Omark actions

[dave]

Hi all,

Just a few things im after inn regards to the humble action.

- Do these actions cope well with high pressure rounds eg. 243AI 6.5-284 etc?
- What triggers are available?
- What if any stocks can be sourced for them?

Weighing up the pros and cons of one or is it easier in the long run to purchase a cheap factory rifle and go from there???

Any help would be great,

Cheers
Dave

[Camel]

Probably depends on what you want to use it for. Ive never held one, but think they are single shot, would be ok for a dedicated varmint gun, but I would want a magazine rifle for hunting.

They should handle any normal cartridges, they were chambered for the 308 after all. Normal reloading practices of course.

You would have to weigh up the costs of re-barrelling, against the costs of a readily available rifle. But please don't let me be the one to stop you building a special rifle that is what you want, I do it myself.

[mick_762]

Will handle anything on a .308 head case size no problems at all.

For "magnum" style cartridges the action is too short.
Davies and a few others are excellent triggers for the Omark, most either have the factory trigger (which isn't too bad really) or a Davies.

Phil Mastin is a well know stock maker, though expensive and be prepared to wait a while (he is busy)
Look around on used guns too, pick up a couple of rifles, and then sell the leftovers.

Make sure you get one that has already been rebarreled as a Neilson adaptor is required at around $300-00.

There is nothing "Humble" about the Omark - Venerable is a better word for the work horse of Target Shooting.

Mick

[Matt P]

Dave
It's a reasonable action for the dollars, primary extraction is a problem as they were never designed with reloading in mind, make sure it has an adaptor already fitted as fitting an adapator blows the budget so to speak, a jewell trigger can be fitted but Davies are more common, most Omarks are worn so it pays to check it over prior to handing over $$$, provided it's in reasonable condition it's a not a bad option although I'd go with a Tikka or Rem 700.
Matt P

[aaronraad]

Hi all,

Just a few things im after inn regards to the humble action.

- Do these actions cope well with high pressure rounds eg. 243AI 6.5-284 etc?

Same as the other bolt actions that were designed for 7.62NATO. In good condition they are safe within standard working limits. In poor condition they can be repaired or just put the dropsaw through it.

Your need to look out for 4 things in my experience.

1. Bolt heads - They're removable and held in place by a pin. I believe the pin was upgrade at one point but it definitely needs to be tight and not ready to slip out - definite safety issue.
2. Bolt head number - The replaceable bolt heads were numbered 1-5 to allow to simple headspace adjustments without have to re-do the chamber. Can't remember which is the longest but it's simple to replace if you're doing custom re-barrelling/re-chambering anyway - not sure if it indicates anything really but should be noted.
3. Primary extraction - There is cam point near the root of the bolt handle and where it contacts the rear of the receiver. This cam point can wear with extensive use and any welding repairs need to consider it's affect on the heat treatment of the system. Applying locking lug grease to the primary extraction cam point will reduce wear considerably.
4. Barrel Adaptor - The Omark rifle action is designed to have it's locking lugs engaged directly into the barrel. The barrel supplied obvious had a recess of the lugs cut into it. Most Omarks though were at some stage added a 'barrel adaptor' (Maddco, Neilson & other brands) so that standard barrels could be used without having to cut the recess for the lugs as well. Instead the 'barrel adaptor' effectively extended the receiver to include the recesses for the locking lugs and allow the barrel to thread onto the other end in the standard fashion. Some barrel adaptors were not hardened correctly resulting in damage to the locking lug set-up and possibly deterioration of accuracy (but we are talking fullbore shooters here). I'm not sure if this resulted in any safety incidents but again it should be checked.

Angel and Neilson Rifles (also Australian made) used an 'improved' version of the Omark action which came at a premium.

- What triggers are available?

I think you still have an option for a factory trigger (talk to Total Solutions Engineering - TSE). Mick is right about the Davies Triggers, but you'd have to check availability.

- What if any stocks can be sourced for them?

I'm sure there a few that you can source fully inletted, but even so you can now get aluminium V-blocks to suit the Omark. I'm assuming, but I would think this makes fitting an un-inletted stock much simpler.

See also the various State Rifle Associations for Omark parts and gunsmiths like Geoff Grenfell (Grenfell Armouring Services).

Weighing up the pros and cons of one or is it easier in the long run to purchase a cheap factory rifle and go from there???

Any help would be great,

Cheers
Dave

I'll disagree with Mick on one point. There is at least one thing 'Humble' about the Omark and that is/was the advertising campaign. It was designed as an affordable option for fullbore target shooters in Australia when we moved from the 303 British to the 7.62NATO as the standard cartridge. As a purpose built single-shot it didn't need to make a song and dance when compared to the converted military actions, the standard factory twin locking lug repeaters, or the expensive custom target actions of the time. I wouldn't be surprised if there are still more sub-MOA (back to 1000y) Omark actioned rifles on the range each weekend in Australia than any other brand. The trend has been moving away from Omark's for a couple of decades, partly due to the disposable income of dedicated target shooters increasing while the premium/custom target actions have only increased slightly.

I wish I knew about Omarks when I was younger, I probably could have afforded a custom rifle instead of living with the Ruger M77 MkII Varmint/Target or Remington M700 VSSF factory clobber instead.

