First trip to the range with M&P 15: what do I need?

[C J]

If a laser is making a clear dot through your bore then it can't possibly be off. Possibly the fact that you're aiming at just 25 yards is the problem. Zeroing at 25 yards vs. 50 yards yields very different results. Are you aware that you have to aim under a target at 25 yards if you have zeroed at 50 or 100 yards? The same happens in reverse. If you zero at a point 25 yards away you will not be zeroed at 50 yards. You will be off a good bit actually. It has to do with the fact that your sights are not on the same level with the bore. You have 2 lines, one from the bore and one from the sight, that intersect at a point. If you zero at 50 yards you want those lines to intersect at that point and you adjust accordingly.

But the plain fact is that if your laser is working well enough to go through your bore is it impossible for it to not be straight after that. That's just the nature of lasers. Using one to zero a rifle won't be perfect because the dot is smaller than the rifle bore so there will be a very slight amount of variation because of that. But it certainly won't be enough to make you miss a large target at 50 yards. My son is a laser research scientist for the Air Force. He's currently working on very important defensive efforts for our military planes.

Basically my son is very close to being a doctor of laser science. He actually turned down the doctoral program because those doctors demand much more money and companies won't hire them as a result. They hire people with masters degrees in the particular field of physics they need. That's my son. He was talented enough that his masters degree was paid for by a foundation and his school loans he got as an undergraduate were paid off also. Physics is the hardest of all college pursuits and anyone with talent in the field can basically write their own ticket to life. Trust me if there's anything I know about it's lasers. My son is a good teacher.

 

[blues7]

There's potential for error in any laser device depending on how it is oriented in its housing tube and how much "wiggle room" there is in the fit into the chamber or muzzle. How much error is dependent on a variety of factors.

There is clearly a bit more room for error with lasers that fit in the muzzle like the one below:

It seems unnecessarily heated and argumentative around these parts this morning. There's plenty of room for differing opinions and experience without taking umbrage, imho.

 

[C J]

You're right that the lasers that fit in the end of the bore are very much subject to variation because they don't really line up with the bore. I was talking about lasers bore sights like this one:

[ame="http://www.amazon.com/Pinty-Laser-Scopes-Sight-Cartridge/dp/B019RNF51O/ref=sr_1_2?ie=UTF8&qid=1464358665&sr=8-2&keywords=laser+bore+sight+.223"]Amazon.com : Pinty Laser Red Dot for Scopes 223 REM Bore Sight Cartridge Sight 5.56 Nato : Sports & Outdoors@@AMEPARAM@@http://ecx.images-amazon.com/images/I/41%2BGBa2TAhL.@@AMEPARAM@@41%2BGBa2TAhL[/ame]

Those shine through the bore and have a very limited amount of play in where they can shine. I should have made that point earlier.

BTW I certainly didn't mean to be contentious or heated or any of the things you said. I just said what I know to be the truth.

 

[VegasPier]

I purchased a factory new AR-15 Sport II last Wednesday. I joined this Forum today, Sunday. I'm going shooting this week.

So this thread was very interesting to me. i'll keep some of those points in mind.

One thing that was not touched upon was prepping the weapon for first time use. Is there anything to be done at home prior to the first time out on the range? One item does come to mind and that is the amount of oil on the inside of the receiver. It seems to me to be way too much. I've seen how to remove the bolt and was wondering if I should take it out and wipe the inside of all that oil--leaving a thin film of oil.

Cheers, VegasPier

 

[Rastoff]

Are you aware that you have to aim under a target at 25 yards if you have zeroed at 50 or 100 yards?

I'm aware that this is wrong. If your gun is zeroed at 100 yards and you're shooting a target at 25 yards, you must aim high.

Basically my son is very close to being a doctor of laser science.
----
Trust me if there's anything I know about it's lasers. My son is a good teacher.

My father was a stock broker. Am I an expert in the stock market?

What I am an expert in is measurement. I can tell you with a certainty that both the lasers mounted in the chamber and the ones mounted in the muzzle can both be accurate and both have unique measurement issues.

There's potential for error in any laser device depending on how it is oriented in its housing tube and how much "wiggle room" there is in the fit into the chamber or muzzle. How much error is dependent on a variety of factors.

This is the most accurate way to state the accuracy issues involved here.

There is clearly a bit more room for error with lasers that fit in the muzzle like the one below:

I disagree. It's not "clear" that there is more room for error with this type. Sure, the rod that goes down the bore can be bent. That can easily be checked by rolling the device on a table. If it's bent it will be obvious.

It does have one advantage though. It has rings that cause the bar to be centered in the bore. This means that it's being perfectly centered on on the bore isn't dependent on the bore being perfect. The chamber mounted variety is completely dependent on the chamber. Of course, the chamber would have to be dramatically off to be a problem.

In the end any discussion about the accuracy differences between these two devices is moot. Neither imitates the trajectory of the round. They are a guess at best. Still, both will get you on paper for the first shot. That's worth the price of admission.

What would be really nice is a laser that could simulate the trajectory of the round. That wouldn't be hard to do, but would require proper orientation of the laser in the bore.

