MKIII* Lithgow General Questions

So I have this old sporter SMLE, dated 1944, which I am mucking around with trying to accurise little by little, but I have some questions.

Firstly, bolt lug bearing: I've tried using felt tip pen on the lugs and test shutting the bolt to see where it bears before being fired, but after taking little amounts of the edge after each test, it seems the main lug still bears what looks like the entirety of the bolt, and hence the shock. I read in a thread here that felt tip pens are not as good as the likes of Engineers Blue, which is apparently toxic anyway, but figured I might share some images for ideas.
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Another thing is the trigger guard recess: After looking at others it looks like this rifle has squashed the wood in considerably, and also sits against the sides of the recess (I have heard this can affect accuracy somewhat). Again I have a picture and am asking for some input.
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Another thing is the bolt head and head spacing: I've fired maybe 10 shots through it and all the cases show protruding primers. I don't have any gauges for this but its obviously a problem. The bolt head even looks corroded around where the case rims butt up to it.
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Finally: This MKIII* looks like it has a set of MKII sight protector ears on it that clip over the barrel, since this rifle now has a set of aperture sights I have done away with the original rear sights and now these protectors are not needed. Can the clips around the barrel affect accuracy that much? Is it worth doing away with them?

The trigger guard looks skew, might be the photo. The bolt head; the striker hole and primer mark look off centre.

Try smoking the lugs in a candle flame to put a layer of soot on them.

You slug the barrel and check the headspace before doing any of that? No amount of fiddling with the lugs or anything else is going to make any difference if the barrel ID is not close to .311" groove diameter and the headspace is bad. It's a horse and cart thing.
Protruding primers is just one indicator. Any extraction issues or difficulty opening the bolt?
Engineers Blue(aka lay out dye) is just ink mixed with grease. A felt marker is just easier to use.

Ignore Sunray, he has a fixation on headspace.
Head space or bore diameter will have no effect on the setting of the bolt bearings.

Bolt bearings can be done on a stripped receiver without a barrel.

Continue. You are on the right track.
First step is to get an even bearing on both bolt lugs, THEN check your headspace.

Use candle soot as Green suggests, or a kerosene lamp flame works well too.

Your bolt head has seen a LOT of rounds. The primer erosion on the face just looks like crap but will still work, but maybe time to change it out.
Most cartridges sit a little off center in most large mil spec chambered rifles, it is a LE quirk that can freak new LE owners out. It wrecks the brass, which was designed to be a one shot use and disposable. Nothing to be concerned about unless you reload, then there are work around solutions if it does become a reloading issue.
But who can say if this bolt head is original and that the erosion was from use in this rifle? The pudding test is to check a fired case.

Trigger guard should tighten down and bear on the bottom face of the trigger guard inletting. The amount of crush is set by the front trigger guard screw bushing. It is important to the correct breeching up of the wood to action. Trigger guard set up has a MAJOR effect of how the rifle shoots.

Poke around to find postings by Peter Laidler. He has done this a few times and has written some excellent instructions in layman's terms.
Everything that you need to know is right here if you do a search.

Daan, not sure what you mean by skew, unless you mean like off-centre.

green, sounds like that could work.

Sunray, don't think I have the stuff to slug a barrel, and headspacing I figure I can fix later with some tighter boltheads, or just use the old rubber ring fire forming trick. Also no extraction issues or anything.

englishman, Sounds alright to me. I reckon I will need a finer file or stone to do it properly and smoothly though if I continue. Would blacking from a lighter or match work just the same as a candle? I reload, but I haven't had enough rounds through this gun to really tell if it kills brass or not, guess we'll find out. I have heard that the trigger is pretty important, and the tell-tale instant stop of the rotation of the main screw is not evident with this rifle, so I presume there is still some room for the wood to crush before it is just trigger guard against busing/collet. I had a quick gander at some of his information the other day, but I'll need to sit down and have a proper read.

Cheers everyone.

A fine Arkansas stone would work well. I wouldn't use use a file, it might me a bit too aggressive to remove the minute amount of metal needed to dress the lugs.

Fine emery paper wrapped around a lollipop stick or similar would work. You really are just touching things up. A couple of strokes on the high points then resmoke and recheck.
More of a polishing session than filing to remove material.

Match or lighter dont kick out enough smoke to be effective. A modern candle is made from petroleum products, old fashioned candles are made from animal tallow if you can find them. I think that it is the oil burning off that creates the black.

