I've not gone into the detail you have, I bought a Wolff 26# once, hoping to decrease lock time a bit, but found it pierced the primer in most of the rifles I tried using it in.  I never got a lot of gas escaping out of the action, but enough to be hard on the firing pin tip.  It was not easy to get that 26# spring on my parkerized Krag as it has a modified 92 bolt sleeve with longer securing stud (sorta between Poyer 2A and 3 bolt sleeve) to fit the uncut guide rib 92 bolt.

It's SPRING time! I have gauged, measured and counted the coils on most all the Krag springs I have and that necessitated several take-downs. Then I mix-and-matched to get some uniformity going in the collection. The older 1898’s with the square cut barrel faces were the test subjects simply because these are the ones I had slated to be next to go to the range – these averaged at 14#-to-cocked; I upped these to 15#. All triggers were spring-matched to 4#. Worked very well at 100 yards (see image) using the tried-and-true: 220 grain Hornady RN with 40gr IMR 4350 & standard Winchester LR primers. It is especially encouraging considering I only shot about 25-30 rounds between two rifles prior to getting those two 3-shot groups in sequence. Even more so because I am a no marksman, haven’t been to range since 2013, was using iron sights, the wind was gusting and I am new to wearing prescription glasses. So now the question is if 16# or 17# will be better? One problem is that when the main spring goes up, there is some creep in the trigger weight and I have about used-up all of my wimpiest OEM trigger springs. The newer 1898’s I have (rounded barrel faces) are pretty much split with 16-to-17#-to-cocked with trigger weights averaging at 5#. I will likely try for 16# mains and live with 5# triggers to test. BTW – I found my Blitzshell Main Spring (Card says 22Lbs) and tested it: 26#-to-cocked (yikes)! So, it seems that there are different ways to measure spring weight because that is WAY too much force (much more than an 16-18# OEM). That said, my quest for the best combination shall continue. I strongly suspect it will also vary by the loads I use – just another variable to consider. I hope this info is of some use to all you all...

'FredC': One of these days I will have to weigh a regular Krag Striker-rod and my 'Headless' Striker-rod and see if there is a significant weight difference. Springfield Armory built these for a brief time (on carbines and rifles) for 'cost savings', which did not pan out. They returned to the regular Striker-rod. I have not noticed a difference in "lock-time" with the streamlined knob.

The regular Knob on the Krag Striker-rod was considered to provide a degree of protection to the eye (by diverting escaping gases in the event of a case failure or pierced primer). It is also a more convenient assist for Bolt disassembly and reassembly. (It's also kind of Pretty and makes a Krag a Krag).

There are down sides to eliminating too much of the Knob. A good 'trigger job' and graphite would pay greater dividends - IMHO.

Although often associated with the Model 1899 Carbine, the 'headless' cocking-piece was an economy move and probably also appeared on Rifles. Mallory and Poyer books both place it occurring in 1900, on Krags ranging from #202,000 to #285,000. It was discontinued due to being more expensive than the 'knob' version.

I spoke with Dave at Wolff Gunsprings yesterday. He said that it was highly unlikely that my package contained the incorrect (higher force of 26#) spring but would replace it under warranty if I desired. He also mentioned that the spring could be trimmed down to reduce the force. I said I will consider the later option. On the question, he said that in the 25 years or so he has been making the US Krag main springs, he cannot recall ever receiving any complaints or other feedback. He also said that he has not sold many of them. I offered by concerns regarding possible rupturing of the primers and that a weaker version of the spring would likely prove a popular seller. I offered the results of my testing of his spring and my best originals and he said the weights of springs are not determined as such – it pertains to one inch of travel. He said the original springs have unquestionably “relaxed” since new (I would be fool to disagree). Still I said, too much is too much – I thanked him for his time and said I would do some testing.