View Full Version : Convert to M4
I have a newer Colt HBar with 20" barrel and flat top reciever. Its an excellent rifle and served me well before deployment. Now that I have returned I'd like to have an M4 like I had while deployed to attend some training courses.
It occured to me the other day that I could convert this rifle into an M4 type platform by having a local gunsmith install a Wilson 16" barrel, and an adjustable buttstock onto the lower reciever all at an affordable price compared to buying a new (or used) carbine.
Does this idea have merit or would you guys recommend otherwise?
Thanks in advance-
Sure I did it with a Bushmaster I had. Make sure you keep your other parts. Colts seem to retain a bit more value than other makes...from a collecters POV.
82ndtrooper
02-22-2007, 17:34
I recently converted an RRA to an M4'rgery. I purchased the Noveske Stainless 16.1" barrel. Polyganol rifling 1:7 twist rate. Along with Troy Ind BUIS and the LarRue Tactical 11" quad rail system. Low profile gas block and mid length gas tube. Noveske barrels came recommended by some in the industry and some here at "QP.COM"
It does require some tools. Namely a barrel wrench and vise. The LaRue Tactical rail required the use a wrap wrench for their propietary locking system.
I also swapped out the A2 stock for the LMT SOPMOD stock. You can install this yourself also, but with a little help from a vice and some torching on the tube. It's like a 500 count thread pillow for you cheek.
I also purchased the LaRue Cantilever mount for the Aimpoint CompM2 2MOA and the LaRue magnifier mount for the Aimpoint 3x. Since I'm new to LaRue mounts, I have to say that they are much nicer than I even expected.
BUIS were from Troy Industries, Front, and the rear is from A.R.M.S. I love the rear sight for it's simple push button release and two aperatures for close in shots and distance shooting.
I'll give ya an end users report on the barrel and accuracy once I get a chance to get it to the gun club. I also used the KX3 Noveske hider. We'll see how this performs during some night time shooting.
Gear Queer, I know, from a non-QP, but I love my guns.
May be easier to pick up a complete upper assembly. That way you only need to punch the pins to get the old setup back. It may cost a bit more, but it would definately be simpler, and wouldn't require the purchase of tools.
Good times,
YMMV
Blake
Genghis_Don
02-22-2007, 17:47
Thinking about a .458 SOCOM conversion to carry while walkabout up here in large carnivore country.
Any experience?
82ndtrooper
02-22-2007, 18:07
Yes ! I have the RRA upper. If you dont mind spending more money on ammunition than on the rifle then go for it !!
I was purchasing Corbon .458 SOCOM, but have now started reloading. It's the only way to enjoy this big bear. If your not a reloader, then skip it. The ammunition costs alone will kill you if you fire that thing more than a couple of times a year.
Just my .02
The Reaper
02-22-2007, 18:10
May be easier to pick up a complete upper assembly. That way you only need to punch the pins to get the old setup back. It may cost a bit more, but it would definately be simpler, and wouldn't require the purchase of tools.
Good times,
YMMV
Blake
Second that. Keep the Colt upper and get an RRA or LMT upper, gear it up like you want.
TR
Genghis_Don
02-22-2007, 18:12
Thanks! yeah was gonna buy the dies too. I just figured it would be a great backwoods rifle when out fishing or riding the four-wheeler. And it would work for black or brown bear hunting.
Thhose pesky brown bears have a way of sneaking up on ya
The Reaper
02-22-2007, 18:13
May be easier to pick up a complete upper assembly. That way you only need to punch the pins to get the old setup back. It may cost a bit more, but it would definately be simpler, and wouldn't require the purchase of tools.
Good times,
YMMV
Blake
Second that. Keep the Colt upper and get an RRA or LMT upper, gear it up like you want.
Thinking about a .458 SOCOM conversion to carry while walkabout up here in large carnivore country.
Any experience?
I would get a good lever gun. There are fewer good heavy game loads for the .458 SOCOM. You also do not want a malfunction if you really need to use it.
