PDA

View Full Version : Will this effect my accuracy?


Gts408
03-18-2012, 2:27 AM
[ UPDATE: I got my upper back today. It took longer in shipping than they took fix it. But the new barrel looks great. I can't wait to hit the range. They even give me a Insight Hx120 flashlight for the time wasted. Pk firearms Great place that backs up their product.]

So i take off my bird cage and installed my new surefire brake on to my 18 DPMS upper, I noticed that i has a dent/nick/chip on the crown of my barrel. I wanted to know if this will hurt my accuracy/precision I could get it cut and re threaded but i feel i shouldn't have to pay for it. I don't know if it is DMPS or PK firearms quality control that didn't catch it. It's a DPMS barrel but PK firearms says the upper are assembled and test fired by them. I don't know which company should be held accountable. Both were sloppy in my in my opinion. But i might just be paranoid. Let me know what you guys think?

http://i1098.photobucket.com/albums/g368/jkiel408/IMG_0175.jpg
http://i1098.photobucket.com/albums/g368/jkiel408/IMG_0174.jpg
http://i1098.photobucket.com/albums/g368/jkiel408/IMG_0172.jpg
http://i1098.photobucket.com/albums/g368/jkiel408/IMG_0178.jpg

A Pic of the bench rifle with the new brake :)
http://i1098.photobucket.com/albums/g368/jkiel408/IMG_0180.jpg

Merc1138
03-18-2012, 2:31 AM
Call the manufacturer and ask them to honor their warranty to deal with the defect.

ChaneRZ
03-18-2012, 2:51 AM
I think you'll be fine. They might not honor the warranty because you already removed the stock flash hider and installed your own brake. They might think you caused that nick. Just saying!

Nice rifle btw.

Gts408
03-18-2012, 2:59 AM
I think you'll be fine. They might not honor the warranty because you already removed the stock flash hider and installed your own brake. They might think you caused that nick. Just saying!

Nice rifle btw.

They could but I had a tool to take off the bird cage, How could i really cause that damage on the inside and how would i have known if i didn't take it off. It really isn't that hard to remove a muzzle brake. But if they do oh well. I guess i'm not buying from them anymore. lol but i'll contact them on monday to see what they can do.

pat4wd
03-18-2012, 8:21 AM
Have you even shot the gun or is it new? I wouuld say shoot it and see.. Proof is in the pudding.. Also why would you say you would not buy from them any more when you have not even talked to them or even shot the gun yet?

I have almost the identical upper I bought from them about 2 months ago and it performs flawlessly and accurately even with cheap ae223 ammo..

pat4wd
03-18-2012, 8:27 AM
It does look like it does have some material possibly obstructing the end of the bore after looking at the pics again but can't tell for sure with the angle of the pic.. And yes I would think it would be a huge effect on accuracy if it did... What seems weird though is it looks like it is at the very bottom of the barrel as it is mounted in the gun like it is a index mark or something.. If there is a small peice actually going up in the barrel it is not right for sure but if it leaves the the end of the barrel perfectly round I would bet it does not effect anything and might be there on purpose..

Let us know how it goes..

Mail Clerk
03-18-2012, 8:32 AM
I'd check it out by shooting it at the range using some premium ammo. Visually I don't beleive it'll hurt your accuracy. If it really gets to you just go to a good gunsmith and have him recrown that area so it's nice and crispy.

If you decide to range test it using premium ammo if your barrel shoots a little larger than 1"/100 yards then it's more than enough accurate.

Good luck,

Mail Clerk:oji:

tujungatoes
03-18-2012, 8:53 AM
Yes a ding on the crown like that can(I'm not saying it will, but it can) affect accuracy. Talk to PK and ask them to either have it re-crowned or replaced. If they're assembling them in house then it should have been caught before it got to you, but hey...sh*t happens. Chances are they'll make it right. Just try not sound all butthurt when you talk to them. you know, that old saying about catching flys.:)

pat4wd
03-18-2012, 9:31 AM
Just checked out my almost Identical 18" upper I bought from PK and it has no marks and appears perfect.. And it shoots perfect as well.. Hope they take care of you..

18" 5.56 stainless 1in8 twist

http://i259.photobucket.com/albums/hh309/pat4x44wd/barrel.jpg

russ69
03-18-2012, 10:18 AM
Yes that could be a problem. That can be re-crowned if it's not a chrome lined barrel. A nice counterbored type crown would be fine.

