Print Page | Close Window

Extractor broken-pressure excursion

Printed From: Enfield-Rifles.com
Category: Enfields
Forum Name: Ishapore Enfields
Forum Description: Let's see those Indian Enfields!
URL: http://www.enfield-rifles.com/forum_posts.asp?TID=12365
Printed Date: November 30 2023 at 7:03am
Software Version: Web Wiz Forums 12.04 - http://www.webwizforums.com


Topic: Extractor broken-pressure excursion
Posted By: 450 Fuller
Subject: Extractor broken-pressure excursion
Date Posted: November 17 2022 at 10:43am
A cast 170 gr bullet caused issues in my Enfield yesterday.
NOT from a warm loaded cartridge, but from what appears to be
a gas check issue spiking pressure.

At any rate, it caused enough of a pressure excursion to send gas back through the primer pocket and rupture the case head; gas also came back through
the bolt; the extractor was broken so a new extractor and spring will be installed. (No damage to pilot/aka owner).
Headspace was not the culprit in this case.

Questions: The bolt is not releasing in its raceway to be removed.
It slides back with the extractor bolt head turning & moving up-but the bolt will not release to be removed. Need to remove bolt to double check on bolt & any remaining brass in chamber. May also double check headspace. Hopefully no bolt damage. (This was definitely beyond a proof cartridge.)

Apex offers both a #1 MK 3 extractor and spring:

This APEX extractor MAY have been originally for the .303 British . Will
this APEX extractor work OK for the 7.62 NATO cartridge in the Ishapore rifle?

-------------
Only the dead have seen the end of war-Plato

Socialism-The equal sharing of misery-Churchill

MACVSOG-5th Special Forces Gp



Replies:
Posted By: The Armourer
Date Posted: November 17 2022 at 10:56am

Is this a 2A / 2A1 or a No1 Mk3 ?

The 2A / 2A1 rifles were very marginal in passing the proof test and actually twisted the body so the proof testing was changed until they passed.
Any over pressure, or using heavier bullets than the 144-150g that they are deisigned for is like playing Russian Roulette.
If using heavier bullets you need to download the powder.

But - to answer your question - NO - a No1 Mk3 extractor (designed for extracting a case with a rim) will not reliably extract a 7.62 (rimless) case.

The profile and length of the 'claw' is very different for the 7.62 round.


Posted By: Goosic
Date Posted: November 17 2022 at 11:16am
450 Fuller: With what you are describing,  ie, the bolt cannot be removed is because the pressure spike caused the bolt body to bend. You might be able to hit the bolt handle with a mallet to get it to budge but, it sounds like you might have junked your rifle.


Posted By: The Armourer
Date Posted: November 17 2022 at 11:51am
Originally posted by Goosic Goosic wrote:

450 Fuller: With what you are describing,  ie, the bolt cannot be removed is because the pressure spike caused the bolt body to bend. You might be able to hit the bolt handle with a mallet to get it to budge but, it sounds like you might have junked your rifle.

I think you have hit the nail on the head.


Posted By: Shamu
Date Posted: November 17 2022 at 12:20pm
Any "incident" that has cause such events should be checked out by a competent gunsmith before proceeding.
For you own safety please don't try to "shade tree 'smiff" this issue.
These are warnings of serious damage.


-------------
Don't shoot till you see the whites of their thighs. (Unofficial motto of the Royal Air Force)


Posted By: Goosic
Date Posted: November 17 2022 at 12:37pm
450 Fuller:
Awhile back. I inadvertently over charged a cartridge. Needless to say, the result was a bent bolt body. After taking a large hammer to the bolt handle, I was able to remove it from the reciever. I took an unissued bolt body and tried to insert that into the reciever and it stopped short of the lug recesses. I took the reciever to my friends machine shop and took some measurements. The slabside/leftside of the reciever had bent outwards from the lug recess back. The short lug on the bolt body was cracked as well.
Do not attempt to repair this rifle unless you have an extremely confident gunsmith willing to vouch for the safety and functionality of it and then give it a good think.


Posted By: 450 Fuller
Date Posted: November 17 2022 at 12:46pm
Agreed. Interesting that I have had no incidents loading 150 gr jacketed bullets.
If/when I get this 2A back functioning, I will stick to the previously
described bullet weights. The SMLE Enfield action did handle the gas better than some might have-as to the shooter...

Thanks for the sage advice.

