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Bushmaster=hate?

rooster2/16

Sergeant
Full Member
Minuteman
Apr 4, 2012
139
0
50
Le Boot
My friend just picked up a Bushmaster Patrol rifle today, his first AR since ETSing. I was curious why do so many dislike Bushmaster. I can't find one problem with it as a first AR. I was thinking about getting one as a bash around/spare.
 
Re: Bushmaster=hate?

Their customer service sucks if not non existent, and their quality control is iffy. Nevermind how bad they screwed up the ACR.
 
Re: Bushmaster=hate?

They tend to have poor Quality control. When in a rush. Like during the Pre-post election scare a few years back. It was very poor. Fit and finsh was very bad. I had a M17 imbus Bullpup from them. When it first came out. Had to send it back 4 times. They replaced it still would not work. I would use there parts. They are all made bye outside vendors. But not bye a rifle from them. Check out Bravo co., RRA, Colt, L.M.T , Or Spikes. All make good to great rifles at the about the same cost
 
Re: Bushmaster=hate?

I have no complaints about mine. I have a Bushy Varminter and I also have their Patrolman's M4 non-chromed barrel on a build. Both are very accurate. I would have no issues about purchasing again.
 
Re: Bushmaster=hate?

Quality is hit and miss. As long as you inspect the rifle through and through before purchasing then you shouldn't have a problem.

Since Freedom Group bought them out they have had shoddy quality control and poor customer service. TFG is more worried about their bottom dollar as opposed to quality.

Bushmaster isn't the only company that is lacking. Check ALL of The Freedom Groups acquired companies and you will see that across the board ... customer service and quality dropped after their merger. The Freedom Group runs companies like you would a clothing manufacturer. The Cheapest material for maximum profit.
 
Re: Bushmaster=hate?

Read up on M4carbine.net. They use out of spec/low quality parts. Their chambers are not true 5.56, causing problems. The list just goes on.
 
Re: Bushmaster=hate?

For what it's worth, I have a bushy that's my beater/loaner. It's been neglected like crazy and it hasn't missed a beat yet. It has the more rounds through it than any of my other rifles and I've only had to switch the gas tube. As long as it's lubed, it runs like a raped ape.

I agree with guys who are saying they there are better options in the same price range. If I were looking for an AR in the 1k price range, I would buy another BCM without thinking twice.
 
Re: Bushmaster=hate?

I used to have a Bushmaster Patrolman's Carbine that I bought back in 2003. Never had any problems with it. FWIW.
 
Re: Bushmaster=hate?

The problem with Bushmaster, as well as DPMS, RRA, etc (don't even get me started on the POS of Olympic Arms) is that these companies cut corners. Instead of taking the extra 30 seconds to stake reciever extensions, Loctite gets used. On bbl nuts, you guessed it, Loctite again. I've seen a factory instaled Quad rail that didn't line up with slotwise with the upper. Commercial spec receiver extension vs using a Mil Spec.

Do any of these issues really pose a problem to the end user? If you want to gun that you can throw into your truck and use once a year when you see a coyote go for it. Can you get away with buying one and running it hard at a course like you would a Colt, BCM, LMT, DD, etc? Yes people have done it. But if you look at the fail percentage from Bushy, DPMS, RRA vs these few I just listed it points the finger in a negative way. Wouldn't you rather just spend a little bit more green and get a better gun?
 
Re: Bushmaster=hate?

Bushy and DPMS are owned by freedom group, all of their products have suffered since the buy out.
 
Re: Bushmaster=hate?

I was at my LGS yesterday and there were a couple Bushmasters along with a couple S&W's and a Colt 6920. The Colt was $150 more than the BM, and the S&W's were 50 bucks less than the Colt-although they had a few extras. Why not spend that little extra and get the Colt? $1029.00 vs $875.00 for the BM.

Not downing BM, I dam sure wouldn't want anybody to shoot at me with one. For what it's worth, I have an OLD BM 308 which was the prototype of the RRA-it is an excellent weapon once I got the BCG replaced due to factory defective BCGs in that early design.

I also noted on the Bushmasters at the LGS--they still claim to be based in Windham, Maine?? Far as I knew, they were bought out and moved somewhere else, and the old BM is now called Windham Weaponry. These were new guns, and one of them was a 308 "Oracle" which is DPMS language, but they all said Windham Me on the lower receiver. Just curious about this.
 
