[bklynpete]

Thanks for doing this test. I'm looking at these two models myself in the Magpul version, so cost will not be a factor. They are within $50 of each other locally. Looking forward to your updates.

[bigmoney890]

Originally Posted by bklynpete

Thanks for doing this test. I'm looking at these two models myself in the Magpul version, so cost will not be a factor. They are within $50 of each other locally. Looking forward to your updates.

This thread is comparing the M&P Sport, not the M&P MOE you are looking at. The Sport is around a $600 gun and the non-sport MOE is twice that price.

[Warp]

Originally Posted by bklynpete

Thanks for doing this test. I'm looking at these two models myself in the Magpul version, so cost will not be a factor. They are within $50 of each other locally. Looking forward to your updates.

In that case I don't see why there is any question. Get the Colt.

As mentioned above, this comparison is one people are interested in because the S&W sport is significantly less expensive than the Colt or the M&P15

[bklynpete]

I tend to lean towards towards the Colt, but looking at the data on this test, it seems the S&W is doing very well as far as accuracy. I have time, so seeing how this goes, is worth it.

[Matthew Courtney]

Originally Posted by bklynpete

I tend to lean towards towards the Colt, but looking at the data on this test, it seems the S&W is doing very well as far as accuracy. I have time, so seeing how this goes, is worth it.

The Colt is exceptionally accurate ar well. I have not tested it right beside my Bushmaster, Colt Sporter, or anything else but the Sport, but it should rank about # 3 in my semi auto inventory accuracy wise. 1.25 MOA right out of the box with multiple loads is not something we often see, despite what you see on the interwebs.

[Contact]

Originally Posted by Airhasz

It's obvious mil spec isn't needed but neither are Z06 Corvettes and there are a hell a lot of them on the road.

There is a Mil-Spec brownie recipe, and I'm willing to bet it's not the best tasting brownie on the face of the planet. Mil-Spec doesn't mean "The Best", it means it was made to the specifications that the military needed (for whatever reason) at that time.

[TangoFoxtrot]

Originally Posted by Contact

There is a Mil-Spec brownie recipe, and I'm willing to bet it's not the best tasting brownie on the face of the planet. Mil-Spec doesn't mean "The Best", it means it was made to the specifications that the military needed (for whatever reason) at that time.

Absolutely correct. AR manufacturers have meet and exceeded these standards.

[Matthew Courtney]

The 6920 and the Sport are now at 2400 rounds. The throat on the Colt measures .18 on my Merchant gauge, a .03 amount of throat erosion being reflected. The Sport wear is .02, as measured on the Merchant gauge with a current reading of .16. We experienced on failure to feed with the Sport when a student replaced a partially depleted pmag with a full pmag and apparently did not get the full mag inserted fully.

Further shooting with gen 2 pmags in my Colt/PSA pseudo Reece build reveal that one can inadvertantly load 31 rounds into a gen 2 pmag. A mag so loaded cannot be fully seated in any of our rifles with a closed bolt. This seems to be what caused the above referenced failure to feed. Thoughts?

We intend to do another round of accuracy tests as soon as the weather cooperates with our schedule. We are looking for a day with calm conditions and minimal mirage.

[fnfalman]

Originally Posted by Matthew Courtney

The 6920 and the Sport are now at 2400 rounds. The throat on the Colt measures .18 on my Merchant gauge, a .03 amount of throat erosion being reflected. The Sport wear is .02, as measured on the Merchant gauge with a current reading of .16. We experienced on failure to feed with the Sport when a student replaced a partially depleted pmag with a full pmag and apparently did not get the full mag inserted fully.

Further shooting with gen 2 pmags in my Colt/PSA pseudo Reece build reveal that one can inadvertantly load 31 rounds into a gen 2 pmag. A mag so loaded cannot be fully seated in any of our rifles with a closed bolt. This seems to be what caused the above referenced failure to feed. Thoughts?

We intend to do another round of accuracy tests as soon as the weather cooperates with our schedule. We are looking for a day with calm conditions and minimal mirage.

As far as overloading the MagPul...well...I don't know how you can train to overcome the occasional operator's headspace & timing. People do make mistakes now and then even when they're trained not to. Maybe have them pre-count the rounds out then load the mags?

[Warp]

Originally Posted by Matthew Courtney

The 6920 and the Sport are now at 2400 rounds. The throat on the Colt measures .18 on my Merchant gauge, a .03 amount of throat erosion being reflected. The Sport wear is .02, as measured on the Merchant gauge with a current reading of .16. We experienced on failure to feed with the Sport when a student replaced a partially depleted pmag with a full pmag and apparently did not get the full mag inserted fully.

Further shooting with gen 2 pmags in my Colt/PSA pseudo Reece build reveal that one can inadvertantly load 31 rounds into a gen 2 pmag. A mag so loaded cannot be fully seated in any of our rifles with a closed bolt. This seems to be what caused the above referenced failure to feed. Thoughts?

We intend to do another round of accuracy tests as soon as the weather cooperates with our schedule. We are looking for a day with calm conditions and minimal mirage.

That'll happen. The 31 rounds into a PMAG is pretty well known, and you cannot seat the mag on a closed bolt (I've tried).

The good thing is that with 30 rounds in a PMAG you can insert the mag on a closed bolt more easily than with 30 rounds in a different mag.

[Matthew Courtney]

Originally Posted by fnfalman

As far as overloading the MagPul...well...I don't know how you can train to overcome the occasional operator's headspace & timing. People do make mistakes now and then even when they're trained not to. Maybe have them pre-count the rounds out then load the mags?

I have since trained myself to make sure that the top round of a magpul mag is on the right. Some mags have the top round on the left when full, so it could get confusing.

Would you characterize the malfunction as operator error, magazine caused, or rifle issue?

