A wind bucking Drive Band Bullet for Long Range Shooting, namely F-Class
Turbulence is rather interesting. While big Devices easily disturb the Flow, small Thing more often live in a laminar Stream. The Reynolds Number characterizes this well. In our Case with multiple Drive Bands on small Devices we introduce Micro turbulences, to avoid Macro turbulences, just as rough Shark skin, rough Air inlets on Race Engines and Turbulence generating Fences on Aero plane wings before Land flaps. So in some Cases it pays to pay a little Price to Gain big Advantages. Such is the Case with multiple thin and shallow Drive bands. Especially when you consider your Target Rifle for 7,62x51 NATO Round, that finally is so slow to reach the transonic Region, you want a Bullet to perform well at those slow Speeds too. So your Design should not too much weigh the Supersonic Range, but emphazise the slower Regions. Bow Wave drag is to be weighed with an optimal Tail design. Now the Drive band induced Micro turbulences allow sharper Tail angles for less Bottom drag. Here you more than regain the Drag you introduced with the Drive bands.
Drive bands features first Drive band tailored to fit the Throat at given
Cartridge length, to guide the Bullet to complete Concentricity, a minimum
Requirement to shoot for precisely. As a Benefit the Rifle shoots precisely.
Least Pressure of all Bullet Designs for given Bullet weight and –length allows
higher Loads for higher Speeds. As a Benefit the Trajectory flattens, Bullets
drifts less in Wind drift and flies longer supersonic.
Drive bands feature less Friction, reduces Barrel heating, and -wearing. As a Benefit, the Shooter gains better Visibility over longer Shot series in Competition; longer Barrel life, less Rifle Maintenance cost.
Hello Lutz How are you today?
My Name is Bill Siegloff. I am a shooter in Australia and build a rifle on a Remington 700 action sleeved. I have a chamber reamer with some subtile differences in its design with a 60 degree shoulder. I have the opportunity to have a 30" long barrel made with a 1 in 7.75" twist. I was wondering weather it would be possible to obtain some of your projectiles for testing as i am writing a technical article on the rifle buildup. I also wondered, whether you have had any troubles to shoot a 300go Sierra MatchKing through your fast twist barrels as a secondary projectile. The case i use is the .300" Ultra Mag improved. It has a slight capacity advantage over a standard .338" Lapua Magnum.
I also shoot F Class and i am interested in your 8 x 70 8 mm cartrige you developed for
F Class and am wondering if you have any information you could share with me on
My Grandfather was born in Hamburg and my grandmother in Austria. One day i would love the opportunity to visit Germany and my father was born in Klagenfurt / Austria after the war before they immigrated to Australia.
Thank you for your time and assistance.
Sincerly Bill Siegloff, Dienstag, 20. März 2007 07:52
St. Michaelis in Hamburg from the Port
I am a Hamburger, so You talk to the right Man! Near Klagenfurt You shall find the Gams = Chamois. Look at the Pictures. So Your Ancestors came from some fine Places. But they must have regarded them to be quite annoying. Else they would not have left Country!
Both the LM-105 and the LM-101 are intended for 9° Twist angle, or 163 mm Twist length for 8 mm or 170 mm for the .338". The 8x70 with LM-101 is 101 Millimeters long, the LM-105 in .338" Lapua Magnum 105 mm, hence their Names. They will not feed from ordinary .338" LM Magazines, designed to accommodate only 93,5 mm long Cartridges. Both the LM-105 and the LM-101 are Haack minimum Drag Bullets, intended to be uses in the .338" LM or it's necked down, blown up Sister, the 8x70, see below. The
8 x 70 Long Range Cartridge = a necked own blown up .338" LM
With some Delay, I just moved the Drawings for the G-06, below
G-06 for F-Class
I expect the Work to be finished in Summer '07. As the whole Project took more Time, than anticipated, I hope to hold Dates, this time. The Tools for the 8x70 Cartridge are not ordered yet, but will be made available in Time, just as the Bullets. Other Rifle Designs are possible, but I believe to have eliminated common Misfits in my Design. Tailored Weight Balance and fast Lock were achieved. Look here:
The G-06 allows to switch Barrels. So You may use the .338" with chap Led Stuff to plink and use either the LM-105 or LM-101 in the .338" LM or 8x70 for Long Range Work, such as F-Class. Though the F-Class limits Bore caliber to 8 mm, the .338" LM had to be necked down. Our Experience with Remington cases is, their Bottom is too soft.