Re: Bushmaster=hate?

For Bushy and DPMS their QA/QC on their l larger frames is much better. For entry into the 308 AR realm they aren't bad. But even then once you start customizing and upgrading you are much better off buying a better product from the beginning. Bushys have their place along with every other tool. I just would prefer something higher end.
 
Re: Bushmaster=hate?

I never shot one but the main reason I never gave them a look was that I didn't like the way the used to look. They always used to have some wacked looking flash hider or comp on it and sometimes some funky looking hand guards. I'd heard about the quality and reliability issues but kind of took them with a grain of salt since people say the same about RRA and I've had 2 RRA AR's that have ran flawless and one of them out shoots my friends LMT in terms of accuracy (I'm sure I'll get bashed by the LMT fanboys and lots of others for saying this but its true).
 
Re: Bushmaster=hate?

I own several ARs including a BM predator ( 20" 1-8 twist fluted barrel ) I really like the way it balances, I bought it for coyote hunting but I didn't use it that much before it went back in the safe, its the only one I have that jams every once in a while ( I do keep it clean and lubricated ) and besides that I haven't find a load that will shoot better than 1.5" at 100 yds with different bullets, weights, etc. I own 3 DPMS ( .204 .308 and .223 ) that are a lot more accurate even with factory ammo and I don't have any jamming issues with them, same with colts.
 
Re: Bushmaster=hate?

IMHO Bushy builds entry level guns for the masses who want an AR. You,kinda get what you,pay for. It may look decent but just put your paws on one and pull the charging handle back on a new one and you will feel the difference immediately.

I've had all kinds of brands of Ar's and you couldnt force me to buy one of thief rigs. The last 3 or 4 I have shot had all had a malfunction of some kind during the first or second mag I fired through them. Unacceptable.

Save your cash and get something else.
 
Re: Bushmaster=hate?

Bushmaster isn't that bad for a beginner gun. I never had problems with mine, except the main problem that I should have paid attention to when I first bought it, It's not an LWRC.
 
Re: Bushmaster=hate?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: hewlett260</div><div class="ubbcode-body">Bushmaster isn't that bad for a beginner gun. I never had problems with mine, except the main problem that I should have paid attention to when I first bought it, It's not an LWRC. </div></div>

+1 on that. What I didn't mention in my post above was since owning all of the diferent AR's including my 2 RRA's, DPMS, Colt and LWRC, I sold all but one of the RRA's which i use for my trail/plinking beater and now roll with LWRC's. Love my SPR!
 
Re: Bushmaster=hate?

Thanks for all the info. I picked one up today for $450. Gonna use it as a beater. Shoots well inspite of the bad image.
 
Re: Bushmaster=hate?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 216</div><div class="ubbcode-body">Thanks for all the info. I picked one up today for $450. Gonna use it as a beater. Shoots well inspite of the bad image. </div></div>

You can't complain at all about a Bushy at that price. The beauty of an AR at that price is you can use it as a beater and learn off of it.

Use that to learn first hand what people are always writing about, meaning run it till parts are to the point of failure. That way you wil know pretty accurately the wear and tear components can take.
 
Re: Bushmaster=hate?

I bought mine back in the "ban" years, it’s been flawless and more accurate than it should have been IMHO. Best groups have been down to 3/8" at 100 with 55 and 60 Vmax powered by H335 and would hold under 1/2 the rest of the time. Upgraded now and the only thing factory is the lower frame assembly. Sadly the new upper (not bushmaster) is not as accurate but it still runs perfect and more than accurate enough to fill the role of a coyote rifle for 500y on in. Shoots about MOA to MOA and a quarter now.
 
Re: Bushmaster=hate?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 346ci</div><div class="ubbcode-body">Bushy and DPMS are owned by freedom group, all of their products have suffered since the buy out. </div></div>


They were sub-par before it too.
 
Re: Bushmaster=hate?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 11B101ABN</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 346ci</div><div class="ubbcode-body">Bushy and DPMS are owned by freedom group, all of their products have suffered since the buy out. </div></div>


They were sub-par before it too.</div></div>

I'd like to challenge your statement. It appears to me from my perspective selling DPMS products that they are not only the best selling brand, selling more than most other brands combined; but, they are also among the most reliable brands, if there is such a thing, based on need for initial warranty service. I'd bet that DPMS may be the most reliable brand out there.

