A Big Thanks

[Snowshooter]

I have been lurking here for months and wanted to make a first post to say thanks. Whenever I had a question about my M&P Sport, I knew that the answer was just a few clicks away. The amount of information that travels across this board is unbelievably valuable. There is no question that I have improved as a shooter and was able to set up my rifle as I wanted it, once I figured out what I wanted.

Great rifle, as everyone here knows, working now to get it a few friends.

Thanks again

 

[JaPes]

Welcome aboard!

If you have any questions just ask.

 

[Snowshooter]

A special thank you to you John. A large part of the wealth of information here has come from you. Whenever someone posted an odd question, it was a sure bet that you had an idea what the answer was.

Thankfully, I don't have many questions at the moment, and I usually look for them before I ask, because if I have had the problem, then someone else most certainly has.

The main thing I am working on at the moment is to determine what part of my rifle cycle is marking the necks of my brass. Waiting on my kinetic puller to come in so I can do some dummy round cycling to figure the cause. I originally thought it was the feed ramps, but now I am leaning towards the locking lug edges. I know it isn't a major deal and doesn't affect function, but I am starting to reload and think that they might negatively affect the brass life.

 

[JaPes]

Got a picture of the brass necks?

 

[JaPes]

A special thank you to you John. A large part of the wealth of information here has come from you. Whenever someone posted an odd question, it was a sure bet that you had an idea what the answer was.

You're welcome, but I'm not the expert by any means.

When I first came to this sub-forum, there were a group of guys that really knew everything. Sadly, they don't frequent this sub-forum anymore. Cyphertext knows who I'm talking about.

 

[Snowshooter]

Got a picture of the brass necks?

That was a tough picture to take. Parallel marks right at the end of the neck. Width between is right at .132.

 

[JaPes]

I've never noticed that on the brass. (Runs to check a random round from the brass bucket). I sampled a few rounds and didn't see parallel marks at the neck running in the direction of the base to the neck. It probably won't do you any good because it's mixed once fired brass out of a 15-Sport, home built AR, and a Tavor.

Maybe someone else will chime in.

 

[gunny4053]

Welcome to the forum, good to have you here. It's hard to tell for certain, but your marks could be from a ruff edge on the feed ramps or possibly a machine mark in the chamber throat. What mags are you using? The angle the cartridges are entering from the magazine may be forcing more contact when entering the chamber and causing the scratches. Just a thought.

Good Luck and good shooting.

 

[sgtsandman]

How bad are the marks? Are they more of a scuff or a scratch? It's hard to tell for sure from the picture. While neither should happen, I would be more concerned with scratching than scuffs. Especially if you plan to reload.

 

[Snowshooter]

I am only using P-Mags. My first inclination was the feed ramps, but the edges there are smooth (ish) and seem to be farther apart.

They are more like a scratch than a scuff. Some are deeper than others, and some are barely there at all. I can catch it with a fingernail. I ran a few through my new reloading press , and most of the marks disappeared, but I could still see the evidence of the mark on a few. Different headstamp brass have the same marks.

It could be in the chamber, but I have looked down there many times while cleaning and haven't seen anything obvious.

My plan is to breakdown some factory rounds and reseat the bullet so I can load them in while I watch what happens.

Plan:
1. Load Dummy with a black sharpie mark at the 12:00 position on the top of the mag
2. Drop bolt onto round
3. Slowly eject round, noting the position of the sharpie mark and see if the scratches appear.
4. If the scratches don't appear while ejecting with the bullet seated, I will load a factory brass empty while riding the Charging Handle, then eject with force.

Anybody see a hole in my theory or have another idea?

My Kinetic puller won't be here until the end of the week, so it will be next weekend before I can do anything.

Thanks again.

 

[Rastoff]

A special thank you to you John. A large part of the wealth of information here has come from you. Whenever someone posted an odd question, it was a sure bet that you had an idea what the answer was.

We are awesome aren't we! However, don't give John the big head. He is an enabler and has probably caused several divorces with his accessory suggestions over the last few years.

 

[JaPes]

We are awesome aren't we! However, don't give John the big head. He is an enabler and has probably caused several divorces with his accessory suggestions over the last few years.

Enabler? Moi?

It's not my fault that everyone needs a Damage Industries silicone spring wire buffer spring, a AR-Restor hydraulic buffer, RRA 2-stage varmint trigger, BCM Mod3 gunfighter charging handle, nickel boron BCG, or a Smith Enterprises Vortex flash suppressor. It's not my fault that Troy Industries produces an alpha rail, buffer tube mounted QD sling point. It's not my fault that Mission First Tactical makes the best minimalist stock. It's not my fault that KNS precision anti-walk pins not only work, but look cool.

 

[sgtsandman]

I am only using P-Mags. My first inclination was the feed ramps, but the edges there are smooth (ish) and seem to be farther apart.

They are more like a scratch than a scuff. Some are deeper than others, and some are barely there at all. I can catch it with a fingernail. I ran a few through my new reloading press , and most of the marks disappeared, but I could still see the evidence of the mark on a few. Different headstamp brass have the same marks.

It could be in the chamber, but I have looked down there many times while cleaning and haven't seen anything obvious.

My plan is to breakdown some factory rounds and reseat the bullet so I can load them in while I watch what happens.

