AR18S – Page 9 – AR180S.COM

February 13, 2015

Bolt Carrier Group Differences

I was first prompted to look at the differences in bolt carrier groups between my guns when I started my Shorty Project. With the purchase of my Vulcan V18 I now had 3 versions of these bolt carrier groups and was able to examine them closely. My hope is that these will be of use in the future when someone finds a BCG and needs to identify what gun it originally came from.

The three BCG’s are, in order from top to bottom, Sterling AR-180, Armalite AR-180B, and Vulcan V18.

The first thing that jumps out is that the Sterling BCG features a chrome bolt and cam pin. The others are parkerized. All three carriers are parkerized as well but the Sterling is a different shade with a slight green tint. The Sterling and Vulcan carriers have a cut out on the right rear that is used to open the dust cover. The Vulcan does not have a dust cover so we can only guess as to why it was put there. The Sterling carrier is machined for the locating lug on the charging handle. The 180B is a simple hole, and as mentioned in an earlier post, the Vulcan has a slot and a hole.

The bottoms are very similar but you can just make out the differences near the firing pin on the Vulcan.

The left side of the Sterling has a radius cut around the guide rod hole where the other two no not. This leads to a divot being left in this area after the machining of the cam pin hole is finished. You will also not that the guide pin of the Vulcan is solid and the others are hollow.

Next I discovered why I was unable to get the Vulcan’s last round bolt hold open to work. There is a angled slot that is machined into all the 180 carriers but not the Vulcan. We must remember that the Vulcan originally used a modified AR-15 lower and they needed it to work with that bolt hold open. My original plan was to copy the 180B hold open but that will only work if I cut this slot. I will first try to re-engineer a different hold open and see if I can make that work.

The remaining pictures are showing the BCG’s in the order, Vulcan, 180B, Sterling. Top to bottom and left to right.

The tops are very similar but you will notice the Vulcan carrier shown has wider flats and a slot cut into the rear face.

Here you can clearly see the biggest difference in that the Vulcan carrier has had a large slot machined into the rear face. This is because the hammer was located further forward on the modified AR-15 lower and they attempted to compensate for that. It did not work too well on this particular gun. The Sterling carrier on the right slows the radius around the left guide rod hole that is not present on the others. You can also make out that the firing pin hole is chamfered and the area around the guide rod holes has been relief cut. . The chamfer was left out on the 180B and caused some problems with the hammer peaning the edges of the hole and was restricting the movement of the firing pin. I modified this area on mine so that would not happen again and this is something you should inspect on your 180B if you own one.

I hope this can be used for reference and be of some use down the road. Feel free to comment if you see things that I missed or have any other questions.

Please subscribe and contact me if you have any questions or would like to contribute in any way.

February 8, 2015

GunLab Visits the Old Pueblo and AR180S.Com gets Blog of the Month

I got a call yesterday that Chuck from GunLab would be traveling through Tucson and he wanted to stop by and meet.

We chatted for quite a while and I got to do a little show and tell so he cold take some pictures for the AR-180 section of his site.

He was passing through on a super secret gun buying mission the details of which I am not at liberty to discuss. But let me just say that his mission was a success and I got to fondle his new acquisition. I’m pretty sure I had a dream about shooting it last night. I hope that becomes a reality someday.

I had a blast talking guns last night and he and his wife are some of the nicest people I have ever met. It was a true pleasure to have them at my home. I also have an open invitation to visit the Lab and I will be heading up there soon.

Chuck also informed me that i received the honor of Blog of the Month at The Firearm Blog

I was shocked that Nathaniel had even found my little ol’ blog but could not be prouder.

Make sure to check out all the articles he has over there, I visit it often and I am always finding something interesting. It is a great site.

Please subscribe and comment with any suggestions on how I can improve my site. They should be up and running but just require approval beforehand to keep the spammers at bay.

Speaking of spam,since my email notices from this site have my personal email as a return many spam filters will immediately drop them in the spam folder. Please white list my site and they should start showing up in the inbox, where they belong.

January 18, 2015

AR-180B Shorty Project Pt. V

January 12, 2015April 20, 2015

Subscriber Pictures #1

Subscriber Tommy was kind enough to send me some pictures from the latest Armalite scope he recently picked up.

You can see it is is an early inverted post scope marked with the serial number 670221.

He also showed us the scope mount that was on his early Costa Mesa when he got it from his dad. It is unmarked just like the one I own. I don’t believe these had serials or any other markings.

I also must apologize to subscriber Jeff as he sent me some pictures some time back and I never posted them.

He has a Costa Mesa gun with a very interesting feature, a bolt hold open that you can actuate from the outside of the gun with the magazine still in the gun.

It is unclear if this was done at the factory or after the fact by a gunsmith. It is a very professional job nonetheless.

If these guns were not so collectable I think it would be a very cool modification to perform as the only way to activate the bolt hold open is to reach in through the magazine well.

Here are a centerfold shot of Jeff’s Costa Mesa.

Thanks to Tommy and Jeff for their pictures and please contact me if you have any you would like to contribute.

December 20, 2014

First Generation AR-180 Scopes

The first generation AR-180 scopes are easy to identify if you know how.

They are marked in meters.

The reticle is of the inverted post style.

The practical uses of this style reticle is mentioned in the manual.

To quote from the manual. “The sight incorporates an inverted post as well as fine cross-hairs. When “holding over” at extreme ranges, this precludes the post from blotting out the target.”

The final distinguishing mark that this scope features is a serial number on the bottom of the base. These will all start with 67 followed by four digits.

My good friend and AR-180 mentor, Rich, has collected all the scope serial numbers he has come across over the years and has found none that are higher than 671000. He has further deduced that these were originally produced for the first 1000 Howa rifles.

Armalite never wanted to go into production and make guns as much as they wanted to design them and then license the rights to others to actually produce.

The fact that they had Howa Machinery produce the rifle is documented in the January 31, 1966 issue of U.S. News and World Report. One small paragraph under the heading “Rifles for Asia” reads.

“Armalite, Inc. the Costa Mesa, Calif., firm that took over the former Fairchild gun division, has developed a new combat rifle, the AR18. This model is to be produced by Japan’s Howa Machinery, Ltd., under a provisional agreement. It would be the first mass production of this rifle, with the Japanese expecting to export some units to such Southeast Asia customers as Thailand and the Philippines.”

Original article found here

After Howa produced the first 1000 rifles but before they could ship, Japan became neutral and would not ship any guns to nations that were in active conflicts.

“Adopted in 1967, the three principles originally prohibited arms sales to Communist nations, countries under United Nations sanctions and countries in armed conflict, but it eventually grew into a blanket ban on all weapons exports.”

From NY Times article.

Early Howa AR-180’s are known to have been converted from AR-18’s so this is the series of events as I have come to understand them.

Howa produced 1000 AR-18 rifles in 1967. They were complete with serial numbered scopes and flash hiders. The Japanese government changed policy and they were not allowed to export them. The Costa Mesa plant was forced to ramp up production and in order to offer scopes as add on accessories, they imported the scopes from Howa as these were not under any sanctions. These scopes were offered up, in plain cardboard boxes, to any who ordered them with no thought given to matching the serial numbers.

Picture found via Google Image Search

In conclusion, this makes for a pretty firm number of these early scopes not counting losses over the years. Less than 1000. Identifying and distinguishing them from the later scopes is pretty straight forward, marked in meters, inverted post reticle, and a serial number starting in 67.

Good hunting and please let me know if you have any pictures of original scope boxes you would like to share.

Please note I have manually added a few email addresses to my subscriber list, let me know if this is a problem and I will gladly remove them.