-------------
Only the dead have seen the end of war-Plato

Socialism-The equal sharing of misery-Churchill

MACVSOG-5th Special Forces Gp


Posted By: The Armourer
Date Posted: November 17 2022 at 12:50pm
Originally posted by Goosic Goosic wrote:

450 Fuller:
Awhile back. I inadvertently over charged a cartridge. Needless to say, the result was a bent bolt body. After taking a large hammer to the bolt handle, I was able to remove it from the reciever. I took an unissued bolt body and tried to insert that into the reciever and it stopped short of the lug recesses. I took the reciever to my friends machine shop and took some measurements. The slabside/leftside of the reciever had bent outwards from the lug recess back. The short lug on the bolt body was cracked as well.
Do not attempt to repair this rifle unless you have an extremely confident gunsmith willing to vouch for the safety and functionality of it and then give it a good think.

That (and the OPs problem) sound typical of the weak Ishapore body and an overpressure 'event'.
This was exactly what the Ishapore factory found happened when they tried to manufacture them from the "supposedly" superior grade of metal - they went back to the same metals as specified by the British and it just squeezed thru the testing.

Extract from “Gun Digest 33rd Anniversary 1979 Deluxe Edition”

Article Author : Mr A G Harrison

Qualification : Former ‘Proof Master’ of the ‘Rifle Factory Proof House, Ishapore, India’


A bolt action rifle similar to the SMLE MkIII*, modified to fire the 7.62mm NATO cartridge, was produced at Ishapore, first in February 1965. The receivers were made of SWES 48 steel and with the NATO proof cartridge the receivers were found to distort with both the dry and oiled proof round. The material was changed back to the EN steel so now the rifles stand up better to dry and oiled proof. 


Posted By: britrifles
Date Posted: November 17 2022 at 1:41pm
I’m curious what the load details are, so we can be sure to avoid this.  

I’ve not shot cast loads in my No. 4 rifles, but it should not be difficult to load safe cast bullet loads.  Typically, velocities must be kept mild to prevent leading the bore, so I really wonder what went wrong here…




Posted By: Goosic
Date Posted: November 17 2022 at 2:23pm
@ The Armourer:
I wrecked a No4Mk1 action body. I was loading up 215grn RN's
and can only assume that one of those rounds was way beyond maximum charge weight. I felt the added kick, heard something make a crunch sound, and the magazine simply fell out. I tried to lift the bolt handle up and it was stuck solid. When I got home I removed the stockset and the scope and then got to work with my 5lb hand sledge. When I got the bolt assembly out you could visually see the bend from the lug contact points back. The short lug was cracked almost completely apart and the threads on the bolthead were flattened.  The only part of the cartridge to remain was the very bottom from the rim up to about 1/4". Everythingelse was pulverized brass.
I unscrewed the barrel, took off everything I could and then cut that reciever up, purposely leaving a couple of reciever bits out of the main bits so nobody could try to weld it back together...


Posted By: The Armourer
Date Posted: November 17 2022 at 3:07pm
Frightening - there is a lot of energy just a few inches away from our face.


It is something we should all be aware of when reloading.
I always switch off the phone and TV and tell the family not to disturb me (unless someone has died).

It only takes a fraction of a second of loss of attention and we can end up double loading, or squib-loading - which can be as bad as it can leave the bullet half way up the barrel and the next shot results in ..................


5th November 2019



Posted By: britrifles
Date Posted: November 17 2022 at 3:11pm
Yes, a “squib” is a dangerous condition.  Especially those who shoot matches with rapid fire stages.  The temptation is to just cycle the bolt rapidly and shoot again.  Well, you know what happens then…

That happened to me once in pistol reloading.  I’ve gotten in the habit to visually inspect all charged cases in the loading block (holds 50 cases) before seating bullets.  


Posted By: The Armourer
Date Posted: November 17 2022 at 3:23pm
Originally posted by 450 Fuller 450 Fuller wrote:


Apex offers both a #1 MK 3 extractor and spring:

This APEX extractor MAY have been originally for the .303 British . Will
this APEX extractor work OK for the 7.62 NATO cartridge in the Ishapore rifle?

Thought I had a picture somewhere - found it ............


7.62 on the left, 303 on the right




Posted By: 450 Fuller
Date Posted: November 17 2022 at 3:26pm
Goosic:

Having wide experience with foreign armament,and having advised foreign
soldiers during wartime-I still tend to err on the side of caution. Mostly.

This rifle has the SN 56198 with an "A" midway above the serial number.
I believe it is a 2A or possibly a 2 A-1 Ishapore Enfield.2000 meter rear sight? No other marks other than a stock rack number.

Having checked the headspace,barrel, and chamber for stuck pieces of brass; action and receiver-bolt inspection; and the bolt returns to battery with only a small bit of extra effort- I decided to
throw caution to the wind. I chambered a jacketed bullet round and-in the spirit of Mellon and WDM Bell, African hunters who used a 1-pound badly headspaced 303 Enfield SMLE----let fly behind a large tree for insurance.

