Does anyone know the material hardness of an AR-15 front sight base, in terms of “rockwell”?
Im hopeing its kind of an industry standard for all AR’s.
Thanx in advance.
“Not particularly hard”. Sorry I can’t be more technical but I’ve done a fair amount of machining on a fair number of them and I don’t think they’re any more than 28Rc.
Thanx,
I was going to guess about rockwell 35 or so. I want to drop a weld over my gas tube roll pin holes and re-drill them. I want to weld it with stainless for some extra strength as Im going to use a homemade solid pin instead of a roll pin.
BTW- This project is for the application of my ares piston kit because Im tired of replacing roll pins.
What is the proper diameter for a solid pin to replace the roll pin?
Jeez seth. seems like that Ares kit sure gives you a lot of grief.
why not sell the kit, and start over with something different?
PWS maybe?
…
I guess I dont see it as grief, I see it as something to do in a field that I absolutly love.
Man… This thread was dug out of the archives. I forgot about it
How did it turn out?
Seth,
A. What is the dia for a solid roll pin?
B. Is is possible that the lack of the end cap caused your roll pin problem?
C. Would using the end cap as a spring help/solve the roll pin problem?
I used a 4-40 set screw to hold the gas tube into the gas block. I tapped the spigot and the gas block (made from the FSB) and installed the set screw with Rocksett. It’s holding up well.
Thanks gotm4 Im glad you chimed in to give some good info as I went a little different route.
Sorry I didnt really stay on top of this subject. I guess I never thought it would be very interesting to anyone.
I never ended up installing a solid pin. I bobbed my front sight base and welded a “Y” shaped bracket on top of it to back the spigot and take the force of the operating system as opposed to the roll pin. The bracket also keeps the spigot from flexing up.
I dont really understand your “end cap” question DuGaul. Would you care to elaborate?
BTW- it turned out great.
Hmm… If someone were to order a large number of such pins made, what would you guys want to see? I may be ordering some springs and pins soon.
Well, on my rig, I used a DD Omega Rail (7") so there was room to keep the forward handguard endcap. I noticed that the endcap performs the same function that your y-bracket appears to do.
(Pardon my crude paintshop skills.)
On a normal gas block the distance from the rearward edge of the block to the gas port hole leaves enough room for a 1/16" gap where the endcap fits. The endcap has a hole for the gas tube to go through.
So when you mount an Ares kit with the endcap still on, the endcap acts like a shim and backs the spigot real tight so the force doesn’t go on the roll pin. Since the spigot fits through the hole for the gas tube, this also acts as a bracket to keep it from flexing up.
If you have a low-profile rig, then you could either dremel away most of the handguard cap so it fits, or you could just make a new bracket out of 1/16" plate metal. Or you could make your own gas block, carefully measured to add the extra 1/16" distance from the rear edge to the roll pin hole.
The next image shows the rough shape you should make a bracket for low profile, or no endcap setup.
I haven’t tested this theory, but I think the way the endcap is shaped makes it act like a spring, taking most or all of the force off the roll pin. The two drawings above are axial view. If I made a third, what the heck, here it is. See below the endcap bends away from the gas block a little bit. When you install the Areas spigot, you have to push it flush against the gas block to get the pin in. This creates compression in the endcap by bending it toward the gas block, using it like a spring. This compression relieves the roll pin of most of the hammer force when you fire the weapon.
It’s interesting this has come out, as it means the Ares kit works if it is installed properly. People who install it without the endcap may be more likely to have flexing problems and roll pin breakage.
BTW, 1/16" is just my guestimate as the thickness of the handguard endcap. I haven’t measured it with calipers. (It’s kind of hard to eyeball it because the sides are crimped.)
Yeah, I pulled my hand guard cap off a long time ago after I bought my troy rail. So I cannot attest to how that may or may not work. Sounds good in theory though, maybe thats how it was designed… I dont know.
Pins
Description Quantity OAL Large End Small End Misc.
A1 sight drum roll pin 1 0.250 0.062
A2 windage drum roll pin 1 0.375 0.062
Bolt cam pin 1 0.800 0.312
Bolt catch roll pin 1 0.437 0.093
Bolt ejector roll pin 1 0.437 0.062
Bolt extractor pin 1 0.446 0.099
Ejection port hinge pin 1 3.850 0.125
Elevation housing retaining pin 1 0.625 0.093
F/A pawl roll pin 1 0.250 0.062
F/A retaining roll pin 1 0.625 0.093
Firing pin 1 3.280 0.155 0.104 .054 (Tip)
Firing pin retainer 1 0.820 0.096
Front sight taper pins 2 0.850 0.143 0.124
Front take down pin 1 1.310 0.248
Gas tube roll pin 1 0.312 0.081
Rear take down pin 1 1.010 0.248
Selector detent pin 1 0.395 0.141 0.124
Take down dent pins 2 0.328 0.091
Trigger / Hammer pins 2 0.905 0.155
Trigger guard roll pin 1 0.625 0.093
the first # refers to length, second # Dia.
You definitely need the handguard cap or equivalent thickness of metal in place for the Ares kit to work over the long run. The piston cup is clearanced for the handguard cap, so it stands off from the FSB without it and puts undue pressure on the gas tube roll pin.