Ishapore No1 MKIII* hard closing bolt

[Lucite]

A week or two ago I posted asking about stock markings on this newly acquired Ishapore No1 MKIII*. Now however I was wondering about a possible mechanical issue. Yesterday I made some dummy cartridges with some spent brass I had laying around. I full length sized it and basically made it to spec, all measurements were bang on, that's when the confusion started. I loaded a stripper clip of the dummy cartridges into the rifle and found out one of two things the magazine doesn't ride high enough in the magazine well for the bolt to grab the first cartridge and secondly when you go to close the bolt on the cartridge I found that the bolt has to be fully forward ( kind of a no-brainer) and if it's something like a 1/16" off it locks up and will not close. I assume this could all be explained by my inexperience with the operation of this particular rifles action but is there a chance it could be something more serious?

Information

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[Peter Laidler]

For the non closing bolt, there's a chance that your bolt head has unscrewed by one complete turn. Correct this problem first. If the cartyridges won't load from the magazine it will only be one problem with a couple of causes. The problem is that they're not high up enough in the magazine well - caused by a defective magazine or that it's not positioned in the magazine well correctly.

If it was all working correctly before, then it's clearly something that you've done since

[Lucite]

For the non closing bolt, there's a chance that your bolt head has unscrewed by one complete turn. Correct this problem first.

The bolt head is completely screwed in, and I guess to clarify it does close but with some force. The rear portion of the large locking lug doesn't like to slide on that portion of the locking surface where it can best be described as a 45 degree angle to a flat, that's the portion where it locks up at.

The problem is that they're not high up enough in the magazine well - caused by a defective magazine or that it's not positioned in the magazine well correctly

I'm thinking the magazine is "defective" because looking at the locking notch portion it appears that is has been ground or some such thing (prior to rifle purchase) I'm confident that this is the cause because I can push the magazine up about 1/16" of an inch and it will catch the rim of the cartridges and it will chamber.

If it was all working correctly before, then it's clearly something that you've done since

This is the first time I did an actual function test and I only took the rifle down to clean it and put it back together the same at it was so its unlikely I put it back together incorrectly not impossible but unlikely.

[Thunderbox]

The rifle is designed to be fed from the magazine. If you place a round in the chamber and then try to close the bolt on it, chances are the extractor is binding on the cartridge rim. Especially true if the extractor is stiff or glued up with old grease. Also check the extractor slot for crud.

Does the bolt close easily with no round in the chamber? Might be that the drill rounds you have made need to be trimmed or resized.

[Lucite]

The rifle is designed to be fed from the magazine. If you place a round in the chamber and then try to close the bolt on it, chances are the extractor is binding on the cartridge rim. Especially true if the extractor is stiff or glued up with old grease. Also check the extractor slot for crud.

The rounds are being fed as they should, where the rim slides up under the extractor

Does the bolt close easily with no round in the chamber? Might be that the drill rounds you have made need to be trimmed or resized

Yes the bolt closes with ease with nothing in the chamber. All the drill rounds are to the spec of the .303 down to the .001 and they function flawlessly in my No4 MK1 so I highly dought they are the cause

[vintage hunter]

If the rounds are feeding from the mag as they should and the bolt closes on an empty chamber there may be an obstruction in the chamber itself or else some time in the past a previous owner may have swapped the bolt head or entire bolt to ''improve'' headspace. When you FL sized the cases did the shell holder contact the bottom of the die? Its rare but sometimes cases fired in one rifle may not fit another even though they've been FL sized. Try a factory round or a new unfired case and see what happens.

[Lucite]

If the rounds are feeding from the mag as they should and the bolt closes on an empty chamber there may be an obstruction in the chamber itself or else some time in the past a previous owner may have swapped the bolt head or entire bolt to ''improve'' headspace.

The chamber from what I can see is clear, the bolt head may have been swapped but I highly doubt it was because the finish matches the bolt and there is no chance its a different bolt because the rifle has all serials matching including the bolt.

When you FL sized the cases did the shell holder contact the bottom of the die? Its rare but sometimes cases fired in one rifle may not fit another even though they've been FL sized. Try a factory round or a new unfired case and see what happens.

The die was set properly and the shell holder did contact the bottom of the die, I guess I should try a factory cartridge to check.

Update---------------------------------------------------------

I put a factory cartridge through it and still the same thing happens, upon further inspection I think it may be due to a number of factors affecting the bolt, the extractor is a bit crudded up, the notched area of the bolt where the cocking piece rotates is also fairly dirty, and possibly spring tension from newer springs although with my limited knowledge about the workings of the No.1 MKIII bolt this is only speculation.

[Lucite]

Sorry for the double post but after closely looking at the action while I was operating it both with and with out a cartridge I have come to the conclusion that it is in fact an issue with the extractor but not on the bolt end rather the notch in the receiver where the extractor fits in. I believe that when the cartridge rim pushes the extractor outwards it is binding somewhere in that notch probably due to old grease and garbage that has built up.


Update--------------

I cleaned out that notch and no noticeable difference was made. I can't honestly say I know what is causing this issue.

Update-----------------------

Well I found out what the culprit was, now the question how do I get it fixed. It turns out that the bolt has some wiggle to it and not just when its fully pulled to the rear either. This play that it has doesn't affect the bolt going into battery when no cartridge in involved but the second you add a cartridge it lifts up the bolt head up slightly causing the top edge of bolt head to hit the portion of the receiver the barrel screws into causing the bolt to bind up.

[vintage hunter]

Remove the extractor and see if the bolt will close................

[Lucite]

Sorry if you didn't see my second update when I updated my previous post but its explains my findings.