AR Sponsor
Posted: 12/28/2007 9:04:30 AM EDT
|
Why cant any manufacture make a 6.8 SPC upper that has the Improved 6.8 Chamber, and m4 extended feed ramps at a decent price? You’re probably going to tell me to get a Ko tonic. But that is not a decent price. If I go with the cheapest upper I still spend around 700 dollars for an upper. If I go with stag, then I don’t get any extended feed ramps. If I go with cmmg, then I don’t get an Improved 6.8 Chamber. So is there someplace where a guy can buy a 6.8 Upper assembly that is a decent price, (500 - 600) shipped, that has m4 extended feed ramps, and has the improved 6.8 chamber? hat |
|
Dear New Member with 25 some-odd posts: Why do you feel you need M4 ramps so badly? You got a happy switch or something? Improved chamber I could understand, but everything I've ever heard about the M4 ramps is that they're pretty much useless outside full auto, which is why it's such a low priority for so many manufacturers. |
|
M4 feed ramps: Because 6.8mm bullets are 1.2 millimeters wider than 5.56mm, the nose of the bullet is lower when the cartridge is at the top of the magazine. M4 feed ramp cuts help the front of the cartridge smoothly transition from the magazine to the chamber. above found Here And below is a link to a thread where people with more posts then me can convince you. The 6.8 and m4 feed ramps thread |
SAAMI spec is what it is. Period. That is is not what is should be is not relevant. This information is taken from both 68forums.com and here on AR.15.com Maker - Barrel Twist / Rifling / Groove / Chamber / Stainless or Chrome Lined / Rifle or M4 Extensions / Muzzle Thread Pitch It does not have the Ko-Tonics developed 1:11" rifling twist w/ 4 grooves nor does it have M4 Extensions, but it is a GREAT deal. It is 1.6 MOA out to 300 yards and is under $550. ETA pull quote taken from the Big 6.8SPC upper test: "STAG Widely available and priced at $525, this upper is honestly what will be the best selling 6.8 upper of the group, and its hard to argue why it shouldn’t be. At 1/3 the price of the majority of entries, this gun shot as well as the best of them at 100 yards. 100 yards is as long as the great majority of shooters will get the chance to use their uppers. I don’t know why, but this was probably the second best shooting gun on full auto. It cycled fast and was quite controllable. It did not provide great results at 300 or 650, but to be honest, 300 yard groups weren’t bad, and it at least turned in groups at 650. I honestly wasn’t expecting to get groups on target at that range, but was surprised that it didn’t throw a shot. While it lacked M4 feed ramps, and had a poorly staked carrier, I did not experience a single malfunction using any of the three types of ammo. I’d probably replace the gas block if I were to get this upper. While the one on the test upper was fine, I have had to replace a cracked Stag aluminum gas block on someone else’s gun before. While I still view the Ko-Tonics as the better value, this is a lot of upper for $525." |
|
Wow, I personally thought the Kotonics I purchased was a great price--IIRC it was the first AR15 upper we've purchased over the past decade in any caliber that was under $1000.00. By the time you get around to changing the necessary items on the Stag, it will be the same price as the Kotonics--based on my experiences to date the Kotonics is a great value. |
Saw your upper on an earlier thread. Very nice indeed, sir. I said in the big 6.8 thread that I though Tim should be ready for a busy 2008, and I still stand by that statement. To my mind, the OP is in the same vein as those who state, loudly, that they will not buy any 6.X upper until they can find the ammo at your local Mega-Mart for $2.50/box. So, the OP can save his pennies and call Ko-Tonics, or buy a STAG right now. It's his money and his choice. Was just trying to moderate the kvetching, by pointing out his one choice, given his price point constraint. But then this is ARFCOM. If there's no bitching, then they're not breathing. BAH! Back to College Football for me!! |
If you read the chart, you would see that we are NOT talking about extended feed ramps, but the Barrel Extension and upper combo. Extended feed ramps can mean that, but it can also mean taking a grinder to the upper. Please see here:  The 10 o'clock picture is a Rifle Barrel Extension with a standard upper. The 2 o'clock picture is a M-4 Barrel Extension with a M-4 upper. The 4 o'clock picture is a M-4 Barrel Extension with a standard upper. The 8 o'clock picture is a Rifle Barrel Extension with a M-4 upper. For the 6.X rounds the 2 o'clock picture is the optimal one. |