 

[DougS]

I used a laser to bore sight my strikefire ll. I lined up the dot and the laser at 75 yards. Afterwards I sat a full beer can at 75 yards to see how close I was. Long story short---nailed the can in 1 shot, never had to adjust at all. Then we sat an explosive target (tannerite) at 125 yards--- one shot. Haven't touched the adjustments since.

 

[mscampbell2734]

I

One thing that was not touched upon was prepping the weapon for first time use. Is there anything to be done at home prior to the first time out on the range? One item does come to mind and that is the amount of oil on the inside of the receiver. It seems to me to be way too much. I've seen how to remove the bolt and was wondering if I should take it out and wipe the inside of all that oil--leaving a thin film of oil.

Cheers, VegasPier

On a brand new AR the more lube the better. The extra oil will not harm anything and will make cleaning the interior of the receiver easier.

In general on new guns more lube is better. Once you've put a couple of hundred rounds downrange and are certain everything works right you can experiment with how much lube you need.

 

[C J]

I'm aware that this is wrong. If your gun is zeroed at 100 yards and you're shooting a target at 25 yards, you must aim high.

Yes I said it backwards. But the idea is still the same. Zeroing at 100 yards won't give you an accurate zero at 25 yards. As for a laser that fits in the end of the bore being as accurate as one that goes in the chamber I've seen a lot of comments that say they aren't as accurate. I've seen them not be as accurate. YMMV

 

[jimbo728]

I used a laser to bore sight my strikefire ll. I lined up the dot and the laser at 75 yards. Afterwards I sat a full beer can at 75 yards to see how close I was. Long story short---nailed the can in 1 shot, never had to adjust at all. Then we sat an explosive target (tannerite) at 125 yards--- one shot. Haven't touched the adjustments since.

You shot a full can of beer? And you call yourself a Navy man?
That can of beer should have been waiting for you when you came in from the range.
Jim

 

[VegasPier]

On a brand new AR the more lube the better. The extra oil will not harm anything and will make cleaning the interior of the receiver easier.

In general on new guns more lube is better. Once you've put a couple of hundred rounds downrange and are certain everything works right you can experiment with how much lube you need.

mscampbell2734,

Thanks for the reply. The bulk of my shooting background is with Glocks. The Glock folks recommend minimal oil, something about oil attracting dirt. That's why I asked.

Cheers, VegasPier

 

[Kadonny]

If a laser is making a clear dot through your bore then it can't possibly be off. Possibly the fact that you're aiming at just 25 yards is the problem. Zeroing at 25 yards vs. 50 yards yields very different results. Are you aware that you have to aim under a target at 25 yards if you have zeroed at 50 or 100 yards? The same happens in reverse. If you zero at a point 25 yards away you will not be zeroed at 50 yards. You will be off a good bit actually. It has to do with the fact that your sights are not on the same level with the bore. You have 2 lines, one from the bore and one from the sight, that intersect at a point. If you zero at 50 yards you want those lines to intersect at that point and you adjust accordingly.

But the plain fact is that if your laser is working well enough to go through your bore is it impossible for it to not be straight after that. That's just the nature of lasers. Using one to zero a rifle won't be perfect because the dot is smaller than the rifle bore so there will be a very slight amount of variation because of that. But it certainly won't be enough to make you miss a large target at 50 yards. My son is a laser research scientist for the Air Force. He's currently working on very important defensive efforts for our military planes.

Yeah, I'm not a n00b to sighting my ARs, I understand holdover/holdunder fully, do you? Your reasoning is backwards.

You can believe me or not, but I'm telling you inside my house my cheapo laser bore sighter, the one you say can't possibly be off, is off. Yes, it's one you place in the breech of the barrel and yes I align it at 25 yards, but at 50 yards on the range the gun should be hitting paper.....and it's not. I've had it happen twice now, so needless to say I don't use it anymore. I'm no laser expert, but I can understand how it can be off. The barrel is a lot bigger than the laser beam, so there is no doubt room for error.

Yes I said it backwards. But the idea is still the same. Zeroing at 100 yards won't give you an accurate zero at 25 yards. As for a laser that fits in the end of the bore being as accurate as one that goes in the chamber I've seen a lot of comments that say they aren't as accurate. I've seen them not be as accurate. YMMV

Ah, ok you corrected yourself.

Zeroing at 25 yards will not yield you sub moa groups on the bull at 50/100 yards, but it should get you on paper and close at least.

 

[tcon]

I've used the cartridge-shaped chamber laser sighters with mixed results. They can get you on a 3" radius at 50yd but I wouldn't expect much beyond. And that is if they are relatively aligned. I would not spend a great deal on this type of sighter. $10 max because it has the potential to save you $10 in ammo. And the batteries go quick too.

Roll the cartridge on a smooth surface like a granite countertop and see if the dot wobbles. If it wobbles, you are not going to get close. Some have three small adjustment screws that can be carefully used to align the dot to not wobble. It can take a while and will exercise you patience.

