M4 Conversion

[BattleAxe]

I have a 90-ish era Colt Comp HBAR that's a heavy pig and want to convert it to more of an M4 style platform with a floated barrel. Is this a fairly easy conversion? Any kits out there? I want the shortest floated barrel without having to jump through any legal hoops.

Am I correct in assuming that a conversion would consist of just a barrel, gas tube, and rails or does the buffer need to be changed? Quality is important.

Also, does swapping the barrel affect headspace and how is that problem dealt with? I'm an ace mechanic so I'm not afraid to do this myself provided I have the tools.

Also factoring cost of parts or tools would I be better off just buying the whole rifle?

 

[MK14 SEI]

Re: M4 Conversion

Have you looked into just buying a complete upper set-up the way you want it?

 

[BattleAxe]

Re: M4 Conversion

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: H2O MAN</div><div class="ubbcode-body">Have you looked into just buying a complete upper set-up the way you want it?

</div></div>
I suppose that would eliminate a lot of issues and make things easy, plus give me the ability to return to factory.

 

[ORD]

Re: M4 Conversion

There are a SH!T-TON of options out there for an M4-style complete upper, although I don't know that what you are describing is an M4 other than having a carbine barrel. Going with a complete upper will allow you to simply pull the takedown pins out of your Colt, remove your HBAR upper and replace it with the carbine upper. You can go any number of routes to get a complete upper with:

1) A3/A4 Flattop;
2) 16" barrel (min. legal length without going SBR unless you want to go 14.5" and have a muzzle device permanently installed by blind-pinning/welding to get you out to the 16" min. length); and
3) a free-float handguard/forend.

Before I (or anyone else) goes off recommending options, you need to decide on a little more detail on the upper you want.

Do you want the M4 profile barrel (cut-down for attachment of the M203 Grenade Launcher)? If not, since you want lighter, I assume that a heavy, bull-barrel is out?

When you say free-float, do you want just a free-float tube with a single swivel stud or do you want a "railed" free-float handguard with picatinny rails for attaching bipods, lights, optics, etc.?

Also, since you are switching to a carbine upper, do you plan on retaining your A2 buttstock or do you plan on coverting to a collapsible stock? No big deal either way...this is something that can be done with little work and 15-20min worth of your time. Just one more thing to think about.

Finally, what's your budget for this project?

 

[MK14 SEI]

Re: M4 Conversion

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BattleAxe</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: H2O MAN</div><div class="ubbcode-body">Have you looked into just buying a complete upper set-up the way you want it?

</div></div>
I suppose that would eliminate a lot of issues and make things easy, plus give me the ability to return to factory. </div></div>

Yes to both points.

To make it even easier, make sure the 16" upper has a complete BCG and charging handle.

 

[BookHound]

Re: M4 Conversion

So, I assume you have a fixed A2 stock on the lower, right? Are you wanting to keep that? Generally, with a 16" barrel carbine (M4-profile barrel) most guys like also using a collapsible stock. It gives you a lot more flexibility.

If you are wanting to also change the stock, you are talking about having to remove the current stock buffer tube and replace with a carbine buffer tube assembly, including a new buffer and spring.

Swapping barrels on your upper is a piece of cake - IF you have the right tools including an action block, vice, barrel nut wrench, etc. A little knowledge of how to swap the barrel wouldn't suck either. So, it would be best to find someone who knows what they are doing and either just let them do it or watch them.

You can re-use your upper, bolt & carrier so if you like those parts and don't want a second rifle/upper you could take off the parts you don't need and sell them to recoup some $$. Just work the math on the various options to figure out what will make most sense to you.

If you were local to me, I'd gladly help you swap barrels, install a rail and swap stocks.

DO you have any pics of what you have now and pics of something close to what you want?

 

[MK14 SEI]

Re: M4 Conversion

BattleAxe, listen to BookHound... he knows what he's talking about and he is very helpful.

Mark, will your new business venture have a store front?