Not true. What they said was that the two extensions did not mate perfectly. Look at picture from Randall's website. M-4 Extensions do not always match up with the upper. No, extended feed ramps does automatically mean M-4. It is deft marketing that does not really answer the question correctly or fully. Now, the STAG upper had a rifle barrel extension and worked just fine in testing. It is just not considered optimal and STAG's use of the 1/2-36 muzzle threading is, IMO, dumb. Now, once we see the RRA product in the marketplace, we will know, definitely, what they use. I just dislike the obfuscation. Me thinks that the RRA product will be as good as all their other products. As I said earlier, the value continuum is in effect and you get what you pay for. That does NOT mean that the STAG or the yet to be seen RRA product are poor, just that if you wanted to extract the utmost from the 6.8, you cannot do so w/o spending $$. IMO, 1.6 MOA out to 300 yards for under $550 is a very good deal. BTW, Zak Smith also averaged 1.6 MOA in his test of the STAG 5H. It can be found here: The 6.8SPC Is it all that? |
What am I missing? Ko-Tonics barrel - $215 (Ko-Tonics) Standard FSB installed - $75 (Ko-Tonics) Upper Receiver - $100 (From Denny) Bolt group - $130 (Ko-Tonics) Barrel nut/delta ring, handguard cap, handguards, gas tube/pin - $50 (where ever) Grand total - $570 |
|
Here is what was written, "The upper and barrel contained M4 feed ramps, but they were very shallow compared to some of the other entries." Now, when the thread was first released, I was able to see the picture that showed the Ko tonic extended feed ramps. They were indeed very shallow. And did not come close to the real m4 extended feed ramps. Now I'm not able to see the pictures, because it tells me bandwith is exceeded. hopefully you can. But I have seen dpms rifles. And I have seen their extended feed ramps. I also learn through research, that Dpms, RRA, and AR15 barrels, grind their extended feed ramps in. And are not true m4 feed ramps. But do what they are suppose to do. Ko tonic extended feed ramps looked just like the dpms extended feed ramps. The ramp is extended, but not as deep as true m4 feed ramps. So I assume Ko tonic does the extended feed ramps the same way dpms, RRA, and AR15 barrels, does them. I do own a model 1 sales 6.8. It fires the majority of ammo just fine. But every once in a while a round will not feed correctly, or will get stuck just before the standard feed ramp. Because of this I wont get a stag, because I know from first hand experience that extended feed ramps are needed. Even a slight extension like Ko-tonics, dpms, and I assume RRA has, will eliminates this problem. Now true, I have not seen the RRA ramps yet. But According to a good source (Steve RRA) They are comparable to dpms, and Ko tonics, and ar15 barrels. |
missing charging handle,(17) 587 Flash hider (20) 607 then all the shipping costs for parts. going be close to 640-650 Then the time to learn to put it together. Or else pay someone else to. For me that would not be the route. Although for others it might. |
|
I have looked at NAG's full-size photos on Photobucket and, to me, the Ko-Tonics 6.8 upper looks like it is a rifle upper receiver that has a barrel with a M-4 Barrel Extension. The radius inside the upper receiver are not, IMO, M-4 feed ramps, per se. This is the shallowness that NAG was referring to. Tim (Ko-Tonics) states on his website that he uses CMT uppers receivers in his builds. The 'shallow' M-4 cuts on the uppers is CMT. I do not think that this matters at all. Also the STAG 6.8 upper is a rifle upper receiver with a Rifle Barrel Extension. Randall's (AR15barrels.com) 6.8 upper looks much the same as the Ko-Tonics, which is to say, IMO, a rifle upper receiver that has a barrel with a M-4 Barrel Extension. Do not know what upper Randall used to assemble his, but since I think it looks like Tim's, I would bet the upper receiver is a CMT as well. To your point regarding your Model 1 Sales upper. You know that you can always dremmel your complete upper to change the feed angle to M-4, right? You'd have to refinish your upper, or just have the bare aluminum, but it is a lower cost option then shell out another $500-$600 buck, right? I think that this is beginning to be nothing more then a mental exercise to nowhere. Were it my choice, I would sell the Model 1 Sales upper and use that money to have a 6.8 upper built by Tim, and be done with it. But that is just me, YMMV |
Yup I missed those. Your shipping is a bit high but $630 gets it done. What? You don't have the tools to build it?!?  
|
I'm aware of both options. And have already decided to sell my upper, and save money for a new one. Hence, is why I'm doing all this research. Either way I go, Ko tonic, or RRA, I feel that I did enough research that both are good choices. |
|
AR Sponsor