What I do not like about Bushmaster, DPMS, and Windham guns is that they fit A2 type front sight bases designed for fixed carry handle guns to their flattop guns rather than the correct F marked type. This makes zeroing a problem when the shaved BDC that comes with these guns is replaced by the user with a mil spec BUIS. In such a configuration the gun will shoot about 10 MOA high and there may not be enough adjustment off the front sight post to zero without running the post up to where it's literally just hanging in the front sight base by a thread.
 
Re: Bushmaster=hate?

I have had several over the years. Barrels have been my best. Current govt. profile c7 rifle upper. Awsome. Past carbine barrels and currently a 14.5 which is also very accurate.
Mag wells on their lowers seemed a bit big to me though.
I like their c7 / a1 reciever and barrels.
 
Re: Bushmaster=hate?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Sterling Shooter</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 11B101ABN</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 346ci</div><div class="ubbcode-body">Bushy and DPMS are owned by freedom group, all of their products have suffered since the buy out. </div></div>


They were sub-par before it too.</div></div>

I'd like to challenge your statement. It appears to me from my perspective selling DPMS products that they are not only the best selling brand, selling more than most other brands combined; but, they are also among the most reliable brands, if there is such a thing, based on need for initial warranty service. I'd bet that DPMS may be the most reliable brand out there.
</div></div>

Challenge all you want, the problems that have come about in freedom group have been noted and proven by many. Just because they sell the most doesn't mean they are the best, I'd bet 90% of people buying ARs are for SHTF or the zombie takeover their neighbor told them about. Nobody cares about quality, buy cheap. Remy used to make a nice rifle, now Savage is kicking their ass.

I do have a older DPMS lower that has treated me well. Any future rigs for me will be built using Mega, quality to the T.
 
Re: Bushmaster=hate?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 346ci</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Sterling Shooter</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 11B101ABN</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 346ci</div><div class="ubbcode-body">Bushy and DPMS are owned by freedom group, all of their products have suffered since the buy out. </div></div>


They were sub-par before it too.</div></div>

I'd like to challenge your statement. It appears to me from my perspective selling DPMS products that they are not only the best selling brand, selling more than most other brands combined; but, they are also among the most reliable brands, if there is such a thing, based on need for initial warranty service. I'd bet that DPMS may be the most reliable brand out there.
</div></div>

Challenge all you want, the problems that have come about in freedom group have been noted and proven by many. Just because they sell the most doesn't mean they are the best, I'd bet 90% of people buying ARs are for SHTF or the zombie takeover their neighbor told them about. Nobody cares about quality, buy cheap. Remy used to make a nice rifle, now Savage is kicking their ass.

I do have a older DPMS lower that has treated me well. Any future rigs for me will be built using Mega, quality to the T.</div></div>

'noted and proven by many", I don't think so. Your comments are from your apparently limited perspective on it all.
 
Re: Bushmaster=hate?

So I put about 500 rounds down the pipe this morning. No problems at all. A slight sight adjustment and at 50-200 meters it was knocking down steel targets like a champ. This is my 4th Ar since etsing in 01 and in spite of what I have read I am happy with it. Now its time to upgrade parts and make it mine.
 
Re: Bushmaster=hate?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Sterling Shooter</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 11B101ABN</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 346ci</div><div class="ubbcode-body">Bushy and DPMS are owned by freedom group, all of their products have suffered since the buy out. </div></div>


They were sub-par before it too.</div></div>

I'd like to challenge your statement. It appears to me from my perspective selling DPMS products that they are not only the best selling brand, selling more than most other brands combined; but, they are also among the most reliable brands, if there is such a thing, based on need for initial warranty service. I'd bet that DPMS may be the most reliable brand out there.

What I do not like about Bushmaster, DPMS, and Windham guns is that they fit A2 type front sight bases designed for fixed carry handle guns to their flattop guns rather than the correct F marked type. This makes zeroing a problem when the shaved BDC that comes with these guns is replaced by the user with a mil spec BUIS. In such a configuration the gun will shoot about 10 MOA high and there may not be enough adjustment off the front sight post to zero without running the post up to where it's literally just hanging in the front sight base by a thread. </div></div>

I'm glad you mentioned that last part of your post, I had that exact problem with a DPMS. I got a smoking deal on one a while back from a friend and couldn't pass it up so I bought one. It did not come with a carry handle. I had a spare one left over from an old Colt I had back in the 90's which I had since sold (after several 1000's of rounds, my first AR, oh the memories) and kept the handle.