 

[BattleAxe]

Re: M4 Conversion

Good questions guys. This is what I have now...it's the AR in the background.

Colt Comp HBAR
KAC rails
EOTech 557 W/MPO
CAA Stock

What I'm trying to do is fill a niche in my collection and want something better suited for CQB and short-to-medium range work in .223. I don't need sub-MOA accuracy and 1 to 1.5 should be fine. Weight isn't as big of an issue as size and in its current trim it's clumsy as hell. The stock and barrel is too long for its intended use. Money is no object but I don't want to go stupid expensive given its role either.

My vision would be 14.5 floated barrel with pinned flash hider, full rail system, Magpul stock, and I'll keep the EOTech.

Quality and reliability are paramount and I'm not opposed to just selling it and buying a new stick. BUT if I can meet my objective with the current platform and save a few bucks I'd be OK with that.

 

[BattleAxe]

Re: M4 Conversion

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BookHound</div><div class="ubbcode-body">Swapping barrels on your upper is a piece of cake - IF you have the right tools including an action block, vice, barrel nut wrench, etc. A little knowledge of how to swap the barrel wouldn't suck either. So, it would be best to find someone who knows what they are doing and either just let them do it or watch them.

You can re-use your upper, bolt & carrier so if you like those parts and don't want a second rifle/upper you could take off the parts you don't need and sell them to recoup some $$. Just work the math on the various options to figure out what will make most sense to you.

If you were local to me, I'd gladly help you swap barrels, install a rail and swap stocks.

DO you have any pics of what you have now and pics of something close to what you want?
</div></div>

I've R&R'd my barrel before and have the tools so I think I can do a floater easily.

 

[BookHound]

Re: M4 Conversion

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: H2O MAN</div><div class="ubbcode-body">BattleAxe, listen to BookHound... he knows what he's talking about and he is very helpful.

Mark, will your new business venture have a store front? </div></div>

Sort of. I'm at American Precision Arms now. Formerly known as Patriot Arms. When I was in the Class 3 business I was sending all our local guys to PA/APA for threading work because I knew it would be perfect and the customer wouldn't have problems. I've been friends with Jered, Dave, Bill and the guys for years. I was fortunate to find something still in the industry I love with good friends who build incredible rifles. I've long said Dave and Jered are the only guys I let work on my personal guns if I'm not doing the work myself. The shop prefers local customers to just give us a heads up when they want to come by so we are sure to have someone available. We aren't to far from you, ya know. ;-)

 

[BookHound]

Re: M4 Conversion

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BattleAxe</div><div class="ubbcode-body">

I've R&R'd my barrel before and have the tools so I think I can do a floater easily. </div></div>

Then it should be an easy change. Some free-float rails use proprietary barrel nuts Others, like some of the Troy rails, use standard barrel nuts. Sounds like the barrel swap should be easy enough for you though. If I can help in some way, let me know.

 

[MK14 SEI]

Re: M4 Conversion

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BookHound</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: H2O MAN</div><div class="ubbcode-body">BattleAxe, listen to BookHound... he knows what he's talking about and he is very helpful.

Mark, will your new business venture have a store front? </div></div>

Sort of. I'm at American Precision Arms now. Formerly known as Patriot Arms. ... The shop prefers local customers to just give us a heads up when they want to come by so we are sure to have someone available. We aren't to far from you, ya know. ;-) </div></div>

Understood and I see that you are real close to the airport and race track.

 

[BookHound]

Re: M4 Conversion

Yep. Airport is right out the back door. We have customers fly here to pick up their guns.

 

[MK14 SEI]

Re: M4 Conversion

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BookHound</div><div class="ubbcode-body">Yep. Airport is right out the back door. We have customers fly here to pick up their guns. </div></div>

That's pretty sweet!






Are my PSI T-shirt and Golf shirt highly prized collectors items yet?

 

[BattleAxe]

Re: M4 Conversion

Hmmm. I may just go with a complete upper. I like to tinker and can do it myself but really don't have much time for it. Thanks for the input guys.