TR
Genghis_Don
02-22-2007, 18:18
I would get a good lever gun. There are fewer good heavy game loads for the .458 SOCOM. You also do not want a malfunction if you really need to use it.
TR
good point ...... already thinking about the Browning in .45-70. I seem to have an addiction for things that slice, shoot, or explode
82ndtrooper
02-22-2007, 18:30
Actually I waiting to hear some end user reports on the 6.8mm SPC. Any QP's wanna pipe in ??
Peregrino
02-22-2007, 19:28
CCRN - Take the advice of TR and Air.177; get a carbine upper and DO NOT mess with changing the Colt upper. It preserves the value (why people fall all over themselves for a Colt, I'll never understand) and you avoid the potential pitfalls of a "frankengun". Besides, it can actually be cheaper (less expensive), especially if you use the Colt bolt assy with the new upper. FWIW - Peregrino
The Reaper
02-22-2007, 20:06
Actually I waiting to hear some end user reports on the 6.8mm SPC. Any QP's wanna pipe in ??
Do you want to pay $1 per round to plink?
TR
good point ...... already thinking about the Browning in .45-70. I seem to have an addiction for things that slice, shoot, or explode
If you just want something for the alders around Fairbanks, look at the short barreled Marlin 1895G 45.70. Real easy to carry on a 4 wheeler, boat or hiking. Small & light enough you actually don't mind carrying it on those late night trips from the tent. I load 54gr H4198, 250CCI Mag primers & 350gr Kodiak HJ FN bonded bullets for about 2170fps. It never jams and I run about 200 rounds a year through it. Hell on the shoulder on paper, but a thing of beauty every fall on Kodiak Island. Goes right through deer and takes care of the tooth & claw crowd.
Do you want to pay $1 per round to plink?
TR
I have been suffering from shock due to ammo cost recently. If prices keep going up, that may be consider inexpensive shooting. Even components is going up. I just bought some 4198 (8 lb keg) for the old price $99.00, new price is $130.. something.
Genghis_Don
02-23-2007, 00:02
Thanks Indian, appreciate the load advice! Where's your stomping ground?
I live outside Wasilla. Shoot at Birchwood, Ft Rich, Ft Greeley with the Alaska Rifle Club. Hunt all over, but Kodiak is my annual "mental health" trip.
Oh, by the way, the factory lever on the Guide Gun is crap and will tear up your hand with HOT loads! If you load heavy, get a loop lever from Wild West Guns in Anchorage (Cabelas carries them too). Wild West is obnoxious and too expensive, but Jim's lever is the only way to go for the Guide Gun.
ccrn, did you get your questions answered, or has this thread been hopelessly hijacked?
I live outside Wasilla. Shoot at Birchwood, Ft Rich, Ft Greeley with the Alaska Rifle Club. Hunt all over, but Kodiak is my annual "mental health" trip.
Oh, by the way, the factory lever on the Guide Gun is crap and will tear up your hand with HOT loads! If you load heavy, get a loop lever from Wild West Guns in Anchorage (Cabelas carries them too). Wild West is obnoxious and too expensive, but Jim's lever is the only way to go for the Guide Gun.
Check out DRC armamemt. Dave Clay makes a damn good product, and he isn't an asshole like West. You can get his loops and some other stuff from Brownells. He also does a damn nice marlin takedown conversion if you can justify the price and are patient enough to wait.
Good times,
Blake
82ndTrooper "Actually I waiting to hear some end user reports on the 6.8mm SPC. Any QP's wanna pipe in ??"
I have built a few AR15s and an AR10 from scratch. I looked at doing an AR15 in 6.8 spc but the cost to make it and mags and ammo are close to what an AR10 costs. Also if you do a CQB class with a 6.8 spc the cost of ammo would probably run around $800+ and I load my own. So I went with the AR10. A lot of parts are interchangible with an AR15 so I still have a problem with what they charge for the AR10 parts but I wanted one so I built it.
