7/16x28 thread adapter for OG suppressors

[MThuntr]

I have a 280AI Kimber that shoots great but has a radial brake that doesn't get much these days. I'm thinking an OG30 would be the ticket. Problem is Kimbers have 7/16 threads. Unknown doesn't make one.

Anyone make a 7/16 to 5/8 adapter that fits inside an OTB suppressor or do I just knock like 1/8" off each of the corners from the Kimber brand one I have?

 

[HuntHarder]

I'd file down your current one and Roksett it on your barrel. If it comes off in the can, it is a PITA. Maybe you could grind a slot in the part that mates against the shoulder, so you could unscrew it out of the can, should it get stuck.

 

[MThuntr]

I'd file down your current one and Roksett it on your barrel. If it comes off in the can, it is a PITA. Maybe you could grind a slot in the part that mates against the shoulder, so you could unscrew it out of the can, should it get stuck.

Getting stuck is a big fear. I think I'll have to see if there's a design I can copy somewhere online

This suppressor would likely get moved between a couple rifles so I may use a very small dab of high temp anti seize.

 

[HuntHarder]

Yeah, it's a problem with OTB that doesn't exist with traditional. If you plan to move the can around, I would defenitly plan for the worst and have a way to remove the adapter, should it get stuck in the can. Notching the adapter and making a price of metal to act as a "key/ screwdriver" to remove it seems like the easiest I could think of.

 

[nm.otter]

N

Post in thread 'Unknown suppressors OG testing'

Oct 11, 2025

If a third party adapter gets stuck inside your OG, then you are going to have a real pain getting it out of there.

This happened here on a Roughtech Superlite with the factory-supplied M15x1 adapter. A drop of blue Loctite on the barrel threads followed by an overnight cure and the OG easily unscrewed. Removing the adapter required 10+ minutes with a heat gun, soft vice jaws, and a fair bit of swearing. Cleaned and degreased again, then Rocksetted. Filed down the hex corners a bit so the adapter fit properly inside the OG and all appears well.

• nm.otter

• 

 

[Antares]

I filed the corners off the factory Kimber adapter and Roksett it on. Hasn’t come loose yet.

 

[Cory_Shoot2Hunt]

I filed the corners off the factory Kimber adapter and Roksett it on, as @HuntHarder suggested. Hasn’t come loose yet.

View attachment 1075380
View attachment 1075381

This^^^

 

[Firth]

I filed the corners off the factory Kimber adapter and Roksett it on, as @HuntHarder suggested. Hasn’t come loose yet.

View attachment 1075380
View attachment 1075381

I think if it ever did came loose, my first try would be to redo the rockset, but with more. Or maybe try a a high strength loctite. I know rockset is better with heat, but I'm not sure which is stronger overall.

 

[Weldor]

Make friends with good machinist.

 

[JCMCUBIC]

I had the same question regarding M15x1. It would be nice if US made more than the 1/2" adapter and that those used the same removal tool. I understand there may not be enough demand though.

I have the tool and two 1/2's ordered.

 

[nm.otter]

M15x1 is too big for a 5/8"-24 concentric adapter.

 

[Cory_Shoot2Hunt]

I get asked not even once a month for an adapter other than 1/2. Or ppl saying they wish we made other ones. I’d say every 45 days? 9/16 is the most common oddball one.

 

[JCMCUBIC]

I get asked not even once a month for an adapter other than 1/2. Or ppl saying they wish we made other ones. I’d say every 45 days? 9/16 is the most common oddball one.

That's what I figured.

M15x1 is too big for a 5/8"-24 concentric adapter.

Not expected.

 

[Foster_65]

I get asked not even once a month for an adapter other than 1/2. Or ppl saying they wish we made other ones. I’d say every 45 days? 9/16 is the most common oddball one.

