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Frameman 1
Senior Member
Joined: July 30 2019
Location: SW Ohio
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Points: 382
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Topic: Bolt closing force. Posted: November 22 2019 at 2:46am |
Can anyone tell me how to measure the force normally required to close the bolt.without a round, on a Ishapore 2A? What would that measurement be?
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There are no Americans in Baghdad!!
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Long branch
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Joined: January 08 2014
Location: Georgia, USA
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Points: 251
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Posted: November 22 2019 at 2:49am |
If you're talking about the force required to turn the bolt down, it shouldn't take much.
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Frameman 1
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Joined: July 30 2019
Location: SW Ohio
Status: Offline
Points: 382
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Posted: November 22 2019 at 3:32am |
Not exactly. I’m asking about the force required to push the bolt forward against the cocking/firing pin spring.
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There are no Americans in Baghdad!!
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Shamu
Admin Group
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Joined: April 25 2007
Location: MD, USA.
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Posted: November 22 2019 at 7:17am |
According to the service manual: The weight required to pull the cocking piece to the half-cock and full-cock positions shall be 3.2 to 4.1 kilograms (7 to 9 pounds), and 5.9 to 7.3 kilograms (13 to 16 pounds) respectively. These weights are checked with a trigger test scale engaged on the head of the cocking piece. Weak striker springs shall be replaced.
This should be the same to close the bolt.
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Don't shoot till you see the whites of their thighs. (Unofficial motto of the Royal Air Force)
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Frameman 1
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Joined: July 30 2019
Location: SW Ohio
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Points: 382
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Posted: November 22 2019 at 9:39am |
Thanks so much ! That’s exactly what I needed. I’ll look for a service manual of my own.
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There are no Americans in Baghdad!!
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Shamu
Admin Group
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Posted: November 22 2019 at 11:42am |
Send me a PM with you e-mail & I'll send you a set as .PDFs
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Don't shoot till you see the whites of their thighs. (Unofficial motto of the Royal Air Force)
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Frameman 1
Senior Member
Joined: July 30 2019
Location: SW Ohio
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Points: 382
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Posted: July 27 2020 at 5:32pm |
Thanks for the advice.
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There are no Americans in Baghdad!!
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Goosic
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Joined: September 12 2017
Location: Phoenix Arizona
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Points: 8792
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Posted: July 27 2020 at 5:54pm |
Explosive wrote:
A bolt that needs force to close on a round is what you want, it eliminates head space.... Headspace bad, no headspace good. |
No no Explosive. When the bolt is closed and force is used to close it,be it minimal force, headspacing is way off. An example of correct headspace would be for the bolt to not close with a .074" NoGo gauge in a 303B Enfield. Now, for the sake of argument you use a cartridge with a rim thickness of exactly. 060". You will have an air gap of .014" between the boltface and the cartridge. If your boltface contacts the cartridge in such a way that force is required to close the bolt,you can cause excessive pressures to build in the chamber during firing and put undue stress on the bolt itself.
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A square 10
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Posted: July 27 2020 at 7:18pm |
yes , but actually rotating the bolt to locked after its forward should only take your thumbs pressure
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Goosic
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Joined: September 12 2017
Location: Phoenix Arizona
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Posted: July 27 2020 at 9:23pm |
Explosive wrote:
I'm not suggesting hammering the bolt handle, but if it's a firm fit it's good.
I had a case just this morning that was too hard to close, I disgarded it. |
I am not suggesting that you are. Opening and closing of a bolt should be smooth as glass with no noticeable resistance, especially with the Enfield rifles. Those should cycle like there is no ammunition being used at all. I have a brand new Remington M700P that cycles rounds so smoothly, I actually have to visually check to make sure a round has been chambered. Same goes for both my No4Mk1* T and my No4Mk1* Long Branch rifles. Headspace is as they were when they left their respective factories and I can cycle a fired and spent round with just my index finger and thumb.
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Goosic
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Joined: September 12 2017
Location: Phoenix Arizona
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Points: 8792
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Posted: July 28 2020 at 12:02am |
Explosive wrote:
Goosic wrote:
Opening and closing of a bolt should be smooth as glass with no noticeable resistance. |
In your opinion.,,, In my opinion headspace is bad. |
This not just my opinion. Any reputable Armourer or Gunsmith will tell you that as well. Head space NEEDS to be adjusted using the necessary tools/gauges to get a true adjustment. Simply changing boltheads to achieve what you can only assume is the correct fit is a very haphazard approach to an issue that can be readily taken care of when using the proper tools and procedures.
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WilliamS
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Joined: March 30 2020
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Posted: July 28 2020 at 12:03am |
Explosive wrote:
Goosic wrote:
Opening and closing of a bolt should be smooth as glass with no noticeable resistance. |
In your opinion.,,, In my opinion headspace is bad. |
It's not opinion though. While having a tight chamber can be good for accuracy, that is only within the bounds of good headspace. A rifle in headspace should close the bolt on a go gauge with the same amount of force it requires to close on an empty chamber. Any extra force required to close the bolt means you are compressing some part of the cartridge and thus will have higher than expected chamber pressure. That's just physics.
