About accuracy |
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philtno
Senior Member Joined: May 04 2019 Location: Blenheim, NZ Status: Offline Points: 261 |
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Posted: August 25 2020 at 3:43pm |
Hi guys,
I guess all of you who are regular dwellers of this place have already seen this video and know all about Lee Enfield accuracy I just went through my bookmarks and came across this one which is from Roger Wadham youtube channel and it's really interesting. The whole set of videos is, actually. Cheers Philtno
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Canuck
Special Member Donating Member Joined: January 17 2012 Location: Agassiz BC Status: Offline Points: 3535 |
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Thanks for posting that video, it is very informative.
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Castles made of sand slip into the sea.....eventually
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britrifles
Senior Member Joined: February 03 2018 Location: Atlanta, GA Status: Offline Points: 6539 |
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I’ve not come across any published information that indicates the accuracy standard for the No. 4 rifle was a two inch circle at 100 yards. Also have never read anything indicating the No. 4 Mk 2 standard was 1.5 inches at 100 yards. Perhaps some rifles would achieve this with selected ammunition, but unlikely the standard issue rifle was that good. Period published information and my own experience would suggest 3 to 4 MOA for the No. 4 is typical. Some of this is ammunition dependent of course, perhaps 2 to 3 MOA with match grade ammunition.
Maj EGB Reynolds states the accuracy standard for the No. 4 Mk I was the same as the No. 1 rifle at 100 feet (five rounds had to be contained in a rectangle 1 inch wide by 1.5 inches high). That translates to 4.5 inches at 100 yards (4.5 MOA). 10% of all No. 4 rifles were tested at 200 yards where 6 out of 7 shots had to be with a 6 x 6 inch rectangle (approx 3 MOA, larger if any shots were near the corners of the rectangle). Didn’t matter where the one flier went. Any rifle passing this standard was issued, those that did not were sent back to be corrected. Reynolds did not not give an accuracy standard for the No. 4 Mk 2, it was not expected to be more accurate than the Mk I, the trigger was mounted to the receiver to address problems encountered in service with the forend wood altering trigger pressure from swelling from humidity. It is known that exceptional No. 4 rifles that are carefully bedded shooting selected match ammunition will group in the 1.5 MOA range, but that is not the norm for an issue rifle. Heavy barreled 7.62 conversions perhaps down to 1 MOA. These tests in production were fired from a mechanical rest with telescopic aiming, so I wouldn’t expect this in prone shooting with aperture sights. Handloads with match grade bullets do make a difference. As does the superb accurizing work that Gossic has done to his rifles has brought them down to Sub-MOA groupers. But these are not stock standard as issued No. 4 rifles fired with service ammunition with the service aperture sights. |
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philtno
Senior Member Joined: May 04 2019 Location: Blenheim, NZ Status: Offline Points: 261 |
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The guys who posted that video has published a book in 2012 called "The 2012 Complete Book on Lee Enfield Accurizing". I have a digital copy of it. Here is his introduction: "he!!o, my name is Roger Wadham, an ex Hollywood writer and set designer with a more than passing affection for these great rifles and all they represent. I met my first Lee Enfield in Los Angeles in 1995 when a friend with a sense of humor handed me a No1 Mk3 on ANZAC day for an outing at the range. Little did Michael, or I, realize what this would start. That lovely Australian made rifle eventually crossed the Pacific back to NZ and is still safe in the safe 15 years later. After that rifle’s arrival I discovered there were other types of Enfield, and I couldn’t say no to buying another one, or two, and now they must be multiplying in the gun safe on their own, because without fail every month or two there seems to be another. Decreasing space in the gun safe, it turns out, is a ‘problem’ other ‘Enfielders’ discover too. In Los Angeles I was well spoiled by the local presence of the Angeles Crest Shooting Range, a large complex at the foot of the San Bernadino Mountains that caters to everyone from skeet shooters to LAPD trainees. It’s a great place to learn to shoot and best of all, they have a range with steel gongs strung out to almost 800 yards. Lee Enfields eat 800 yards for lunch. Do that kind of shooting for a while and it doesn’t take long before 300 yards starts to feel like 50, and one’s accuracy improves quickly. It doesn’t take long shooting at these distances before any rifle owner starts to think about the nuances of the bullet’s flight, how the rifle works and why. This began the ongoing enjoyment of bettering my shooting. For myself unexpected health issues have taken me off the firing line, but having got the Enfield bug, new directions have led to me building the website Enfield Resource.com. In addition I’ve been enjoyably building target rifles for a few years, fun shooting with friends, and with this book have now turned pen to paper" |
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The Armourer
Senior Member Joined: June 23 2019 Location: Y Felinhelli Status: Offline Points: 1246 |
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The 'official' accuracy requirements : SMLE TESTING Trial
shots were first fired and, if necessary the foresight was adjusted laterally,
or replaced by one of a different height, until the shots on the target were
within the required limits. Five rounds were then fired, and four of the five
shots had to be contained in a rectangle 1 inch broad by 1½ in high. Rifle
which failed this test were rejected. At 600 yds 10 shots were fired, nine of
which had to fall within a 2 foot circle. No 4 RIFLE TESTING No 5 TESTING Throughout World War 2 much of the accuracy testing was done by women
shooters who quickly became proficient at the job. To speed up the procedure,
the telescope layer was dispensed with, and aim was taken in the normal way
through the back sight. The .1 inch aperture in the back sight was too large
for easily laying a correct aim at 100ft, and a small spring steel adaptor was
used. |
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britrifles
Senior Member Joined: February 03 2018 Location: Atlanta, GA Status: Offline Points: 6539 |
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Philtno, I have Rogers book. Some good information in there. I think he gives a better description of the accuracy standards in his book.