I would really like some 9/16 adapters. Early on I had a lot of mine threaded 9/16 as recommended by my smith. Wasn’t a bid deal as I only had traditional. Now with a couple of otb I’m nervous and would love to buy some with the tool

 

[Cory_Shoot2Hunt]

I would really like some 9/16 adapters. Early on I had a lot of mine threaded 9/16 as recommended by my smith. Wasn’t a bid deal as I only had traditional. Now with a couple of otb I’m nervous and would love to buy some with the tool

@Salmon River Solutions can explain this better…

 

[Salmon River Solutions]

We could make 5/8-24 to 9/16-24 adaptors but it would be a lot different than the 1/2-5/8.

There isn't enough material to support the 9/16 internal and 5/8 external. So the 9/16 thread would be approx .500" in length, a portion of thread relief, then about .625" of 5/8 thread. Depending on what can your losing approx .625" of the reflex.

It's still possible, but would just have the added length and weight and cost.


Ken

 

[Cory_Shoot2Hunt]

We could make 5/8-24 to 9/16-24 adaptors but it would be a lot different than the 1/2-5/8.

There isn't enough material to support the 9/16 internal and 5/8 external. So the 9/16 thread would be approx .500" in length, a portion of thread relief, then about .625" of 5/8 thread. Depending on what can your losing approx .625" of the reflex.

It's still possible, but would just have the added length and weight and cost.


Ken

I figured you’re way more qualified to answer this. Thanks Ken

 

[Foster_65]

We could make 5/8-24 to 9/16-24 adaptors but it would be a lot different than the 1/2-5/8.

There isn't enough material to support the 9/16 internal and 5/8 external. So the 9/16 thread would be approx .500" in length, a portion of thread relief, then about .625" of 5/8 thread. Depending on what can your losing approx .625" of the reflex.

It's still possible, but would just have the added length and weight and cost.


Ken

Not arguing at all as you’re far more qualified than me but right now I’m using the precision armament adapter and it doesn’t add any length. Maybe it’s all around different but just curious

M4 Muzzle Thread Adapter

Engineered for 1/2-28 or 9/16-24 barrels. Easy install, perfect alignment, superior heat resistance.

precisionarmament.com

 

[Salmon River Solutions]

Not arguing at all as you’re far more qualified than me but right now I’m using the precision armament adapter and it doesn’t add any length. Maybe it’s all around different but just curious

M4 Muzzle Thread Adapter

Engineered for 1/2-28 or 9/16-24 barrels. Easy install, perfect alignment, superior heat resistance.

precisionarmament.com

You can 100% make them.

I can break them (at middle of thread tolerancing) with two fingers and a normal 3/8" drive that's 6" long.

A 9/16-24 internal thread has a major internal diameter *minimum* (that's the thread depth maximum) of .5625".

A 5/8-24 external thread has a thread major (minimum diameter the thread tool would theoretically cut to) of .565" - .578".

If you ran the 9/16 at max, and the 5/8 at the minimum you would end up with an external thread, and an internal thread, separate from one another. You can run them at a minimum and max that they stay together in one piece. But I'm not making something I wouldn't use myself.

Wow that's way more math than I normally have to do. I'm always just stuck scheduling or on the phone nowadays.

Ken

 

[Foster_65]

You can 100% make them.

I can break them (at middle of thread tolerancing) with two fingers and a normal 3/8" drive that's 6" long.

A 9/16-24 internal thread has a major internal diameter *minimum* (that's the thread depth maximum) of .5625".

A 5/8-24 external thread has a thread major (minimum diameter the thread tool would theoretically cut to) of .565" - .578".

If you ran the 9/16 at max, and the 5/8 at the minimum you would end up with an external thread, and an internal thread, separate from one another. You can run them at a minimum and max that they stay together in one piece. But I'm not making something I wouldn't use myself.

Wow that's way more math than I normally have to do. I'm always just stuck scheduling or on the phone nowadays.

Ken

That is very good info and I appreciate it. Makes a lot of sense. Thank you