Bushmaster A1 upper receiver questions

[RyanS]

I've got a couple of ideas for my next rifle, with a KISS truck gun being one of them. I've been looking around for an A1 upper and it seems that the Bushmaster is about all I can find. Does anyone know if it has M4 cuts? If not, who makes a 4150 CL 1/7 14.5" or 16" barrel w/out an M4 barrel extension that will work? Is there a better alternative to the Bushmaster? Thanks.

[C4IGrant]

Originally Posted by RyanS

I've got a couple of ideas for my next rifle, with a KISS truck gun being one of them. I've been looking around for an A1 upper and it seems that the Bushmaster is about all I can find. Does anyone know if it has M4 cuts? If not, who makes a 4150 CL 1/7 14.5" or 16" barrel w/out an M4 barrel extension that will work? Is there a better alternative to the Bushmaster? Thanks.

I like the truck gun concept (KISS), but never really understood the carry handle thing (A1, A2, A3). Why not just buy a flattop and put a LT BUIS on it? It is fixed and an A1.

BM guns (unless special ordered) do not come with M4 cuts. So I would go with an LMT as it uses 4150 steel, 1/7 twist with M4 cuts.


C4

[AR15barrels]

Receivers with fixed carry handles are stiffer than flattops.
Not that it matters if you are only using iron sights.
Comparing the cost of a flattop with a LaRue rear sight added, it's surely less expensive to go with the A1 receiver.
As the A1 receiver is all one piece, it's one less screw to come loose and part to fall off.

[C4IGrant]

Originally Posted by AR15barrels

Receivers with fixed carry handles are stiffer than flattops.
Not that it matters if you are only using iron sights.
Comparing the cost of a flattop with a LaRue rear sight added, it's surely less expensive to go with the A1 receiver.
As the A1 receiver is all one piece, it's one less screw to come loose and part to fall off.

The strength issue really doesn't matter IMHO. The thing I have learned though is that when people paint themselves into a corner (like they do with A1 and A2 upper receivers), they tend to regret it as at some point they generally want an optic on the weapon.


C4

[AR15barrels]

Originally Posted by C4IGrant

The thing I have learned though is that when people paint themselves into a corner (like they do with A1 and A2 upper receivers), they tend to regret it as at some point they generally want an optic on the weapon.

Absolutely.

However, there is something to be said for having the skill to not NEED an optic.
Having an iron-sight-only gun is one way to build those skills.

We all have other rifles WITH flattops and optics anyways.
EVERY rifle does not need to have a flattop.

I have a "parts gun" that's built on an A1 receiver.
One of these days I will get around to putting a rail system on it to make the surefire more solid...



I try to shoot this gun once a year in 3 gun matches to keep proving to myself that I can still use iron sights.

[C4IGrant]

Originally Posted by AR15barrels

Absolutely.

However, there is something to be said for having the skill to not NEED an optic.
Having an iron-sight-only gun is one way to build those skills.

We all have other rifles WITH flattops and optics anyways.
EVERY rifle does not need to have a flattop.

I have a "parts gun" that's built on an A1 receiver.
One of these days I will get around to putting a rail system on it to make the surefire more solid...

http://ar15barrels.com/gfx/scrap.jpg

I try to shoot this gun once a year in 3 gun matches to keep proving to myself that I can still use iron sights.

It is kind of a "given" that people need to be comfortable with their irons. Most of the carbine classes I take generally make you shoot a portion of the class with your irons.

I think every rifle should be a flattop with a flip up or fixed BUIS. That way you NEVER stuck and if you want to sell it, you will get your money out of it much easier.


C4

[DRich]

I used a forged DPMS A1/C7 upper when I assembled built my C7 clone last year. You can get them at Brownells for a decent price. I used a 20" CMMG 1:7 gov't profile barrel for the project. No M4 cuts for either component. I run nothing but 69gr and 77gr ammo through it and it works like a charm.



I have other rifles with flattops and optics, but I tend to shoot this one more. As Hyde would say, "It reminds me of a simpler time."

[AR15barrels]

Originally Posted by C4IGrant

It is kind of a "given" that people need to be comfortable with their irons. Most of the carbine classes I take generally make you shoot a portion of the class with your irons.

I think we are creating a new breed of shooter who is not proficient with iron sights.
Flattops and optics only add to this.
Everyone should own at least one AR that's got no optics.

I own two, an M16 clone and the parts gun above with it's M4 barrel on an A1 receiver.

[DRich]

Originally Posted by AR15barrels

I think we are creating a new breed of shooter who is not proficient with iron sights.

This is very true. I can't count the number of times I've heard young "shooters" at my range say, "Iron sights are OK, but you really need a scope if you want to shoot more than 100yds." Many of them have called me a liar when if I try to tell them I use my A2 at 600yds during High Power comps. I'm typically a patient man, but I've given up on trying to educate them. I'm more than willing to help a shooter who wants to learn, but it's getting pretty rare to find one of those people anymore.

[Robb Jensen]

Originally Posted by AR15barrels

I think we are creating a new breed of shooter who is not proficient with iron sights.
Flattops and optics only add to this.
Everyone should own at least one AR that's got no optics.

I agree. Only when you've mastered irons do I believe you should step up to non-magnified optics. I can shoot irons better than I can any Aimpoint or EOTech. Like I said in another post, I see this everytime I'm zeroing one of my ARs that has both irons and optics. My group size is small withthe irons and increases when using the Aimpoint or EOTech.