With the 6.8 spc I decided to have a barrel for a Thompson Contender made. 15" Shilen made by JD at SSK Industries. I shoot 135 Sierra GK with Benchmark and Fed primers and I get about a 2.5" group at 200 yds. It's a great PA deer hunting gun and the round appears to be well suited for white tail. As far as a combat round in an AR I couldn't say. Maybe Gene or Longrange have had more experience with it in an AR15 or mini 14.
ccrn, did you get your questions answered, or has this thread been hopelessly hijacked?
rgr.
I think the general consensus from those in the know is a new upper.
Im already on it.
The question remains then what about my existing lower, willit be worth while to simply change the buttstock to use with a new M4 upper?
The mani goal over all was to save money which is in short supply right now having been gone!
Thanks to all for the replies-
The question remains then what about my existing lower, willit be worth while to simply change the buttstock to use with a new M4 upper?
You can buy a complete RRA M4 buttstock kit for $59, which includes the wrench to install the castle nut, from Eagle Firearms. It's pretty easy to swap the stocks, but you mentioned you have a gunsmith. The only thing with the RRA kit is it uses a commercial extension tube, so if you ever wanted to upgrade to a SOPMOD stock, you would need to get a mil-spec tube, which is a different diameter. It is available from DSA for about $20, or you could spend about $40-45 for a VLTOR, CMT or LMT mil-spec tube.
Another option is to get an M4 stock kit with a mil-spec tube, like from CMT/Stag. That kit will run about $69-80 depending on which vendor you choose. Eagle Firearms has it, but they are out of stock. Check out the vendors in the Equipment Exchange on ar15.com.
The tax man has been gracious this year so...
Ive found a guy in my state that has 7 Colt 6721's for around 1200. Im thinking seriously about picking one up especially considering the latest legistlation up for consideration.
Questions are as follows:
Do you guys have an opinion either way about the heavy barrel?
Is this a good carbine to take to class ie CQB at Blackwater etc?
Thanks-
Pat Rogers at EAG does an excellnet carbine course, as well as Larry Vickers and Ken Hackathorn-they are different in approaches, but all excellent. I have also found that Bill Jeans runs a fantastic class as well. I am planning on taking a Paul Howe class in the future as I have heard nothing but positive about his courses in the circles I frequent. For L/E classes, Scott Reitz is my top choice.
A couple options on your build...............what do YOU need the gun to do?
I sent an identical gun to yours to Noveske to have a LaRue rail put on and a precision barrel for urban sniping work.
You can do an LMT MRP upper and convert it from a 10.5 5.56 to a 14.5, to an SPR, to a 6.8 in minutes with only a torque wrench. I use this system extensively and it is expensive initially, but is very versatile.
For a good GP carbine, you could simply send your upper to SAW in Arizona and have a Colt 16" LE M4 contour barrel installed and be done. I like A1 fixed stocks myself. If you are going to put a retractable stock on it, do yourself a favor and use a Mil Spec tube, and preferably Colt.
Good luck
If you are active-duty MIL or LE, LMT will sell you a complete carbine, with one 30rd mag, sling, and manual. There's even a dealer who sells them at a discount. I talked to a cop who bought one last year, and his carbine, with the LMT cut carry handle BUIS, was cheaper than my LMT upper and lower purchased separately (I'm a civilian), with no BUIS. It was considerably less than $1,200, which sounds high for a 6721. Knesek Guns sells the 6721 for $1,115, and the 6920 LE Carbine (1/7 M4 barrel) for $1,175.
The LMT has a 16" government profile 1/7 twist M4 barrel, versus the 16" HBAR 1/9 twist of the Colt 6721.
Smokin Joe
03-12-2007, 14:49
The tax man has been gracious this year so...
Ive found a guy in my state that has 7 Colt 6721's for around 1200. Im thinking seriously about picking one up especially considering the latest legistlation up for consideration.
Questions are as follows:
Do you guys have an opinion either way about the heavy barrel?
Is this a good carbine to take to class ie CQB at Blackwater etc?
Thanks-
The 6721 is a good rifle but with the 1/9 twist you may have some accuracy issues if you shoot a heavier bullet.
I personally think the 6920 is a more versatile barrel.