I have one of those miniature decorative oil lamps that I picked up at a dollar store. The fuel I use is kerosene or Varsol mixed with a touch of motor oil. It has a round wick and smokes like a bast*rd when lit and turned up without the glass chimney.

I have also tried using cedar slivers or birch bark whisps to make the soot which is an old traditional stockmakers trick. It works well but I prefer the voluminous smoke kerosene lamp.
Magic marker does work, but the lamp wick soot is flat black, very sensitive and shows contact really well.

Remember you are grinding the case harding off which is not very thick, leading to more serious problems if you break through. Camphor is also a good smoke blackener.

Us old service & full bore shooters always had a tin of camphor in or range gun case for smoking front sights and barrels, it to when lit up "smokes like a steam train go up a steep hill."

As far as the protruding primers, that might be a sign of low pressure cartridges. I cannot speak to the specific loads you were using, but generally speaking, if light loads are used, the pressure will be insufficient for the case head to be driven back against the bolt face. In this case the walls of the case expand to grip the chamber and the primer is forced back, out of its pocket, until stopped by the bolt. This might also be accompanied by dark, sooty case necks/mouths.
With higher pressure loads (factory ammo for example), the head is forced back against the bolt and the primer goes with it. No protrusion is possible as the pocket/head move together, along with the primer , all to be stopped by the boltface.

I handload some very light target loads for an old lee-metford of mine. Cast bullet in front of a light charge of Trailboss. Very low recoil, and the primers all back out of their pockets a few thousandths of an inch. Case mouths a little sooty.

This is not to be confused with primer extrusion, where a high-pressure load causes the primer to "flow" and flatten.

A picture could tell us plenty. I have shot several thousand rounds of 303 mk 7 surplus and have never seen a primer back out (not a low pressure load, and pocket crimped). I few years back, I bought some old Winchester 180 grain ammo at a gun show. Fired that stuff and the primers did back out slightly, and the load did feel light.

Hope this helps.

englishman, cheers for the comparison in the smoking techniques. I'll have to shop around and see what I can get out in the bush here :D.

Bindi, yeah silly me I only found out about that perhaps a few hours after I started this process, hence I am asking before going any further.

CINDERS, I have heard of smoking the sights to reduce glare, but never knew what to use, cheers.

smleaddict, you might have just hit the nail on the head: The primer protrusion happened when using these 150gr 'minimum' down-loads (I made them up with the lowest suggested amount of AR2209 powder from the ADI reloaders books), for the fact that with these old guns I want to make sure they won't blow up, so I keep the hot loads well away from them. Only problem is that I thought the phenomenon where the cases grab the chamber and do not butt into the bolt was supposed to happen, hence you don't polish the inside of your chambers and make them slippery. I always thought that the bolt was only meant to take a small part of the force from being discharged as the case bit into the chamber walls rather than slide back. Maybe this just doesn't apply to LE's.

Thanks everyone, this is really helpful stuff.

Skew trigger guard: twisted/not flat? From the photo it seems to bottom out on one side and sits proud on the other.

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I have examined the guard closely, but I don't have the experience or the keen eyes to spot if it is the case.

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Here we have our mixed brass. I really am thinking it is these downloads since I used this stuff in a few different rifles and got the same result, some of this brass may be from my No4 but its all the same.

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And trigger guard. Looks pretty straight to me. If it is skewed then it would be in the recess of the wood correct?

From the photos the trigger guard looks OK. Lay it on a flat surface to see if there isn't a gap somewhere. If there isn't, fine.

If the trigger guard isn't seated evenly in the wood something in the fore end isn't right. Without handling the rifle I can't say more. If seats evenly no problem.

If all are as they should be it's the photo causing the questions.

Yeah the trigger guard recess could by all means be bearing unevenly as I have been poking around in there trying to make sure there are no odd contacts acting side to side to side on it. Possible I've nicked something.

Yup, from the photos of your cases, I would say they are low pressure and wouldn't worry about the primers backing out. My guess is if you'd bump up your loads in half-grain increments, you'd gradually see those primers stay in their pockets. If you're happy with that loads performance, I say fire away. The loads for my Metford all look like that, and its only a good load for 50 yards, but its cheap and fun.

Sounds good to me smle. I guess I don't have to radically headspace all my rifles after all. Thanks for that.

Can you get your hands on a set of go/no go gauges? They would be the definitive indication of a serviceable headspace.

Your cases and primers show a low pressure load, as others have stated. It will not hurt anything IMHO.

I don't have a set laying around but I want to to get them.