Replacement Bolt Assembly

 

I'm getting a replacement bolt assembly next month from Springfield Sporters, and I was wondering what do I need to look for in order to make sure it fits properly. 

 

I have the No4 Mk1.  Are you talking about these.

 

 

I take it that I'll need to get some of that blue contact liquid so that I can make sure the lugs are making full contact at the same time on each side of the receiver?

I used an Arkansas stone (better than carburundum) to remove the high spots to get contact on both sides and tapped some beer can metal around the bolt to avoid scraping that when using the stone on the lugs. Make very careful and slow process so you don't overdue it! To get good head space you don't want to be removing too much off the lugs. You fit the bolt lugs to match the rifle! do not try and alter the rifle receiver lug area.

There is a thread here regarding my bolt fitment; but I'm an amateur and rely on the articles written by the pro's.

You definitely need the proper head space gauges; I bought a full set of Oakie gauges. Having the set of 3 helps because you need to know how much metal you can remove; and it's not very much! literally a couple of thousandths of an inch. 

I managed to get contact at both lugs and pass the Go gauge (70 thou) test, which gives me 4 thou to spare before the Field gauge fail at 74 thou. If I hadn't had the 70 thou gauge it would be too easy to end up very close to the field gauge limit, which was where the original bolt was!

It will be difficult to get the same size contact area on each side; so go very carefully and keep checking it after every couple of stroke of the stone. You really do need to take the time; it's easy to wreck the bolt. once I got contact on both sides, I stopped. Then test fired it with a few rounds to settle it in a bit, then rechecked the contact. 

Best of luck, 

Zed.