Filter

"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.

Accessories Dometic CFX3 75DZ Dual Zone Cooler (Refrigerator/Freezer) with Cover

Up for sale is a Dometic CFX3 75DZ Dual Zone Cooler (Refrigerator and Freezer) with protective cover. It is in "like new" condition and was never used. This was because I was posted abroad for a couple of years and did not have access to it. I'm only selling this one because I no longer need it; the new trailer I bought has a cooler installed.

These coolers retail for over $1100 and the covers for them cost $179. I'm selling everything for: $700. It would be ideal for anyone who is involved in overlanding and/or going on extended self-supporting road trips for PRS/NRL matches, camping, hunting, etc.

I reside in Chapel Hill, North Carolina and would prefer to handle this sale in person. I have no problem driving a reasonable distance to drop it off. If a buyer wants the cooler shipped, all costs will be their responsibility.

Feel free to PM me with any questions/requests for additional photos.

Thanks for checking out my listing and have a good one! S/F!

IMG_2175.jpg
IMG_2173.jpg
IMG_2176.jpg
IMG_2177.jpg

SCAR as 6 ARC / 6G Platform?

IMG_2928.jpg



Anyone done a 6 ARC SCAR yet? Seems like the beefed-up SCAR bolt would do wonders compared to the more fragile retrofit design of forcing a standard AR15 bolt to accommodate a 6ARC case. While the JP one (pictured on right) does fine in one of my 6ARC builds, it clearly not designed for that large of a case head. Certainly, no engineer would design it like that on purpose.

On the other hand, the SCAR 16 is massively overbuild for 5.56 (as it was designed with multicaliber geometry in mind that never manifested as the SCAR 17/20 took over all the work), and seems like at the 6ARC case head dimensions it would be perfect. The SCAR also already has steel side rails inside the receiver for the cam pin, much like Geissele's SOCOM offering, intended to alleviate excessive wear from a larger-than-designed cartridge adapted to the AR platform.
  • Like
Reactions: mig1nc and dswogger

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

IMG_1003.jpg

IMG_1005.jpg
  • Like
Reactions: BoreBear

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.

Attachments

  • rsar1.jpg
    rsar1.jpg
    682.8 KB · Views: 88
  • rsar2.jpg
    rsar2.jpg
    696.8 KB · Views: 83
  • rsar3.jpg
    rsar3.jpg
    628.2 KB · Views: 77
  • rsar4.jpg
    rsar4.jpg
    550.9 KB · Views: 66
  • rsar5.jpg
    rsar5.jpg
    509.7 KB · Views: 63
  • rsar6.jpg
    rsar6.jpg
    366.7 KB · Views: 74

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

Attachments

  • IMG_7272.jpeg
    IMG_7272.jpeg
    4.3 MB · Views: 241
  • Like
Reactions: Stevenhansell

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*****



IMG_1237.jpeg
IMG_1238.jpeg
IMG_1240.jpeg
IMG_1239.jpeg
IMG_1241.jpeg
  • Like
Reactions: simonp

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

Attachments

  • IMG_5376.jpeg
    IMG_5376.jpeg
    3.6 MB · Views: 47
  • IMG_5377.jpeg
    IMG_5377.jpeg
    3 MB · Views: 46
  • IMG_5378.jpeg
    IMG_5378.jpeg
    3.6 MB · Views: 43
  • IMG_5379.jpeg
    IMG_5379.jpeg
    548.3 KB · Views: 48