Thread: Omark .308 target rifle

Ok, now for something a little different to my normal smaller caliber varmint rifles.

I got given this old Omark target rifle about 15 years ago.



Didn't know anything about them at the time, so hit Google and did some research. The book "Bolt Action Rifles" by Frank de Haas was also a good reference.

This thing was HEAVY; the receiver walls are 8mm thick, and the barrel is 650mm long and 22mm diameter just behind the front sight (the muzzle it machined down to fit the Parker Hale front sight).

I had no idea of whether it would shoot, and didn't want to spend too much to find out. I obtained a rear peep sight to fit and purchased some 144gn FMJ target rounds from the local big bore rifle club.



The results were quite promising so I bought a pic rail and some rings and had the action D&Ted. The stock had been shortened so I added a Blackwood spacer and rubber grind-to-fit pad (grinding just exposed the steel insert in one place - bugger). Picked up some Lee collet dies, opened up some of my Win .243 brass and set about developing some loads. Scope was just a Simmons Whitetail Classic 6.5-20x50 that had been on my .22-250. Again it seemed to shoot well.

Over time the scope got replaced with a second hand Zeiss Conquest 6.5-20x50, then the Sightron 5-25x50 it currently wears. I picked up a two stage Davies trigger shortly before their production ceased - it's a beauty.





For quite a few years it got an occasional use at the rifle club shooting F class at anywhere between 300 to 1,000 yards.



My brother and I were so impressed with how it shot that we purchased another second hand one and set it up for dad to shoot at the club; it too has proven to be quite accurate. It seems to be an earlier model with the lighter profile barrel similar to the one in the Frank de Haas book.



More recently it's had a couple of weekend trips to a property New South Wales with member L461 where rabbits abound and shots on warrens out to 800m are possible.

These old rifles can provide a very cheap basis for a custom HB single shot. While I replaced the trigger on mine the factory trigger is very similar to a Rem M700 and can be pretty good. The bolt lugs engage in the back of the barrel so rebarreling requires an adaptor. One approach I have read about is to use the stub of the old barrel as the adaptor. This is an example from an Aussie forum of an Omark that has been rebarrelled to .22-250 and fitted into a synthetic Winchester Sharpshooter (I believe?) stock.



Marcus

I had one a while back. Heavy and a cheap accurate rifle. One of the quirky things with them is the locking lugs on the bolt lock into the barrel not the action. You used to be able to get an adaptor way back it you wanted to rebarrel them, not sure whats available now days. Perfect rifle if you dont need to carry it far and want to spend the day sniping. I sold mine and had a 6 5 06 built to do this. The omark would of been more accurate

I think they made a few in 223 as well

They did, the adapter was called a neilson adapter and opened up the possibility of anything with a .473 ish case head. Converting them to magazine was attempted but never successfully A mate had one in 223 and I've still got one rebarrelled with a bull barrel in 3006 done by gundoc in 2008 according to the markings. Silly accurate but stupidly heavy. Mike Collins got me a large pin bolt for it as people at the range were "uncomfortable" with the small pin version.

I purchased an Omark action with the Neilson adaptor from Din Collings back in the day. Got Steve Blencarne on the North Shore to fit a heavy No 5 26" barrel in .220 Swift to it.
I was very interested to see how it would shoot, so prepared 20 rounds with increasing powder charge of what was marked on the plastic milk bottle as Vihtavuori N140 (I was given this powder by a friend).

First shot of the lowest powder charge, and the Shooting Crony read as an error. I noticed a stiff bolt release, and the primer was a bit flattened but not too bad. Second shot read 4200fps. I thought it must be another error, as that speed was far too high for a 55-grain bullet, and again, a difficult bolt release with slightly flattened primer. So I put another round in the chamber with the same powder charge and pulled the trigger.

Ka-boom... the rifle exploded.

Had bits of metal in my face and right eye. Had to go to Auckland Hospital on a Sunday, and an eye surgeon was called in from his weekend off. He did his best, but there is still some metal in my eye, so if I ever need a head MRI in the future, I can't due to the magnets in the machine possibly pulling the small pieces of metal out.

I took the rifle to Steve Blencarne, but he couldn't salvage the action. He did free the bolt though, and reckoned I was really lucky as the bolt lugs had moved forward due to the pressure. Turns out the powder was not N140 but the faster Vihtavuori N130 that my friend had mislabeled.

Yep a Nielson-type adaptor is required to allow rebarrelling







Here are the pages from the Frank de Haas book.




I also have an edition of Guns and Game magazine where an Omark was rebarrelled to 6mmBR as a cheap varminter/casual target rifle.

Marcus

Originally Posted by Hermitage

I purchased an Omark action with the Neilson adaptor from Din Collings back in the day. Got Steve Blencarne on the North Shore to fit a heavy No 5 26" barrel in .220 Swift to it.
I was very interested to see how it would shoot, so prepared 20 rounds with increasing powder charge of what was marked on the plastic milk bottle as Vihtavuori N140 (I was given this powder by a friend).

First shot of the lowest powder charge, and the Shooting Crony read as an error. I noticed a stiff bolt release, and the primer was a bit flattened but not too bad. Second shot read 4200fps. I thought it must be another error, as that speed was far too high for a 55-grain bullet, and again, a difficult bolt release with slightly flattened primer. So I put another round in the chamber with the same powder charge and pulled the trigger.

Ka-boom... the rifle exploded.

Had bits of metal in my face and right eye. Had to go to Auckland Hospital on a Sunday, and an eye surgeon was called in from his weekend off. He did his best, but there is still some metal in my eye, so if I ever need a head MRI in the future, I can't due to the magnets in the machine possibly pulling the small pieces of metal out.

I took the rifle to Steve Blencarne, but he couldn't salvage the action. He did free the bolt though, and reckoned I was really lucky as the bolt lugs had moved forward due to the pressure. Turns out the powder was not N140 but the faster Vihtavuori N130 that my friend had mislabeled.

Holy cow, wow!

You can see even from the bolt shroud that they share a fair bit of Rem 700 DNA.

The reason for the larger diameter cross pin change to the bolt is that the original design had a major weakness. That pin locks the separate bolt head to the bolt body. Over time, some of these pins fractured and the real danger was the rifle could fire without the lugs being engaged. At least three people lost their face in Oz/NZ from this. The fix was to change to a bigger diameter pin that was more robust.

A good decade ago, I was given an Omark which I slightly sporterised for my brother down South. He had use for a still-stalking rifle on a farm with many deer. The stock was rough from being left in a damp garage but the barrel was surprisingly corrosion free. Shortened the barrel a bit, fitted a spare scope and thinned down the stock slightly. First three shot group was under 1/3". He shot a few deer with it apparently.