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9/22/2017 12:11:25 AM
Posted: 8/3/2005 6:54:12 PM EDT
I've heard you guys talk about Bushmasters having an odd sized FSB. I'm about to have one (20") with a removable carry handle and want to trade out the upper for one with a fixed carry handle. Will this cause problems when I go to zero it? Also, can you point me to someone who will thread on an A2 flashhider in case I can't find a trade? TIA
Link Posted: 8/3/2005 6:56:56 PM EDT
Colt has the "odd sized FSB". Everybody else has the same FSB. You should be OK with a removable carry handle and the Bushmaster FSB. If not, Bushmaster sells the +0.040" that will solve any problem you have. I still think you should be OK with what you have.
Link Posted: 8/3/2005 7:20:18 PM EDT
Thanks Mongo. What's the purpose of it on the Colt?
Link Posted: 8/3/2005 7:27:57 PM EDT
[Last Edit: 8/3/2005 7:28:57 PM EDT by YELLOWV]

Originally Posted By Badkennedy:
Thanks Mongo. What's the purpose of it on the Colt?



To properly zero the sights. The Bushy as well as others that don't use the taller F marked FSB A3 carbines have to almost screw the front sight post out all the way to zero. Like Mongo said this is easily remedied w/ the .40 taller sight post. I dont believe it's a problem on a 20" and if you switch to an A2 upper you will be fine as well. However trading an A3 upper for an A2 is not a good move IMO.
Link Posted: 8/3/2005 8:08:18 PM EDT
Well, I have a Colt 6920 and I never take the carry handle off. I really like iron sights and I'm afraid if I go putting some $300 glass on it I'll surely break it. Maybe, maybe not. Also, I may want to shoot it in Highpower and I'm not sure about the A3 handle being legal.
Link Posted: 8/3/2005 8:22:10 PM EDT
I think the A3 handle is legal in highpower but I could be wrong. You'll have to ask SWO Daddy he is the resident highpwer guy. You would be at a serious disadvantage shooting highpower w/ a 6920 though. Also a carry handle wont give you as much sight range as an A2 upper.
Link Posted: 8/4/2005 3:56:48 AM EDT
I didn't mean the 6920 for competition, that's what I'm getting the 20" Bushmaster for.
Link Posted: 8/4/2005 5:10:58 AM EDT
Colt uses the CORRECT height front sight base.


Link Posted: 8/4/2005 5:35:54 AM EDT

Originally Posted By AKM:
Colt uses the CORRECT height front sight base.





Ya, ya, I know, and they use the CORRECT sized FCG pins in their civvy line of rifles also.
Link Posted: 8/4/2005 10:34:31 AM EDT

Originally Posted By Badkennedy:
I didn't mean the 6920 for competition, that's what I'm getting the 20" Bushmaster for.



Oh okay. Duh You're going to want to get a good trigger and free float tube to be competitive as well as an A2 upper. That and a lot of practice.
Link Posted: 8/4/2005 10:38:53 AM EDT

Originally Posted By mongo001:


Ya, ya, I know, and they use the CORRECT sized FCG pins in their civvy line of rifles also.




Blah blah colt blah blah magic bolts blah blah ......
Link Posted: 8/4/2005 1:39:24 PM EDT
[Last Edit: 8/4/2005 1:41:58 PM EDT by shamayim]

Originally Posted By AKM:
Colt uses the CORRECT height front sight base.





Horse poop!


Up until the advent of the M4 for general issue in the Army, Colt used the same higher front sight post that Bushie sells, on it's carbines, and used the standard front sight base. The ONLY reason I can figure that they went to the higher base on the M4s is that when the M4 became general issue, the Army didn't want unit armorers to have to stock two different front sight posts. Thus, the higher base. It's the only reason I can come up with that makes any sense.

My Colt SP1 carbine, circa 1978, came with a higher (round) post, and when I replaced it w/a square profile current type last year, I had to get the higher Bushmaster unit.

There is no "correct" height for an AR sight base. Just two different ways to get to the correct height for the post.

Link Posted: 8/4/2005 2:33:25 PM EDT
Oh okay. Duh You're going to want to get a good trigger and free float tube to be competitive as well as an A2 upper. That and a lot of practice


Wasn't tryin' to be ugly about it, I can see where you got the idea. So you think the A2 upper is better for a strictly competition rifle? Any suggestion on a cheap trigger job?
Link Posted: 8/4/2005 9:21:41 PM EDT

Originally Posted By Badkennedy:
Oh okay. Duh You're going to want to get a good trigger and free float tube to be competitive as well as an A2 upper. That and a lot of practice


Wasn't tryin' to be ugly about it, I can see where you got the idea. So you think the A2 upper is better for a strictly competition rifle? Any suggestion on a cheap trigger job?



Oh I didn't think you were trying to be ugly I just wasn't paying attention to what you wrote. A2 upper is definately better for highpower shooting. It gives much more sight range for long range matches. If you are doing service rifle matches an A3 makes no sense. Your never going to be shooting with optics anyway. That is why all the dedicated CMP/DCM type rifles are A2's. As for the trigger I wouldn't really skimp. It is an intregal part of the rifle for competition although the RRA NM trigger is quite good and not expensive, also Chip McCormicks trigger is very good and not too expensive, Jewell, accuracy speaks and KAC also makes great trigger but for more money. You are going to want a 2 stage trigger w/ 4.5lbs total pull weight.
Link Posted: 8/5/2005 3:44:23 AM EDT
Okay, one more question: I see all the large pin/small pin stuff going on just like the FSB stuff. Which one will the Bushmaster have, and also, which one will my 6920 have if I decide to put one on it?
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