When clambering the thing, do it softly. In an AR, don;t slam it in. Put it in with your fingers and ease the carrier forward and finish seating it with the forward assist.

When ejecting, don't let it hit the floor. Sofa. I had a .308 cartridge type that I paid $8 for. No adjustment screws but had very little dot wobble. I got my scope clicked in using my neighbor's black horse fence at 75 yards. When I pulled the bolt back, it hit the floor. Wobble city. But the rifle was within 3". $8 justified.

 

[mscampbell2734]

mscampbell2734,

Thanks for the reply. The bulk of my shooting background is with Glocks. The Glock folks recommend minimal oil, something about oil attracting dirt. That's why I asked.

Cheers, VegasPier

OK you have to be careful comparing Glocks to other weapons. I carried Glocks for years as a uniform duty weapon and it does have its advantages.

The reason for minimal oil is because the Glock design has minimal metal to metal contact. Look at the size of the frame rail inserts, how small they are.

Now look at the size of an AR bolt carrier. That's a lot of metal flying back and forth, potentially making contact with the interior of the receiver its full travel.

After you shoot it some inspect the bolt carrier. You should see wear spots on the carrier "rails" That's where you really want to lube. The rest of the carrier just a light coat.

 

[CGhelofxr]

Just go to aisle 7, 8 and 9 buy one of everything in sight, if it looks cool buy two or three!

 

[C J]

es, it's one you place in the breech of the barrel and yes I align it at 25 yards, but at 50 yards on the range the gun should be hitting paper.....and it's not

Sorry but that isn't what I said at all. What I said was that beam of light coming out of your barrel is going to go straight inline with the bore of the rifle as long as it's shining through the bore and not reflecting off the sides. What your gun does has absolutely nothing to do with what I said. Lots of things can go wrong with a gun. A laser is a straight line of light and will continue on until it spreads out enough that it can't be recognized. Lasers aren't perfect but figure a few hundred yards before you see any significant spread of the beam. Even then it will still be straight out from the bore.

That's all I said. I said nothing about the stuff you think I said. If you zero your rifle by a laser that's mounted in the chamber then it will be aligned with a perfectly straight line from that laser through your bore. The thing is as you obviously know the sight you're using won't be on the same plane as the bore laser. You will be on a different plane and where the two lines intersect (one coming from the laser and the other the sight) that's where you will be zeroed. That's still no guarantee that your rifle will hit that spot, which is what you think I said but I didn't, because not all rifles shoot straight and not all ammo flies straight. That stuff is obvious. That's why laser is just a guide to get you close. You have to adjust relative to the offset of your sight and the peculiarities of your particular rifle. If your bore isn't straight your bullets won't fly straight. It's that simple. The laser can still shine straight through a slightly curved bore because it's a smaller size than the bore.

I don't see much point in beating this horse any more. I won't be posting on this subject again. I'm not here to argue things. I know for a fact that what I said is true. If you want a more detailed explanation please use a private message. Goodbye.

 

[blues7]

 

[Kadonny]

Sorry but that isn't what I said at all. What I said was that beam of light coming out of your barrel is going to go straight inline with the bore of the rifle as long as it's shining through the bore and not reflecting off the sides. What your gun does has absolutely nothing to do with what I said. Lots of things can go wrong with a gun. A laser is a straight line of light and will continue on until it spreads out enough that it can't be recognized. Lasers aren't perfect but figure a few hundred yards before you see any significant spread of the beam. Even then it will still be straight out from the bore.

That's all I said. I said nothing about the stuff you think I said. If you zero your rifle by a laser that's mounted in the chamber then it will be aligned with a perfectly straight line from that laser through your bore. The thing is as you obviously know the sight you're using won't be on the same plane as the bore laser. You will be on a different plane and where the two lines intersect (one coming from the laser and the other the sight) that's where you will be zeroed. That's still no guarantee that your rifle will hit that spot, which is what you think I said but I didn't, because not all rifles shoot straight and not all ammo flies straight. That stuff is obvious. That's why laser is just a guide to get you close. You have to adjust relative to the offset of your sight and the peculiarities of your particular rifle. If your bore isn't straight your bullets won't fly straight. It's that simple. The laser can still shine straight through a slightly curved bore because it's a smaller size than the bore.

I don't see much point in beating this horse any more. I won't be posting on this subject again. I'm not here to argue things. I know for a fact that what I said is true. If you want a more detailed explanation please use a private message. Goodbye.

That's fine. You are trying to school everyone on lasers and you didn't know or didn't know how to properly explain yourself on the characteristics of the difference between a 25/50/100 yard zero. You can talk for hours about laser accuracy and it doesn't mean that a cheap laser bore sighter is accurate, or even accurate enough. That's what we are talking about, correct?

 

[DougS]

You shot a full can of beer? And you call yourself a Navy man?
That can of beer should have been waiting for you when you came in from the range.
Jim

It was rolling around in the back of my truck, probably really skunky.

 

[jimbo728]

It was rolling around in the back of my truck, probably really skunky.

Well, OK then. I guess that`s forgivable.
Jim