Sunday 4 October 2009

and the winner is: the .338-06 A-Square!

I get more muzzle velocity out of less powder:

**** Input data:                         Date: 4-Oct-2009     Time: 15:46:16
Cartridge................. = .338-06 A-Square
Projectile type........... = 8.58, 9., Möller 8,5 mm KJG S with boattail
 
Max.avg.pressure(Piezo A-S)= 448 MPa     Shot start / init pressure = 15 MPa
Projectile weight       (g)= 9.007       Groove caliber         (mm)= 8.59
Length of cartridge    (mm)= 84.84       Length of case         (mm)= 63.35 
Case capacity       (cu.cm)= 4.48        Length of projectile   (mm)= 30.48 
Length of barrel       (mm)= 560 
**** Values calculated:
Seating depth          (mm)= 8.99        Volume displaced    (cu.cm)= 0.52 
Comb.chamber volume (cu.cm)= 3.96        Projectile travel      (cm)= 50.56 
**** Input data:
Propellant type........... = ADI AR 2219
Charge weight...........(g)= 3.732       Load density......(g/cu.cm)= 0.942
Heat of Explosion   (kJ/kg)= 4000        Ratio of spec. heats cp/cv =  1.231 
Solid density     (g/cu.cm)= 1.57        Weighting factor...........= 0.50
Burning rate factor Ba(1/s)= 0.67        Pro-/degressivity factor a = 0.4497 
Burning limit ......... z1 = 0.5         Combust.Chamber Vb(m³)= 3.962779E-6
Factor.................. b = 1.6         X-S.Area of Bore A(m²)= 5.695E-5
Bulk density      (g/cu.cm)= 0.950       Projectile mass mp(kg)= 9.007E-3
Loading ratio           (%)= 99.1        Projectile travel x(m)= 5.0563E-1
 
**** Results calculated:
Maximum pressure ........ =  430 MPa     Way of projectile at Pmax =  37.1 mm
Muzzle velocity  ......Ve =  999 m/s     Muzzle pressure .......Pe =  60 MPa
Project. energy at muzzle =  4493 J      Fraction of powder burnt  = 99.7  %
Projectile travel time from 10% Pmax to muzzle = 0.88 ms



updates on own rifle

I have finished joining a gun club, it is Hilltop. I will probably not end up buying my equipment there, as I am particular about stuff and they don't appear to be good at accommodating stuff that is out of the ordinary. Also their prices are high. I got my gun safe 60 € cheaper elsewhere.

I am ending up buying not a .17 HMR, but a .22 lr, since not a lot of ranges in the country are actually certified for anything bigger than .22 lr. hence my rifle is the Savage Mark II BTVS. I have the serial number, most of the other stuff, 2 references - BTW they will likely be called, so one should warn them ;) I was bemused to read in the shooting boards how people were outraged that their references were actually called and. Guys it is called 2reference" not "names of parson or teacher I know the name and address of".

Oh and I am buying the gun in Norn Iron, since a) the guy could deliver faster and b) it is cheaper, £580 vs €800 from a shop in Cavan.

Cruelty to animals

I can't say this on the hunting boards but let me be clear on this: I consider hunting on horseback "par force" or coursing with hounds to be cruelty to animals. I despise it and I will not be solidarical with people who do it. I have recently been directly asked to be that and no. Just because you can't see the tortured creature I am not obliged to be solidarical with your actions. I despise this kind of hunting from the bottom of my heart.

This has got me thinking

I appears that Nitrochemie do not offer powders for reloaders any more. I will try and verify that tomorrow though. I have calculated two loads for the .338 Federal and the .338 RCM (which I had to fudge on the basis of the .300 RSAUM, since my QuickLoad doesn't have that cartridge yet).

**** Input data:                         Date: 4-Oct-2009     Time: 13:25:07
Cartridge................. = .338 RCM Fudge II - from .300 RSAUM
Projectile type........... = 8.58, 9., Möller 8,5 mm KJG S with boattail
 
