Bolt heads No.4 Mk.1 LE.....

D

Dantforth

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Is there a thread which explains all of this? From my limited knowledge they go from shortest, a #0 to the longest, a #3. I have a rifle with a number three head which will not headspace. This bolt head is .638 inches long. I have another rifle with a bolt head which is not numbered (that I can locate) and it mikes at .646-.647. Well, something is amiss here as if the #3 is longest at .638" where does the .647" bolt head fit in? Have I got all of this backwards?
Dave
 
I don't have the specs for theoretical lengths at hand. IIRC #s 0, 1, 2 increase in .005" increments, #3 is .010" longer than a #2. Perhaps your #3 was altered to fit.
I'll check the loose heads I have and see if any are usefully longer than .638". Of course, the head has to screw in properly.
 
Sizes of bolt heads....

Were there any other sizes made? 0 - .620-.625, 1 - .625-.630, 2 - .630-.635, 3 - .635-.640. Now, why do I have one which is not marked that measures .646 inches? I am using an expensive set of calipers...digital and the #3 measures correctly. Boy!!! Does anyone have a #3 longer than .638?
 
If all else fails, try another bolt with that bolt head. It may just solve the problem.

In any case, I hope you were using an .074 field gage, and not a SAMMI one
 
Here's what the Armourer's Manual published, although I have found that with manufacturing tolerances of the time, your mileage may vary. ;)

It will either be marked 0, 1, 2, or 3.

The difference is the different lengths of heads.

0 .620 to .625"
1 .625 to .630"
2 .630 to .635"
3 .635 to .640"

Hope this helps...

Regards,
Badger

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Badger Dog .....sleeping?

Not very often do I find the Badger Dog out of cink! One of the very few times. Must have been a "seniors moment"!
Even "if" I believe the No.4 bolt head theory....this doesn't explain the length of the one I measured. Could it be that "Fultons of Bisley" had access to longer bolt heads? The rifle this bolt head is on is one of the "Regulated by Fultons" rifles. Any other opinions guys? Really...does anyone have a bolt head ... #3... which is longer than .638"? Dave
 
As stated above, the only other alternative is to try another bolt body in hopes that it will be slightly longer and will only require a shorter bolt head.....I have done this before and had it work for me, but it helps to have a number of bolt bodies on hand to try.....
 
Dantforth, you say this rifle won't headspace, is it too tight or too loose? I have a Savage #4 with a 3 head that mikes at 639 that stretches new factory ammo. When I get a bit of time I'm making a Cerrobend cast of it to see whazzup.
 
Dantforth said:
Not very often do I find the Badger Dog out of cink! One of the very few times. Must have been a "seniors moment"!
Even "if" I believe the No.4 bolt head theory....this doesn't explain the length of the one I measured. Could it be that "Fultons of Bisley" had access to longer bolt heads? The rifle this bolt head is on is one of the "Regulated by Fultons" rifles. Any other opinions guys? Really...does anyone have a bolt head ... #3... which is longer than .638"? Dave
Click to expand...

Remember I said I know a gunsmith who charges $50 to install a barrel? He told me that included whatever needs to be done to set headspace up, including welding the bolt head face and grinding it to correct dimension, since it's not always possible to find the right one. I wonder if that long one is a special oversize one or was built up in that manner?

Is that Fulton rifle a No 4? I thought they were No 1 Mk III actions, or did they do No 4's as well?

When you are checking the headspace, are you gently moving the bolt handle with your fingertips and stopping as soon as you feel slight resistance? It's very easy to close a bolt on a gauge even with good headspace, the bolt action produces tons of mechanical advantage. Not a good thing to do...

As John Sukey asked, is your gauge a mil spec Field or SAAMI spec Field?
 
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It is too loose.....

The trouble with using a different bolt is the fact that the rifle then becomes "non-matching" and is worth considerably less money. It is a number "4" and is marked Regulated by Fultons. I have not shot it. I do not know what type of guage my gunsmith is using. He told me that he cannot feel any resistance on the guage when closing the bolt. I know that another bolt which is less worn is the answer because we have tried that ...but...I dealt for this as "matching". I guess I can quit looking for a longer bolt head. Thanks....Dave
 
Dantforth said:
The trouble with using a different bolt is the fact that the rifle then becomes "non-matching" and is worth considerably less money. It is a number "4" and is marked Regulated by Fultons. I have not shot it. I do not know what type of guage my gunsmith is using. He told me that he cannot feel any resistance on the guage when closing the bolt. I know that another bolt which is less worn is the answer because we have tried that ...but...I dealt for this as "matching". I guess I can quit looking for a longer bolt head. Thanks....Dave
Click to expand...

Since the bolt must be matched, the answer must be to build up that long bolt head you have...
 
