Do I Need This For My New Suppressor?

[Thy.Will.Be.Done]

I've got a Geissele Super Duty Carbine, with the as built OEM Surefire 3 Prong Flash Hider. Can't help but wonder if I'd be good to go having a quality build without having to test alignment but would hate to be proved wrong on that one. Does every build truly need this for suppressors?



https://www.surefire.com/products/su...lignment-rods/

[S Jenks]

With that setup you’ll probably be fine without one.

My story: I bought both 9mm and 5.56 rods after having a minor end-cap strike when shooting either a PTR-9C or Uzi Pro with my Rugged Obsidian 9 and tri-lug adapter. Being a suppressor noob I didn’t realize you shouldn’t brace off a barricade when using tri-lug (or ever, really).

I bought the rods mainly to see how much flex was happening with my various mounts. Quite a bit with tri-lug, not so much with direct thread or or YHM’s mounts of the Turbo T2.

[Casual Friday]

I would not take the risk, but it's your can.

Don't pay 80 bucks for a Surefire or Geissele. Buy the appropriate size drill rod from McMaster Carr, cut it to length and chamfer the ends. They run about 20 bucks last time I checked.

[4gallonbucket]

Yes McMaster Carr drill rods -- but make sure you get the one that has a straightness specification.
I first ordered without and they came loose packed in a cardboard box. There was a little bit of wobble in the .217" rod.

[whomever]

Yes McMaster Carr drill rods -- but make sure you get the one that has a straightness specification.
I first ordered without and they came loose packed in a cardboard box. There was a little bit of wobble in the .217" rod.

Can you share which ones have a straightness spec? I just spot checked a few and they have precision ground ones that have a diameter tolerance, but I didn't see any that had a straightness spec. Maybe I'm not looking in the right place.

I ask because the precision ground was the first thing I thought of, but when I checked several pieces on a surface plate, none of them were particularly straight.

I ended up springing for the Geissele ones.

[mtnbkr]

Slightly different question:
If you have a gun/can combo that is demonstrably safe, and do not intend to put the can on a different firearm, do you need one of these rods for periodic checks?

Due to ignorance on my part, I've never checked this under the assumption that using quality guns and cans to begin with mitigated the risk, but I don't know if there's an ongoing need as well.

Chris

[4gallonbucket]

Can you share which ones have a straightness spec? I just spot checked a few and they have precision ground ones that have a diameter tolerance, but I didn't see any that had a straightness spec. Maybe I'm not looking in the right place.

I ask because the precision ground was the first thing I thought of, but when I checked several pieces on a surface plate, none of them were particularly straight.

I ended up springing for the Geissele ones.

for 5.56 bore-
0.212": Tight-Tolerance W1 Tool Steel Rod https://www.mcmaster.com/8890K189/

for 30 cal bore-
0.295": Tight-Tolerance W1 Tool Steel Rod
https://www.mcmaster.com/8890K227/

I first ordered the "Tight-Tolerance Multipurpose Oil-Hardening O1 Tool Steel Rods" -- then I noticed there was no straightness spec and there is some visible wobble when rolled on glass. I noticed the "W1 tool steel" rods have a straightness spec of 0.005" per foot.
I have not ordered these yet, but I plan to do so soon.

[whomever]

I noticed the "W1 tool steel" rods have a straightness spec of 0.005" per foot.
I have not ordered these yet, but I plan to do so soon.

Thanks!

Note that .005/ft is .007 or so over the length of the rod. IMHO, that's quite a bit relative to what you are trying to measure (the Geissele spec is .001 over the length of the rod).

I just measured the end hole on a 30 cal suppressor and got .370 or so; (370-308)/2 = .031, so a collision ought to show up. If it were me, I'd mark a line on the end of the rod and rotate it to check at a few orientations, as a sanity check. You've used up some of your tolerance stack, so care is in order.

If you do get some and have a way to check (surface plate? lathe ways?) please post the straightness of what you get. I think I have ordered some of that and got a little more wobble than spec, but I might be misremembering. Or, it doesn't take much tender love from UPS to change that spec by a lot :-(.

Good luck, the price is certainly attractive!

[Screwball]

We are all adults, and can make our own decisions…

I personally will not fire a suppressor on a firearm if I haven’t checked alignment. If there is a change of that setup… like I pulled the muzzle device for whatever reason… I’ll check again.

I won’t normally recheck. Make sure the muzzle device and can are not faulty and be sure they mount up correctly. If an issue arises… recheck alignment.

I likely will have less to worry about with my main suppressor, which is a Griffin Bushwhacker 46. If I mount it on an AK, those 0.46” holes will take a lot of issues to cause a baffle strike… but I’ll still check. If I swap a 0.30” end cap, worst thing likely will be a new end cap. But I rather not have to spend $80 on a new end cap…

I got a bunch of rods from a forum that talks about building your own suppressors… it was linked from AR15.com. I will apologize that I do not remember the name, but they were extremely cost effective and straight. Was nice because I got into suppressors right when I wanted to add a bayonet lug on my M1A. Good tools to have, even if just installing a muzzle device.

[23JAZ]

Can you share which ones have a straightness spec? I just spot checked a few and they have precision ground ones that have a diameter tolerance, but I didn't see any that had a straightness spec. Maybe I'm not looking in the right place.

I ask because the precision ground was the first thing I thought of, but when I checked several pieces on a surface plate, none of them were particularly straight.

I ended up springing for the Geissele ones.

What would be the best diameter for checking alignment on a 9mm?