You may want to do what Nyeti said and send it to Specialized Armament Warehouse in Chandler, AZ. Ken does great work.
For obvious reasons Id prefer a 6920 over the 6721 but other than barrels Im not sure theres much of a difference.
The 6721's are in my state NIB and could be had in a dat which is why Im considering it. Im not sure why Colt even made an M4 variant with a heavy barrel truth be told.
Ive heard good things about LMT from members of this board but would still prefer Colt if the pricei s similar.
Thanks for the imput-
For the record, I use my current carbine for basic military shooting skills from closer than 7 meters out to 350 meters based on training Ive already recieved and am recieving. My unit uses M4's. Id like to get a carbine I could take to class ie military CQB though I suppose I could take my 20' Hbar just as well.
Ive heard good things about LMT from members of this board but would still prefer Colt if the pricei s similar.
Does Colt still use oversized fire control pins, odd-sized takedown pins and install a block in the lower receiver?
The Reaper
03-12-2007, 19:43
Razor:
AFAIK, yes, which combined with their politics, is reason enough not to buy Colt when others make equal or better quality.
Colt lives only as long as the M-4 contracts last.
TR
Smokin Joe
03-13-2007, 01:35
Does Colt still use oversized fire control pins, odd-sized takedown pins and install a block in the lower receiver?
It depends...
On the semi- only models they use .170 dia. pins and on the MIL/LE (Read: Auto) rifles they use .155 dia pins.
AFAIK, yes, which combined with their politics, is reason enough not to buy Colt when others make equal or better quality.
TR, exactly my point; thanks for the back-up.
Smokin' Joe, being one of the unwashed masses, that means they would still deliberately screw with me, the consumer, so I couldn't use readily available mil-spec parts. Ain't that nifty of them?
Smokin Joe
03-13-2007, 16:38
TR, exactly my point; thanks for the back-up.
Smokin' Joe, being one of the unwashed masses, that means they would still deliberately screw with me, the consumer, so I couldn't use readily available mil-spec parts. Ain't that nifty of them?
I totally agree, its bullshit.
The LMT has a 16" government profile 1/7 twist M4 barrel, versus the 16" HBAR 1/9 twist of the Colt 6721.
LMT will sell me a base carbine with "no bells or whistles" (their words) for 1050.00 which is their mil discount for me.
Thats before I get a FFL to place the order and recieve it for me not to mention waiting months to get it. Interestingly all but one of the FFLs on the LMT website for my state no longer carry their product.
Id most likely prefer a 1/9 twist as much of the ammo Id shoot (for practice) will not be the heavier grain-
The Reaper
03-15-2007, 20:36
LMT will sell me a base carbine with "no bells or whistles" (their words) for 1050.00 which is their mil discount for me.
Thats before I get a FFL to place the order and recieve it for me not to mention waiting months to get it. Interestingly all but one of the FFLs on the LMT website for my state no longer carry their product.
Id most likely prefer a 1/9 twist as much of the ammo Id shoot (for practice) will not be the heavier grain-
If you read my review of the LMT 10.5" carbine, I think you will know what I think.
I took it to a shooting school for a class, and it was the only shorty there that ran reliably.
Try it, you will like it. And you get what you pay for.
Ask for the match two-stage trigger as well as ther SOPMOD buttstock, if you can afford it.
If I couldn't afford the LMT, I would look at Rock River as a good second choice.
Just my .02, YMMV.
TR
LMT will sell me a base carbine with "no bells or whistles" (their words) for 1050.00 which is their mil discount for me.
Thats before I get a FFL to place the order and recieve it for me not to mention waiting months to get it. Interestingly all but one of the FFLs on the LMT website for my state no longer carry their product.
Id most likely prefer a 1/9 twist as much of the ammo Id shoot (for practice) will not be the heavier grain-
My apologies for not being clear. You have to go to a specific dealer, not the factory. The cop I spoke with bought his complete LMT carbine from Pete at ar15salesDOTcom. Give him a call and tell him you are mil and are calling in reference to his ad here: wwwDOTar15DOTcom/forums/topic.html?b=7&f=21&t=255335. I have purchased two LMT lowers from him and am a satisfied customer.
