what 308 lower is compatible w/ Armalite uppers?

[huckberry668]

I'm confused about this. so which lower will 'definately' work w/o any modification on Armalite uppers?
thanks

[Flux Capacitor]

I'm confused about this. so which lower will 'definately' work w/o any modification on Armalite uppers?
thanks

Armalites. Thats about it.

[bwiese]

Many folks here use Vulcan/Hesse HAR25 lowers with Armalite uppers without problems. I don't think any mods need to be made, other than some shims to the Armalite 10rd magazines.

Calguns user 'CG' has the scoop on this. His works fine.

[adamsreeftank]

Many folks here use Vulcan/Hesse HAR25 lowers with Armalite uppers without problems. I don't think any mods need to be made, other than some shims to the Armalite 10rd magazines.

Calguns user 'CG' has the scoop on this. His works fine.

If CG had luck with is Hesse, he may have just been lucky. I have examined several Hesse Har-25 lowers and they were all out of spec in that the buffer retainer hole was too far back. This causes the buffer to hit the retainer instead of pushing the bolt all the way into battery. The result is the buffer gets dented and the retainer will eventually break. It takes some careful work with a mill to fix this problem. All of the Hesse uppers I have seen were also out of spec, but if you use an Armalite upper, that won't matter.

problem.JPG

[C.G.]

If CG had luck with is Hesse, he may have just been lucky. I have examined several Hesse Har-25 lowers and they were all out of spec in that the buffer retainer hole was too far back. This causes the buffer to hit the retainer instead of pushing the bolt all the way into battery. The result is the buffer gets dented and the retainer will eventually break. It takes some careful work with a mill to fix this problem. All of the Hesse uppers I have seen were also out of spec, but if you use an Armalite upper, that won't matter.

[ATTACH]3674[/ATTACH]

I've had that problem with a FAB-10, but not with either of my two HAR-25s. I have AR-10 blueprints and they match perfectly to those, in spite of the crappy finish. I can't speak of others. The only thing was the HAR-25 was a 1st generation lower and has to be modded to accept a second generation bolt catch.

Two things:
1) You can only match an Armalite upper nowadays anyway, good luck finding a Hesse upper (and I wouldn't want it anyway).
2) It is not easy to tell from the pic, but your buffer tube looks like it is screwed in too much.

[adamsreeftank]

...
2) It is not easy to tell from the pic, but your buffer tube looks like it is screwed in too much.

Maybe you are looking at the last thread on the receiver. The tube is back far enough to allow the pin to move freely. If you are saying that based on how much of the retainer is covered, that is due to the hole being too far back, as I described above. The picture shows the lower before I modified it and moved the hole forward. Now it works properly and the buffer protrudes the required amount to engage the rear of the bolt carrier.

Interestingly, the person that suggested the problem with the buffer retainer location said he had fixed that problem on several Fab-10s. After I worked on the Har-25s, I pulled out an old Fab-10 that I had an A1 upper on and lo-and-behold the buffer was chipped. When I pulled the upper off, I could tell it had the exact same problem. The buffer retainer is too far back. I'm not going to bother trying to fix it though.

[C.G.]

Maybe you are looking at the last thread on the receiver. The tube is back far enough to allow the pin to move freely. If you are saying that based on how much of the retainer is covered, that is due to the hole being too far back, as I described above. The picture shows the lower before I modified it and moved the hole forward. Now it works properly and the buffer protrudes the required amount to engage the rear of the bolt carrier.

Interestingly, the person that suggested the problem with the buffer retainer location said he had fixed that problem on several Fab-10s. After I worked on the Har-25s, I pulled out an old Fab-10 that I had an A1 upper on and lo-and-behold the buffer was chipped. When I pulled the upper off, I could tell it had the exact same problem. The buffer retainer is too far back. I'm not going to bother trying to fix it though.

Makes sense, I couldn't tell from the pic. And yeah, I am not going to worry about the FAB-10 either.

Anyway, my two HARs may have been later models or they had a better machinist on duty that day.

[tiger222]

fwiw~ Gunrunners can mill the inside of the Armalite upper for $100 to mate better to a HAR25 lower that uses the DPMS/SR25 mag. It runs like a SOB on anything! The only "fly" in the oinment is the bolt hold open does not function on the last round, which is ok with me.

[C.G.]

fwiw~ Gunrunners can mill the inside of the Armalite upper for $100 to mate better to a HAR25 lower that uses the DPMS/SR25 mag. It runs like a SOB on anything! The only "fly" in the oinment is the bolt hold open does not function on the last round, which is ok with me.

Armalite upper fit both of my HARs without a hitch. What exactly did they have to mill? If it is opening the bolt catch slot to fit generation 2 bolt catch, that can be done with a Dremel and about 20 minutes of your time.

[tiger222]

Armalite upper fit both of my HARs without a hitch. What exactly did they have to mill? If it is opening the bolt catch slot to fit generation 2 bolt catch, that can be done with a Dremel and about 20 minutes of your time.

CG the DPMS mags apparently sit slightly higher than the M1A mags so the inner front and sides above the magwell is relieved to make room - will take some pics if you like?

[C.G.]

CG the DPMS mags apparently sit slightly higher than the M1A mags so the inner front and sides above the magwell is relieved to make room - will take some pics if you like?

Gotchya. I prefer the Armalite mags myself, even if they do fit a little sloppy, so far hasn't influenced function.

[BLKTALN]

Many folks here use Vulcan/Hesse HAR25 lowers with Armalite uppers without problems. I don't think any mods need to be made, other than some shims to the Armalite 10rd magazines.

Calguns user 'CG' has the scoop on this. His works fine.

yep. one avail. on gunbroker.

link

[pc_city]

If CG had luck with is Hesse, he may have just been lucky.

Here's a pic of my HAR-25 buffer after 400 or so rounds with Armalite & Noveske Uppers.

Adam, I think you have bolt carrier, buffer stop, or upper issues.

[adamsreeftank]

Here is a quick diagram to show what I have found:

hesseMess.JPG

In the top configuration, the rear of the bolt carrier is flush with the upper receiver and the buffer protrudes slightly from the back of the lower receiver. This is the way it is supposed to work. Every AR that I have inspected that has functioned well looks like this.

The lower configuration shows what I found with the Hesse parts that I have access to. The Hesse uppers don't allow an Armalite bolt carrier to line up with the rear of the upper, and the lowers don't allow the buffer to protrude, or even be flush with the lower receiver.

I have looked at many Hesse uppers and lowers, and they were all slightly different. Some lowers were worse than others. One lower was close enough that it might work with an armalite upper but might not. The rest were too far off and require modification of the buffer retainer hole. One hesse upper did allow the rear of the bolt carrier to be flush, but the barrel protruded a bit too far into the receiver and created a ledge that would probably catch the tip of the bullet.

[C.G.]

yep. one avail. on gunbroker.

link

Funny, that is the second time I've seen that the Seller states they take FAL mags.
The first guy was from Texas? and sold one to someone here.

To add, my buffers look just like PC City's but one has more rounds.