Irons = nice tiny groups.
Aimpoint/EOTech = more of a small 'pattern'.

Non-magnified optics for me are just a lot faster.

[Skintop911]

Irons first. Basic skill with iron is then bolstered by the integration of optics.

Reliance upon optics without the underlying foundation masks shooter issues, and leaves the shooter hanging when murphy comes calling.

I prefer the A1-type/field-sight uppers when a flat top is not required. Combine that assembly with an A2 aperture and you have a winner.

[C4IGrant]

Originally Posted by AR15barrels

I think we are creating a new breed of shooter who is not proficient with iron sights.
Flattops and optics only add to this.
Everyone should own at least one AR that's got no optics.

I own two, an M16 clone and the parts gun above with it's M4 barrel on an A1 receiver.

I don't think "we" are doing anything. Scopes and such have been around for a very long time. It is people responsibility to practice with their irons. Its kind of like saying that guns kill people.

Optics make for a much faster shooter. They are also a MUST have on a night fighting weapon.

Having been a dealer for many years, I see the same pattern played out over and over again. Customer buys an A1/A2 shoots it and then realizes that he wants an flattop. Sells the gun (loses money), just to get a flattop AR.

By getting a flattop with a flip up or fixed rear, you are getting the exact same thing as an A1/A2 and have the option do something else at a later date.


C4

[PALADIN-hgwt]

xxxxx

[AR15barrels]

Originally Posted by Skintop911

I prefer the A1-type/field-sight uppers when a flat top is not required. Combine that assembly with an A2 aperture and you have a winner.

I ran a 3/16" drill bit through the short-range aperature on my A1 receivered carbine.
Talk about a HUGE aperature.
It's very fast.

[Whytep38]

Originally Posted by C4IGrant

By getting a flattop with a flip up or fixed rear, you are getting the exact same thing as an A1/A2 and have the option do something else at a later date.

This question is one that has no right answer. Grant is correct for most folks. Not everyone has the $$$ for multiple ARs, and a flattop gives its owner many more options.

But ...

I prefer my A2. Less stuff to deal with. For my SD needs, which are rudimentary, optics won't make much difference, day or night. But mostly, there's a certain usefulness to a barebones rifle that you just don't get from something with lots of attachments. It's more than simply learning how to shoot with irons. Actually, it's hard to describe. It's ... Ol' Betsy that you can always count on.

If that doesn't appeal to you - and it doesn't for most folks - the flattop is a better choice.

[LOKNLOD]

I think we're all second-guessing RyanS. Maybe he's trying to save a few bucks, since it's a truck gun and an A1 type is a little cheaper than a flat-top + LT rear. Maybe he doesn't have the kind of spare cash to let a $300 optic ride around on a trunk gun. Or maybe he just likes A1 uppers.

Ryan, I think you can order CMMG barrels with rifle extensions and non-F FSBs. I've got an A1 upper I've been wanting to put their light-weight 14.5 middy barrel on for a while now.

Is it important to use a standard height FSB with A1/A2 uppers?

[Skintop911]

Originally Posted by AR15barrels

I ran a 3/16" drill bit through the short-range aperature on my A1 receivered carbine.
Talk about a HUGE aperature.
It's very fast.

Yup, and a worthwhile upgrade for sure.

I opened up a few to a (approx) distance halfway between the A2's small and large. Can't recall the size, but it was a good compromise.

[Whytep38]

Originally Posted by LOKNLOD

I think we're all second-guessing RyanS. Maybe he's trying to save a few bucks, since it's a truck gun and an A1 type is a little cheaper than a flat-top + LT rear. Maybe he doesn't have the kind of spare cash to let a $300 optic ride around on a trunk gun.

Frankly, that was a big consideration for me when I got my A2 upper. I already had flat-tops and didn't want to spend more cash than necessary for my purposes. I'm glad to say it turned out better than I expected.

For a trunk gun, an A1 upper is probably the best choice. I imagine (but don't know) that irons added to a flat-top could more easily get bumped out of alignment than would happen to A1 sights.

However, if we're talking about long-term cash savings, Grant has a valid point. Buying a rifle you'll be happy with for decades is cheaper in the long run than buying a rifle that you're happy with only for a short time.

[turrican]

Originally Posted by AR15barrels

I think we are creating a new breed of shooter who is not proficient with iron sights.

I agree. It's too bad too because the AR sights are so nice compared to most everything else IMO.

I bought my son his first rifle for his 12th Birthday. He is good with the irons but he doesnt have a choice. He wants an aimpoint but that he will have to save up for. At his current pay rate that will take a year or two.

[RyanS]

Thanks for the comments guys. In response to Grant's comments, I totally agree with him that the flat top is by far more versatile than than an A1/A2 upper. In fact, I am one of those folks who had an A2 and ended up trading it for a flat top. However, that was at a point in my life when I needed to trade to defray the costs and when I really didn't know what I wanted. After some years of shooting the AR platform and finally getting to a point where money isn't such a issue anymore, I've come to the point where I can incorporate/build a little variety in my meager one gun collection. I've tried and owned many styles and finally decided that there is no one style that will keep me fully interested all of the time. Variety is nice. So, now that I've already a good start in my 6920, which will soon be joined by an LMT M4, I want to add an A1 rifle, a 20" A4 style rifle, and a precision stick. Which one to come first is up in the air. These of course are goals which will hopefully be achieved, albiet at a very, very slow pace.