[Warp]

Originally Posted by Matthew Courtney

I have since trained myself to make sure that the top round of a magpul mag is on the right. Some mags have the top round on the left when full, so it could get confusing.

Would you characterize the malfunction as operator error, magazine caused, or rifle issue?

Primary cause: Operator
Tertiary cause: Magazine

95% operator. I simply make sure that, after finishing loading a PMAG, I can push down on the top round and there is still downward movement. Problem solved.

[fnfalman]

Originally Posted by Warp

Primary cause: Operator
Tertiary cause: Magazine

95% operator. I simply make sure that, after finishing loading a PMAG, I can push down on the top round and there is still downward movement. Problem solved.

Or down load a mag by a round or two. If 28-rounds can't handle it, I don't think 30-rounds is going to make a difference.

[vettely]

Originally Posted by fnfalman

Or down load a mag by a round or two. If 28-rounds can't handle it, I don't think 30-rounds is going to make a difference.

Precisely.

[Warp]

Originally Posted by fnfalman

Or down load a mag by a round or two. If 28-rounds can't handle it, I don't think 30-rounds is going to make a difference.

Why download a magazine when there is no reason to?

[MarkCO]

Originally Posted by Warp

Primary cause: Operator
Tertiary cause: Magazine

So what is the secondary cause?

[Warp]

Originally Posted by MarkCO

So what is the secondary cause?

None. I just wanted to express how I really think operator error is all there is to it.

[ithaca_deerslayer]

Originally Posted by Bimmer1

I think once you have to replace parts (if the round count is equal between both guns) then the test is over. Most of us have a common interest when comparing the two.........1) Reliability and 2) Failure of parts when both guns are used in the same manner and have equal or close to equal round counts.

I agree.

[fnfalman]

Originally Posted by Warp

Why download a magazine when there is no reason to?

Apparently there's a reason to: overload the mag and can't lock it into the mag well.

[ithaca_deerslayer]

Originally Posted by Matthew Courtney

I've already consulted several other scientists about the validity of the test under our planned protocols, they will produce valid data because they are up to standards consistent with scientific testing.

Burden of proof? The only burden of proof in scientific testing is that a test has to be repeatable. It does not have to be repeated. Simply being repeatable makes it rational to believe that in the absence of contrary data, the data given is valid.

Since you have no stated credentials as either an educator or a scientist, it is also rational to believe that you are merely an Internet fan boy trying to pre-empt some finding by attacking our testing procedures. Relax, all I expect to find is that there are trade-offs when selecting a rifle and our goal is to simply document those trade offs for people thinking of buying a rifle.

The chances against us getting a defective rifle are pretty high. We have had thousands of firearms come through our courses and I haven't seen a defective one yet. Dirty ones, unlubricated ones, worn out ones, abused ones and firearms that needed to be broken in.... But no defective ones.

As a first step, whatever test you develop is fine. Having it so others could repeat it is great.

But as a second step sampling becomes important. You, the OP, are not expected to sample because it would cost too much money. But you might not want to dismiss the idea in general.

If a bunch of stuff is made, and if we can't test them all, drawing a statistical sample allows an efficient way to estimate about the entire population of what was made. Industry does that on their own products they make (if they want to assure quality).

[Matthew Courtney]

Originally Posted by ithaca_deerslayer

As a first step, whatever test you develop is fine. Having it so others could repeat it is great.

But as a second step sampling becomes important. You, the OP, are not expected to sample because it would cost too much money. But you might not want to dismiss the idea in general.

If a bunch of stuff is made, and if we can't test them all, drawing a statistical sample allows an efficient way to estimate about the entire population of what was made. Industry does that on their own products they make (if they want to assure quality).

Without a doubt, larger samples will tend to produce more valid data sets than smaller samples. By the time we finish with these rifles, either the tecnologies or consumer preferences may be past the point where our data is even relevant, much less worth generating on a larger scale. We will see.

[ithaca_deerslayer]

Originally Posted by Matthew Courtney

Sport 095 *accuracy eval 7/6/2012 *am *temp 88 wind 260@3
Firing direction 262 *5 shot groups

Hornady 75 gr bthp match *1.672 *1.249 .887 avg *1.269

Black hills 77 gr bthp match *3.827 * 3.471 *2.673 avg 3.324

Fiochhi 50 gr v-max * *.619 *1.258 *1.161 avg 1.012

Avg of averages - 1.868 +-.2

On your facebook link, I believe the numbers for the Hornady 75gr and Black Hills 77gr are reversed.

I apologize if you've already addressed this. Just wanted to make sure of which one the gun likes more.

[Matthew Courtney]

Originally Posted by ithaca_deerslayer

On your facebook link, I believe the numbers for the Hornady 75gr and Black Hills 77gr are reversed.

I apologize if you've already addressed this. Just wanted to make sure of which one the gun likes more.

The numbers were reversed when I posted them here from our notes. The numbers on the Facebook page are the correct figures as they match our notes. One of the reasons we decided to simply start posting the data at a single location is to reduce the chances of publishing errors. Of course, the second to last column on the facebook page has the wrong inventory number for the Colt.

When we collect and the record the data we have 2 people verifying that we record it correctly in our notebook, so that is the copy "for the record". Any discrepancies are resolved by checking our original notes. If it is not in our original notes, it did not happen.

[ithaca_deerslayer]

Originally Posted by Matthew Courtney

The numbers were reversed when I posted them here from our notes. The numbers on the Facebook page are the correct figures as they match our notes.

That's good news, as I'm a Black Hills fanboy

[Matthew Courtney]

Originally Posted by ithaca_deerslayer

That's good news, as I'm a Black Hills fanboy

Glad to hear it! Plenty of Hornady fans gave me crap because the steel match does not like us.