Atec Hertz (H2) / Tikka

[the_greenman]

If you own a Tikka and are thinking of an Atec Hertz H2 then you may want to read!

Recently acquired a brand new Atec Hertz H2 model mod for my Tikka CTR. Factory 5/8s threaded.

Test fired the new mod using various types of factory ammunition and wasn't able to get anything even resembling a group.

Went back to my gunshop and their engineer checked both rifle and moderator and found the moderator wasn't sitting true against the barrel to the point it appeared to have been shaved by an exiting bullet. Potentially not a manufacturing error but an overly long thread?

Jackson Rifles were contacted and initially insisted the rifle should have a more pronounced undercut on the screw thread.
Fortunately my gunshop pointed out that as Tikka probably have 40% of the UK market, it would be unreasonable to expect the owners of the rifles to have to alter their rifles to simply fit a consumable item.
Needless to say the moderator is now back at my gunshop awaiting return to the importer.
The DPT that now sits on it shoots hole on hole.

 

[Mike L]

My atec hertz works fine on my tikka.

 

[the_greenman]

My atec hertz works fine on my tikka.

Maybe I got lucky and got the odd one

 

[Mike L]

Maybe I got lucky and got the odd one

Made on a Friday

 

[Farmer_J]

I’ve just seen a pic of the inside of an H2, it appears if your thread is too long then yes it will foul on the internal birdcage part of the mod so no chance of sitting snug against the undercut.

 

[Keith Edmunds]

Perhaps not a related topic but I've got an H2 on my .243 and it seems very prone to oxidising despite being very well maintained. Even the photos of the demo H2 in a recent 'Rifle Shooter' magazine (last pic) showed signs of oxidisation? Perhaps my expectations are too high?

 

[scotch_egg]

I knew I had read of issues regarding the under cut on muzzle threads relating to Tikka Tac A1 and CTR models.

A quick google search came up with this thread on ukvarminting.

Tikka TAC A1: GMK Response to Muzzle Thread issues

Just an update for anyone who has experienced issues using exact for cal mods on TAC A1s: There's an issue which affects some CTR and some TAC A1 rifles whereby the threads have no been undercut as according to Tikka "they were designed for use with a clamped muzzle brake and do not require an un...

ukvarminting.com

 

[takbok]

Good moderator, inadequate muzzle thread IMO. A simple washer may have solved the issue.

 

[jthyttin]

If I understood correctly, Tikka 5/8"-24 thread is not relieved at the point where it joins the shoulder in the barrel. At least 1/2"-28 thread (used in AR-15, M16, M4 etc.) is not relieved by the spec. I won't be surprised if the same goes for 5/8"-24. If that is the case, mod manufacturers should've taken note and incorporate the relief in the mod thread.

Here in Finland, generally accepted spec for "spigot" and "sako" threads incluce relief at the barrel shoulder. I cannot see anything "sako" in the thread that's missing the straight tenon, IIRC the name was established about the same time as Ase-Utra stroke a deal with Sako being their exclusive distributor in Finland (that was a shame and drove up the prices).

 

[the_greenman]

Made on a Friday

Or

I knew I had read of issues regarding the under cut on muzzle threads relating to Tikka Tac A1 and CTR models.

A quick google search came up with this thread on ukvarminting.

Tikka TAC A1: GMK Response to Muzzle Thread issues

Just an update for anyone who has experienced issues using exact for cal mods on TAC A1s: There's an issue which affects some CTR and some TAC A1 rifles whereby the threads have no been undercut as according to Tikka "they were designed for use with a clamped muzzle brake and do not require an un...

ukvarminting.com

Thanks for this! Interesting and worrying read. I'll pass this on to my gunshop.

 

[Mungo]

Perhaps not a related topic but I've got an H2 on my .243 and it seems very prone to oxidising despite being very well maintained. Even the photos of the demo H2 in a recent 'Rifle Shooter' magazine (last pic) showed signs of oxidisation? Perhaps my expectations are too high?

Don’t maintain it!

I can’t understand why anyone ever opens up a mod.

 

[Keith Edmunds]

Don’t maintain it!

I can’t understand why anyone ever opens up a mod.

I just like seeing white stuff growing inside.

 

[ColinBr]

Mine works fine on my CTR with the same thread.

 

[the_greenman]

Mine works fine on my CTR with the same thread.

Then potentially it was a dud thread on the mod?
Tbh I've no idea. Just posted this in case anyone else was looking to go down the same route and found they couldn't group with a normally very accurate rifle.

 

[ColinBr]

Then potentially it was a dud thread on the mod?
Tbh I've no idea. Just posted this in case anyone else was looking to go down the same route and found they couldn't group with a normally very accurate rifle.

Yes definitely worth posting.
Does look to be either a manufacturing fault at either end.

 

[@theroedeerguy]

No problem with the thread cut on a Blaser

 

[bogtrotter]

I have the same mod on a Sako with no problems.

 

[jthyttin]

I have the same mod on a Sako with no problems.

And which thread? Presumably not factory cut 5/8"-24?

 

[gixer1]

I knew I had read of issues regarding the under cut on muzzle threads relating to Tikka Tac A1 and CTR models.

A quick google search came up with this thread on ukvarminting.

Tikka TAC A1: GMK Response to Muzzle Thread issues

Just an update for anyone who has experienced issues using exact for cal mods on TAC A1s: There's an issue which affects some CTR and some TAC A1 rifles whereby the threads have no been undercut as according to Tikka "they were designed for use with a clamped muzzle brake and do not require an un...

ukvarminting.com

I heard that as well, I wonder if it was an issue with the rifle and that moderator have a slightly tighter tolerance on the thread.