The variations of rings and mounts for Tikka rifles are not well known, so I thought it was time to post what information I have. This post is mainly focused on the Tikka M55/M65 rifles, plus the later M558/658 and M595/695 models. In Tikka nomenclature (prior to the current T3 series), a model number starting with a 5 (55, 558, 595), denotes a medium action (.308 length) and a 6 denotes a long action (.30-06 length). Tikka made these rifles in two action lengths, rather than three as did Sako, so Tikka rifles in .222, .223, etc. are built on medium length actions. Tikka offered a much shorter menu of caliber options than Sako, although that has expanded over time. The Ithaca LSA-55 and LSA-65 rifles were identical to the Tikka M55 and M65. All, or almost all, Tikka centerfire sporting rifles have used a parallel dovetail scope mount milled into the action. This contrasts with the tapered dovetail used by Sako. The Tikka dovetail is identical in size to the one used on the CZ 527, except that the Czech rifle has a locating pin located off-center on the rear ring, which fits into a recess on the dovetail. The factory rings for the M55/65 series, which were manufactured from the early 1970's through the late 80's, are shown below. They have an attractive streamlined shape and the upper half is held in place with four screws. The rings bear the name "Tikka" engraved or stamped into one side. I believe these rings were made in more than one height, but I have only seen one height, which I would call a medium. It is high enough to mount most 40mm scopes if the scope does not have an adjustable objective. A Leupold 40mm AO scope will not clear the barrel with the usual Tikka rings. The rings are intended to be mounted at the rear of the front and rear dovetails, and they have removable locating screws. These screws have a dished slot like a Redfield scope mount screw, but smaller. I've never seen a driver made to fit them, but it's easy enough to grind a screwdriver blade or bit to fit. The lower half of each ring is machined from a single piece of steel, incorporating the clamping piece as part of the ring. These fit quite snugly on the rails even before tightening the clamp screw, and it's not unusual that you have to use a screwdriver as a wedge to open up the slot when mounting the ring. The clamp screws require a Redfield-type curved driver bit. Warne makes some very nice rings that clamp onto the Tikka rail. Both permanent and QD variations are available. They also used to make this ring for Sako dovetails, but unfortunately those have been discontinued. Here are photos of the dovetails on an M55 and a pair of original Tikka rings for the M55/M65 series. Note that the action is also drilled for aftermarket scope bases. Most M55/65 rifles, and all 558/658/595/695 rifles, are factory drilled and tapped. Weaver and others make bases to fit. The indexing screws sometimes get lost, and originals are all but impossible to find. Here's a pair with replacement screws. I took M4 Allen head screws, added a snug-fitting black washer, and good as new. Here is a set of Australian-made Hillver aftermarket rings for Tikka. They are much higher than the factory rings that were marketed by Ithaca. I picked up a set of these, or something similar, on eBay a couple of years ago. When Tikka replaced the M55/65 series with the 558/658, they also changed the ring design. The upper ring half is held with two screws rather than four and the indexing screw has been eliminated. Here's a 695 with these rings. (I believe these are factory rings, but I am not 100% certain as I do not have the factory packaging. I got this rifle secondhand and I think the rings were on the gun when I got it.) Below is a newer factory mount that appears to be identical, or nearly so, to the current Optilock, but the packaging does not say Optilock. The rings have a cleverly designed plastic insert that self-adjusts to 1" or 26mm. They also fit the Sako TRG series, which use a Tikka-type mounting rail with the addition of recesses for an indexing pin. The removable pin is for the TRG; I've never seen a Tikka that uses this setup. Conetrol also makes a clamp-on base for the Tikka dovetail. Conetrol rings are a pain to install, but they are extremely attractive, being designed without ring screws. The joints in the rings are all but invisible and there are no protrusions. The rings fit together like a puzzle and everything is held together by the cone-tipped set screws on the bases, which also provide windage adjustment. I was pleasantly surprised recently when a Tikka I bought had a set of Conetrol mounts and rings in the box, unmentioned by the seller. Here are the bases, mounted on an M55. I haven't gotten the scope mounted on this gun yet. Here's a set of Conetrol rings on a Sako L461, just to show what the completed setup looks like.