Gunsmithing Your thoughts wanted on new gas block design???

[sawman556]

So I am designing this new gas block.

If you're bored and want to catch up with a thread I started on arfcom, I would be grateful.

I know there are some damn good machinists in here, so I thought I would ask for your thoughts.

What do you think about my new gas block??? - AR15.COM

 

[Sako man]

most defiantly looks a lot easier to install. I imagine some thread lock for those synch hex bolts.

 

[mark5pt56]

I've often said why not machine a spline on the barrel and corresponding ones for the block. It would be indexed properly and the pinning would be optional or even a set screw, but I prefer pinning. I know this doesn't have splines though. Would make install easier in a sense.

 

[sawman556]

How are you going to spline barrels?

I plan on ditching the top set screws and have spots for pinning.

What steel would be best? 400 series stainless? This is O1 tool steel.

 

[308boltgun]

Sawman

I see you are from NJ and I am guessing that's what prompted this design. The biggest advantage that I see to this design is for use with barrels that have welded on flash hiders. This would allow you to change a barrel without having to "remove" the flash hider.

I would like to see something that makes sure the 2 halves stay aligned properly, i.e. a top-to-bottom pin

 

[ORD]

+1 on the above. I can definitely see a market for such a new product/offering in places where muzzle-devices are legally required to be permanently affixed, and also for those folks who are running pinned/welded devices for non-NFA reasons like to get shorter barrels up to/over the 16" line.

Having just reviewed the BARFCOM thread, I agree that some sort of a "clamp-on" design may help to eliminate the pinning/etc. of the block but I can't see how, without it costing a ton both in terms of mfging cost and end-user cost, to get that done. My only other suggestion would be to see if you can't find a way to may it in an adjustable design as well as many folks want adjustability for use with suppressors, or otherwise just to fine-tune their rifles/carbines to the optimum potential/cyclic rate/etc.

 

[Raufoss]

Honestly keep it KISS . Pinned gas block is a reliable and proven design.

Rule for gas block from my test:
No multi parts: More place for failures and WILL loosens no mather what steel you will use and how tight the machining is done
NO set screws: Documented that can put undesired tension on the barrel and it is more part to loose .Because anything that is made to screw will unscrew someday)
No Flip up iron sight on gas block

 

[mark5pt56]

I'm not a machinist, etc. But that's all it is, an extra step in manufacturing. And technically could be done with your two piec edesign. I think the major advantage would be with fixed sight options. Although Vltor has demonstarted the strength of thier clamp design.

How are you going to spline barrels?

I plan on ditching the top set screws and have spots for pinning.

What steel would be best? 400 series stainless? This is O1 tool steel.

 

[sawman556]

So you guys understand what I am trying to do.

The pins could be run from top to bottom. That would lock the 2 parts together plus catch the barrel???

I'd probably leave the 2 bottom set-screws to help align it with a dimpled barrel and help hold it in place while pinning???

I use Permatex 27010 successfully on my 1 piece gas block screws. Even if you lost a screw it wouldn't matter since it's pinned.

2 pins .09375" x .750" like this:

McMaster-Carr

Type 420 Stainless Steel—Stronger than 18-8 stainless steel and more corrosion resistant than steel. Minimum Rockwell hardness is C46.
Extra strength pins are thicker, making them roughly 30% stronger than their standard counterparts.

 

[sawman556]

 

[Geno C.]

Maybe a bit longer for a little added strength?

 

[sawman556]

As it is now should be plenty strong. I want to keep it light as possible and be able to be covered by 10" FF systems.

 

[sawman556]

No more thoughts?

 

[thespecialist]

Random thought, and it may be a silly one but may also be worth exploring. The only thing I see that causes any concern is the angles that the halves lock together at. It looks like the notches are machined parallel to each other at 90 degrees, that may or may not allow the block to "grow" and loosen enough to cause leakage issues as it heats up. Changing those angles a bit may help keep the pieces from moving, maybe machine the top half with an 80 degree angle and the bottom with the corresponding angle to lock them together both vertically and horizontally.

Like I said, completely random but may be worth exploring.

 

[Gunfighter14e2]

Yes if your going to make the wheel rounder, add a complete finger only adjustable gas shut off. Not a 3-4 way just either on or off which only requires a 90* or less turn.

 

[MarkCO]

Looks expensive to machine (comparatively) and prone to leakage.

 

[Gunfighter14e2]

Looks expensive to machine (comparatively) and prone to leakage.

Yes it does (leakage)but, I'd install it with Sleeve and Bearing mount or ring the gas hole in it for a copper wire over lap seal.