I called DPMS and asked them just to make sure that it would fit and they said sure. So I slapped the handle on it and took it to the range. The first several rounds didn't even hit the paper. I ran out of elevation on the rear site so I put some back on and started on the front. By the time I walked it up I had the front site almost all the way up. Another turn or two and it would have probably came out. So yeah, it is a problem and people need to know that all rear sites and carry handles will not work.
 
Re: Bushmaster=hate?

I don't hate Bushmaster, just like I don't hate that bitch that gave me crabs, but I know I never want to F**k with her again!
 
Re: Bushmaster=hate?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Ivan R</div><div class="ubbcode-body">I don't hate Bushmaster, just like I don't hate that bitch that gave me crabs, but I know I never want to F**k with her again! </div></div>

LOL
laugh.gif
 
Re: Bushmaster=hate?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Sterling Shooter</div><div class="ubbcode-body">
'noted and proven by many", I don't think so. Your comments are from your apparently limited perspective on it all. </div></div>

Must be why my Savage barrel has 0 runout and my buddies 700aac has enough to be seen with the naked eye. You keep buying their crap, I'll choose the best for my hard earned money.
wink.gif
 
Re: Bushmaster=hate?

DPMS makes a front sight post 0.030" taller than standard for that little problem.
Why they don't just put F marked sights on from the get-go I have no idea, unless maybe they cost more.
Did y'all forget the fact the OP got his rifle for $450?? Although I normally say buy the best you can afford, I'd buy a dozen BMs at that price.
 
Re: Bushmaster=hate?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mtrmn</div><div class="ubbcode-body">
Did y'all forget the fact the OP got his rifle for $450?? Although I normally say buy the best you can afford, I'd buy a dozen BMs at that price.
</div></div>

Thats why I jumped all over it. $450 was just to cheap to pass on.
 
Re: Bushmaster=hate?

You guys know F marked A frame FSBs are only for carbine length setups to compensate for the shorter sight radius, right?
 
Re: Bushmaster=hate?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Snake Plissken</div><div class="ubbcode-body">You guys know F marked A frame FSBs are only for carbine length setups to compensate for the shorter sight radius, right? </div></div>

Here's the scoop on the effect of sight radius: The same detachable carry handle BDC is used on both the M4 and A4. On an A4, elevation wheel and windage drum have a 1/2 MOA value per click. On an M4, the windage drum and elevation wheel have a 3/4 MOA value per click. The click value for the F or A2 front sight on an A4 or A2 is about 1.2 MOA. The click value for the F or A2 front sight on an M4 is about 1.75 MOA.

The reason flattop M4's and A4's use the taller F marked front sight base is to support a 600 meter requirement for the BDC detachable carry handle rear sight, which had to be made taller than the fixed carry handle sight to meet the requirement, since its shaft does not reach below the upper receiver's surface as does the fixed carry handle's sight stem.

There are some A4's out there assembled by RRA, DPMS, and Bushmaster which use the A2 front sight base as do A2 fixed carry handle rifles. But, when mil-spec BDC's are attached to these flattop guns they will usually shoot about 10 minutes of angle high, that's 20 inches high at 200 yards. Thing is, the folks who are putting these guns together apparently don't know they have a problem. Some folks just don't see how 40 thousandths of an inch could be meaningful.

One more thing, when zeroing the A4 for 300 meters at 25 meters, the 6/3 index on the elevation wheel is temporally abandoned with 2 clicks up to the Z mark. After zeroing at 25 meters the sight is adjusted counter clockwise back to the 6/3 index and the line of sight will now intersect bullet path at 32 and 300 meters.
 
Re: Bushmaster=hate?

Ok today I tore the bushlackluster down and wow!!! the trigger springs, firing pin, gas piston rings, extractor and charging handle are pure shit. cheaply produced and not up to what I would consider to be quality.
With that in mind I have started searching for upgrades. I have a good feeling that this can be made into a quality stick.

