#4 MK1 What the heck rifling is this ???????????

Skylark 4

Find a box of Hornady .312 174 grain round nose bullets and see how your rifle shoots. I had a two groove Maltby just like yours and these Hornady bullets were the most accurate. If you No.4 is tight in the draws area and has the correct up pressure it should shoot very well

The two groove barrels was an American experiment to produce machine gun barrels faster and cheaper. And they worked so well they were adopted for wartime use on rifles. I also had a 1943 two groove Remington 03-A3 and it liked the Hornady 170 grain flat point bullets made for the 30-30. A flat base bullet kicked in the A$$ will expand and fill the bore when fired so don't worry about your bore size. As long as your rifle is bedded properly and at the high end of up pressure at the fore end tip it should shoot better than you can.


Give your wood a good soaking in a 50/50 mix of raw linseed oil and turpentine and this may tighten up your stock as the wood soaks up the 50/50 mix.
 
Skylark 4

Find a box of Hornady .312 174 grain round nose bullets and see how your rifle shoots. I had a two groove Maltby just like yours and these Hornady bullets were the most accurate. If you No.4 is tight in the draws area and has the correct up pressure it should shoot very well

The two groove barrels was an American experiment to produce machine gun barrels faster and cheaper. And they worked so well they were adopted for wartime use on rifles. I also had a 1943 two groove Remington 03-A3 and it liked the Hornady 170 grain flat point bullets made for the 30-30. A flat base bullet kicked in the A$$ will expand and fill the bore when fired so don't worry about your bore size. As long as your rifle is bedded properly and at the high end of up pressure at the fore end tip it should shoot better than you can.


Give your wood a good soaking in a 50/50 mix of raw linseed oil and turpentine and this may tighten up your stock as the wood soaks up the 50/50 mix.

The two groove was no experiment, look up the 1837 Brunswick Rifle. It had already been proven that it works. it was actually the British that reminded the Americans about the two groove barrels Archival material passed on to Clark Campbell for updating his fine Springfield '03 book in 2003 essentially covers the historical genesis of British influenced reintroduction of 2-groove rifling in WWII , so won't be repeated here. Suffice to say, the Brits introduced it through their American contract with Savage Arms Co. late in 1941. As an alternative to their standard 5-groove barrel, it was calculated that using 2-groove instead "...can release 12 or more rifling machines to other uses", and at the same time not affect the ballistic properties of the rifle.
 
One thing to keep in mind, the bullets back in those days had exposed lead bases. The powders they used back then, were relatively fast. This was on purpose. They could have easily completely encased the core in jacket metal.

When the relatively fast powder ignited, it smacked up against the exposed lead in the jacket and caused the metal to obdurate into the grooves to fill them properly and make a tight seal. This did a lot of good things for accuracy.

Modern barrels don't usually have such deep rifling. With today's solid base bullets, it isn't necessary.

As biged mentioned, if the ways are sound and the pressure pads in the fore end are ok, and little if any warping hasn't taken place over the last 70 years, accuracy should be just fine.

Mcpherson, you are correct in the fact that the Brits approached the US suppliers about 2 groove bores.

I am not sure they used Brunswick tech though as an example.

The cast lead bullets used in Brunswick 2 groove rifles were cast with a ring around the ball. They were very unsatisfactory for use in a stressful situation. The rifles quite literally became pikes or spears when things got close and hot.

The new jacket tech at during the first war, enabled the 2 groove experiment to be successful.
 
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Yes the Brunswick two groove is different from the Lee/Springfield two grooves, but none the less, it is the same idea. The big difference between the two is the 1837 Brunswick is a muzzle stuffer and required a banded ball to work ,while the Lee/Springer barrels have a projectile force through from the back end, swagging the bullets, forcing the bullet to fit the contours of the barrel. The British never used the technique as an example (the grooves in the Brunswick being somewhere around a 1/16th on an inch deep), but rather used the idea as a proven example that 2 grooves will spin the barrel just as well as 4, 5 or 6 grooves will. And like mentioned before, it was calculated that using 2-groove instead "...can release 12 or more rifling machines to other uses.