LovingTheYear1911
03-18-2012, 10:41 AM
I would re-crown it. Look around for some local gunsmiths instead of sending it in (only if they wont honor their warranty).

But from what I've learned, a damaged crown like that will affect accuracy.

elsolo
03-18-2012, 10:54 AM
It looks like the damage was done before the parkerizing, hard to claim it was done by you if that is the case.

If it bothers you, then I would contact the vendor first, DPMS second.
Both will likely tell you it's no big deal, and it probably is not a big deal.
The perfect target crown is less important when a muzzle device is attached, so I have been led to believe. But how will you know if it is affecting accuracy? Much like barrel break-in it is impossible to prove if a slight difference was achieved.

If it were mine, I would just lap the crown with a ball tool and valve grinding compound.

Gts408
03-18-2012, 12:07 PM
Have you even shot the gun or is it new? I wouuld say shoot it and see.. Proof is in the pudding.. Also why would you say you would not buy from them any more when you have not even talked to them or even shot the gun yet?

I have almost the identical upper I bought from them about 2 months ago and it performs flawlessly and accurately even with cheap ae223 ammo..

i said if they just blow me off than the only thing i can go is not give them anymore of my money. but i really like their stuff. It would be sad if it came to this.


But thanks for the all info guys. i'm get a hold of PK because they are the ones i paid for the upper and they should have caught it before they kick it down to the customer. If i known, i wouldn't have bought a defective barrel from them. I just hate that i have to take the time and effort to get this fixed when i should of got what a ordered a non-defective barrel. They knew before they put the bird cage on but they mounted it and sold it anyways. But people make mistake it's ok just as long as they try to rectify their mistake.

AlliedArmory
03-18-2012, 2:43 PM
That will definitely effect accuracy. Call them up and see what they will do for you.

m24armorer
03-19-2012, 12:42 AM
Can fix it for ya in 10 minutes. You remove the hider and bring the upper only. Starbucks in Gatos works. We do lots of stuff behind the building. No charge, it's just too easy.

thevic
03-19-2012, 1:08 AM
If you cant get it replaced, PM kendog4570. Hes an excellent smith in Aptos. He counterbored 1/2" or so and crowned my double chrome lined Noveske after it was damaged. Accuracy was unaffected.

http://i868.photobucket.com/albums/ab248/vpsmedeiros/arsenal/23b26061.jpg
http://i868.photobucket.com/albums/ab248/vpsmedeiros/arsenal/91473274.jpg

Gts408
03-19-2012, 12:30 PM
Update: they called me back today and said they will make it right. They are going to put on a new barrel. Now I just have to send it out. Great customer service. :)

tujungatoes
03-19-2012, 12:34 PM
Good to hear it was a no hassle deal.

russ69
03-19-2012, 1:43 PM
If you cant get it replaced, PM kendog4570. Hes an excellent smith in Aptos. He counterbored 1/2" or so and crowned my double chrome lined Noveske after it was damaged. Accuracy was unaffected.
http://i868.photobucket.com/albums/ab248/vpsmedeiros/arsenal/91473274.jpg

It looks like a good job but on a chrome lined barrel that would have cut the plating and the under-plating. I'm not sure of the plating process (I'd have to look at the spec) but it's possible to expose under plating materials that can get attacked by standard bore cleaners and eventually that might lead to the chrome flaking off. Just a heads up.

thevic
03-19-2012, 3:15 PM
This barrel has a few thousand down the pipe after this work and there is absolutely no flaking. The throat will pobably wear out before that might even happen. I clean the bore about every 200-300 when I see groups opening on it so it's been hit with various solvents many times. I also usually have o focus cleaning in that counter bore too because it will build up a lot of residue.

Even the smith told me it was a possibility that it would chip, but it didnt happen. Could be how well it was lined, or the machine work! :)

elsolo
03-19-2012, 3:34 PM
I don't think there is any "underplating" on a chrome lined barrel. It is hardchrome, which is chromium directly on steel. Decorative chrome plating is copper-nickel-chrome, that can flake after the copper layer gets dissolved by a bore cleaning copper solvent.

Gts408
03-29-2012, 8:25 PM
Update: I got my upper back today. It took longer in shipping than they took fix it. But the new barrel looks great. I can't wait to hit the range. They even give me a Insight Hx120 flashlight for the time wasted. Pk firearms Great place that backs up their product.