t_6_20/37387 ... tml&page=1

What do you guys make of this? A bunch of people are saying that the Fiocchi 158's and 158's in general are bad to shoot out of pistols and should be for subguns only. I usually treat most of what is said on TOS with a heavy dose of skepticism, but two of the people making the claims are reputable industry people, one being Steve from ADCO. This is the first I have heard of this, and I don't really understand the reason behind the claims. The energy numbers don't seem to be all that significant. I personally have at least 1,000 rounds of Fiocchi 158gr through my G17/Trident 9 combo, and I am sure lots of you guys have a lot more than that. What am I missing here?
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Re: 158gr a no no out of pistols?

Post by 66427vette » Sun Jul 01, 2012 9:16 pm

Never an issue here with it.

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twodollarbill
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Re: 158gr a no no out of pistols?

Post by twodollarbill » Sun Jul 01, 2012 9:19 pm

Looks like the can failed at the threads. so In my mind, something was wrong with the thread depth.
Blame it on the ammo.....interesting.
I've shot a lot of IMI UZI 158gr "blue tip" through my suppressed handguns with no problems. No Fiocchi 158gr.
We will have to follow this one and see what Gemtech says.

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Emilio
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Re: 158gr a no no out of pistols?

Post by Emilio » Sun Jul 01, 2012 9:53 pm

Looking like a Gemtech problem to me. Seen more than one GT do this. :roll:
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RogaDanar
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Re: 158gr a no no out of pistols?

Post by RogaDanar » Sun Jul 01, 2012 9:56 pm

Yeah I definitely wouldn't blame the ammo for that particular failure, I was just surprised to see people saying that the ammo was bad for handguns.
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Emilio
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Re: 158gr a no no out of pistols?

Post by Emilio » Sun Jul 01, 2012 10:05 pm

RogaDanar wrote:Yeah I definitely wouldn't blame the ammo for that particular failure, I was just surprised to see people saying that the ammo was bad for handguns.

It is a gemtech fanboy site,, you bet it a Ammo problem! :lol:

Let's see that with a Liberty or Octane. :mrgreen:
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Re: 158gr a no no out of pistols?

Post by Bendersquint » Sun Jul 01, 2012 10:21 pm

My guess is that it has something to do with concentricity of the threads or lack thereof. We have seen this often, especially in their Multimounts.

In the last couple weeks we received a couple more GemTech cans that are grossly out of concentricity in the threads.

I think the ammo just accelerated the separation of the threads, they should be using a finer thread pitch than what they do.

I have shot 158gr in most of my cans with no issues at all, not sure where Steve is coming from.

Ammo is the easiest thing for someone to blame a problem on.

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Re: 158gr a no no out of pistols?

Post by Historian » Mon Jul 02, 2012 8:07 am

Bendersquint wrote:My guess is that it has something to do with concentricity of the threads or lack thereof. We have seen this often, especially in their Multimounts.

In the last couple weeks we received a couple more GemTech cans that are grossly out of concentricity in the threads.

I think the ammo just accelerated the separation of the threads, they should be using a finer thread pitch than what they do.

I have shot 158gr in most of my cans with no issues at all, not sure where Steve is coming from.

Ammo is the easiest thing for someone to blame a problem on.
+2!

No excuse for a professional machinist to turn out a hazardous product.

At least they could be more innovative and blame, say, continental drift, solar flares, or even
quantum entanglement.

Amazing that the beginners on this site demonstrate more care and success threading concentrically on their
'hobby lathes' than the so called professionals with their CNCs. Who is working for them,
relatives of the sterling Red Jacket or Gun Smoke machinists? :)

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Re: 158gr a no no out of pistols?

Post by TROOPER » Mon Jul 02, 2012 10:20 am

I read a little bit into that post. It was agreed that there was no baffle-strikes. The only other option is that the 158 is loaded too hot, but that seems extremely unlikely that it would be operating out of SAAMI specs; and especially far enough out that it is solely responsible for that can's damage. At any rate, there doesn't seem to be any bulging in the tube, so it looks like a general failure due to the common, violent action of the silencer riding through a semi-autos jack-knifing slide cycle as opposed to a 'kaboom!' caused by too much pressure.