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The Armourer
Senior Member
Joined: June 23 2019
Location: Y Felinhelli
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Points: 1246
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Posted: July 28 2020 at 12:38am |
Goosic wrote:
Explosive wrote:
Goosic wrote:
Opening and closing of a bolt should be smooth as glass with no noticeable resistance. |
In your opinion.,,, In my opinion headspace is bad. |
This not just my opinion. Any reputable Armourer or Gunsmith will tell you that as well. Head space NEEDS to be adjusted using the necessary tools/gauges to get a true adjustment. Simply changing boltheads to achieve what you can only assume is the correct fit is a very haphazard approach to an issue that can be readily taken care of when using the proper tools and procedures. |
Explosive - if you would care to have the opinion of the UK's most Senior Armourer who served his Apprenticeship on Lee Enfield's, and, has written a number of books on the subject it is :
It’s important here to remember the often said phrase among Armourers
of ‘DON’T OVER CHS’. Here’s another thing to remember during this. Because
there is a camming action operating while OPENING the bolt, called ‘PRIMARY
EXTRACTION’ this action also operates when closing the bolt. And the same
primary extraction forces that will enable the infantryman to force the bolt
closed and unlock and extract a possibly distorted she!! case, covered in wet
silt and mud in the saltwater magrove swamps of Johore in Malaya that’s caused
the case to stick hard to the chamber walls will also enable the butchers or
bubbas to close the bolt hard against the gauge. NO-GO on the .074” gauge is
when, using the lightest finger and thumb action on the knob causes a slight feel
of resistance.
The next question you’re going to ask is ‘….where during the bolt
closing movement is this slight feel of resistance acceptable --- Is it almost
closed or, hardly closed or in between’? Good question and the answer in the
bible reads thus: ‘…with a 0, 1 or 2 bolt head, there must be resistance onto
the .074” gauge prior to there being a minimum of .050” from the underside of
the bolt lever to the contacting point of the body socket’. Then it goes on to
say ‘…….With a No3 bolt head the left edge…………..’ But I want you to forget this
because the statement was too ambiguous. I suggest that you use my maxim of
‘WITH ANY SIZE OF BOLT HEAD FITTED THERE MUST BE RESISTANCE OF THE BOLT ONTO
THE .074” GAUGE PRIOR TO THERE BEING A MINIMUM OF .050” FROM THE UNDERSIDE OF
THE BOLT LEVER TO THE CONTACTING POINT OF THE BODY SOCKET. I want the master
Masons among you to learn that by rote!
Using this criteria, if a No3 bolt head starts to resist half way
closed and a No2 resists at .051” from the body side, then use the No2 bolt
head. Remember DON’T OVER CHS
There are a couple of reasons for this. Firstly, it is from a point
when the underside of the bolt handle is approx .15” from the sharp curve
between the top of the body and the side of the butt socket, that the bolt
effectively ceases to move any further forwards and is effectively locked.
The second is that prior to the point of fully locking, a feature called
‘mechanical safety’ comes into operation and (it’s getting technical now……….)
the stud on the cocking piece will strike the stud between the short and long
cam groove at the rear of the bolt causing a diminished force of blow to the
striker, resulting in a mis-fire! Phew!
You will understand that this is a highly condensed précis of events
taking in months of learning, investigating and examining undertaken by
apprentices and I’m trying to cram it into a 40 minute lesson!
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Goosic
Senior Member
Joined: September 12 2017
Location: Phoenix Arizona
Status: Offline
Points: 8792
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Posted: July 28 2020 at 12:47am |
Frameman 1 wrote:
Thanks for the advice. |
Frameman.
Do not take the advise from Explosive. The man is misinformed and his assertions,if taken solely from his comment,could have negative consequences...
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The Armourer
Senior Member
Joined: June 23 2019
Location: Y Felinhelli
Status: Offline
Points: 1246
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Posted: July 28 2020 at 12:52am |
Goosic wrote:
Frameman 1 wrote:
Thanks for the advice. |
Frameman.
Do not take the advise from Explosive. The man is misinformed and his assertions,if taken solely from his comment,could have negative consequences... |
Frameman,
I'd go a little further than Goosic and say "this guy is giving potentially dangerous information" given this thread, and, his thread about 'overloading' the 303 cases with unknown powder.
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Frameman 1
Senior Member
Joined: July 30 2019
Location: SW Ohio
Status: Offline
Points: 382
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Posted: July 28 2020 at 4:31am |
I will respond to any advice received from the web with the same degree of caution I use when looking at political parties. Trust but verify. Thanks again everyone. Very interesting subject and solutions.
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There are no Americans in Baghdad!!
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