It fired and functioned OK-albeit without extraction.

If you were looking for a 2A extractor, where beyond Apex and Ebay would you
look?
(No more cast bullets-I violated my self-imposed rule of none in bottleneck cases. Straight wall cases like the 45-70 and 45-90 are more forgiving.)Still plan to have a gunsmith inspect this rifle closely.

Thanks-

-------------
Only the dead have seen the end of war-Plato

Socialism-The equal sharing of misery-Churchill

MACVSOG-5th Special Forces Gp


Posted By: Goosic
Date Posted: November 17 2022 at 3:45pm
Numrich Gun Parts.  Search "Enfield Extractor" and the 308 Extractor will pop up.


Posted By: Shamu
Date Posted: November 17 2022 at 4:26pm
If specific over charges are involved this is the wrong place to discuss them.
You are all very experienced reloaders but other readers may not be.
I'm gong to let this ride because it has a lot of good info, but if unsafe reloading becomes a big part I'll be obliged to close it.
If you must discuss "Elmer Keith Commemorative Overloads" please go to PMs to do so.
Thanks.


-------------
Don't shoot till you see the whites of their thighs. (Unofficial motto of the Royal Air Force)


Posted By: Goosic
Date Posted: November 17 2022 at 4:51pm
My point was just to acknowledge the dangers of an overcharged  cartridge using my experience only shamu. No more, no less...


Posted By: Shamu
Date Posted: November 18 2022 at 9:12am
No problem.
Just checking on the old "thread drift".


-------------
Don't shoot till you see the whites of their thighs. (Unofficial motto of the Royal Air Force)


Posted By: 450 Fuller
Date Posted: November 20 2022 at 5:05pm
Since many of you have traveled the road of parts replacement and SMLE disassembly, I will pose an issue. This same 2A1 requires replacement of the extractor and spring.
Parts headed my way.

BUT-I do have a VERY stubborn extractor screw, and my thinking is that the original extractor spring may be exerting pressure on the screw shaft. The screw slot is starting to get burred, and it's time for second opinions.
Enfield experienced gunsmiths seem almost non-existent here in this area.

-------------
Only the dead have seen the end of war-Plato

Socialism-The equal sharing of misery-Churchill

MACVSOG-5th Special Forces Gp


Posted By: Shamu
Date Posted: November 21 2022 at 10:05am
Dress the screw slot first.
use an impact driver?


-------------
Don't shoot till you see the whites of their thighs. (Unofficial motto of the Royal Air Force)


Posted By: 450 Fuller
Date Posted: August 24 2023 at 3:14pm
Very conservative loading practices used, and will be continued.

-------------
Only the dead have seen the end of war-Plato

Socialism-The equal sharing of misery-Churchill

MACVSOG-5th Special Forces Gp


Posted By: Sapper740
Date Posted: August 26 2023 at 3:00am
I own a 2A that I take to the range from time to time.  I was initially blissfully ignorant of the issues with the 2A and action body warping but soon read about that on this forum and others.  I imagined I dodged a bullet as I was shooting near maximum .308 Winchester handloads in it with 168 grain SMKs.  Sometimes God protects fools and no unpleasant incidents occurred.  Now, I only shoot factory 7.62 NATO or mid-range handloads with pulled M80 147 grain bullets.  


Posted By: Goosic
Date Posted: August 26 2023 at 7:54am
Using 41.7grns of IMR4064  or 42.0grns of IMR4895 under a 168grn Sierra MK with a C.O.L. of 2.830" will generate pressures with within the safe range for use in an Enfield rifle. My 7.62mmNo4Mk*...


Posted By: paddyofurniture
Date Posted: August 26 2023 at 9:49am
Great!

-------------
Always looking for military manuals, Dodge M37 items,books on Berlin Germany, old atlases ( before 1946) , military maps of Scotland. English and Canadian gun parts.


Posted By: Sapper740
Date Posted: August 26 2023 at 1:17pm
*DO NOT REPLICATE THIS LOAD IN YOUR ISHAPORE 2A OR 2A1!*

I was torching off 46.5 grains of BL-C(2) under a 168 grain SMK until I learned better.

*DO NOT REPLICATE THIS LOAD IN YOUR ISHAPORE 2A OR 2A1!*




Posted By: britrifles
Date Posted: August 26 2023 at 1:28pm
I wouldn’t shoot that load in a No. 4 7.62 conversion either.  



Print Page | Close Window

Forum Software by Web Wiz Forums® version 12.04 - http://www.webwizforums.com
Copyright ©2001-2021 Web Wiz Ltd. - https://www.webwiz.net