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Re: 158gr a no no out of pistols?

Post by cajun 22 » Wed Jul 04, 2012 1:15 am

I have shot the fiochi 158 out of three handguns suppressed without issue. It is subsonic ammo so the "hot" issue is a no-go. It is a can problem.

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Re: 158gr a no no out of pistols?

Post by Bendersquint » Wed Jul 04, 2012 2:05 am

Dealt with a Gemtech can that was threaded out of concentricity today.

It starting to be a trend, so far its not restricted to 1 lot/batch of suppressors.

I hope they get this fixed.

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Re: 158gr a no no out of pistols?

Post by Historian » Wed Jul 04, 2012 8:08 am

Bendersquint wrote:Dealt with a Gemtech can that was threaded out of concentricity today.

It starting to be a trend, so far its not restricted to 1 lot/batch of suppressors.

I hope they get this fixed.
Is it just me or does this raise storm flags on a company that has
apparently no quality control? Anyone who has even a glancing
acquaintance with machining finds it difficult to conceive how
the most basic skill of threading can be botched up repeatedly.

We do not hope that car shops put the ignition wires back in order,
that munitions manufacturers do not put faulty components
into sidewinder missiles, that pharmacists measure out the correct dosages and medicine,
that lead is not again mistakenly placed in baby formulae from China.

They seem to have the rejects who made the 1975 Trabant in East
Germany on their floors.

Compliments to the creators of this board for having the
'Angie's List' of suppressors and associated firearms.

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este
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Re: 158gr a no no out of pistols?

Post by este » Wed Jul 04, 2012 12:16 pm

Forget pistols.... If you want to see a s--t show, ask hkpro.com about 158gr in an MP5! You'd think there we're dozens of YouTube videos of MP5s exploding and nearby killing children and puppies.

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Re: 158gr a no no out of pistols?

Post by Bendersquint » Wed Jul 04, 2012 1:40 pm

este wrote:Forget pistols.... If you want to see a s--t show, ask hkpro.com about 158gr in an MP5! You'd think there we're dozens of YouTube videos of MP5s exploding and nearby killing children and puppies.
Protect the puppies, don't use 158gr ammo! :roll:

I have shot it in my MP5 and hasn't exploded............yet.

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Re: 158gr a no no out of pistols?

Post by 57fairlane » Mon Jul 09, 2012 3:29 pm

Been answered, I've shot 158gr out of a hk usp9 with zero problems.

Meters better than 147gr I might add.

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Re: 158gr a no no out of pistols?

Post by rockman96 » Mon Jul 09, 2012 7:45 pm

I've shot the 158gr through three separate pistol hosts and a Multimount....never any issues.

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Re: 158gr a no no out of pistols?

Post by Tango2249 » Mon Jul 09, 2012 7:48 pm

158GR Fiocchi is the sheeet out of a Trident9!
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Re: 158gr a no no out of pistols?

Post by kaotic504 » Mon Jul 09, 2012 7:55 pm

i bought 2k rounds of Fiocchi 158gr when it was on sale at an ammunition to go store. :) i only have a few boxes left, so i went through over 1800 through my Evo 9 and my USP SD. no issues. he said no casings were damaged, i'd say it's the suppressor.

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Re: 158gr a no no out of pistols?

Post by John Titsworth » Wed Jul 11, 2012 12:33 am

este wrote:Forget pistols.... If you want to see a s--t show, ask hkpro.com about 158gr in an MP5! You'd think there we're dozens of YouTube videos of MP5s exploding and nearby killing children and puppies.

That is because you don't know s--t about mp5s and 158 grain ammo, but people in the know do..but you have never been in the know and you never will be... :lol:

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Re: 158gr a no no out of pistols?

Post by Bendersquint » Wed Jul 11, 2012 12:59 am

John Titsworth wrote:
este wrote:Forget pistols.... If you want to see a s--t show, ask hkpro.com about 158gr in an MP5! You'd think there we're dozens of YouTube videos of MP5s exploding and nearby killing children and puppies.

