Winchester bolt won't close uncocked

I bought a Winchester bolt last week on eBay to replace the slightly worn but still functioning Eddystone bolt that was on my early (s/n 65030) Winchester M1917 when I bought it. The W bolt appears to be unworn with a black Parkerized finish. It had two easily replaceawble worn or non-M1917 parts. The extractor was from a totally different rifle and the top of the sleeve was ground down. They look like they were tossed on the bolt by the seller to make it a complete bolt. I replaced the old sleeve with a NOS W sleeve that I bought previously and used the extractor from the Eddystone bolt that's stamped with a "CV" and nothing else. The new W bolt head spaces well on a 30-06 SPRG field gauge as did the E bolt. All parts on the M1917 rifle are now Winchester except the CV stamped extractor which is a later replacement, and the stock which is a "T" stamped replacement.

The W bolt is stiffer than the E bolt but cocks and closes like it should. The one thing it won't do is close completely in the uncocked position (closing the bolt with the trigger pulled). My E bolt would close easily both ways, cocked and uncocked. I compared both bolts side-by-side to look for obvious differences but saw none except the EN stamped cocking piece on the E bolt shows some wear while the W stamped cocking piece has zero wear.

Any ideas what might be the cause?

Update:

The problem is solved but the cause will never be known. I tried the E striker assembly in the W bolt and it worked perfectly - easily closing cocked and uncocked. I tried the W striker assembly in the E bolt and it also worked perfectly. I then tried the W striker assembly back in the W bolt and it worked perfectly. There must have been some unseen obstruction that prevented prior closing attempts but I'll never know what it was.

I can see a big difference in the fit of the W bolt when compared to the E bolt. It's much stiffer in all modes of operation. The black Parkerized finish and lack of wear at the bearing points makes me think it could be NOS. Applying some gun oil loosened it up some, but it's still tight.

So, now the rifle is nearly parts-correct. Only the stock and extractor are non-W parts. It took me several years to find the mechanical parts and I expect it will be several more years before I find a good W stock.

Another update:

I found several W stamped extractors on eBay last week and bought one. it's stamped with a W on the reverse side near the claw and has a S stamped near the other end. Anyone know what the S means? It works well and looks exactly like the current CV stamped extractor except it has a gas hole drilled near the claw which probably means it may have been designed for an early W M1917 (which mine is). Now it's all parts-correct except the stock.

Long ago I read that there were some dimensional differences on very early Winchester M1917 rifles, and they were not allowed to go overseas as a result. I also wonder if you got some P14 parts.

I also suspected the same. But, after numerous tries and experimenting by swapping parts around, it loosened up and now works great. Some of the very early Winchesters, which mine is with s/n 65030 and circle star on the receiver, were built with parts that were't supposed to work with Eddystone and Remington M1917s. Yet, my rifle was almost all R and E small parts when I bought it. They all didn't fit exactly right but they worked.