.303 Enfield Delima - Page 2

kestak · June 19, 2010, 05:26 AM

Greetings,

303guy, it is your first post and it explains perfecly the phenomenon. I wish I could write English like that....

It must be a record for a first poster to have such a quality post...

Thank you

Sport45 · June 19, 2010, 07:08 AM

Topload and 303Guy, welcome to The Firing Line!

303Guy,

Excelent first post. Stick around and jaw as long as you like.

Topload,

Great questions. If it was my rifle I'd first try taking the scope off and see how it shoots at 50 yards with irons. That would eliminate scope or mount effects.

My Arisaka has a similar bore and shoots pretty well with the Hornady 174gr .312" bullets. You might want to give those a try as well.

303Guy · June 20, 2010, 02:18 AM

Thank you both for your kind words. That is the warmest welcoming I could possibly have hoped for! I am actually quite moved.

I should point out that I do make mistakes (most of the time

) and I do go off topic quite a bit.

I am after all, a mere mortal.

kestak, they say English is one of the most difficult languages - I don't know, I'm not good at languages. You are a better man than I.

DocAitch · June 20, 2010, 07:06 AM

Kestak, I apologize for the rude use of the term BS. I certainly didn't mean to hurt your feelings. I get bristly when I suspect BS baffling.
Biophysics is pretty basic math, I remember a partial differential equation for electrical conduction in a nerve and not much else more difficult. Its like languages that you don't use-my Russian (which I haven't used since 1967 when I got out of the Army) is reduced to some horrendous curses and my French is little better.
303guy,
I can understand what you are saying to some degree, but doesn't that spiraling path spiral about a median line that we can consider "the ballistic trajectory", and since the bullet is spinning, are not those "external forces" which are related to the yaw and spin of the projectile applied equally from all sides relative to that median trajectory and therefore self cancelling?
Enlighten me.
Also, while the doppler radar data would be useless to me, some nice pictures would be great(truly, with explanations)
DocAitch

kestak · June 20, 2010, 08:27 AM

Greetings,

Apologies accepted.

For the spiraling I'll try to explain it simply in bullets points:
First: let's assume the shooter always points exactly at the same place.

1 - The bullet always has the same drop from gravity effet.
2 - The bullet yaw may start with the back of the bullet at any place in the 360 degree circle.
3 - Hence, the spiral will vary. For example, for shot A the apogee of the spiral will be at 30 feet from the muzzle, for shot B it will be at 40 feet, etc...
4 - Each case and bullet and powder charge varies a little bit. long range Competition shooters try to make that little variation as little as possible. But it still exists. It will afftect also the spiral multiple apogees positions. There is also the barrel harmonic. The barrel will bever be at the same temperature from shot to shot at least if you put it for a few hours in a controlled temperature room.
5 - The bullet stabilization does not occur always at the same speed. For some bullets, the full stabilization (it is never full BTW) may occcurs at 150 yards, for some others it may occur at 151 yards, ect...it is never at exactly the same place BECAUSE the spiral is not the same all the time.

When you think about the laws of physics, you think about absolutes with no variations. There are litterally tens if not millions of variations depending how close is your measurement.

To really make it simple and not make your head explode, just think that the army guys of the beginning of the 20th century liked very much that yaw. the round was deadlier at close range and more precise at long range. It is really the best of both worlds....

303Guy · June 21, 2010, 04:26 AM

I've bee trying to find that source but so far I haven't been able to. I'll keep looking.

303Guy · June 21, 2010, 06:23 AM

Found it.

http://www.nennstiel-ruprecht.de/bul...ex.htm#Figures

Quote:

... doesn't that spiraling path spiral about a median line that we can consider "the ballistic trajectory",

Yes, that would be so.

The link presented here does not cover the Lee Enfield and the 303 Brit Mk VII bullet. That bullet is believed to follow a spiral path from muzzle to quite some distance downrange, possibly damping out to a large extent? I don't know. It did have a long useable range - one mile target shooting!?

