A2 Front Sight Tower Adjustment

More
16 years 3 months ago #207 by Hoss0013
A2 Front Sight Tower Adjustment was created by Hoss0013
I've always wondered why I had a huge bias in the rear sight windage until I put a new duplex cross sight post in the front: the A2 assembly is canted to the left. I've not got around to it, in the year I've had my LR 308-AP4, to make this change and so just lived with the huge bias on the rear. Now, to adjust the front sight assembly, I figure I'll just back out the taper pins a bit and after truing the rifle in my vice, true the sight assembly. But they're pretty fond of their seat in there. Anyone have any suggestions before I escalate the force to back the taper pins out to make this adjustment, some advice so I don't make matters worse? It seems I'll have to put some lube on the taper pins to get them to come out, then degrease/dry them and love'em back into place to keep the new trued adjustment. Just want to make sure I'm on the right track. Thanks,
Hoss

Please Log in or Create an account to join the conversation.

More
16 years 2 months ago #216 by crux
Replied by crux on topic Re:A2 Front Sight Tower Adjustment
Yikes, gunsmith I am not but I do know the agony of misalignment with the sights. I ended up taking it to the manufacturer and saying "make better". More power to ye on the repair work.

Please Log in or Create an account to join the conversation.

More
16 years 2 months ago #217 by Hoss0013
Replied by Hoss0013 on topic Re:A2 Front Sight Tower Adjustment
I got word from DPMS customer service and they wanted to do the adjustment in house, so I sent off the upper yesterday, via UPS air on their bill. I'm thinking they're going to heat-release the taper pin set or just reset the barrel into the receiver, which would probably be easier; I'm curious as to what would be the preferred action.
Hoss

Please Log in or Create an account to join the conversation.

More
14 years 9 months ago #2974 by Keller3778
Replied by Keller3778 on topic Re:A2 Front Sight Tower Adjustment
I had the same problem but the cant was so bad that the rear windage was adjusted all the way to the right and it still was off. I called DPMS and they told me to send it in. I asked the repair dept if this was common and they told me while some deviation is within spec occationally a really bad one gets out. As far as I can tell the pin grooves are set after the barrell is treaded and if they aren't right on you need to replace the barrel. So thats what they did. I should be getting back on Tuesday. They have a very quick turnaround on repairs.

Please Log in or Create an account to join the conversation.

More
14 years 9 months ago #2977 by BUILDING MY SASS
Replied by BUILDING MY SASS on topic Re:A2 Front Sight Tower Adjustment
It is funny, I got the same speech about "once in awhile, one gets out" from ArmaLite....I guess, in a way, it's nice to know that it happens with other manufacturers as well...sorry to hear about the bad one....mine was the extractor.... :dry:
BMS

Please Log in or Create an account to join the conversation.

More
14 years 9 months ago #2981 by ar10fan
Replied by ar10fan on topic Re:A2 Front Sight Tower Adjustment
i have ran in to the same problem with a dpms mtself but rear and front were at a off angle i turned the rail attachment on the rear sigh it disappeared on the reat cant for the life of me believe there is a diffrence then the sight and the machining the pin i removed from the front was a tapered pin in and out only one direction i would suggest that you at least try driving the pin out the other way beena long time since i ran into this but think the pin drive fron left to right or out the election port side hope this migh help some i plan to replace my front signt wit a yankee hill front sight that screws on via 4 bolet then i will drill it for a pin also

Please Log in or Create an account to join the conversation.

  • a Guest
  • Visitor
  • Visitor
14 years 9 months ago #2983 by a Guest
Replied by a Guest on topic Re:A2 Front Sight Tower Adjustment
I aint going to explain the adjustment on the front sight to keep you all from a trip to the ER but heat release, tell me your kidding.
Don't take any factory tours. Rock River don't use the taper pins so thats another fun adjustment.MSH

Please Log in or Create an account to join the conversation.

More
14 years 9 months ago #2986 by Keller3778
Replied by Keller3778 on topic Re:A2 Front Sight Tower Adjustment
MSH, Where in the process are the groves cut for the FSB pins? I'm not a gunsmith nor pretend to be but I figure the more I know about how the weapon was made the better I can use it.

Please Log in or Create an account to join the conversation.

  • a Guest
  • Visitor
  • Visitor
14 years 9 months ago #2987 by a Guest
Replied by a Guest on topic Re:A2 Front Sight Tower Adjustment
Usualy that is the last machine opperation on the gun and sometimes they have complete holes through the barrel instead of slots. The barrel and all parts are parked and finished first. This is done after the barrel nut and delta ring assembly has been installed. And you will never find 2 front sights that match or will interchange. But the adjustment is done with a big read hammer. Read the Marine armors hand book. Do I need to call 911 yet. Look set the rear sight to battle 0. Get 2 ball peen hammers and a V block and some help. To knock the pins loose put the face of 1 hammer on the small side of the pin and pop it loose with the other hammer with one good lick. Get them loose and swing the sight to where you think you need to go. Lightly tap the pins back in and shoot it for 0. It may take more adjustment but you get the idea. When you get it zeroed put a drop of loctite 290 on the front barrel sight post contact area. It will wick in place and stay put. Only a drop!!!!!!!
The pins don't even need to be there after that. We glue all the national match rifle sights on this way and they get beat around. Note this is the only place on the gun that you use 290 locktite. Don't use it on anything else. MSH

Please Log in or Create an account to join the conversation.

More
14 years 9 months ago #2988 by ar10fan
Replied by ar10fan on topic Re:A2 Front Sight Tower Adjustment
well that was what i was trying to tell the fellow thanks for putting it in words more plain tha ni iys evident that you know what you are talking about yes ballpeen hammers are used so much more that folks know i never will forget getting to go through the colt plant years ago and they ard darn sure rough on the single actione when they put them together i have no griope about the dmpms so far i supose some thint the armalite is better i dont know anything about the angle of the magazine angle folks talk about but the bottom line in my opinion if the rifle is not right when you get it send it back and have them make it right it migh help the next customer there is no reason for them t o ship a rifle that is not right it we will not accept them they will come upto par pretty fast i would think

Please Log in or Create an account to join the conversation.