Armourer, that’s the section from Reynolds book I was paraphrasing. There’s another source, AU Queens Prize winner James Sweet. Here is what he wrote:
My own experience is in line with what Mr. Sweet wrote back in the 1950’s and 60’s when the LE rifles were used in international competitive shooting. At that time, the bullseye on the Bisley Targets were 2.5 MOA for 5 points (200, 300, and 600 yards). The 500 and 1000 yard target bull was 3 MOA, the 900 yard bull 3.3 MOA. A score of 50 was not very common, particularly beyond 200 yards. So, if it is believed that the standard issue No. 4 Mk I shot within 2 MOA and the Mk 2 shot 1.5 MOA, the average scores on the Bisley Targets (at Short Range anyway) would have been 50, especially from the top marksman in the country. All this changed when the UK NRA rules changed in the late 1960’s to allow 7.62 Cal match rifles and a 4 lb heavy barrel was allowed on the No. 4 rifle. Suddenly, clean scores of 50 were more common, and a means was needed to break ties. Targets were changed, score rings got smaller, V (or X) rings added. |
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britrifles
Senior Member Joined: February 03 2018 Location: Atlanta, GA Status: Offline Points: 6539 |
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Most of you know that the subject of LE accuracy has been something I’ve been very interested in for a long time. Here is another description, this from the Parker Hale Instruction Manual on Service Rifles. It is worth reading, and very objectively states the facts.
Note the statement that a first class Match Rifle with ICI “Streamline” cartridges (match ammunition) can hold a vertical angle within 2 minutes. So, saying that the as issued No. 4 rifle accuracy standard with service ammunition is 2 inches at 100 yards might be a stretch. Here, the Parker Hale manual is referencing an NRA journal article that the LE Service rifle and Mk VII cartridge to be within 5 minutes. |
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Shamu
Admin Group Logo Designer / Donating Member Joined: April 25 2007 Location: MD, USA. Status: Offline Points: 17603 |
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It wasn't technically speaking measured that way. They used something called "Figure of Merit" which was a calculated number created from an actual group. Let me see if I can paste a .PDF of it. |
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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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britrifles
Senior Member Joined: February 03 2018 Location: Atlanta, GA Status: Offline Points: 6539 |
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Shamu, I believe that’s how ammunition accuracy was defined, going back at least to the days of the P53 Enfield. Usually 20 rounds minimum to get a stable value of the FOM (mean radial dispersion from the mean point of impact). It would be interesting to find what the WWII acceptable FOM was for Mk 7 ammunition.
There is no mathematical way to relate FOM to the center to center extreme spread (MOA) of a group. The FOM is the average radial distance of each of the individual shots to the group center. What I do like about FOM is it gives a better indication of the accuracy of the typical shots, where as group extreme spread only tells you the distance of the two widest shots.
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Shamu
Admin Group Logo Designer / Donating Member Joined: April 25 2007 Location: MD, USA. Status: Offline Points: 17603 |
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I think it was for both? (but not at the same time)?
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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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britrifles
Senior Member Joined: February 03 2018 Location: Atlanta, GA Status: Offline Points: 6539 |
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The “American” way of expressing accuracy as the center to center extreme spread of the group is not the FOM x 2. The FOM is an average distance of all shots from the group center. Multiplying that number by two, and drawing a circle of that diameter around the mean point of impact would normally only encompass half the shots in the group. The other half are outside of this circle, and the FOM wont tell us how far out the two widest shots are.
So, if for example the FOM of Mk 7 ammunition was 8 inches at 600 yards, you would expect 5 out of 10 shots to fall outside a 16 inch circle formed around the MPI if the shots are randomly dispersed within the group. Accuracy expressed as the extreme spread of this group is not 2.67 MOA. It is likely closer to twice that value (5.3 MOA). You just can’t relate these two numbers in any way. There is only one case where the FOM x 2 equals the C-C extreme spread. That is where all the shots in the group are equal distance from the group center, such as a group that was perfectly radially dispersed around the edge of a score ring on the target. Statistically a very rare case. |
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Shamu
Admin Group Logo Designer / Donating Member Joined: April 25 2007 Location: MD, USA. Status: Offline Points: 17603 |
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Yeah I think the American way is better FWIW.