Max.avg.pressure(Piezo SAA)= 448 MPa     Shot start / init pressure = 15 MPa
Projectile weight       (g)= 9.01        Groove caliber         (mm)= 8.59
Length of cartridge    (mm)= 71.76       Length of case         (mm)= 50.88 
Case capacity       (cu.cm)= 4.67        Length of projectile   (mm)= 30.48 
Length of barrel       (mm)= 560 
**** Values calculated:
Seating depth          (mm)= 9.6         Volume displaced    (cu.cm)= 0.55 
Comb.chamber volume (cu.cm)= 4.12        Projectile travel      (cm)= 51.87 
**** Input data:
Propellant type........... = IMR 4895
Charge weight...........(g)= 3.731       Load density......(g/cu.cm)= 0.905
Heat of Explosion   (kJ/kg)= 3860        Ratio of spec. heats cp/cv =  1.2431 
Solid density     (g/cu.cm)=  1.58       Weighting factor...........= 0.50
Burning rate factor Ba(1/s)= 0.61        Pro-/degressivity factor a = -0.15 
Burning limit ......... z1 = 0.6         Combust.Chamber Vb(m³)= 4.121772E-6
Factor.................. b = 1.6         X-S.Area of Bore A(m²)= 4.7291E-5
Bulk density      (g/cu.cm)= 0.890       Projectile mass mp(kg)= 9.007E-3
Loading ratio           (%)= 101.7       Projectile travel x(m)= 5.1871E-1
 
**** Results calculated:
Maximum pressure ........ =  430 MPa     Way of projectile at Pmax =  43.5 mm
Muzzle velocity  ......Ve =  978 m/s     Muzzle pressure .......Pe =  71 MPa
Project. energy at muzzle =  4310 J      Fraction of powder burnt  = 99.9  %
Projectile travel time from 10% Pmax to muzzle = 0.96 ms


and

**** Input data:                         Date: 4-Oct-2009     Time: 13:25:07

Cartridge................. = .338 RCM Fudge II - from .300 RSAUM

Projectile type........... = 8.58, 9., Möller 8,5 mm KJG S with boattail

Max.avg.pressure(Piezo Wil)= 440 MPa     Shot start / init pressure = 15 MPa
Projectile weight       (g)= 9.01        Groove caliber         (mm)= 8.59
Length of cartridge    (mm)= 71.12       Length of case         (mm)= 51.16 
Case capacity       (cu.cm)= 4.67        Length of projectile   (mm)= 30.48 
Length of barrel       (mm)= 560 
**** Values calculated:
Seating depth          (mm)= 10.51       Volume displaced    (cu.cm)= 0.55 
Comb.chamber volume (cu.cm)= 4.12        Projectile travel      (cm)= 51.93 
**** Input data:
Propellant type........... = Norma 200
Charge weight...........(g)= 3.031       Load density......(g/cu.cm)= 0.969
Heat of Explosion   (kJ/kg)= 3850        Ratio of spec. heats cp/cv =  1.239 
Solid density     (g/cu.cm)=  1.58       Weighting factor...........= 0.50
Burning rate factor Ba(1/s)= 0.555       Pro-/degressivity factor a =  6.5 
Burning limit ......... z1 = 0.3         Combust.Chamber Vb(m³)= 3.126928E-6
Factor.................. b = 2.2         X-S.Area of Bore A(m²)= 5.695E-5
Bulk density      (g/cu.cm)= 0.952       Projectile mass mp(kg)= 9.007E-3
Loading ratio           (%)= 101.8       Projectile travel x(m)= 5.1934E-1
 
**** Results calculated:
Maximum pressure ........ =  430 MPa     Way of projectile at Pmax =  32.1 mm
Muzzle velocity  ......Ve =  948 m/s     Muzzle pressure .......Pe =  46 MPa
Project. energy at muzzle =  4047 J      Fraction of powder burnt  = 100  %
Projectile travel time from 10% Pmax to muzzle = 0.92 ms

So this is pretty much 30m/s more muzzle velocity in exchange for a bigger cartridge, possible problems with sound moderation and maybe greater difficulties getting a licence. OTOH this increases the usable range of the KJG from 200m to just over 250m.

Saturday 3 October 2009

and more on cartridges - this time the .338 RCM

Well, me being me, when I had my rummage around for .338 cartridges, I stumbled upon the .338 Ruger Compact Magnum. Regardless of some silly marketing blahblah ("same power as a .338 Winchester Magnum, but from a 20" barrel" - yeah right) it turns out that it has basically the same volume as the .338-06, so we should still be able to use it with a 25mm over-the-barrel moderator, but it is a short action cartridge, which will not only potentially allow for a shorter barrel (which I am not usually a fan of, but let's not forget that a moderator adds something like 15 to 20cm to the length of the barrel), but also makes a "short, fat magnum", which means better combustion than in a long catridge. So quite possibly one can get a few more m/s out of it. And the added effective barrel length of a short action doesn't hurt my feelings either.

On  the other hand, the .338-06 gets a similar performance with lower pressures. This is from Hodgdon, since my version of QuickLoad doesn't have the .338 RCM