Just as a point of reference, here's the breakdown on my pieced together new LMT carbine:
- Defender 2000 lower, single stage trigger, Tango Down grip (now Ergo), Gen II M4 stock on a mil-spec tube (with the castle nut staked at the factory, just like Colt), $330 shipped from Pete, plus $15 local FFL transfer fee. See if he will discount the two-stage trigger and SOPMOD stock for you.
- 16" M4 upper, bolt carrier group (properly staked gas key, also just like Colt), charging handle, plus DPMS CAR handguards, $572 shipped from a different dealer.
- Total out the door, $917, with no sights. And I remember the cop telling me he got his rifle cheaper with his LEO discount from Pete. When you compare Pete's price, remember it includes the LMT rear BUIS, which is around $120. You are also getting one 30rd mag, a sling, and a manual, none of which is included in my price.
If I couldn't afford the LMT, I would look at Rock River as a good second choice.
Just my .02, YMMV.
TR
Sir,
Thanks for the advice, Ill go with either of those two.
Ive read your essay on carbines and see that you recommend the 1/9 twist for lower grain ammo. Though I prefer the LMT carbine a bit more than the RR, LMT only comes with a 1/7 twist which might pose a problem as I shoot a variety of ammo mostly due to affordability and availability.
So thats my conundrum-
Peregrino
03-17-2007, 12:51
CCRN - Get what you want and quit worrying about barrel twist. 1/7 will shoot 55 gr. just fine; especially for anything you're likely to do with a carbine in the US. I have everything from 1/7 to 1/12 and ALL of them shoot 55 gr. just fine. 55 gr. is "blasting ammo" good for plinking/training at reduced ranges (IMNSHO < 150m = reduced ranges; especially when most "blasting" is done at <100m). It's primary value is affordability. If you want social ammo, use something else (and re-zero the weapon!). POA/POI shifts whenever you change bullets. FWIW all of my "plinkers" (carbines are plinkers :p ) are 1/9 for economic reasons, e.g. adequate quality, availability, and reasonable price. I'm currently using an RRA and a "frankengun" and they both run like sewing machines. TR and others have discussed the pitfalls of the various approaches (specifically the frankengun) and their advice should be heeded - caveat emptor. I can't justify the expense of an LMT right now, though I an jelous of TR's. RRA is a quality product for a reasonable price and they can be counted on to fix unfortunate "hiccups" (have to admit it's annoying when that happens and QA/CS are not up to expectations). I've owned several Colts over the years; I can't justify ever buying another one. My .02 - Peregrino
The Reaper
03-17-2007, 13:02
Sir,
Thanks for the advice, Ill go with either of those two.
Ive read your essay on carbines and see that you recommend the 1/9 twist for lower grain ammo. Though I prefer the LMT carbine a bit more than the RR, LMT only comes with a 1/7 twist which might pose a problem as I shoot a variety of ammo mostly due to affordability and availability.
So thats my conundrum-
Unless you are a match shooter, the 1x7" should stabilize most of the rounds you will find just fine.
You have to decide whether you want the ability to shoot the 69 gr. plus bullets, which due to overall length include the military M856 Tracer round. If so, then you really need the 1x7". If you never plan to shoot the heavier and more expensive rounds, the 1x9" will work just fine.
Unless you are competing, I would look for a military-type 16" barrel from LMT, RRA, or Colt with the chrome lined bore.
HTH.
TR
I just saw that RRA now offers what appears to be a true government profile (light under the handguards) chrome-lined barrel, even though they call it a Lightweight. (http://www.rockriverarms.com/item-detail.cfm?ID=AR0202ASY&storeid=1&image=bblr407.gif&CFID=35617281&CFTOKEN=26082441) Offered in 1/9 or 1/7 as a $40 option on the rifles.
OK I know what to do now.
Thanks once again for the advice, I appreciate it. Ill place an order monday and post picks when it comes-