Plan:
1. Load Dummy with a black sharpie mark at the 12:00 position on the top of the mag
2. Drop bolt onto round
3. Slowly eject round, noting the position of the sharpie mark and see if the scratches appear.
4. If the scratches don't appear while ejecting with the bullet seated, I will load a factory brass empty while riding the Charging Handle, then eject with force.

Anybody see a hole in my theory or have another idea?

My Kinetic puller won't be here until the end of the week, so it will be next weekend before I can do anything.

Thanks again.

The only thing I might do differently is to load and press a round in by hand and then use something like a cleaning rod to push the round out first to see what you get first. If it's a chamber issue, that might show something first. It might also help to sharpie everything but the 12:00 position so that any scuffs or scratches will show up better.

If nothing shows up with that or with what you are going to do, a spent cartridge might be needed since they are swelled some from being fired.

I might be totally wrong but just some ideas to throw your way for you to think about.

 

[Snowshooter]

That sounds like a good idea. I will add that into my plan. I plan to keep trying different combinations until I find what is making the mark.

I want to try it now, but doing anything like that with live ammo is just a bad idea. I can wait...

 

[gunny4053]

Enabler? Moi?

It's not my fault that everyone needs a Damage Industries silicone spring wire buffer spring, a AR-Restor hydraulic buffer, RRA 2-stage varmint trigger, BCM Mod3 gunfighter charging handle, nickel boron BCG, or a Smith Enterprises Vortex flash suppressor. It's not my fault that Troy Industries produces an alpha rail, buffer tube mounted QD sling point. It's not my fault that Mission First Tactical makes the best minimalist stock. It's not my fault that KNS precision anti-walk pins not only work, but look cool.

John, you should be getting a commission from those guys.

 

[Snowshooter]

Update - Bench report

Thanks again for all of the suggestions.

Well, I couldn't wait any longer and my four legged friend decided that 4:45 was a good time to get up this morning, so I had some spare time.

UPS has decided that the items to finish my reloading setup need to wait until Sat to be delivered, so I wanted to work with what I had.

For those who want to skip the rest of this long winded post, it is the locking lugs - confirmed.

Process:

Split receivers, run a brush and a patch into the chamber to make sure no debris is in there, confirmed with bore light.

Grabbed some brass I used to setup my sizing die, they are between the cuts on my Wilson size gauge. Lengths below 1.750 except one at exactly 1.760. Marked necks completely with Sharpie and make a 12:00 index mark. Thanks for the idea sgtsandman. I made sure any visible previous mark was at the 9:00 position.

Removed BCG and fed long case into the chamber with the neck on plastic patch tip on my rod. Rod inserted backwards from muzzle to breech. Pushed case in with tip of pen and pushed back out with rod. No marks on neck, (case with Blue dot in picture).

Took other cases and pushed into battery with the BCG. Easier said than done, that action spring does a lot of work.

Pulled case out slowly with Charging Handle. I could literally see the brass neck being shaved by the locking lugs. I tried to get a picture of the process as it happened, but it isn't so great.

Took one case and put the rod tip into it while I pulled the handle so the ejector wouldn't flip it until it was clear of the lugs. No marks.

The marks are much clearer in this picture along with the long case that has no marks on it.

So, the final question is will Smith do anything about this? I am going to call later today and ask. I am willing to do just about anything myself, but I don't have the tools to clean up the back side of those lugs. If I pulled the barrel out, maybe, but I don't really want to pull apart a rifle that runs so great. My purchase was within the last year and my round count is about 1K. I know that this will probably wear down with use, which sounds fun, I just don't want to unnecessarily shorten the brass life.

Thanks to you guys for the help. I will update once I call them.

 

[MichiganScott]

Having run a bunch of AR's over the years, I've come to the conclusion that most of them will scratch up your cases. It's purely accidental if they don't.

I used to be concerned about the scratches but no longer worry about them. The necks get dinged up by the brass deflector, the rims get chewed up by the extractor and ejector, the body of the case gets dented when they hit the ground or each other, and we accidently step on them.

Although I'm an inveterate reloader, I figure four loads in a .223 case dedicated to AR's is doing pretty good. We have to remember that Eugene Stoner was more concerned about 100% function than the number of times the empties were reloadable.

 

[JaPes]

If S&W says it's within operating tolerance, then there's nothing you can do. You do not want to freely admit to a CS rep that the cause for your concern is brass preservation for reloading. Shooting reloaded ammo voids warranties, and it's better they don't know that I may or may not shoot reloads.

The only other thing I can think of is that the ejector spring might be slightly out of spec. You can try replacing it. To make the job easier, I highly suggest buying a jig. It helps to prevent sudden onset, short duration Tourette's syndrome.

 

[Snowshooter]

Ok, I am glad that I got hung up with time on the range with the family and didn't make it to call Smith. I didn't figure that they would do anything, but thought it might be worth a call; guess I should avoid it. I suppose until I start seeing issues I will go on with it until I can work on the ejector or smooth out those lugs. I can always save any that split prematurely to convert into 300 BLK.

I am already stricken with that particular affliction. You should have seen me when I replaced the end cap under the castle nut and lost the spring..twice. Found it both times though.

Thanks again for all of the comments and ideas.