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"Over Gassed" AR's Fact or Fiction? Other Perspectives

I see a lot of postings suggesting AR failure to feed malfunctions may be because their rifle is "Over Gassed" and I really have to question this. For backdrop, I have built up and test fired in excess of 500 AR-15's, many of them with custom or wildcat cartridges, and with a myriad of barrel lengths, gas system lengths, etc., where there was no recognized or normally accepted port sizing (had to figure it out).

One of the main arguments of the failure to feed malfunction as relates to "Over Gassing" is that the bolt carrier and bolt speed is too fast.

I have yet to see "Over Gassing" as a source of a failure to feed malfunction to be a real issue for a few reasons:

1. The speed of the carrier and bolt coming forward to feed a round is almost 100% governed by the stiffness of the buffer spring and the weight of the buffer.
2. If a rifle is "Over Gassed", that may speed up the retreat of the carrier and the unlocking of the bolt out of battery, but it does not per se speed up the carrier and bolt coming forward (i.e. the buffer typically hits the back of the buffer tube and the dead plastic end of the buffer softens that strike so it's not metal to metal, but it's not a trampoline effect, nor was an AR buffer system designed to do that).
3. An AR gas system is set up to bleed off all gas immediately after the bolt opens out of battery (i.e. it blows out the vent holes in the side of the carrier) so it's not like the system holds onto excess pressure to somehow convert that into carrier or bolt speed coming forward.

I am also not a big fan of adjustable gas blocks and I have seen plenty of issues with them (taken a bunch of them off customer guns a returned them because they were a source of a problem that did no exist). First off, an adjustable gas block is of no value at all unless the rifle is over ported. All an adjustable gas block can do is cut back the amount of gas being delivered into the gas system from the port, it can never add more than can come through the port. It may have some value for someone that wants to run something like a 300 BO where they want to shoot subsonic "heavies" with a real fast powder through a can to run very quiet (ergo they have a very large port to do that), but then wants to shoot supersonic and push bullets to the max where chamber pressures are running double what they are with a subsonic loading. Even then, what I typically see is an AR cycling back hard and ejecting aggressively but that's about it.

I have probably "opened a can of worms" here with this discussion but there are other perspectives on the issue involved.

SOLD WTS: New Barrett MK22 .300 NM Barrel and Mags

Selling the following barrel and mags. Purchase with confidence based on available description/pictures. Prices are shipped. I can take payment through PayPal FF or Venmo.

Brand new barrel, bolt head, and two (2) D magazines that came with MK22. Includes ZCORR anti corrosion bag within Barrett barrel bag. Will ship in box that came from factory for barrel kits.

  • Caliber: 300 NM
  • Length: 26"
  • Twist: 1-8
  • Color: Coyote
  • Muzzle Device: Barrett AML brake
  • Retail price: $1,675 just for barrel kit & one (1) magazine

Price: $1,200.00 Shipped

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SOLD Sig Rattler LT upper

I have a used but not abused, approximate round count of about ~500, Sig Rattler LT upper receiver for sale. It comes with the upper, shorty rail, longer SD rail from Midwest, sig metal BUIS and Forward control design charging handle. The dot, forward grip and rails scales are not included and the lower isn't for sale. This is chambered in 556/.223

Asking $1650 shipped

If you have any questions please let me know.

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Accessories WTS MPA Matrix Pro…SPF

Selling my like new MPA Matrix Pro Rem SA in Black. Prestine condition except for a small blemish in the cerakote on NVG bridge. Includes all accessories and a Grey Ops Barricade Stop.

If interested please PM contact information and plan to discuss sale details via phone to avoid fraud concerns. Sale will not happen without direct communication between myself and purchaser. Asking $SPF

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SOLD Spuhr SP-4011 (34mm UniMount) 1.10” Height / 0 MOA Cant. (SOLD)

Spuhr SP-4011 Mount in 34mm ring size. Discontinued and Hard to find. This is the Lowest Spuhr Mount made at only 1.10" in Height and 0 MOA Cant. It's in decent shape and works flawlessly with its 5 screw mount design. This is a Perfect choice for your Tactical Bolt Action Rifle due to its Low Profile and Built in Bubble Level.

Only $320 Shipped & Insured.

*****Reduced to Only $280 Shipped*****



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SOLD Leupold Mark 5 HD 2-10x30 TMR FFP

Selling a like new in excellent condition Leupold Mark 5 HD 2-10x30 TMR FFP non-illuminated (179702). Has been mounted but never used. it has just been sitting in my safe.

Sold
No trades please

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SOLD Proof 308 Carbon TL3 Prefit 20 Inch... Price Drop..

Proof 20" Carbon Fiber 308 Win Prefit Barrel for a Zermatt Bighorn TL3 or SR3 Action Threaded 5/8x24 at the muzzle ......350rds Fired and shoots anything I have put through in (168s, 175, 180s) All Half MOA or better ......... sold Shipped........

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