Wish me luck, I might need it!!!!!!!
 
Re: Bushmaster=hate?

Be sure to check the staking on the gas key screws and if it's a carbine, stake the locknut for the buffer tube.

I recommend a Armalite or RRA 2-stage trigger for and affordable and rather nice trigger.
 
Re: Bushmaster=hate?

My Colt post-ban "match target competition" 20" HBAR had an F-marked front sight on it from the factory.
 
Re: Bushmaster=hate?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 216</div><div class="ubbcode-body">Ok today I tore the bushlackluster down and wow!!! the trigger springs, firing pin, gas piston rings, extractor and charging handle are pure shit. cheaply produced and not up to what I would consider to be quality. </div></div>

Can you elaborate?
 
Re: Bushmaster=hate?

I really enjoy my bushmaster Predator. I got it in 2007, I think that was before the FG takeover. Believe it or not, but it shoots .5" groups at 100 yards with several different non-match FMJ loads. With good match ammo it is more around .25" when I do it right.

I did have reliability issues with it, until I learned that you have to run AR's wet. With a good squirt of CLP every 300 rounds or so I haven't had a reliability issue for 2000 rounds without switching a single part. Don't clean 'em, lube 'em!
 
Re: Bushmaster=hate?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Sterling Shooter</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Snake Plissken</div><div class="ubbcode-body">You guys know F marked A frame FSBs are only for carbine length setups to compensate for the shorter sight radius, right? </div></div>

Here's the scoop on the effect of sight radius: The same detachable carry handle BDC is used on both the M4 and A4. On an A4, elevation wheel and windage drum have a 1/2 MOA value per click. On an M4, the windage drum and elevation wheel have a 3/4 MOA value per click. The click value for the F or A2 front sight on an A4 or A2 is about 1.2 MOA. The click value for the F or A2 front sight on an M4 is about 1.75 MOA.

The reason flattop M4's and A4's use the taller F marked front sight base is to support a 600 meter requirement for the BDC detachable carry handle rear sight, which had to be made taller than the fixed carry handle sight to meet the requirement, since its shaft does not reach below the upper receiver's surface as does the fixed carry handle's sight stem.

There are some A4's out there assembled by RRA, DPMS, and Bushmaster which use the A2 front sight base as do A2 fixed carry handle rifles. But, when mil-spec BDC's are attached to these flattop guns they will usually shoot about 10 minutes of angle high, that's 20 inches high at 200 yards. Thing is, the folks who are putting these guns together apparently don't know they have a problem. Some folks just don't see how 40 thousandths of an inch could be meaningful.

One more thing, when zeroing the A4 for 300 meters at 25 meters, the 6/3 index on the elevation wheel is temporally abandoned with 2 clicks up to the Z mark. After zeroing at 25 meters the sight is adjusted counter clockwise back to the 6/3 index and the line of sight will now intersect bullet path at 32 and 300 meters.
</div></div>

Good post, I'm keeping this one. Thanks for the info.
 
Re: Bushmaster=hate?

It pains me to read this, the Bush Master Name use to mean quality in the AR world. It appears the search for the all mighty dollar has ruined the brand and its name. I own a post pan, pre end of the assault weapon ban Bushy that runs like a top. I purchased it from a budy of mine in 2004. At the time I was living in NJ, therefore its 16" heavy barrel didn’t have a bird cage and the stock was an A2 fix style, the upper was A2 as well. After the ban went away I had the barrel threaded for a bird cage, added a flat top upper, and a collapsible stock. I’ve had zero issues with it. It shoots sub 1” MOA all day long utilizing an ACOG. Like most gun enthusiasts I desire a Colt, because it’s a Colt. I was going to sell the bushy to fund the Colt but I fear recent history has sullied the name so much that I won’t get enough out of it now. My recommendation, if you can find a bushy that was made before the buyout get it. If not run away!
 
Re: Bushmaster=hate?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 997/2man</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Sterling Shooter</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Snake Plissken</div><div class="ubbcode-body">You guys know F marked A frame FSBs are only for carbine length setups to compensate for the shorter sight radius, right? </div></div>

Here's the scoop on the effect of sight radius: The same detachable carry handle BDC is used on both the M4 and A4. On an A4, elevation wheel and windage drum have a 1/2 MOA value per click. On an M4, the windage drum and elevation wheel have a 3/4 MOA value per click. The click value for the F or A2 front sight on an A4 or A2 is about 1.2 MOA. The click value for the F or A2 front sight on an M4 is about 1.75 MOA.