DocAitch · June 26, 2010, 08:36 PM

.303Guy, Thanks for the pix .The last one seems to be the most pertinent to the question in hand, I will have to study the original.
DocAitch

June 19, 2010, 05:26 AM	#26
kestak Senior Member Join Date: June 13, 2007 Location: Augusta Georgia Posts: 157	Greetings, 303guy, it is your first post and it explains perfecly the phenomenon. I wish I could write English like that.... It must be a record for a first poster to have such a quality post... Thank you __________________ abundans cautela non nocet

June 19, 2010, 07:08 AM	#27
Sport45 Senior Member Join Date: May 25, 1999 Location: Too close to Houston Posts: 4,196	Topload and 303Guy, welcome to The Firing Line! 303Guy, Excelent first post. Stick around and jaw as long as you like. Topload, Great questions. If it was my rifle I'd first try taking the scope off and see how it shoots at 50 yards with irons. That would eliminate scope or mount effects. My Arisaka has a similar bore and shoots pretty well with the Hornady 174gr .312" bullets. You might want to give those a try as well. __________________ Proud member of the NRA and Texas State Rifle Association. Registered and active voter.

June 20, 2010, 02:18 AM	#28
303Guy Junior Member Join Date: June 16, 2010 Posts: 8	Thank you both for your kind words. That is the warmest welcoming I could possibly have hoped for! I am actually quite moved. I should point out that I do make mistakes (most of the time ) and I do go off topic quite a bit. I am after all, a mere mortal. kestak, they say English is one of the most difficult languages - I don't know, I'm not good at languages. You are a better man than I. __________________ Regards 303Guy

June 20, 2010, 08:27 AM	#30
kestak Senior Member Join Date: June 13, 2007 Location: Augusta Georgia Posts: 157	Greetings, Apologies accepted. For the spiraling I'll try to explain it simply in bullets points: First: let's assume the shooter always points exactly at the same place. 1 - The bullet always has the same drop from gravity effet. 2 - The bullet yaw may start with the back of the bullet at any place in the 360 degree circle. 3 - Hence, the spiral will vary. For example, for shot A the apogee of the spiral will be at 30 feet from the muzzle, for shot B it will be at 40 feet, etc... 4 - Each case and bullet and powder charge varies a little bit. long range Competition shooters try to make that little variation as little as possible. But it still exists. It will afftect also the spiral multiple apogees positions. There is also the barrel harmonic. The barrel will bever be at the same temperature from shot to shot at least if you put it for a few hours in a controlled temperature room. 5 - The bullet stabilization does not occur always at the same speed. For some bullets, the full stabilization (it is never full BTW) may occcurs at 150 yards, for some others it may occur at 151 yards, ect...it is never at exactly the same place BECAUSE the spiral is not the same all the time. When you think about the laws of physics, you think about absolutes with no variations. There are litterally tens if not millions of variations depending how close is your measurement. To really make it simple and not make your head explode, just think that the army guys of the beginning of the 20th century liked very much that yaw. the round was deadlier at close range and more precise at long range. It is really the best of both worlds.... __________________ abundans cautela non nocet

June 21, 2010, 04:26 AM	#31
303Guy Junior Member Join Date: June 16, 2010 Posts: 8	I've bee trying to find that source but so far I haven't been able to. I'll keep looking. __________________ Regards 303Guy

June 20, 2010, 07:06 AM	#29
DocAitch Member Join Date: March 16, 2010 Location: North of Baltimore Posts: 60	Kestak, I apologize for the rude use of the term BS. I certainly didn't mean to hurt your feelings. I get bristly when I suspect BS baffling. Biophysics is pretty basic math, I remember a partial differential equation for electrical conduction in a nerve and not much else more difficult. Its like languages that you don't use-my Russian (which I haven't used since 1967 when I got out of the Army) is reduced to some horrendous curses and my French is little better. 303guy, I can understand what you are saying to some degree, but doesn't that spiraling path spiral about a median line that we can consider "the ballistic trajectory", and since the bullet is spinning, are not those "external forces" which are related to the yaw and spin of the projectile applied equally from all sides relative to that median trajectory and therefore self cancelling? Enlighten me. Also, while the doppler radar data would be useless to me, some nice pictures would be great(truly, with explanations) DocAitch

June 26, 2010, 08:36 PM	#33
DocAitch Member Join Date: March 16, 2010 Location: North of Baltimore Posts: 60	.303Guy, Thanks for the pix .The last one seems to be the most pertinent to the question in hand, I will have to study the original. DocAitch