I plan to purchase an ARMS 18 base for my M1A. I have not decided if I should get the ARMS throw lever base or the ARMS throw lever scope rings. It would be more expensive to purchase the throw lever base as I would still need to buy the rings. Does anyone one know if the throw lever scope rings from ARMS is a good combination for the ARMS base. I will even take opinions. I just want to make an educated purchase that I will not regret. I will probably buy a Leupold Tactical from D & R Sports Center as they seem to have the best prices that I have found.
http://64.224.40.78/miva/merchant.mv

I have found that the lower you set the scope, the greater the chance of bouncing the ejecting brass off of the windage knob, however the higher the scope the more dependant you will be on a cheek piece to get a proper cheek weld.

I went with the A.R.M.S #18, #19A (not ACOG)& #21 STANAG Rings.

I could get the ARMS high mount throw lever rings and that would put the scope a little higher. Do you know if the throw lever rings are return-to-zero just like the ARMS 19 base is? I have visions of taking off the throw lever base or rings and use the NM sights occasionally or at least should something happen to the scope then I could use the sights. I like the set up you have with the 18, 19 and 21 rings, but that would cost me a little more.

The A.R.M.S. mounting system is guaranteed to repeat zero and yes going with the set-up that I have will cost you more than just going with a #18 & #22 high.

3006deer, I use the #22, high throw rings without the 19A rail.  I needed the high rings because my scope has a 50mm objective.  The rings repeat a perfect zero, which for me, is 300 yards.  I can remove the scope in about five seconds and reinstall it in about the same amount of time.  Brat is correct about the cheek weld though, the higher you go the harder it is to get a good weld.  You may have to install a cheek pad whichever way you decide to go.  My brass does bounce off of my windage turret cover.  However, this is not a problem for me.  It leaves a lot of brass on the turret cover and dings it up a bit, but I do not have a hang up about it.  Others might.

Another thing to consider is eye relief.  The ARMS #18 has limited cross slots for mounting the rings.  Depending upon the relief you need the 19A might be a good choice since it gives you more slot locations for your rings.