Norma cuts Cases, grinds them, then check Hardness after a Plan. See the shining Engravings!
I know RWS and Lapua make the most sturdy cases, the 8x68S and the .338" LM: Therefore those would be the two Cases to build a Performance cartridge on. The G-06 takes the ~ 15 mm Bottom from the .338" LM, to allow to shoot Standard Ammunition; so the Derivatives are based upon that. If You like a G-06 in Summer, please let me know.
I have not tried Sierras in there, but Lapua Scenar do fine.
You don't know me, I found your information and email address while doing some research on necking down and improving the shoulder case angle of the .338 Lapua to 8mm. I'm in the US, state of Wyoming, we do some very long range hunting and target shooting. I have a Sako TRG-42 .338 Lapua that I'm experimenting with. I've necked down the .338 Lapua to .300 and .325 (8mm), and would very much appreciate any load data and case dimensions you could give me on an improved version of the .338 Lapua necked down to 8mm. Also I would appreciate information on twist rates for the barrel, recommended throat length for the chamber, and the Lothar Walther barrels, number of rifling grooves, polygon or standard etc.
Best Regards, Richard Saxton, Gillette Wyoming USA, Sonntag, 17. Juni 2007 22:29
after too long Delays the Gewehr-06 is to become Reality this Fall. Beside the added .338" LM, the main Cartridge will be the 8x70, a, as You call it 8mm-.338 Lapua version. I send You You the current Drawings as a pdf-File. In this Case the Bullet was first and everything else came last. Currently I work on the Dies. I wonder how best to solve the Concentrity issue while seating the LM-101 Bullet.
I was probably have my current Age when I was last in Wyoming but remember a wide open Country. A quick Search brought me this Picture:
by Betty Salisbury
My inspiration depicts the great sunsets that are displayed over our mountains, lakes and forests. Wyoming is known for its great outdoors and wildlife but let's not forget the beauty Wyoming displays at sunset. Source
So You do hunt and shoot Paper. While the LM-101 is a Paper bullet, I may, with slight Modifications, i.e. a hollow Point, covered with a black Plastic tip turn it into the Very long range hunt bullet. I actually plan to do so, to land THE Long shot on a Man sized live Target (not necessary by myself, but definitely with my Gear). Save Enemies, equal sized Game will do as well. As I wrote may Times, low Wind drift required long and slender Bullets, that then require steep Twist angles. I go for 6+ Calibers Length and 9° Twist angle. Such a 8 mm land bullet requires 162 mm Twist length.
Folks with more Experience than me, told me to use at least 1° Taper on the Case body, so I choose 1.1.° . Then the Throat should be not too steep. 1.5° full Cone angle (Watch out: You Americans usually specify half Angles only. So don't confuse half and full Cone angles!) seems Performance cartridges a reasonable Throat Angle. A well designed and not too steep Throat needs no Leade (like the Weatherbys us so much). Such Design benefits from a longer consistent Life through Burn out, I believe.
Else You might just by a Gewehr-06 and have it all done for You.
Waidmannsheil, Lutz Möller,
Thanks for responding, I do appreciate any information you
can give me. Case dimensions on your 8mm-.338 Lapua (8mmx70mm?) and/or reloading
data would be very much appreciated also. I have a very good friend that lives
close, that was born and raised in Germany if we need any language translation.
Best Regards,, Rick Saxton, Gillette, WY, Montag, 18. Juni 2007 01:27
Thank you for the information the your 8mm-.338 Lapua. I may do something slightly different, more like an Ackley Improved version. I read more of your very interesting and educational information posted on your web site. I am very interested in the gain twist rifling, and the logic behind it is sound. There are two USA barrel makers, Kriiger and Bartlien, that do the cut rifling process (instead of button rifling). They may be able to do the gain twist.
I prefer the four groove rifling over the standard twist because of the lower surface contact area and resulting lower friction. Do you have any opinion on this. Some of the local long range shooters (and Palma) are going to three groove rifling now. Lothar Walther apparently has a proprietary stainless steel for their barrels, maybe improved machineability or better durability over R416, any thoughts there?
Richard, please see Rifle Barrels !