One thing to keep in mind, the bullets back in those days had exposed lead bases. The powders they used back then, were relatively fast. This was on purpose. They could have easily completely encased the core in jacket metal.

When the relatively fast powder ignited, it smacked up against the exposed lead in the jacket and caused the metal to obdurate into the grooves to fill them properly and make a tight seal. This did a lot of good things for accuracy.

Modern barrels don't usually have such deep rifling. With today's solid base bullets, it isn't necessary.

As biged mentioned, if the ways are sound and the pressure pads in the fore end are ok, and little if any warping hasn't taken place over the last 70 years, accuracy should be just fine.

Mcpherson, you are correct in the fact that the Brits approached the US suppliers about 2 groove bores.

I am not sure they used Brunswick tech though as an example.

The cast lead bullets used in Brunswick 2 groove rifles were cast with a ring around the ball. They were very unsatisfactory for use in a stressful situation. The rifles quite literally became pikes or spears when things got close and hot.

The new jacket tech at during the first war, enabled the 2 groove experiment to be successful.
 
Lol, I guess you over looked it when I posted it earlier. Guess that is the problem with threads that have more than one page.

I Googled two groove barrels looking for what I read about air cooled quick change machine gun barrels. I could not find anything and do not remember where I read about the machine gun barrel testing. Cordite loaded ammunition was banned from machine gun use and the U.S. did not make cordite powder. During WWII the U.S. made .303 British ammunition with single and double base powders and even double base powders were banned for machine gun use in Britain.

My point being air cooled machine gun barrels wore out quickly and testing was done with two groove barrels, but I can not find any printed material online on the subject. And I do not remember where I read about it, but it dealt with emergency wartime production and allocation of existing production equipment.

One link to the Remington Society of America or one book written by Clark Campbell is not the entire history of WWII two groove barrels. It also didn't free up 12 or more rifling machines, all it means is is a two groove barrel can be produced twice as fast as a four groove barrel.

You can Lol all you want but history isn't contained in just one book on a single rifles history.
 
My lol, was about the fact that I already posted the same like earlier

I Googled two groove barrels looking for what I read about air cooled quick change machine gun barrels. I could not find anything and do not remember where I read about the machine gun barrel testing. Cordite loaded ammunition was banned from machine gun use and the U.S. did not make cordite powder. During WWII the U.S. made .303 British ammunition with single and double base powders and even double base powders were banned for machine gun use in Britain.

My point being air cooled machine gun barrels wore out quickly and testing was done with two groove barrels, but I can not find any printed material online on the subject. And I do not remember where I read about it, but it dealt with emergency wartime production and allocation of existing production equipment.

One link to the Remington Society of America or one book written by Clark Campbell is not the entire history of WWII two groove barrels. It also didn't free up 12 or more rifling machines, all it means is is a two groove barrel can be produced twice as fast as a four groove barrel.

You can Lol all you want but history isn't contained in just one book on a single rifles history.
 
While the 2 groove barrel was adopted for the later Model 03-A3 and 03-A4 Springfields, it is interesting that they were not made up as substitutes/replacements for either the M1 Garand or the M1903 Springfield standard 4 groove barrels. Johnson Automatic Rifles did make 2 groove replacement barrels for the M1917 Enfield in WW2 while High Standard made 4 groove barrels for both the M1917 and the M1903. Both Springfield Armory and Sedgeley Arms produced 4 groove replacement barrels for the M1903 at various times during WW2.
 
Presumably the reference to "freeing up twelve rifling machines" was a calculation based on the machine time required to rifle a given number of barrels by each method: five groove or two groove. In other words they were talking in man & machine hours, not literally using 12 less machines. At least that would be my guess.
 
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