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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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britrifles
Senior Member Joined: February 03 2018 Location: Atlanta, GA Status: Offline Points: 6539 |
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I was looking thru my copy of Hatcher’s Notebook, a very informative work by Major General Julian S. Hatcher. He gives the accuracy standards for the Frankford Arsenal (FA) .30 Cal Match ammunition loaded in the 1920’s and 1930s (during part of that period, he was in charge of FA). The Mean Radius was typically just over 2 inches at 600 yards. He stated that the group extreme spread is typically 3 times the mean radius, so that would be 6 to 7 inches; 1 MOA ish. Very respectable for ammunition mass produced at that time. This ammo was used in the US National Matches prior to WW II.
He also gave the 600 yard mean radius accuracy standards for WWII .30 Cal M2 Ball at 7 inches and .30 Cal AP at 10 inches (which typically equates to 3.5 MOA for Ball and 5 MOA for AP). Production ammunition had to be within this maximum, but many ordinance plants bettered this standard. Does anyone have any references for .303 Mk 7 ball ammunition maximum mean radius (Figure of Merit)? Shamu, the attachment you had on one of your posts in this thread gave 8 inches, was this an example, or have you seen this as the actual maximum? If it was 8 inches, this puts it in line with US .30 Cal Ball ammo at 4 MOA. I’ve not seen any references to the ammunition used for the accuracy acceptance tests for the No. 4 rifle in Reynolds book. But I would think they used selected production ammunition known for good accuracy and not just “run of the mill” ball ammo. The 1943 and 1944 production Mk 7z Defence Industries ammunition I have groups about 2.5 to 3.5 MOA fired off the bench. I also have some Dominion Arsenal 1951 Mk 7z produced for the 1952 and later DCRA annual Matches at Connaught ranges which groups about 1.5 to 2 MOA. These are averages of 10 shot groups fired off the bench with my Long Branch Fulton Regulated No. 4 Mk 1/3. The remarkable thing is that this ammunition is still 100% reliable and right on the velocity specifications at the time (I’ve chrono’ed this ammo). My Dad got it back in the early to mid 1960s, and had been stored indoors since that time. |
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Shamu
Admin Group Logo Designer / Donating Member Joined: April 25 2007 Location: MD, USA. Status: Offline Points: 17603 |
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Somewhere there is a comparison between the no 1 & the no4. It has pretty much what you're looking for. Let me see if I can find it. Here you go its a video: |
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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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britrifles
Senior Member Joined: February 03 2018 Location: Atlanta, GA Status: Offline Points: 6539 |
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Shamu, this video was the subject of this post. I’ve never come across any published information of authority that says the No. 4 Mk I rifle was designed To shoot a “2 inch circle at 100 yards”. Also never seen anything that shows a No. 4 Mk 2 was “designed to shoot a 1.5 inch group at 100 yards”. I wonder where he got that information...
My question is about the ammunition, what was the accuracy standard for Mk 7 ball ammo? Perhaps The Armourer has something on this. Of course, we can’t determine what the accuracy of any rifle is without the accuracy of the ammunition meting part of this. Ammunition accuracy is usually judged by shooting from a heavy test barrel secured to a very rigid receiver bolted to a bench to eliminate all aiming and shooter errors. |
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Goosic
Senior Member Joined: September 12 2017 Location: Phoenix Arizona Status: Offline Points: 8792 |
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I did find some interesting information on the MkVIIz ammunition britrifles. It is the TSI of the ammunition that is generated that peaks my curiosity. Cartridge S.A. Ball .303 inch Mark VIIIz" was approved in January 1938 to design DD/L?8877 and shown inn LoC Paragraph B.2623 dated July 1939. A modified bullet was made from 1942 to design DD/L/14049. The Ball Mark VIIIz bullet weighed 175 grains and had a lead/antimony core with either a cupro-nickel or gilding metal envelope, although the former was little used. The bullet was boattailed with one cannelure. Originally the boattail was "stepped" down from the diamete of the body but after 1942 the design was changed to one where the boattail was smoothly continued from the main diameter. The propellant charge was between 37 and 41 grains of nitrocellulose to give a muzzle velocity of about 2,550 feet per second at a pressure of 20-21 tsi. The headstamp included the numeral "VIIIZ", after 1945 changing to "8Z", and a purple primer annulus. Although the .303 inch Ball Mark VIIIz was designed for long range fire in Vickers guns, it could also be used in rifles in emergencies or special circumstances, contrary to what is often claimed about it being "hot" machine gun ammunition. Although producing a slightly higher pressure, 20-21 tsi compared with the 19.5 tsi of the Mark VII, Bren guns were proofed at 25 tsi and so were well within the pressure limits. "Pamphlet 11, Small Arms Ammunition" states that Ball Mark VIIIz may be used in rifles and Bren guns when less flash is required, e.g. at night. It should be noted that barrel life using this ammunition starts to degrade after 6000 rounds being used.
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