[rothamber]

I got home this evening and found that my new POF 6.8 16" upper had arrived. :mrgreen:

The barrel is marked '6.8 SPC II 1:11.3"

The new Robar NP3 coating on the receiver is attractive, but I must admit I prefer the outside to be black. I believe I remeber reading on Robar's site that the whole receiver must be done rather than just the inside.

If anyone is interested, I'll try to post some pics if I can figure out how.

 

[TackDriver68]

Re: POF 6.8 Upper Arrived

Congratulations

Please post a few pics when you can!

 

[hitman]

Re: POF 6.8 Upper Arrived

How long did it take to get it?

 

[ron169]

Re: POF 6.8 Upper Arrived

To upload an image, you need a hosting site like www.photobucket.com . Set up an account there and follow the instructions to upload an image. After doing so it should have the html image code or link, right click copy that code/address. Then when you make a post here click the "Img" button below the subject box which will put a couple of img encased in brackets. Paste the images web address between the img and brackets. Then click preview to see if it works.

Hope that helps

 

[ArtFWTx]

Re: POF 6.8 Upper Arrived

Congrats Rothamber! I think you're first on the block with the new POF 6.8 barrel, well at least the first person to report having one.

I can't wait to see it. Of course 4000+ members also want a range report too!! :lol:

 

[rothamber]

Re: POF 6.8 Upper Arrived

I placed my order on 12/28/08, the first day of two that they were listed on the website.

Also, I just noticed that it appears to use standard "rifle" feed ramps rather than the M4 ramps most builders seem to use on their 6.8s. I don't know how important this is with the fatter 6.8 case. Hopefully this won't make a difference.

Thanks guys for the help on the photos. I'll work on the pictures.

If weather is fitting, I'll try to get some range time early next week.

 

[T.Rexford]

Re: POF 6.8 Upper Arrived

Definately shoot us a range report!

 

[marinesg1012]

Re: POF 6.8 Upper Arrived

Range report

and pics also

 

[ArtFWTx]

Re: POF 6.8 Upper Arrived

The feedramps can be added easily if you find you need them. No big deal.

 

[coldair]

Re: POF 6.8 Upper Arrived

very nice

 

[BLACK LION]

Re: POF 6.8 Upper Arrived

M4 ramps would basically be a preference and not a necessity...

is the receiver billett???

 

[Test_User]

Re: POF 6.8 Upper Arrived

Are you sure they don't have them? That is a huge surprise. Does the barrel extension look to be a standard not M4 as well Thinking maybe a receiver got thru without them??? M4 feed ramps on ALL 6.8s should be considered Mandatory. The original designers and tester of this round felt they were so improvement they listed them as mandatory and have proven to be needed. There are a number of posts from people without them that have had sporadic feeding issues with certain loads. While some can make a case for them not being needed on certain 5.56 configs the 6.8 is a stubbier fatter bullet and case with a different mag follower etc... It has to rise up higher to hit the extensions ramps without running into the inside receiver wall. The lower to mag fit and their fit to the upper all effects this. Not to mention the ammo specs (bullet, COAL, etc). It is why some never have an issue and others have horrible issues. The whole point is M4 ramps make it a non issue for the most part. IMO the reason for piston ARs is that they are suppose to be a step up in reliability, durability, and performance over even the best DI guns. To not include extended ramps on any such gun is a step backwards that makes no sense IMO. The cost of them is minimal at best and there use is main stream. While some may argue how much they are needed in certain configs I don't think you can find any reasonable person that can state they have any negatives to having them. The same can certainly not be said about not having them. IMHO, they should be included on any premium AR and on all 6.8s. This does not mean that everyone that has a AR without them is going to have issues. As I am sure there are people on this board that could state that. Its a matter of it could and has been proven to do so. It is no different then staking gas key screws, pinning gas blocks and the like. There area plenty of guns that don't have these and have never had issues but they are much more likely to have issues then ones that do use these specs.

Again I am quite surprised they are not included and if that is the case I would suggest you cut them in if you feel you are able to do a good job. If not has a smith or other person that is. In the mean time there is no reason not to go out and run the crap out of that awesome new gun and have a great time. I like a lot of things that POF has do with their uppers and their lowers are awesome and one of the best out there for sure. I don't want you to think this is an attack on POF cause its not its only an issue of the inclusion of M4 ramps for the AR 6.8 platform in general. I personally prefer to cut my on ramps so I can perfectly meld them in and make them to the dimensions I feel is best but I do start with a M4 barrel extension.

 

[rothamber]

Re: POF 6.8 Upper Arrived

Yes, I'm pretty sure about the non-M4 extensions. I've got my wife's camera with a macro lens out and a new photobucket account so I should be able to get some photos posted tomorrow.

I was also able to get some range time in today and ran into a few fustrations. The SSA Sierra OTM (not combat loads) fed and functioned just fine, but the SSA 90 Sierra Varminter Combat Loads failed to feed, presumedly due to the rifle feed ramps, on numerous occasions. Mags used included PRI and CProducts. I didn't bring a Barret becuase they're so long when working from the bench. Note that the tip of the ninely gr varminter is quite a bit more "open" than than the OTMs.

