AR9 barrel swap

Tomme boy

Well-Known Member
I got in a new barrel for my AR9 pistol. I don't want to deal with the whole brace thing that is going on anymore. It is just a matter of time before it will have to go.

So I ordered a new 16" barrel. I got a Wilson Arms 16" with a front sight installed on it already. It is F marked for using a clamp on sight. Works perfect with the handguard I have on the upper already. Wilson cuts the barrel to the same length as a regular carbine gas with plastic guards. There is just no gas tube.

Got her all switched over except the sling swivel. That and the sight pin assembly came in a baggy. Have not done a front swivel before. It is riveted on. Should not be too hard.
 

Tomme boy

Well-Known Member
Went out and sighted the gun in today real quick. Ran a couple loads over the chrono to see if there was much difference in speeds between the 7.5" barrel and the 16" on it now. Very surprised it was exactly the same speeds. 135gr mihec roundnose was 1352fps. And a 135gr flat point was 1241fps. Both shot at 5 feet distance from the chrono.

Both are loaded with the same charge of SW Auto Pistol. The difference in speed is the round nose has to be seated deep to stay out of the rifling.

Hands got cold and had to leave the target. 10 shots went into a quarter sized group at 20 yes. I am happy with that.
 

Tomme boy

Well-Known Member
Yes. I seen a few guys get about 200fps more by going to a carbine barrel. I can not check the ejection pattern as I use a brass catcher. Usually you can tell how warm the loads are by the ejection pattern and distance they throw the brass.

I might have to grind in a small feed ramp on the face of the barrel. Both bullet would not feed from a full mag. Just the first round. It did not do this with the other barrel. That is the only difference.
 

Tomme boy

Well-Known Member
Been having some issues with trying to eject a loaded round from the chamber. I tried the normal and seated the bullet a little deeper. Then deeper. Then deeper.........

I then checked to make sure a factory jacketed round would load and eject. Well that even had a little resistance ejecting the round. It marcs all around the bullet.

So I beat a soft lead slug into the throat to measure it. 0.3535" so it looks like I will need to ream the throat or shoot some lapping bullets to open it up. It is a regular phosphated barrel so nothing hard to work through. I have not seen my fire lapping kit in several years.
 
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CWLONGSHOT

Well-Known Member
Ya gonna need +P or even +P+ to see those velocities "grow". Im kinda suprised "reg" 9mm dosent actually SLOW for ya!!

In my 45 16" it sure do!! But +P is speedy at about 1300!


Yes odd ya didnt have those issues when ya mounted the bbl.... some kind of lead build up maybe??
 
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Tomme boy

Well-Known Member
I think the bullets have grown in the loaded ammo. I have all the bullets now sized at 0.3555" i just have to load a couple to see how they are. The ones i had loaded for the short barrel were sized at 0.3565". They are tight in the body of the case also. They are a little tight in my G19 also. They were not sticky at all in this before. And now they are a little bit hard to eject.

These bullets have been sitting after sizing for about 5 months. They have not grown any so I should be good to go.
 

Tomme boy

Well-Known Member
I had to grind in a feed ramp on the face of the barrel to get to feed better. I copied the ramp the PSA short barrel had. It is feeding 100% now with the flat point 135gr MP bullet.

I ran almost 200 rounds through it today. It was funny watching all the people looking at me shooting the 32rd mags. I had a Full 50cal can of the 9mm I was shooting. Heard a couple people say walking past me " look at all that 9mm! " thought I might get mugged by all the looks everyone was giving me. LOL!
 
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CWLONGSHOT

Well-Known Member
I had to grind in a feed ramp on the face of the barrel to get to feed better. I copied the ramp the PSA short barrel had. It is feeding 100% now with the flat point 135gr MP bullet.

I ran almost 200 rounds through it today. It was funny watching all the people looking at me shooting the 32rd mags. I had a. Full 50cal can of the 9mm I was shooting. Heard a couple people say walking past me " look at all that 9mm! " thought I might get mugged by all the looks everyone was giving me. LOL!
Dont let that "Unsupported chamber" crowd hear that!! :embarrassed::rofl::rofl::rofl::rofl:;)
 
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Tomme boy

Well-Known Member
The chamber on these have a very deep and wide bevel already. Never cut into the actual chamber. From this.
1623726452943.png


To something like this.

1623726212550.png
Not my pics. Borrowed off the net
 
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