Factory rings that come with these guns are way too high. It is my understanding that this is because the earlier guns did not have a sculpted bolt handle and the height was necessary. I searched for a lower mount for my CZ 527 (17 Hornet) and finally put Talleys on, but they are only minimally lower than the factory rings. A european manufacture base and ring set was advertised as 3/8", but was closer to 1/2". (Right with the Talleys). CZ Factory is .550.

Buddy just acquired a 550 in 6.5x55 and is in the same boat.

What's the lowest arrangement available for these guns? (conventional 1" tube, no oversize objectives.).

Thanks.

Mediums are lowest (mostly).

I think the lowest for a 527 are the Hunker mounts from James Calhoon, they are low enough that you may need a modified bolt handle to clear the ocular (depends on when your 527 was made):

http://www.jamescalhoon.com/

Another option is to put a Pic rail on it with low Weaver rings.

At Mackay_Sagebrush's suggestion, I put some medium rings for Tikka's on mine, found them on ebay for about $20:





Sorry, can't help with the 550.

I think that Warnes are approximately the same height as the hunker mounts. I’m not sure that Warne even makes lows for the 527. I have a 527 with a Leupold 3.5-10x40 in Warne mediums. Bolt handle clears the ocular by 2-3mm on the bottom, but not too tight on the bolt handle (side). Plenty of room upfront on the objective - could maybe even go up to 50mm. This is a newer rifle with the reshaped bolt handle. Limiting factor still seems to be bolt handle clearance, but mine is comfortable. I don’t know how to post pics here, if you pm me, I’d be happy to email or text pictures

I know nothing about the 550s, but I’d recommend that you research Warne. They are nice.

I had warne mediums on a 550 with a VX2 3-9x40 and they were perfect. The bolt/ocular fit was closer than the objective/barrel clearance. I haven't tried anything with a big ocular but I would expect it would to need Warne highs

Warne Mediums are .425" and highs are .535". I've got Warnes on all my CZs and they fit well.

I have gone another way.

I take 2 number 39 Weaver bases, which have very little dish to their bottoms, and I flatten those bottoms.
I then drill and tap the top of the CZ receiver just like any other old rifle, but in the case of the CZs it's super easy because the tops are flat too.
After those are installed you can use any weaver ring you want to use, including the supper lows all the way to Tunnels, off-sets, 30MM and anything else. The Weaver bases, once flattened are only about .165" high.

I never liked how high the other options are, but the age-old Weaver system works perfectly.
Here are 2 pics of a 375H&H I did for a friend with this type of mounting system. In my opinion, it looks low and clean, and they allow for a low mounted scope on a custom stocked rifle, so the user can also use the irons comfortable, which in the case of the 375 above was asked for so he can use the British express sights when he likes. the weaver system returns to zero well and is fast and easy to remove and replace in the field with no more then a Swiss Army Knife (or any pocket tool with a straight screw driver on it.

Custom CZ 375 3 by Steve Zihn, on [bleep]
Custom CZ 375 2 by Steve Zihn, on [bleep]

Weaver really should bring out some bases for exactly this application, but getting them to do it has proven impossible so far.

Plan of action is to try the Warnes, and I really like the creative approach submitted by Szihn. It is hard to believe no manufacturer has addressed this, given the quality and popularity of these guns.

At least look at the sportsmatch rings. I use them on Tikka t3's. It'll be a different dovetail size, but I know they make them for CZ. I can't speak for clearance or heights, but I recall someone using them on a CZ527 recently, and it looked like the lowest and cleanest system I've seen so far.

About ten years ago when I first bought my CZ550 FS in 9.3X62 I checked on the height of available detachable rings. Talley's were the lowest I could find at that time. Haven't looked since. Depending the the scope's ocular diameter, the Talley's may be too low to fully clear the bolt handle. My rifle now wears a Leupold 3X Big Bore and the handle clears nicely. It would bump the ocular of a Nikon Monarch African 1-4 that I had for awhile.

The lowest rings I've seen that clear the bolt handle with the older (pre 2015 mfg. 527 CZs) are Tikkas. It's my understanding you can get lower with the newer rifles. I've got the Tikkas on my 2001 527 .223 with an unmodified bolt handle using a Leupold 2-7x33. You can just get a piece of copy paper between the eye piece and the bolt handle but it works. I like them a lot better than the stock CZ rings.

The medium Leupold CZ-style rings were the lowest they suggested and were perfect for my CZ550 AmSaf .375 + Leupold VX-R 1.5-4x20.

Probably should have went with the Warnes, but I was in a gawdawful hurry. Good so far.

Warne medium 1" ring is 0.425"

Talk to Alaska Arms LLC. They once made me a set of cz rings so low, that I had to take some material off the bolt handle, to clear the scope. This was a 7.62x39 carbine with open sights. The scope was a 1-4 vx3.

By gully do I miss that rifle. So cheap and fun to target practice with.

https://alaskaarmsllc.com

i'll second the factory tikka t3 rings. i have them on a couple 527 americans and they work great and low as possible. so low in fact if you don't have the new factory modded bolt handle you just might rub. mine did and forced me to order a new bolt handle from cz.
Big Ed