mp15 barrel problem

[cddanjr]

Hi I have 2 mp15 optics ready 5.56 rifles. One equipped with a low end red dot scope, shoots great groups indoor at 25m. less than 2". The other has Eotech red dot, and although that doesnt matter, it will not shoot groups smaller than 5-7" at 25m.

I have switched shooters, no difference, switched uppers, same thing. had several other shooters including the RSO's at the range try it to see if its just that I am a bad aim, but no. Im pretty good.

took the flash supressor off, and cleaned alot of residue off the end of the muzzle, and in case of a burr on the end of the barrel, I used some 400grit paper rolled up and "deburred" the end of the barrel, all to no avail.

This rifle is just 4 months old and only had about 500-750 rounds thru it. always cleaned with brass/bronze brushes in the direction of firing, always material softer than the barrel metal.

Anyone else had a tough time with the barrel like this? I have an email in to S&W, awaiting for their answer.

thanks
chuck

 

[PainterlyShotgroup]

I think there was another fellow who had a similar problem with his OR. Have you checked your barrel nut? It might be loose...

 

[cddanjr]

after youtube tutorial

I watched a couple of youtube tutorials about r&r of the barrel, and was unable to move the taper pin in the front sight mount.

On the optics ready MP15 there is a small 2 groove picatinny topped piece that holds the gas tube. I am unable to punch the single taper pin that anchors the piece to the barrel. Tried both directions, argh.

I guess Ill send the upper to S&W since it is only been used for 4 months at most.

IS THERE A S&W ARMORER WHO DOES WARRANTY WORK OUT HERE IN THE WEST? SO. CAL.?

Thanks for your input. Any other people with similar problem?

Thank you again.

 

[PainterlyShotgroup]

I watched a couple of youtube tutorials about r&r of the barrel, and was unable to move the taper pin in the front sight mount.

On the optics ready MP15 there is a small 2 groove picatinny topped piece that holds the gas tube. I am unable to punch the single taper pin that anchors the piece to the barrel. Tried both directions, argh.

I guess Ill send the upper to S&W since it is only been used for 4 months at most.

IS THERE A S&W ARMORER WHO DOES WARRANTY WORK OUT HERE IN THE WEST? SO. CAL.?

Thanks for your input. Any other people with similar problem?

Thank you again.

That "small 2 grove picatinny topped piece" is called your gas block. You can remove the gas tube without having to remove the whole gas block. There is a roll pin in the gas block which holds the tube in place. You should be able to tell if the barrel nut is loose without having to remove either.

Also, the sarcasm at the end of your post isn't appreciated. If that's how you thank someone trying to help you, I doubt you'll get a lot of help from people here.

 

[cddanjr]

Im sorry if you thought it was sarcasm, it was not. Simply wondering if anyone else was having this ongoing problem.

the nut is very tight, gas tube is moveable in its alignment.

Like I said previously, I will send the upper in to S&W for warranty work.

btw, I do not bow and scrape to anyone, if you thought my reply was sarcastic, then maybe you should not offer you input, even though I DID thank you for your reply. TWICE.

 

[PainterlyShotgroup]

Thank you again.:rolleyes

That's where the misunderstanding is. That was like saying "thanks for nothing"

But I'm glad it is just a misunderstanding. Emoticons....

Thank you for your thank you's

I'm sure someone with more info on the subject will chime in. Also, have you called Smith yet? They may already be aware of an issue with certain OR's.

 

[cddanjr]

I was hoping since this is a S&W forum, someone from S&W might be monitoring the threads, but it is the weekend, so i shall wait til monday.

 

[Buffalohunter60]

I have found when removing tapered pins...first make sure you are driving the small end of the pin. You can usually tell if you just look at it close. next make sure the block is supported with something very solid that has no give to it. A good pin punch and a sharp rap with a good hammer and they usualyl pop right out. If there is any "give" it will just absorb the shock and not move the pin...a solid set up makes a big difference. There are a lot of good guys here with lots of experience that have usually done about anything you can do to one of these rifles and theyn have been very helpful.

 

[cddanjr]

Buffalo Hunter, thanks for the reply.

I followed trying to remove the pin in the same direction as in the youtube vid. Very vigorous attempts. tried in the opposite direction to no avail. even built a hardwood "cradle" for the gas block to rest on with a hole for the pin to fall in. Must be right on the edge of sucess. hmm, guess Ill wait for S&W to contact me.

I look forward to great exchanges of information and meeting the enthusiasts on this forum. thank you for the welcome and your replies.

Chuck

 

[arizona98tj]

I cringed when you said you sanded the end of your barrel. Truthfully, I'm not sure how a company will view that in regards to warranty work.

What is the chances of your optic/mount being loose? I may have missed when you said you swapped optics on the upper. If I didn't, have you considered this?

I had a bad barrel, from the factory, on a bolt gun. Before I sent it in, I pulled the rings and scope, mounted it on a known good rifle, and then shot a tight group to prove to myself my optics were OK.

Edit: Is that ~2" group @ 25 meters shot from a good rest, such as a sand bag? Honestly, that is not good at all...you are looking at something in the neighborhood of about 6 to 8 MOA setup. At 25 meters, you should be seeing groups around the 1/2" mark or a bit better, depending on ammo and your skill level.

