Case not ejecting on a fired round

[montana]

I already own a Teslong bore scope and went halves with a friend on a Lyman. (The Teslong is the better of the 2). I confirmed with a friend regarding the issues of the offset that is referenced in the Brownells ling post by mdram. Quite aware with not having measured to make sure the 2 ports did not line up that I am ultimately at fault, I just have never run into this issue before. In my personal collection I have built 9 AR uppers and have built/assisted a few of my friends in another 12 or so builds. Totally un-expected find reguarding the repositioning of the gas block on the barrel... Live and Learn!

I will be out shooting this rifle tomorrow verifying this solved the problem.

Sounds like a plan, keep us up-dated.

[Old Bob]

If the barrel is made to Mil-spec dimensions there will be a gap (approx. .03") between the gas block & the barrel shoulder. The gap is for the G.I. Handguard cap.

[Klem]

So who is at fault? The gas block manufacturer for incorrectly drilling the port in the block, or the barrel manufactured for incorrectly drilling the gas port in the barrel 1mm further down the barrel (closer to the muzzle of the barrel?!?[ATTACH=CONFIG]18346[/ATTACH]

Stug,

Neither manufacturer is at fault - your barrel has been machined to accommodate the 0.025" handguard gap, but your gas port manufacturer assumes a more modern free-floating handguard will be used.

Nowadays, civilian AR15 shooters prefer the free floating design handguards so don't need the gap. Barrel manufacturers accommodate this by machining the port closer to the shoulder so you can push the block neatly up against it (your previous builds). However, the old clam-shell handguards need a credit card width gap (.025") to align holes with the barrel. It's an old trick to use a credit card to align the ports. With your barrel you can configure it for either clamshell or free-floating handguards.

While the gas port will be machined carefully, many gas block holes are more generous to accommodate a slight lack of alignment. Not all however, and 0.025" is a lot of misalignment.

I recommend measuring the gap between the edge of the block and the centre of its hole; then the barrel shoulder and the centre of the port. If they are the same you can push it up against the shoulder.

[Stugotz]

"your barrel has been machined to accommodate the 0.025" handguard gap"


Like I mentioned in previous post, the company that did the barrel for me could have made it a lot easier by letting me know it was machined this way...

[montana]

"your barrel has been machined to accommodate the 0.025" handguard gap"


Like I mentioned in previous post, the company that did the barrel for me could have made it a lot easier by letting me know it was machined this way...

When I see a comment "the AR rifle is a lego set" I have to cringe. With the Plethora of different after market parts by different manufacturers, stacking tolerance and problems are a given. Your short stroking apparently caused by the barrel journal being cut to fit a mil spec hand guard is a good example. Many armorer courses only deal with mil spec rifles and tolerances. Most will never gets into the morass of after market parts and tolerances..Geissele and LaRue use thicker trigger and hammer pins compared to standard mill spec pins. They will work fine in a mill spec lower but the longer hammer pin needed in the new plastic KE ARMS plastic receiver should not be used with the Geissele or LaRue triggers. Hammer and trigger pins were designed to rotate in the lower receiver, yet KE ARMS plastic receiver hammer and trigger pins don't rotate. And Most people thought Karl's WWSD rifle used a cassette type trigger to prevent blown primer malfunctions lol. They had a receiver rug for standard triggers developed years before the what would Karl rifle do. The truth is, if the pins don't rotate the stress is put directly onto the hammer and trigger decreasing their life. There are after market captive pins being sold as a solution for walking pins. This creates its own problems while ignoring the actual problem and solutions.. Mil spec 5.56 gas port sizes don't work with under power commercial ammunition so most barrel manufacturers over size their gas ports. This will over gasses the rifle using NATO spec ammunition and decrease the life of the rifle. Then we can add the equation of different calibers. The capacity for problems are endless, yet many are clueless to these potential problems until their rifle quits and then they will almost invariably blame the wrong part or cause of the malfunction..

[Klem]

"your barrel has been machined to accommodate the 0.025" handguard gap"


Like I mentioned in previous post, the company that did the barrel for me could have made it a lot easier by letting me know it was machined this way...

Why is your lack of knowledge someone else's fault?

[Klem]

Go easy on the manufacturer, they expect you to know - and now you do.

[Stugotz]

Just got back from the range and the rifle functioned perfectly. Not a single failure to eject a single brass case. What I really find amazing is the fact that ALL of the loads I worked up for this build into an inch or less (center to center). I had a couple group into 1/2" C to C.

[montana]

Just got back from the range and the rifle functioned perfectly. Not a single failure to eject a single brass case. What I really find amazing is the fact that ALL of the loads I worked up for this build into an inch or less (center to center). I had a couple group into 1/2" C to C.

That's great, good job. Sounds like you have a real shooter. I love happy endings

[mdram]

"your barrel has been machined to accommodate the 0.025" handguard gap"


Like I mentioned in previous post, the company that did the barrel for me could have made it a lot easier by letting me know it was machined this way...

this is why i had mine dimpled for the gas block