The reason flattop M4's and A4's use the taller F marked front sight base is to support a 600 meter requirement for the BDC detachable carry handle rear sight, which had to be made taller than the fixed carry handle sight to meet the requirement, since its shaft does not reach below the upper receiver's surface as does the fixed carry handle's sight stem.

There are some A4's out there assembled by RRA, DPMS, and Bushmaster which use the A2 front sight base as do A2 fixed carry handle rifles. But, when mil-spec BDC's are attached to these flattop guns they will usually shoot about 10 minutes of angle high, that's 20 inches high at 200 yards. Thing is, the folks who are putting these guns together apparently don't know they have a problem. Some folks just don't see how 40 thousandths of an inch could be meaningful.

One more thing, when zeroing the A4 for 300 meters at 25 meters, the 6/3 index on the elevation wheel is temporally abandoned with 2 clicks up to the Z mark. After zeroing at 25 meters the sight is adjusted counter clockwise back to the 6/3 index and the line of sight will now intersect bullet path at 32 and 300 meters.
</div></div>

Good post, I'm keeping this one. Thanks for the info.
</div></div>

I agree, so Im guessing that my rifle which was originaly a post ban with an A2 upper, which as been converted to a flat top, but reatins its original front site will not be accurate past the 100 zero that I did at 33. Good thing Im using an ACOG like I was issued.
 
Re: Bushmaster=hate?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: usmc1488</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 997/2man</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Sterling Shooter</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Snake Plissken</div><div class="ubbcode-body">You guys know F marked A frame FSBs are only for carbine length setups to compensate for the shorter sight radius, right? </div></div>

Here's the scoop on the effect of sight radius: The same detachable carry handle BDC is used on both the M4 and A4. On an A4, elevation wheel and windage drum have a 1/2 MOA value per click. On an M4, the windage drum and elevation wheel have a 3/4 MOA value per click. The click value for the F or A2 front sight on an A4 or A2 is about 1.2 MOA. The click value for the F or A2 front sight on an M4 is about 1.75 MOA.

The reason flattop M4's and A4's use the taller F marked front sight base is to support a 600 meter requirement for the BDC detachable carry handle rear sight, which had to be made taller than the fixed carry handle sight to meet the requirement, since its shaft does not reach below the upper receiver's surface as does the fixed carry handle's sight stem.

There are some A4's out there assembled by RRA, DPMS, and Bushmaster which use the A2 front sight base as do A2 fixed carry handle rifles. But, when mil-spec BDC's are attached to these flattop guns they will usually shoot about 10 minutes of angle high, that's 20 inches high at 200 yards. Thing is, the folks who are putting these guns together apparently don't know they have a problem. Some folks just don't see how 40 thousandths of an inch could be meaningful.

One more thing, when zeroing the A4 for 300 meters at 25 meters, the 6/3 index on the elevation wheel is temporally abandoned with 2 clicks up to the Z mark. After zeroing at 25 meters the sight is adjusted counter clockwise back to the 6/3 index and the line of sight will now intersect bullet path at 32 and 300 meters.
</div></div>

Good post, I'm keeping this one. Thanks for the info.
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I agree, so Im guessing that my rifle which was originaly a post ban with an A2 upper, which as been converted to a flat top, but reatins its original front site will not be accurate past the 100 zero that I did at 33. Good thing Im using an ACOG like I was issued.</div></div>

It's not about accuracy, just an issue when zeroing when a BDC function is sought from a mil-spec BDC sight. Initially, you can expect your rifle to shoot about 10 MOA high with the BDC bottomed out. This will require at least 2 full revs of the front sight counter clockwise, which puts the rifle out of spec. That's to say two full revs up and the front sight is very close to falling out of its base. The solution is an extended front sight post. I wish folks like DPMS, WW, and Bushmaster would just fit their flattop offerings with the correct F marked front sight base in the first place. Thing is folks don't complain because they rarely attempt to zero their irons.
 
Re: Bushmaster=hate?

Any and all hate directed towards Bushmaster is well deserved. They have put out some real turds over the years. Their QC is borderline criminal.