[RC20]

I came across the magazine waiting at the store for my drugs (legal of course).

Its an amazing coverage of the platform and while I was aware of hte wide spread interest and offering (both guns and accessories ) it really brings hone the range and depth of all of them. Its plain hyge. From thee .458 SOCOM that seems insane to Remingtons new offering offering as a hunting gun.

What stuck me was that the XCR comes out as by fare superior to the offerings. Instead of a tube over the barrel you add the 1913 rials to, it has the rails there already. If you don't want to use the rails, you get inexpensive plastic covers and make it hand friendly.

Multi caliber is easier and does not require all sorts of special tools, indexing or a factory torque, and by doing away with the upper (basically most of the an AR15) you are not repeating all those parts you already bought.

Article on free floating actually being more accurate, the XCR has it. I wrote them and told them that they should have included the XCR, as it stand unique in the offerings, not just a variation of the old M16.

Don't get me wrong, there are some cool offerings, but when all is said and done, none match up toe the XCR, but its a great reference book to have around.

 

[dont_tread_on_me]

Very true sentiments all.What still baffles me is how people still defend the impingement system as being superior to a piston.The XCR is by no means perfect,but what product of the hand of man is.I don't like to beat a dead horse,but I'll say it again.The XCR is the most bang for your buck.(pun intended)It offers more innovation,more features and build quality for the money than any other battle carbine/Assault rifle type weapon on the market.Frankly I can't understand how they sell them for what they do,and still turn a profit.Not enough of the "old school" thinkers in the gun industry/tactical community are willing to accept that the AR isn't the Holy Grail.Alex is a smart cookie,and I'd be willing to bet this isn't the last evolution of this weapon you'll see,if not a completely new one.

 

[EricCartmann]

You guys should know by now the sole purpose of magazines and some forums (not this one) is too sell guns. The highest bidder gets the cover

 

[dont_tread_on_me]

You are so right,it's all about the Benjamins.It is still a damn shame.It speaks to the age we live in,I bet Elmer Keith nor Jack O'Connor would endorse something simply because it was popular,sure they may possibly have been paid for product endorsement.However the old timers more than likely would not endorse something they didn't personally believe in.I don't think integrity is entirely gone,but they don't want to rock the boat either.

 

[Ishpeck]

What still baffles me is how people still defend the impingement system as being superior to a piston.

I found it especially astonishing to see apologists for the Direct Gas Impingement system on a forum like WeTA (http://wethearmed.com/index.php/topic,901.0.html) which was started by a guy who wrote THIS article: http://www.madogre.com/Interviews/Hate_the_AR15.htm

 

[MickeyC]

I'm also not sure how they can claim a piston gun to be free floated. The piston, tube etc all act as a pressure bearer on the barrel. It's close but in no way is it fully floated as on a bolt gun. Same for the AR.

 

[variablebinary]

Direct gas works great...if by great you mean worst performer

 

[Whiskey three six]

Careful V.B., Double check the source of that chart.

 

[variablebinary]

Careful V.B., Double check the source of that chart.

http://www.defensereview.com/modules.php?name=News&file=article&sid=1084

http://www.military.com/NewsContent/0,13319,158468,00.html

http://www.defensetech.org/archives/003908.html

http://www.defenseindustrydaily.com/the-usas-m4-carbine-controversy-03289/

 

[Ishpeck]

I'm also not sure how they can claim a piston gun to be free floated. The piston, tube etc all act as a pressure bearer on the barrel. It's close but in no way is it fully floated as on a bolt gun. Same for the AR.

So true. At the level a free-floated barrel begins to matter, just about ANY mechanism that feeds ammo for you is likely to affect your precision.

 

[MickeyC]

Free floating does help accuracy. A piston system or gas return system does however affect the free float and inconsistent action can cause issues. The AR does well as the gas tube contains no moving parts and barrel frequency doesn't change shot to shot. It's a little different in a piston gun.

Admittedly though, for utmost accuracy, one needs to true the bolt/breech interface and also have a clear path from the magazine to chamber to ensure no deformation of the round during feeding etc.. also reducing the effect of the gas system on the barrel helps too and the XCR solution of having a floating gas tube works quite well.

Complicatd enough, but little touches help.

 

[o313]

Free floating does help accuracy. A piston system or gas return system does however affect the free float and inconsistent action can cause issues. The AR does well as the gas tube contains no moving parts and barrel frequency doesn't change shot to shot. It's a little different in a piston gun.

Admittedly though, for utmost accuracy, one needs to true the bolt/breech interface and also have a clear path from the magazine to chamber to ensure no deformation of the round during feeding etc.. also reducing the effect of the gas system on the barrel helps too and the XCR solution of having a floating gas tube works quite well.

Complicatd enough, but little touches help.

The whole point of a proper gas system/Piston and adjustable gas valve is to limit the movement of the action while the bullet is still in the barrel. both the AR and the XCR are pretty close to as good as you can get as far as delaying movement.

"barrel frequency" with regards to the AR/XCR has 100 times more to do with the thermal mass of the gas block then "moving parts". A barrel that heats/cools evenly is a consistent barrel, every hot spot on a barrel acts like a knuckle on a finger when it gets hot, so the cleaner the outside of the barrel the more consistent the metal expands and contracts thus the "heavy barrel" heats up slower to counter heat causing deflection and in the end a change of impact.

