Threading a semi auto for a suppressor.

Cass

Not looking for recommendations as i have two people i'd turn to for this, but wondering how hard or easy it is.

With a regular bolt action it's a case of removing the barreled action or barrel and turning in the lathe. With a semi auto it's a little more complicated to remove the barrel and leaving it in the action is a no go. Had one person suggest i do it with a tap and die set, but i don't care if it was laser guided there is no way i'm allowing anyone, least of all myself, to go near the gun with a tap and die set.

The rifle has a good bark as it is so i need to reduce the heard report. So anyone have this done, was it difficult, etc.

Thanks.

dazed+confused

Using a die alone isn't an option anyway, as you would have to first turn the barrel down to the correct thickness on a lathe. So either way the barrel will have to come off.

Cass

Exactly.

The barrel dimension means it's okay for 1/2 unf, M14, or M15. Nothing bigger. This means some of the barrel needs turning down. To try and do with a die set from the outset means it'll make a balls of it assuming you manage to even get the die set started (which i highly doubt), and you end up having to get it done right anyway.

Snakezilla

The only time a tap or die should be used on a firearm is in the mechanism for screws etc.

It depends what type of set up your smithy has Cass. If he has a centre driven 4 jaw chuck you can get away with not taking the barrel off. I use one in work , they are for turning down non cylindrical work pieces. Tuning down the muzzle to the correct dia. doesnt require the barrel to be turned at warp speed so obviously with the bolt and mechanism completely stripped so all you have is the housing and barrel , its pretty safe. Cutting the threads will be even slower again. It just depends on having the right set up. Hope that can be of some use .

Cass

Cheers lad.

juice1304

is it for the r15? why cant you remove the barrel? You just need a vice block and action wrench which are really chap for them, and there is no messing with headspace as its already headspaced with the barrel extension etc..

Cass

juice1304 wrote: »

is it for the r15? why cant you remove the barrel?

Didn't say it couldn't be removed just that it's something i've never done or seen and as such i was asking how it's done. As said above about regular rifles you use the barrel vice/wrench to remove the barrel and work away. With the semi there is the gas tubes (if that is what they are called) and some other features that i'm not well read on. You probably know more about it that i, but as it uses the gas to cycle the action i was wondering if its something that is tricky or may cause problems if stripped down.

You just need a vice block and action wrench which are really chap for them, and there is no messing with headspace as its already headspaced with the barrel extension etc..

Just to be clear i won't be doing this myself. I know and understand about the working of guns, even to a limited extent the new rifle, but i'm by means qualified or competent to do any such work myself. It'll be going to an RFD.

juice1304

Its easy enough, But you or the rfd etc.. need the action/receiver block as when you torque on the barrel nut it can damage the upper receiver. I would say its even easier than a normal barrel to be honest anyone can do it to be honest. Hand guards off muzzle device if you have one off, slide the gas block and tube off the barrel, loosen the large barrel nut with the appropriate ar tool and simply pull the barrel and extension out of the receiver, it has a corresponding pin on the barrel extension and notch in the receiver etc.. Its a pretty handy job should only take 5 mins but i would invest in the tools as they are cheap enough €30 or so.
I would say that is the very reason that ar's are so popular in the states as everyone just builds them from parts as a project as its something to do and there isn't much that can go wrong as all the stuff like headspace is already done.
I certainly wouldn't put the barrel and receiver in a lathe though.
Good luck with the new toy anyway, its a lovely rifle koodos on the licence too.:cool::pac::D

Grizzly 45

Seeing I just had one done on my barrel for the R25 while up calibering it to 308.I can tell you its "easy" IF you have the right tools and knowhow. Otherwise its a recpie for trouble. You need to definately get the armourers wrench for the appropriate model Ar15 or AR10.They are around 50$ or ask online here ,a couple of lads have them.Taking it apart isnt a biggie at all.Also helpful is a vice and a upper reciver work block,some folks make these out of wood or plasticYou need this for barrel removal and re tightning,also a torque wrench is needed
1] seperate the upper and lower [2] unscrew the handgaurd [3] Remove charging handle and bolt carrier group [4] Remove two grub screws from under the Gas block,and gas pipe retaining pin [5] Slide gas block off barrel [6] remove gas pipe from gas block and lower barrel nut.[7] Put upper reciver on the work block and clamp block in the vice.Use the armourers wrench to undo the Barrel upper reciver nut. [8] seperate barrel from reciver nut.
Thats it pretty much taken apart to go and be threaded.

