AR-15 shooters....

[Blmpkn]

Check Midway USA and Natchez. They seem to have the best prices for decent stuff. Cheaper Than Dirt! Is known to price gouge everytime there is some sort of crisis to justify it.

Looks like I'm gonna have to do some deep digging.

Nothing strikes my fancy that isn't 200$.. and it's making my brain hurt.

Decent quality flipups (metal) can be had all over the place for well under 2 bills... but for some reason nice looking peep/post combos can not why.

May just end up with a budget reflex at this rate This silly little ammo waster certainly doesn't call for trijicon quality after all..

 

[sgtsandman]

Looks like I'm gonna have to do some deep digging.

Nothing strikes my fancy that isn't 200$.. and it's making my brain hurt.

Decent quality flipups (metal) can be had all over the place for well under 2 bills... but for some reason nice looking peep/post combos can not why.

May just end up with a budget reflex at this rate This silly little ammo waster certainly doesn't call for trijicon quality after all..

Magpul makes a decent plastic site but I don't remember what they go for anymore. They are pretty tough for plastic. You just don't want to mount them on a railed gas block. The heat will melt them.

 

[Blmpkn]

Magpul makes a decent plastic site but I don't remember what they go for anymore. They are pretty tough for plastic. You just don't want to mount them on a railed gas block. The heat will melt them.

I have a pair of the OG magpul flip ups on another pistol build.. recently moved them there from a flat-top carbine.

When they were on the carbine I definitely had the front mounted on the gasblock though lol

I've never really run mag after mag through the thing in quick succession though.. always have a variety of stuff to shoot when I go so I'm always switching back and forth.

 

[gaz]

@Blmpkn
I have used these fixed sights on every AR that I assembled. They are Daniel Defense "Rock N Lock" sights but I have seen them listed as "A1.5's" from other distributors. They are made of Al but it's good stuff and light; I have experienced zero issues after initial sight in.

On sale I've seen them for just under $100 for the front/rear set. On the Daniel Defense web sight they can be seen in many of their fully assembled rifles.

 

[Blmpkn]

@Blmpkn
I have used these fixed sights on every AR that I assembled. They are Daniel Defense "Rock N Lock" sights but I have seen them listed as "A1.5's" from other distributors. They are made of Al but it's good stuff and light; I have experienced zero issues after initial sight in.

On sale I've seen them for just under $100 for the front/rear set. On the Daniel Defense web sight they can be seen in many of their fully assembled rifles.

Those definitely are a nice pair of sights.. just too tall for this particular build. Total length is barely 17" lol.. super stubby. Full height sights would look kinda out of place IMO.

This is the pair I really want... I just really can't justify the price at the moment

 

[Blmpkn]

Alright fellow nerd-patriots.. TF do I do about this?

9mm rig got jammed, buggering up the inside end of the charging handle. Now the charging handle is stuck shut/closed.. and I don't have any files small enough to try and smooth it out...

Can't remove the bcg with the CH stuck in there obviously... Does removing the bolt from the carrier allow a guy to get the rest of it out? I can't remember.

Been waiting to shoot this damn thing for months.. finally get an optic on it and everything immediately goes wrong lol ugh killin me.

*Can't remove bolt from carrier.. definitely gotta smooth out the CH with it all in the receiver somehow.. don't wanna do any damage to the receiver though gah.

 

[gaz]

@Blmpkn
Separate the upper and lower, then use a grotesque amount of Break free or the like.

From your picture, it looks as though the Aluminum charging handle has been "pseudo staked" in place, in it's channel by the brass. I would persuade the charge handle out, uppers are pretty tough and may not even take a scratch from the handle.

If you will be the person swinging the hammer, put the upper in the freezer over night (10-12 hours), that will afford you the most possible wiggle room. Be ready to go to town as soon as it exits the freezer.

If that doesn't sound like your bag, drop it off with your trusted gunsmith and let them take care of you ..)

 

[Blmpkn]

@Blmpkn
Separate the upper and lower, then use a grotesque amount of Break free or the like.

From your picture, it looks as though the Aluminum charging handle has been "pseudo staked" in place, in it's channel by the brass. I would persuade the charge handle out, uppers are pretty tough and may not even take a scratch from the handle.

If you will be the person swinging the hammer, put the upper in the freezer over night (10-12 hours), that will afford you the most possible wiggle room. Be ready to go to town as soon as it exits the freezer.

If that doesn't sound like your bag, drop it off with your trusted gunsmith and let them take care of you ..)

I managed to un-bungle it.. and sanded the handle smooth so it ran through the receiver nicely. Shot it again.. aaand had another near exact jam where the open end of the casing was smashed up against the CH.

Took it back inside.. grabbed the instructions pertaining to the buffer assembly.. and read a tidbit about removing the retaining pin & spring if experiencing cycling issues. Did that... Shot it again.. still jamming not AS bad .. but still getting wobbed up

*** Just went out and dropped one single round into the chamber (no mag).. bang.. and no ejecto... Perhaps these rounds just aren't hot enough for it to cycle properly? They're regular load 115gr fmj

 

[Blmpkn]

Alright... Did a little reading and found this..

