I know what you mean.  At my age, I can't shoot a decent group anymore without a scope. The classifieds section associated with this forum has a source for scope rails, but I investigated their 3 inch rail, and found that I would need to cut some wood from the top of my model 1898.  However, not all 1898s are the same. I understand that some early 1898s had a rear sight from the 1896 model.  The wood might be cut differently to accommodate that difference. It might be possible that the top wood on yours could handle a 3 inch scope rail without any cutting.  On the other hand, if you don't mind drilling, their 6 inch rail might be good.

The rear sight on the rifle is 3.75 inches ahead of the receiver. the sight elevates to the rear and has no side rails to speak of.  It is also adjustable for windage by rotating (loosening)a short lever at the fron of the assembly.
The rifle was purchased by my grandfather in the early 1920's as part of a government sell-off of surplus firearms following WW I.
Not sure what the "standard" rear sight looks like, but this one is very similar to those found on the 1903 springfield.
And yes, I hate the idea of altering the rifle, but have no intention of ever parting with it, I'll let the next generation of my family fight over it when I'm gone as I no longer have an heir.

Andy:  What are other specifics of your 1898 Krag?  (barrel length, front sight, state of stock, refinished, sporterized?).  Lots of Krags have been rendered into the "Shooter" catagory long ago by sporterizing and refinishing.  It's just a shame nowadays to have anything collectable ruined.  When I was a teen, I remember reading an article on preserving and maintaining firearms.  The author's main point was that you never really own a firearm.  You are entrusted to be its custodian for a period of time.  Enjoy it but preserve it for the ages.  That mind set governs a lot of enthusiasts.

As for general specifications--barrell lenght from receiver to muzzle is 30". It has an "insert" type front blade. (which I found bent over when I rfetreived the rifle from storage, so need to take to the range to re-zero.) It has a full infantry stock and is in the original form as it was sold to my grandfather following WW I. It has not been sporterized and was sold as military surplus. This was apparently a large sell-off of surplus rifles as he once told me he could have bought either a trapdoor springfield, the Krag or an 1903.  He chose the Krag.  Hunted with it for many years, then past it to me.  It was the first "big-game" rifle I used for several years.  It is definitly a shooter, just from use. Serial number is:55897, and have I ever been wrong!!! I scrubed off the serial number to read it better and found right beside it "model 1896".  Except for normal wear and tear over 100+ years, it has been lovingly maintained.
Recently attempted to buy a headspace gauge for the rifle but the item was temporarily out of stock. (never knew there was such a thing, or that it was needed.) Supplier is supposed to notify me when they are once again available.
Any help with additional information on the rifle will be greatly appreciated. For instance, where can I reference the serial number?

2nd P. S. to butlersrangers; I am not familiar with S&K. Who are they and how can I contact them?

contacted S&K, they said that their scope mount will not fit my Krag.

Andy:  I quickly checked Poyer's book "The American Krag Rifle and Carbine".  Serial # 55897 was probably made in February 1897.  Your 1896 Krag Rifle likely saw use in the Spanish American War.  To drill holes in its receiver would ruin an interesting and apparently original rifle (30" barrel & full length stock).  Every year the number of original Krags lessens, usually due to fire, flood, or storms.  It is a real shame when collectable guns are lost due to misguided gunsmithing.  Putting a scope mount on your Krag's receiver by drilling and tapping holes will ruin your heirloom and turn a $800-$1500 desireable rifle into $400 of parts.  I don't know in what state of condition your rifle is.  I don't know if you have paperwork from when your grandfather purchased it from the government.  It would be fun to see some pictures of it on this Forum.  If you post some photos, you will get a lot of good info. and advice.  You might consider selling your rifle at a collector's price and pickup a sporterized Krag for shooting.  The scope rail that replaces (temporarily) the rear sight and allows a long eye-relief scope is a good option.  Just leave your hand-guard off the rifle for clearance.  (To take the handguard off:  Remove the rear sight, Take the barrel and action out of the stock with handguard attached, Wipe the barrel with a lightly oiled cloth, Rotate the handguard 180 degrees and pull it forward off the barrel).  Store your handguard with an appropriate diameter dowel inserted in the clip-springs to prevent spring tension from cracking the wood.  Never, Never snap a Krag handguard over or off a barrel or dowel.  Slide the handguard on and off.