Redding has made custom sizing dies for me many times before, and I buy my own custom made chamber reamers. I generally go with my own ideas, but there is so much more information to gain my conversing with knowledgeable people like yourself.
Your bullet design is interesting, among other bullets I use the Barnes MRX and TSX bullets (www.barnesbullets.com).
Best Regards, Richard Saxton, Dienstag, 19. Juni 2007 01:18
Thank you the interesting information. I have not yet bought
a single point cut rifled barrel, but I may try one of Krieger's. I don't know
much about Bartlien barrels I have bought many Shilen barrels in the past, but
my preference now is Lilja barrels. Lilja has some very good technical
information on their website. I'm a mechanical engineer, I do understand the
button rifling process. I work for LeTourneau Technologies, a subsidiary of
Rowan Companies (offshore oil drilling). I take two to three months off in the
fall and run an hunting outfitting and guide service, not open to public, just
to Rowan Companies clients such as BP, Shell, Anadarko etc. Mostly Elk, Moose
and Rocky Mountain Big Horn Sheep. I provide the horses, hunting gear and
guides, we mainly hunt the Wyoming Teton Wilderness Area and try to keep the
Grizzly bears out of camp.
I have many chamber reamers as a set of rough cut, finish reamers, and headspace gauges. I have some 'short throat reamers' also, which I would be very interested in trying on a gain twist barrel. I buy the barrels, and chamber and thread for the action, and do the contour and installation myself. Sometimes I buy short chambered barrels and do the finish reaming myself if it's some type of improved version of the original. I have lathes, milling equipment, and one CNC machine.
The dies are normally .0035" smaller than the chamber, depending on whether the cartridge is belted or not. If I use a modified belted cartridge, I make sure that the dies are made so that the case headspaces on the cartridge shoulder, not the belt. The difference in the dimension between the chamber and the sizing dies depends on whether the intent is for hunting or target shooting.
Thermal expansion is substantially different between the brass alloys used in various cases, and barrel steels. Sometimes we hunt at higher elevations (7,000 to 11,000 feet) with temperatures that may vary from 70 degF to -30 degF.
I send my dimensions to Redding, they make the dies, I don't. After I fire several rounds in the new chamber, I send the fired empty cases to Redding and they pattern my final benchrest dies according to the size of my fired cases. So my dies are made strictly for that particular chamber, not to be used for a different rifle of the same caliber.
I have chamber reamers for 6.5-8mm Remington Magnum, 6.5-.284 Winchester, 6.5-.300 WSM, 25-06 Ackley improved, .257 Ackley Improved, 6mm Rem Ackley Improved, .300 Dakota, 6.5x7mm Dakota, 8mmx.338 Dakota, .260 Rem Ackley Improved, .338-.416 Rigby Improved, and several more.
What would be the cost of a Lothar Walther gain twist barrel in US dollars?
Best Regards, Richard Saxton, Mittwoch, 20. Juni 2007 03:08
Dear Mr. Moeller,
Do You know by any chance a source of information where I can find information for 9 mm Luger polygonal barrel? I don’t think it should be proprietary information but I have a hard time finding it.
I was also surprise to find that currently none of the companies in the world manufacture polygonal progressive barrels. I have a hard time understanding why!
I read Your article on 8x70 and LM-101. I do have a Heym SR-30 straight pull in 8x68S and will be interested to replace a barrel to accommodate LM-101 bullets. There is only one problem – originally LM-101 was designed for 8x68S and now You decided to use necked down .338" LM. Will I be able to use Your LM-101 in 8x68S and do I have to make any changes to barrel (I think that barrel has to be the same but my knowledge is limited). Can You send me specification for barrel so I can order it. Can I purchase barrel from you? How much is a barrel?
Best Regards, Ted Chackter, Mittwoch, 25. Juli 2007 04:26
Dear Mr. Chackter,
the LM-101 may well be used from a 8x68S. To take full advantage from its Potential, a non standard Throat would enhance the Possibilities. Remember, You need a 9° steep Twist, that are 163 mm Twist length. Your Heym Barrel most likely will have 280 mm long Twist, so there is no Way to use that for the LM-101.
I wrote You some Advice on the Polygon 9 mm Barrel, so why would You not start there. I cannot supply further Information.
Sincerely, Lutz Möller