Surefire Optimized Bolt Carrier

[John Hearne]

It seems like a neat concept and is consistent with the points Sullivan brought up with the Forgotten Weapons guys.

Two issues. 1) It fills a fairly small niche. If you are shooting a suppressed Mk18 full auto then this seems like a really good idea. As you move away from that - longer barrel, no suppressor, no full auto - it seems to be less necessary. 2) The unanswered question is whether the increased length of bolt carrier group travel will result in broken bolt catches as seen in the 9mm SMG variants.

[Tokarev]

The unanswered question is whether the increased length of bolt carrier group travel will result in broken bolt catches as seen in the 9mm SMG variants.

Good question. Maybe that's why it took a couple years to get to market. Maybe Surefire was tweaking the weight to help prevent bolt stop breakage.

[Tokarev]

In stock here:

https://www.centurionarms.com/Produc...eid=ade0e45bf8

Sent from my SM-G930P using Tapatalk

[JclInAtx]

Inrange tv did an interview with Jim Sullivan and they discussed the bolt carrier as well as the extended capacity mags and had some video of full auto mag dumps. It was a while ago, and may have been multiple videos.
I think this is it but my phone isnt playing nice with it.
https://www.full30.com/watch/MTcx/in...ar-15-designer

[spyderco monkey]

What problems is this designed to solve, other than bolt bounce? Is it just supposed to be a 'better mousetrap'?

The OBC is about 3 things primarily:

1. Reducing FA rate of fire for improved controllability. It cuts ROF from 850-900rpm to 600rpm, resulting in better controllability and less ammo consumption.

2. Reducing bolt impact. This was one of the principles behind Sullivan's Ultimax machinegun. The bolt has an additional 0.4" of travel, allowing more of its rearward energy to be absorbed by the buffer spring prior to the bolt bottoming out. This should reduce recoil/sight movement in both FA and Semi auto.

3. Improving magazine reliability. Reducing bolt cycle speed gives the magazine spring more time to raise the bullet into position. This is especially important for suppressed FA weapons, but also will likely improve the reliability of extra capacity magazines like the Surefire 60 - which was also designed by Sullivan.



https://www.recoilweb.com/watch-reco...bc-135516.html

And the original Jim Sullivan interview, showing the increase in controllability:
https://youtu.be/gOUKXIrDE0I?t=604