Putting it back is more or less the same in reverse.Except when it comes to tightning down the barrel reciver nut.That has to be done to a correct foot pound setting.Have a look on the net for this ,there are some good sites like AR15.com that has the whole procedure in pictures and details and have the correct FT/lb settings.You have to do a "tighten/back off" sequenceto seat the nut correctly on the upper.Somewhat like motor cylinder head bolt torqueing.
By rights if you have the tools its according to the US military armourers workshop a 20 min job to swop out the service rifle barrel with a new barrel and including head spacing.
Took about an hour to do when I had i tdone in 243 cal this year.

Vegeta

Suppressor have any impact on the cycling of the rifle? Are the gas systems tunable?

Cass

Not sure on the tuning aspect, but in terms of affecting the working of the rifle, no.

My mate has one on his. It works fine, but one thing i did notice is there is a significant amount of fouling that comes back into the chamber. Now they are not the cleanest rifles in the world unsuppressed, but with one on it can cause or lead to an increase in fouling. The suppressor on his one does not interfere with the working of the gun, the cycling of the action or movement" of the gases. The gas(es), and again i'm guessing here, have already been "re-directed" to do it's work before it reaches the suppressor so i'm not expecting an issues.

Grizzly 45

None sofar on mine.Couple of over load,where the action has cycled back but not ejected the spent casings and started back with them and jammed on the rising fresh round.Although I think that is more a mag fault and ammo combination than the gun itself ,as it doesnt happen with the replacement P mags I got for it.Havent done a speed run with it yet to see what happens when things get really hot,but I doubt its a major issue.
Yes,do not expect nice clean brass to come out of your mag if you only fire a couple of shots. Brasso and some elbow grease if you are fussy .Be grand.:)

gunhappy_ie

Cass wrote: »

i did notice is there is a significant amount of fouling that comes back into the chamber.

Its the nature of the beast particularly with the platform that you are running. Gas will leak out of every orifice possible including around the charging handle so its a good idea to wear shooting glasses.

Im not sure how your mate keeps his gun but where you will run into problems is if you do not clean your gun regularly it will jam up.

GH

Cass

gunhappy_ie wrote: »

.............. so its a good idea to wear shooting glasses.

You can sing that. Again had to learn that the hard way.

Grizzly 45

Little update. Had to break in the new barrel yeterday,so I decided to test this out with the silencer.Did groups of four shots between cleaning for 24 shots[Hope thats ok for a break in??] Ran two strings of four fast shots,and no issues whatsover with the action. Single shots,no problem either.So conclude my problems was the mag and ammo.
Couple of AR pointers.

If you are getting gas leaks back out thru the charging handle,somthing is not right. It should have expended most of the gas impulse by then out the ejection port and should be on the return momentum from the mainspring. You might want to check the bolt carrier piston rings and thats dead simple.
Pull the bolt carrier,dissamble the firing pin out of it. .Put the bolt and carrier as a unit on a flat surface standing up on the bolt face.If the weight of the carrier collapses onto the bolt.STOP and DO NOT USE!! The bolt carrier rings are worn out/damaged and need to be replaced[Recommended to be done at appx 5000 shots] If it doesnt collapse its fine to use.They work like the piston rings in a car and also keep the chrome line in the bolt carrier clean,check too that the holes in the side of the bolt carrier are fully clean and free of carbon and obstructions. Either that or you are using som rather hot loaded ammo for that to happen.

Do NOT clean the gas tube.Replace if necessary or damaged.There is alot of pressure coming down that line so it keeps itself pretty clean,and the risk of getting anything even micro bits of lint down there is too risky.
TIP if you replace the gas tube after a total tear down.some clear nail laquer on the outside end of where it goes into the gas block works as a good seal.

Get a bottle of FIRE CLEAN oil from Brownells[at a cheap price for the oil ridicilous shipping price that cost as much as the bottle of oil.:(] This stuff was designed for guns running alot of ammo thru a silencer.Clean your bolt carrier and can with it and it literally makes cleaning of any parts a wipe off with a kitchen towel for carbon build up.

Unless you are in a desert or jungle enviroment,keep th AR REASONABLY clean and "moist" with lube on the bolt carrier mostly[not sopping wet or bone dry] it will work anytime all the time.
Happy shooting
Grizz.