That is because you don't know s--t about mp5s and 158 grain ammo, but people in the know do..but you have never been in the know and you never will be... :lol:
John, since you are in the MP5 know please let us know why no 158 in MP5's.

I have fired it in mine suppressed and there have been zero problems with the can or the weapon. 158gr is all one of my customers feeds his MP5's as well and no problems after thousands of rounds.

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Re: 158gr a no no out of pistols?

Post by eric10mm » Wed Jul 11, 2012 10:39 am

Bendersquint wrote:
John, since you are in the MP5 know please let us know why no 158 in MP5's.

I have fired it in mine suppressed and there have been zero problems with the can or the weapon. 158gr is all one of my customers feeds his MP5's as well and no problems after thousands of rounds.
I'm not John, but the simplest explanation is that the gun does not like to run using bullet weights that far from what it was designed for, much like M1 Garands don't like random non-M2 spec ball ammo shot through them. Sure there are now specific loads from ammo mfrs that are designed to work in a M1 Garand, and reloaders have been making good ammo for them for decades. But random off-the-shelf .30-06 ammo is not suggested to run through them unless you have a good supply of spare op-rods on hand. :wink:

The roller-delayed blowback system of the MP5 uses camming surface angles on the bolt locking piece to determine exactly when to unlock the bolt head and allow the carrier to cycle. The key here is the "blowback" part of the action. The rollers delay the unlocking of the bolt head until the pressure curve has diminished enough to impart only a safe recoil impulse to the carrier. Fire an MP5 without rollers in place and your body may be needing some replacement parts as there is insufficient mass in the MP5's carrier to properly damp the recoil impulse down to safe levels. Try it with a rifle round and there is no maybe to it. As a side note, when all the MP5 clones started flooding the market, Vulcan (Hesse) offered a straight blowback clone. Due to their questionable re-engineering of a well-proven action design it was an utter failure and is arguably just plain unsafe to shoot. Their plan was to up the recoil spring's rate, add weight to the carrier and install a polymer buffer (bumper) behind the carrier. It did not work.

The MP5s system was designed around a bullet weight of 115-124 grains at "industry standard" high velocities for those weights. Mess with the weight, or recoil impulse, of the bullet and you change delicate balance of exactly when in the pressure curve the action unlocks and cycles and you are eventually going to have issues up to & including potentially catastrophic ones. Run the "correct" ammo that the guns were designed to run and the guns will hum along until the cows come home.

To this end HK offers locking pieces with different ramp angles to better function with "non-standard" ammunition. The MP5SD is a great example. Due to its barrel ports to slow down the bullet, HK offers different locking pieces for it. The SD guns will not run properly with a non-SD locking piece, if at all. Later the ammunition market developed 9mm 140+ grain bullet loads which start out at subsonic speeds and don't require barrel ports to slow them down. The problem is they don't have enough ass to cycle the SD guns with their gas-bleeding barrel ports.

Original full-power 10mm ammo is STOUT stuff and proved to be too much to handle for the FBI trainees in their issue handguns so they spec'd a downloaded FBI "light" load ammo that much of today's commercial 10mm ammo is loaded to mimic. Eventually the manufacturers said "well, if we're going to download the 10mm ammo that much, we might as well load it into a smaller envelope" and suddenly the .40S&W arrived on the scene. For the FBI's MP5-10mm gun they made a "high impulse" and a "low impulse" locking piece since there were two distinct power levels of 10mm ammo available over the years.

I hope that helps explain why 158gn bullets are not generally recommended for use in MP5 guns.

Regarding using 158gn bullets in pistol, I can't help you. But I would imagine they are longer than 147gn pills and the barrel's twist rate might come into play with regards to bullet (in)stability.

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Re: 158gr a no no out of pistols?

Post by twodollarbill » Sat Jul 28, 2012 3:28 pm

If anyone was wondering about this one....he posted pics of his repaired "shorter" can.

http://www.ar15.com/forums/t_6_20/37387 ... tml&page=5

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