The varminter loads also short stroked--every time. Granted, this is with a heavy buffer (the MGI) along with the Tubb CS springs, and the Carrier Weight Systems (with Tungsten insert). This exact configuration had worked very well on my two prevoius Kotonics/CA uppers, the prupose of such was to delay bolt unlocking and preserve my brass as much as possible. But apparently the light bullet and fast purning powder wasn't enough to cycle the action.

I'll try to provide the update, with photos, tomorrow.

 

[rothamber]

Re: POF 6.8 Upper Arrived

Okay, let's give this a try...

The upper right out of the box. I usually prefer basic black, but the Robar NP3 coating looks okay. Everything looked to be in tip-top shape fit and finish wise.

I placed the upper on a Sabre Defense lower with Geissele trigger, Ergo Tactical Deluxe grip (good for big hands), ACE skeleton stock, Tubb CS spring, MGI buffer, Tubb CWS. Norgon Ambicatch, and ambi safety (yeah I'm a southpaw). The monster Leupold Mk4 8.5x25 was on just for bench shooting.
The POF 308 in the photo has functioned flawlessly so far, though I can't say from initial impressions that it has earned its Mk4 either, accuracy-wise.

Tim, here are a few mediocre photos of the feed ramps. As you can (hopefully) see, they are definitely not extended.
BTW, the goop you can see in the one photo post shooting is Tetra grease. I don't care how many times they say "runs without lube" I can't bring myself to voluntarily to run an AR dry, so I applied some Tetra grease and Slip 2000 per my SOP with DI ARs.

If time allows, I'm going to try to make it out shooting again in a few weeks. I'll put in a regular buffer, remove the CWS, and try keeping the Tubb CS spring when I try the 90 gr. varminters again. If it still short strokes, I'm not sure where to go with it. I guess I could stick with the 110-115 gr bullets which cycled fine, but I have a nice stack of 90 gr TNTs waiting to be loaded I'd hate not to be able to use in this upper.

As far as the lack of extended feed ramps, I'll at least wait until the 30 day money back guarantee expires before I start trying to Dremel out some :wink: The narrower pointed OTM bullets seemed to have less feeding issues than the wider hollow point of the varminters, but frankly I'm pretty annoyed that a brand new nearly $1500 upper (hope my wife doesn't read this) won't feed pretty standard ammo :evil:

I also think I'll be running a box of Final Finish through the barrel to see if I can get better groups through the nitrided barrels they use. I'm going to do the same thing with my POF 308. I'll try to post some before and after photos if I can make it happen.

I also have a new PRI 6.8 barrel and an older Kotonics barrel that I'm going to try the Adams arms gas-pistons on if everything goes as planned.

 

[joshuades]

Re: POF 6.8 Upper Arrived

Yes, I'm pretty sure about the non-M4 extensions. I've got my wife's camera with a macro lens out and a new photobucket account so I should be able to get some photos posted tomorrow.

I was also able to get some range time in today and ran into a few fustrations. The SSA Sierra OTM (not combat loads) fed and functioned just fine, but the SSA 90 Sierra Varminter Combat Loads failed to feed, presumedly due to the rifle feed ramps, on numerous occasions. Mags used included PRI and CProducts. I didn't bring a Barret becuase they're so long when working from the bench. Note that the tip of the ninely gr varminter is quite a bit more "open" than than the OTMs.

The varminter loads also short stroked--every time. Granted, this is with a heavy buffer (the MGI) along with the Tubb CS springs, and the Carrier Weight Systems (with Tungsten insert). This exact configuration had worked very well on my two prevoius Kotonics/CA uppers, the prupose of such was to delay bolt unlocking and preserve my brass as much as possible. But apparently the light bullet and fast purning powder wasn't enough to cycle the action.

I'll try to provide the update, with photos, tomorrow.

That MGI buffer. It's not the rate reducing buffer by any chance. I had gotten one of those for mine (DI rifle) and had problems with the bcg not locking back. By the time I was done modifying the buffer, all the weights were replaced by plastic spacers I made and the internal springs were replaced by much weaker springs (of all things a spring out of a click pen). The reciprocating mass just didn't have the momentum to compress the springs inside the buffer and that would cause it to lock back on the bolt carrier instead of the bolt.

 

[BLACK LION]

nice rigs... set up is very nice...

it doesnt feed hp bullets reliably without those m4 feedramps does it... I think even with the m4 extension there is a chance they can get hung up between the end of the receiver and beginning of the barrel extension... I would contact pof and see if they can fix that for you since you paid so much for "reliability"

I envy your collection

 

[joshuades]

nice rigs... set up is very nice...

it doesnt feed hp bullets reliably without those m4 feedramps does it... I think even with the m4 extension there is a chance they can get hung up between the end of the receiver and beginning of the barrel extension... I would contact pof and see if they can fix that for you since you paid so much for "reliability"

I envy your collection

With the M4 ramps, you need to check and see that the cuts line up right. It's no big deal if the extension doesn't come all the way to the cuts in the reciever. If the extension goes past the cuts in the reciever, there's a chance the round will hang up on the lip created by the protrusion of the extension.