Your comment about the floated barrels on an AR vs an XCR are totally ludicrous!"Free Floated" is ridiculous when used on any rifle that has attachments directly to the barrel. Regarding feed angles the comment regarding the round being damaged upon feeding into the breach?? Are you shooting lead bullets?

 

[dont_tread_on_me]

The feed ramps are obviously there for a reason,If the angle is correct you don't need as much or any feed ramp to aid the entrance of the cartridge into the chamber because it will be aligned more with with bore/chamber.Even with full metal jackets if a round nose dives it can cause misfeeds and bullet setback,with soft point or ballistic(polymer tip)rounds the nose can be damaged or deformed.
Take the original 1911 for example,not much of a feed ramp,and the round hits that ramp,vs a more modern design,say a Sig or Glock where the rounds sit higher in relation to the bore and there is a much more developed feed ramp....conclusion? The old original government model didn't like anything but hardball ammo,the others will feed damn near any bullet profile .

 

[o313]

The feed ramps are obviously there for a reason,If the angle is correct you don't need as much or any feed ramp to aid the entrance of the cartridge into the chamber because it will be aligned more with with bore/chamber.Even with full metal jackets if a round nose dives it can cause misfeeds and bullet setback,with soft point or ballistic(polymer tip)rounds the nose can be damaged or deformed.
Take the original 1911 for example,not much of a feed ramp,and the round hits that ramp,vs a more modern design,say a Sig or Glock where the rounds sit higher in relation to the bore and there is a much more developed feed ramp....conclusion? The old original government model didn't like anything but hardball ammo,the others will feed damn near any bullet profile .

Lets not over-simplify feeding issues.

Obviously you don't want the feed ramp near vertical etc..

 

[dont_tread_on_me]

It's not vertical,the round is more in line with the bore,not pointing up.It's just sitting higher.It's not over simplification it's common sense,that if the rounds path to the bore is straighter there's less shit in the way to stop it.In other words it's doesn't have to hit a feed ramp because it's not coming in from as severe an angle,but going directly in to the chamber.

 

[o313]

It's not vertical,the round is more in line with the bore,not pointing up.It's just sitting higher.It's not over simplification it's common sense,that if the rounds path to the bore is straighter there's less shit in the way to stop it.In other words it's doesn't have to hit a feed ramp because it's not coming in from as severe an angle,but going directly in to the chamber.

Are you referring to something specific on the AR/XCR or just making a general observation?

 

[dont_tread_on_me]

It was my mistake in my last post because I thought you meant the feed angle not the feed ramp being vertical.No ,you obviously wouldn't want a vertical feed ramp.My point is that if if the bolt strips the cartridge from the magazine and pushes the cartridge forward at a less acute angle vs another type of firearm,then your need for a feed ramp at all is minimal,because it's headed straight for the chamber.The XCR design places the magazine higher in the well vs an AR style platform.
I think Mickey was trying to point out that if the feed angle were less severe (like on an XCR vs an AR) that accuracy wouldn't be affected because there would be less bullet deformation from striking the feedramp,whereas the XCR wouldn't do that because the the feed angle is less acute.A straighter shot to the hole has to be more reliable,I believe that what the Robinson design team were after by the higher magazine placement.

 

[aziator]

It was my mistake in my last post because I thought you meant the feed angle not the feed ramp being vertical.No ,you obviously wouldn't want a vertical feed ramp.My point is that if if the bolt strips the cartridge from the magazine and pushes the cartridge forward at a less acute angle vs another type of firearm,then your need for a feed ramp at all is minimal,because it's headed straight for the chamber.The XCR design places the magazine higher in the well vs an AR style platform.
I think Mickey was trying to point out that if the feed angle were less severe (like on an XCR vs an AR) that accuracy wouldn't be affected because there would be less bullet deformation from striking the feedramp,whereas the XCR wouldn't do that because the the feed angle is less acute.A straighter shot to the hole has to be more reliable,I believe that what the Robinson design team were after by the higher magazine placement.

I would agree with most of that. Actually, up until a few days ago I would believe all of that. I read an article (I know, don't believe everything you read) in a gun mag about a test a guy did on the effects of damage to bullet tips. I believe he was shooting .308 and using soft point rounds he basically deformed the tips. Some he hit with a hammer, some he cut off at a 45 degree with a cutoff wheel, some he used a file to make an angle. One set he even loaded the bullets into the case backwards (I think all the ammo was reloads that he did for the project). It was quite interesting to see the results. I want to say in most cases there was no adverse impact on accuracy from normal to deformed tip. Amazingly enough the ones loaded backwards had the best accuracy in his test. I don't have the magazine here but I will look for the article online. I want to say it was one of the hunting/rifle magazines.

 

[MickeyC]

It was partly deformation but also the risk of the bullet being rammed into the case and causing overpressure when fired. Each making rounds less consistent and thus off point of aim.

 

[dont_tread_on_me]

It was partly deformation but also the risk of the bullet being rammed into the case and causing overpressure when fired

Good point,that one slipped my mind.