"One “fragile” aspect of the 9mm AR is the ejector. With the upper and lower apart, or the magazine adapter out of the gun, the front end of the ejector can get bumped out of alignment. It needs to be REALLY close to rubbing the slot in the bolt for consistent operation.

The face of the ejector also needs to be square to the axis of the bore, or if not, the edge closest to the center of the gun should be more prominent. Go the other way, and the ejector more “suggests an exit” for the case."

Looks like I just need to do a little tweaking with some pliers. That'll have to be a project for another time.

Super excited to get this thing running smoothly.

One upside to the day though.. my super budget red dot is pretty close to zero right out of the box. Windage is off a touch but elevation is dead-nuts

 

[IsNotAYahoo]

Evening Blmpkn,

I have built a few of these before and the recoil portion of it can be a real pain in the tuchus sometimes. Let's start with the usual: what type of buffer and spring are you using for your set-up?

While many manufacturers recommend .308 springs, I most often see ar15 carbine and rifle springs used if the spring is too stout it will cause the short cycle.

The next item to check is if the weight itself; they tend to run heavier to absorb the greater recoil force you can buy steel and tungsten weights, and try swapping those out one at a time to fine tune.

When I had to figure out my PCC I found this site here which talks about 9mm buffer systems in depth; I still find the site very informative.

It looks like you are using an adapter on a standard 15 lower with colt mags. I use glock lowers, so not my expertise, but your adapter should have a feed ramp like this: check the height of it. While you're doing that check the height of the inserted magazines as well. Either of those being too tall in the receiver could be dragging on the bolt as it comes back to battery. You can shorten and/ or polish anything contacting the bolt, adjust the magazine release ledge to lower your magazine, or deepen the grooves of the bolt with an end mill (or the cursed dremel but going very slow is highly advisable if you do.)

Finally, it appears you have an older style of feed cone on your barrel. While it shouldn't cause any issues in this situation it could cause feed problems with larger (or longer) bullets once you get the thing cycling properly. If there are troubles with that you can always machine a deeper cone into the chamber end, or speak to Macon Armory about it (I think he was one of the first folks to figure that one out, or you can always buy a new barrel from him if you don't want to mess with that one.)

Good luck and let me know if you have any questions. I've only built a couple PCCs, but they are pretty fun and I do enjoy shooting them.

 

[Blmpkn]

Evening Blmpkn,

I have built a few of these before and the recoil portion of it can be a real pain in the tuchus sometimes. Let's start with the usual: what type of buffer and spring are you using for your set-up?

While many manufacturers recommend .308 springs, I most often see ar15 carbine and rifle springs used if the spring is too stout it will cause the short cycle.

The next item to check is if the weight itself; they tend to run heavier to absorb the greater recoil force you can buy steel and tungsten weights, and try swapping those out one at a time to fine tune.

When I had to figure out my PCC I found this site here which talks about 9mm buffer systems in depth; I still find the site very informative.

It looks like you are using an adapter on a standard 15 lower with colt mags. I use glock lowers, so not my expertise, but your adapter should have a feed ramp like this:View attachment 120234 check the height of it. While you're doing that check the height of the inserted magazines as well. Either of those being too tall in the receiver could be dragging on the bolt as it comes back to battery. You can shorten and/ or polish anything contacting the bolt, adjust the magazine release ledge to lower your magazine, or deepen the grooves of the bolt with an end mill (or the cursed dremel but going very slow is highly advisable if you do.)

Finally, it appears you have an older style of feed cone on your barrel. While it shouldn't cause any issues in this situation it could cause feed problems with larger (or longer) bullets once you get the thing cycling properly. If there are troubles with that you can always machine a deeper cone into the chamber end, or speak to Macon Armory about it (I think he was one of the first folks to figure that one out, or you can always buy a new barrel from him if you don't want to mess with that one.)

Good luck and let me know if you have any questions. I've only built a couple PCCs, but they are pretty fun and I do enjoy shooting them.

My lower is a Spikes dedicated lower for colt mags, and the buffer I'm running is a 3 or 3.5" stubby unit from a company called tacfire. I bought the complete upper from 2atactical.com.. extremely budget.. 3" barrel, blowback operation. Has a GIANT flash can on the end of it though to bring it out past the handguard.. can must be 3" long or so. I like the idea of going to a 5" barrel with a regular length brake on it.. so a barrel swap may happen sooner than later.

The buffer is kind of a funky setup.. but it had decent enough reviews and being so short was suuuuper attractive. It's length was more or less the reason I decided to build a pistol caliber rig.

 

[IsNotAYahoo]

My lower is a Spikes dedicated lower for colt mags, and the buffer I'm running is a 3 or 3.5" stubby unit from a company called tacfire. I bought the complete upper from 2atactical.com.. extremely budget.. 3" barrel, blowback operation. Has a GIANT flash can on the end of it though to bring it out past the handguard.. can must be 3" long or so. I like the idea of going to a 5" barrel with a regular length brake on it.. so a barrel swap may happen sooner than later.

