OzFclass

I am still looking to find a way to dismantle an Omark firing pin and spring.
This would be handy as I like to replace the spring every 12 months as well as for cleaning...would also be good to help with matching sized brass to chamber for that feel of close to zero headspace.

I know some guys in WA that know about Omarks. Some are 'smiths, some just have been around for 40 years, and never "done the paperwork". One in particular is someone you dont like.

Incidentally Rob, having mills and lathes does not a smith make - true enough. Neither does a qualification make you a smith.... like car mechanics, you have to go with one you trust, nothing more than that.

littlebang556 wrote:I am still looking to find a way to dismantle an Omark firing pin and spring.

Here's a Remington equivalent.

http://www.sinclairintl.com/cgi-bin/cat ... type=store

Some spring compressors capture the bolt shroud with a couple of fingers. The name of the game is to squeeze the spring enough to expose the pin that holds the sear to the back of firing pin. If you can work out a way to jerrybuild something that will do the same job.......

John

Thanks to the above post my Omark is all better now.

After all that hard work to get an accurate rifle, which it now is and just 4 shoots left for the year I will be selling it.

I will post some pics later for all to see but general description is:

Re-Blued Omark action (DE325) w/bolt (reduced FP 60 thou), w/maddco adaptor, 28" S/S 7.7T Krieger barrel, Davies trigger, aluminium bedding in Jerricho walnut stock with adjustable cheekpiece and 3 way putt plate, front and rear variable iris's with fully restored TMAC rear, mirage band. Scope rail also included.

Will post in the for sale section later along with price. Will also sell another Omark 5.56...the one that shot my record 100.20 in TR 600y...and is still a real goer...but will be sold without sights but is drilled for mounting scope and would suit both TR and FC....trouble and strife wont let me keep them all if I am to get another.....besides, I would have to buy a bigger safe.

I will be replacing it with my 1st brand new action and will be manufacturing an aluminium stock.

Cheers guys.

Rob.

Does anyone know if replacement bolt parts for remington type rifles are interchangeable with omark...mainly looking at shroud, pin and spring...

Kind Regards

Rob Alman

Hi can some one explain how you fixed the cam action of the bolt after firing? I am having this diffuculty in one of my omarks at the moment and would like to clear it up. I havent had to use the cleaning rod method of extraction but the bolt action is very different from my other omark.
Cheers

Sorry to say that extraction problems and Omarks is the way they are. Keith is right about mucking around with timing issues - which is what we are talking about.

The ramp type of extraction cam can work well, or not at all, depending on wear, changing bolt heads etc - it is all tied in together. It is really a trigonometric issue - due to the angled surface of the cam, any tiny change in length (that is specifically the distance between the front of the handle cam, and the bolt lug face) is multiplied by the angular distance.

Retiming the bolt would include closing the distance mentioned above, down to something like 0.005", then having to recheck that the lugs dont intersect with the body lugs on opening etc.....this is why it should be done by a smith. Having all that play in bolt diameter, bolt head pin etc makes it tough to make the thing work correctly.

Most I have seen lately have barely any extraction at all, maybe 0,5mm or 0.020" due to badly worn surfaces. To fix this properly, means doing more work on the action than it is likely worth.

I would not just change a bolthead without resetting the chamber depth - if it was required after measuring. "A few thou" is more than what would be considered acceptable. It is either right, or it isnt, there is no middle ground with head spacing.

Interesting considering it just came back from a "smith" after having a new barrel fitted and chambered, there was no issue with the old barrel however comparing my bolts from each rifle the one i am having trouble with has far more movement than the other which is that close to none that it is unmeasurable, surley if this is the problem you talk about it would have been picked up by my "smith"??