 

[storeyteller]

I'd try switching optics as well.

 

[cddanjr]

I used my other mp15 with a burris red dot optic, very inexpensive. I switched out shooters with my wife, she shot poorly with my rifle, and I shot well with hers, we switched uppers, same result. even put a 4x9x40 scope on it, to no avail.

I had what looked like the calcium from your water on the front of the barrel, sanded that down to the metal, and then "coned" a piece of 400 grit wet dry sand paper to see if it relieved any burrs right at the end of the barrel/rifling. Not really worried that S&W will hassle me for the minor attempts at solving the problem, if it does well that is another story.

as far as grouping these are straight outta the box rifles, less than 500-750 rounds so 2" with a red dot is ok for now, but I understand what your shooting at. hehe. btw, bench rested bipod shooting. i would expect extremely tight groups eventually!

 

[Foxtrot]

Wait a second, i'm confused here. You said you swapped uppers, but...:

1. The barrel goes with the upper but the problem did not follow the upper?

2. The red dot has what to do with this...are you saying that it shot poorly with a certain red dot or with a certain barrel?

3. Sanding? For what? The only "burrs" that could cause any possible problem at the end of the barrel would be metal or an obvious obstruction and those would be obvious and not calcium looking.

Something odd here, you swapped uppers but the problem stayed with the weapon lower and did not follow the upper that has the barrel on it. If thats the case, the problem is not with the barrel.

 

[Maddmax]

I was hoping since this is a S&W forum, someone from S&W might be monitoring the threads, but it is the weekend, so i shall wait til monday.

That might be all they do is just monitor (hide and watch). I doubt if there is a "dedicated" person from CS or CC that just jumps in to solve problems,this site is HUGE and I haven't seen or heard about one or any. "Most" people would say,call CS,tell them the problem (nicely),get a shipping lable and send it in for work with a discription of the problem. S&W picks up the "Ticket"both ways. Your scratching around sanding "could" be a problem....

 

[oneyeopn]

Ok one quick question, you attempted to remove your gas block after looking at a video. If I may ask what kind of rifle was in the video? Most AR's remove their gas block pins from the left side out the right. S&W's are backwards to that you drive from the right side out the left. If you attempted to drive the pins out backwards first then you more than likely swelled the pins into the holes and they are going to be very difficult to remove now, as was stated earlier the smaller end, although that might not be easily evident is the side that goes out first. Driving them in harder is almost impact welding. It has not been common to have accuracy issues with the M&P15's quite the opposite but we did have one member report a loose barrel nut. The pin for the gas tube will come out either side, you can remove this and tighten the barrel nut up if necessary. Good luck and please keep us posted.

 

[storeyteller]

I'd clean the bore real good, remove any copper fouling, get it space shuttle clean and shoot it again. If it still wouldn't shoot I'd send it back. Probably wouldn't volunteer any other info than that either. 500-700 rounds shoulda removed any burrs which are sometimes associated with the gas port hole.

 

[cddanjr]

WOW! awesome responses! Foxtrot, The problem IS with the upper/barrel. That is the part that was involved in all the switching. the upper is the common denominator in all the combos. no matter which lower, or shooter, or optic that one upper shot crappy.

Madmax, I guess I just want it fixed asap. If my sanding was a problem, well I'll upgrade the barrel, I just want accuracy.

Oneyeopn,

I just dont think Im striking the pin hard enough, the rifle in the vid was a replacement for the mp15, adding the barrel, and a front sight/gas block. I tried driving it out the same direction as the guy in the video, but did budge. I like trying, but if it doesnt come out with moderate effort, i might be wrong.

Thanks to all who replied, I will stay in touch throughout this fix.

Chuck

 

[oneyeopn]

Yeah use a 2x4 with some holes drilled in it for the pins to come out through and whack them hard, if you have a cut tip punch it will cut off the excess that gets spread out from setting or bumping the pins. I did have to use a pretty good amount of "whack" to get mine out!

 

[cddanjr]

I'd clean the bore real good, remove any copper fouling, get it space shuttle clean and shoot it again. If it still wouldn't shoot I'd send it back. Probably wouldn't volunteer any other info than that either. 500-700 rounds shoulda removed any burrs which are sometimes associated with the gas port hole.

When i first got the rifle and cleaned it, the bore looked almost like it was a damascus metal, that is, instead of nice shiny rifling, and grooves, the barrel looked like steady skid marks down the length. I spent most of the early shooting at 15yds, with red dot optics, changing in new parts, butt pad, new pistol grip, trigger. i really didnt notice the lack of accuracy till i put on a scope.

Kinda frustrating, but patience is the key. I'm sure S&W will suss it out.

chuck

 

[cddanjr]

Yeah use a 2x4 with some holes drilled in it for the pins to come out through and whack them hard, if you have a cut tip punch it will cut off the excess that gets spread out from setting or bumping the pins. I did have to use a pretty good amount of "whack" to get mine out!

Yeah think I'm gonna wait for S&W to reply. Marine, thanks for your service.

Chuck