View attachment 120318

The buffer is kind of a funky setup.. but it had decent enough reviews and being so short was suuuuper attractive. It's length was more or less the reason I decided to build a pistol caliber rig.

Now that's cool! I have a goal to do something like that myself although I might try for one of those buffer-less uppers (Foxtrot Mike looks decent) and get a folding stock to put on it, which I think would be awfully fun.

Since you mentioned the brand of tube you are using, I did a bit more searching. While looking I found this page talking about short buffer tubes (spikes not tacfire, but similar), it mentioned when you have less than 22-24 oz of reciprocating mass (both bolt and buffer combined mass) usually that’s compensated by stiffer springs.


That led me to two possibilities:

The buffer springs might be too stiff. I encountered this on a 10.5" ar15 build. I had too much buffer spring/weight for the rearward force produced by my shorter barrel and it short stroked. I looked at the Tacfire site and found the set-up you have. There are two springs: likely a primary/ recoil spring, and a guide-rod/ buffer spring. Since there is no buffer weight in the setup the provided springs are probably extra stiff to compensate.

If you swap the springs it might resolve the problem: primary for a more flexible spring, and the secondary with a stiffer spring should allow the rearward force to overcome the first spring still have the second spring catch the bolt at the end of travel (to stop it from slamming into the buffer tube rear.)


Or it could instead be the combined travel length of bolt and buffer. It could be too long for the tube because it's a 9mm bolt and not an AR15 bolt carrier.

The 9mm is a blowback system which produce more rearward force so there shouldn’t be any reason it can't overcome the force of your buffer system. But because of that same reason 9mm bolts are weighted to slow down that force (regular buffer weights are not enough.)

Your buffer has what appears to be an insert designed to fit into the tail of an ar15 bolt carrier to kept the primary spring in place. If your ar9 bolt has a weight in the tail blocking the insert from fully inserting that would cause the combined length of bolt and buffer system to be longer than expected stopping the rearward travel (very similar to a too stiff spring.)

If it is a weight in the way you could remove the 9mm bolt’s steel weight, and use a shorter tungsten weight further up the tail which should allow the tail insert to fit (this would require some machining possibly.)

There is also a company that makes "short bolts" foir their buffer system for this very reason. I'll have to keep an eye out for it and coem back if I can find it.

 

[Blmpkn]

Now that's cool! I have a goal to do something like that myself although I might try for one of those buffer-less uppers (Foxtrot Mike looks decent) and get a folding stock to put on it, which I think would be awfully fun.

Since you mentioned the brand of tube you are using, I did a bit more searching. While looking I found this page talking about short buffer tubes (spikes not tacfire, but similar), it mentioned when you have less than 22-24 oz of reciprocating mass (both bolt and buffer combined mass) usually that’s compensated by stiffer springs.


That led me to two possibilities:

The buffer springs might be too stiff. I encountered this on a 10.5" ar15 build. I had too much buffer spring/weight for the rearward force produced by my shorter barrel and it short stroked. I looked at the Tacfire site and found the set-up you have. There are two springs: likely a primary/ recoil spring, and a guide-rod/ buffer spring. Since there is no buffer weight in the setup the provided springs are probably extra stiff to compensate.

If you swap the springs it might resolve the problem: primary for a more flexible spring, and the secondary with a stiffer spring should allow the rearward force to overcome the first spring still have the second spring catch the bolt at the end of travel (to stop it from slamming into the buffer tube rear.)


Or it could instead be the combined travel length of bolt and buffer. It could be too long for the tube because it's a 9mm bolt and not an AR15 bolt carrier.

The 9mm is a blowback system which produce more rearward force so there shouldn’t be any reason it can't overcome the force of your buffer system. But because of that same reason 9mm bolts are weighted to slow down that force (regular buffer weights are not enough.)

Your buffer has what appears to be an insert designed to fit into the tail of an ar15 bolt carrier to kept the primary spring in place. If your ar9 bolt has a weight in the tail blocking the insert from fully inserting that would cause the combined length of bolt and buffer system to be longer than expected stopping the rearward travel (very similar to a too stiff spring.)

If it is a weight in the way you could remove the 9mm bolt’s steel weight, and use a shorter tungsten weight further up the tail which should allow the tail insert to fit (this would require some machining possibly.)

There is also a company that makes "short bolts" foir their buffer system for this very reason. I'll have to keep an eye out for it and coem back if I can find it.

This buffer system ditches the weight in the bolt for the insert bit I got in my fingers, it's hollow for the spring to fit through and the forward end of the spring rests against the "inside" of the bolt. No idea how much reciprocating mass it has.. Ill have to find a scale and weigh it. I believe I'm relatively safe in assuming iit's just an issue with my ejector though.. hopefully.. just gotta find some more time to mess with it.

The last round I fired through the thing I did without a mag in it.. and it didn't even try to eject. Racked back the charging handle and the spent casing was still at home in the chamber.