If your #3 head is .638" long, its within spec. #3 heads command a bit of a premium. If you are going to have one built up, why not start with a common, cheap size? The #3 head could be saved or sold.
A military NO GO is .074", commercial is .068". If your smith is using a SAAMI gauge, the rifle could still be in military spec. Having said that, it is unlikely that Fulton would have set up a rifle for target shooting with generous headspace. Also, a rifle that is at the upper military limit will produce cases that are not good candidates for reloading.
 
tiriaq said:
". If your smith is using a SAAMI gauge, the rifle could still be in military spec. Having said that, it is unlikely that Fulton would have set up a rifle for target shooting with generous headspace. Also, a rifle that is at the upper military limit will produce cases that are not good candidates for reloading.
Click to expand...

Now that I understand better what the issue is, I'm with tiriaq....

Take the rifle to the range "as is". Put on a set of glasses and fire a few rounds of commercial S&B, or any brass that has only been loaded once. Check the casing for stretching and deep firing pin hits on the primer issues. The firing pin protusion on a No.4 should be between .040 and .050.

If the primer looks like the pic below, you have a head space problem. If it's a normal dimple and no case stretching (incipient separation appearance), then I'd shoot it without worries. The one below is from one of ~Angel~'s Enfields that I do this same test on every time she gets a new one, before she shoots it. I changed the bolt head on this one from a #1 to a #2 and the primer hits became normal with minimally case stretch.

Just my opinion and personal method for Enfield checking.

Sorry I misunderstood your original quation....

Regards,
Badger

303FNB.jpg


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tiriaq said:
If your #3 head is .638" long, its within spec. #3 heads command a bit of a premium. If you are going to have one built up, why not start with a common, cheap size? The #3 head could be saved or sold.
A military NO GO is .074", commercial is .068". If your smith is using a SAAMI gauge, the rifle could still be in military spec. Having said that, it is unlikely that Fulton would have set up a rifle for target shooting with generous headspace. Also, a rifle that is at the upper military limit will produce cases that are not good candidates for reloading.
Click to expand...

You're right of course, sell the oversized bolt head for $50 and get a 0 built up...;)

One thing I don't understand about .303 chambering- headspace is one thing and is only measured at the rim. However, why did they make these things so loose at the neck area? Last time I fired my 49 Long Branch, which is unissued, I noted that the brass expanded forward considerably when fired...I guess they set them up like that on purpose due to anticipated dirty battlefield conditions? Seems to me they could be a lot more precise...wasn't that what .303 Epps was about?
 
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cantom said:
I noted that the brass expanded forward considerably when fired...I guess they set them up like that on purpose due to anticipated dirty battlefield conditions? Seems to me they could be a lot more precise...wasn't that what .303 Epps was about?
Click to expand...

I think you're right on ... :)

In the Milsurp Knowledge Base, there's the "Technical Articles for Milsurp Collectors and Re-loaders"http://www.milsurps.com/forumdisplay.php?f=25 forum.

It contains a very good article with animations from Parashooter........

Headspace 101 for .303's (click here)http://www.milsurps.com/showthread.php?t=10

Regards,
Badger

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A more modern situation exists with current belted magnums. They headspace on the belt, so body dimensions aren't critical. Fireforming compensates for loose tolerances. Like .303, magnum cases can be prone to separation because of repeated stretching. Magnums, like the .303, respond to necksizing - or treating the cases as if rimless, and headspacing off the shoulder.
Dantforth - if the rifle does have seriously excess headspace, handloading "fitted" cartridge cases is the easiest and cheapest solution, if you handload. Also, if you want to borrow my military gauges, just drop me a PM.
 
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Dantforth said:
The trouble with using a different bolt is the fact that the rifle then becomes "non-matching" and is worth considerably less money. It is a number "4" and is marked Regulated by Fultons. I have not shot it. I do not know what type of guage my gunsmith is using. He told me that he cannot feel any resistance on the guage when closing the bolt. I know that another bolt which is less worn is the answer because we have tried that ...but...I dealt for this as "matching". I guess I can quit looking for a longer bolt head. Thanks....Dave
Click to expand...

If you want your own excellent cloned military Field headspace gauge, contact CGNTZ member Gairlochian. If you have it you'll use it many times...I also got the front sight tool and firing pin tool...very functional and very good to have- I've used all three several times.

http://www.canadiangunnutz.com/forum/showthread.php?t=124675

I also bought a SAAMI spec(0.70") Field gauge on ebarf, I like it because every rifle I've checked with it has passed easily and that is better than a pass with the more generous military gauge...

I can't imagine that Fulton Regulated rifle being that loose...I wish the bunch of us were there with our gauges and a case of beer...
 
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Tiriaq, the Fulton rifle is not the one with the problem. It is very tight and it is the one with the longer than specs bolt head. The one with the problem is a Maltby rifle with a Savage bolt which has had the serial number force matched. I have just purchased another bolt which was in as-new condition with a #2 bolt head which I believe has taken most of the play out of it. I will have it checked tomorrow. I really do appreciate all of the help. By the way...this new bolt has a marking on the cocking indicator FY MK II...Can anyone assist with this mark? I thought there was no serial number on the bolt handle but do see a very light Longbranch number which should easily be force matched to the rifle. I see that a member makes headspace guages. I was thinking of pricing a set of factory guages....what are the prices like?
 
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