Brass and headspace question

BB, when I'm trying to get as much accuracy out of an individual No4, I will use a bolt head that allows the bolt to close, with just a bit of pressure, rather than easily dropping into place.

There is one thing you don't mention here, which is very critical for headspace issues as well as best accuracy.

How much contact do you see on the locking lugs when the bolt is cammed into full #### mode?

You need to be careful with this as you can create other issues, not safety related, by changing bolt heads.

It's very easy to check, just use a felt pen to mark the contact area on both lugs and close the bolt, you don't even have to have a cartridge in the chamber. The pressure from the cocking piece spring, while engaging the sear will be enough to scrape away the ink if there is any contact.

Check the contact surfaces on your locking lugs for pitting or excessive wear on one side. If needed, carefully stone the lug with the most contact until you have relatively even contact on both sides.

I've run into several No1 and No4 rifles which had only ONE lug taking all of the stress. Not an unsafe condition, but not conducive to best accuracy.

Once you have the lugs squared, then it's time to get picky about headspace.

If the lugs aren't contacting evenly when the cartridge is fired, the rest is all for naught.
 
I haven’t looked into it, but I will when I get around to setting it up with the new parts. I’ll likely take it out spring bear hunting a few times again this year, so I’ll leave it the way it is till I have some time to give it my attention. It’s always been an accurate rifle and been reliable since day one that I’ve had it. Now that I know brass will fit I will get around to it over the summer.

It’s always been a great shooting rifle, if I do my part it will shoot 1”-1.5” five shot groups at 100m and not much larger at 200m. I really have nothing to complain about with this one, it’s a shame it was sporterized actually. It’s a ‘42 LB No.4 Mk1*, aside from the cut stock nothing else has been bubba’d. Bolt # matches although I suspect it was force matched and it has an early style safety lever, no number on the magazine either. I’ve always thought if I could find proper LB marked stock pieces and metal bits it’s missing it would be a good resto candidate.
 
Butcherbill said:
Quick question on a no.4 Lee Enfield, I picked up a couple longer bolt heads to tighten up headspace. It’s current headspace is acceptable but can be improved, I’ve been keeping brass separate for this rifle and it’s all fire formed on the existing bolt head.

If it won’t chamber on the new tighter bolt head what is the best approach? My thought was a light shoulder bump till it chambers snug and re form it to the new headspace, I haven’t changed bolt heads yet or tested if brass will chamber, just thinking about it in case it is an issue. I have a longer #1 than it’s current bolt head as well as a #2 to play with.
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Size it. Set your FL die to bump the shoulder back .002". If that doesn't chamber, then do it again another .002". If that doesn't work, run the die all the way down with some cam-over. However, if you have to push the shoulder back more than 4 thou just to close the bolt, I'd stick with that first bolt - you're working your brass pretty hard at that point, and may even need to polish down your shell holder to get the clearance you need.

Remember that 303brit headspaces off the rim, but you can control the clearance after it's been fire formed using the right dies and technique.
 
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