[mick_762]

Bloody good answer there Aaronraad.

[curan]

Does this help? I don't know much about F class, but it looks well priced........

Price: $690
Advertised: 17/04/2014
Comment: Angel M80 target rifle, Phil Mastin stock, Krieger stainless steel barrel. 308 comes with a spare 223 Krieger barrel, also an original Shultz & Larsson barrel. 308 and scope rail set up for F class.

http://www.usedguns.com.au/Product.aspx?p=34554

regards, curan

[Branxhunter]

Based on my experience (somewhat limited I know) an Omark can provide surprising performance for little outlay.

I have no idea of the history of mine - it came to me looking like a POS but it just plain shoots. It has the factory barrel with the front sight block on it. I have tried 125gn Speer TNTs, 150gn Sierra SPs and 155gn A-maxes in it so far and it has given me tiny little groups with all three. Groups tend to be very consistent with windage barely changing as powder charge increases.

The biggest improvement I found was fitting the Davies trigger. I actually wanted a single stage with curved trigger blade, but in the lighter configuration ( from memory 8 oz to 1.5lb) I could only get a two stage, and the curved trigger blade is no longer made. After using it I am sold on the two stage for a target rifle. It is a stunning trigger. I have had to increase the pull weight on the second stage because it was just too light for me as supplied, but now I have a defined change between the two stags with the second stage still being quite light.

A big shout out to Adam Davies too - he put the trigger together for me and sent it through in the weeks before the recent Queens. When it turned up it was obvious that the sear was a lot further forward than on the factory Omark trigger, with the result that when fitted the firing pin fall was greatly reduced and misfires occurred. I rang him about it, and he said to send it back and he would machine a new sear with the sear face a lot further back. I mailed it on the Monday before Queens, and it turned up in my mail box on the Friday - no extra charge. A great product and service that you cannot fault - what's not to like?

I agree with aaronraad that the adaptor is essential if you want greater flexibility in what you end up using the action for. I wouldn't mind picking up another action with an adaptor and toying with a 6br, or a blown out .22-243 to sling some 80-90gn projies, or a .......

Marcus

[monsoon35]

Whoops

[Tony Z]

For years i have used or helped set people up with Omarks for long range BR. With a properly timed adapter and roller cam for extraction they can be quicker to use than many custom actions. Somewhere on here is a very good vid of albow shooting his 30 JAT, a fatter 30/06 AI, in his Omark with an adapter and roller i made and fitted. The Omark is in fact not limited to 308 bolt head size as TSE now makes a magnum face bolt head for cases like 300 WSM etc. But if you are like me you just make a new bolt head to any configuration or extractor style you wish. A truly versatile action.

By coincidence i am currently making a new sleeve from 420 MFQ that does away with the need for an adapter completely as well as making it optional drop port or left load/eject and suited to Rem 700 type triggers and stocks with an integral recoil lug. More importantly i can close up the tolerances and bolt release position to take away that dreaded Omark bolt wobble. The work involved in making the adapter is near as much as making a whole new sleeve. I will post up the results when it's done. If albow is about maybe he can repost that link and maybe show some pics of his action.

[mick_762]

G'day Tony,
Mate can you give a bit more info on that sleeve your making that sounds like a bloody good option for customizing the Omark?
Maybe make a new thread so as to not hijack this one away from the requested informayion?

Cheers

Mick

[adamjp]

Many years ago, my father and I campaigned two Omarks in silhouette shooting.

Using the original factory barrels they were rechambered to 30/06 AI. The rifles handled the 144gn FMJs for the shorts, and 180gn bullets for the Rams without any problems at all. The only irritation is that to remove an unfired round the bolt needed to come out too.

One was subsequently rebarreled to 6.5x55 ARCH, and then again to 22/250 with a 1:8 barrel. This rifle went from the original stock, to a custom Lee Six Silhouette stock, to an adapted Wild Dog Remington 700 SA stock as the 22/250 (search for Frankenrifle). It is now in the possession of a member here and I understand it still shoots well.

The Omark is a very versatile action and with the modification of the adapter and the extraction cam on the bolt handle will continue to make very suitable LR varmiters for years to come.

IMHO the factory trigger is very good and does not need to be replaced, just adjusted.

[Tony Z]

Mick most adapters I have made over the years have been 1 1/16 × 16 TPI as used by Remingtons etc primarily to stop tenon swell that leads to sticky extraction with relatively low pressure loads. This has been one ot the drawbacks of Omarks. The current sleeve I am doing will be 1 1/8 × 16TPI.

[adamjp]

Mick most adapters I have made over the years have been 1 1/16 × 16 TPI as used by Remingtons etc primarily to stop tenon swell that leads to sticky extraction with relatively low pressure loads. This has been one ot the drawbacks of Omarks. The current sleeve I am doing will be 1 1/8 × 16TPI.

I've often wondered if the stub of the original barrel could be machined to be an adapter for a standard Rem 700 barrel. Would certainly make for some cheap conversions.

I have a stub sitting here for that purpose but have not got any further.

[Tony Z]

The very first adapters were just barrel stubs.