Sunday 27 September 2009

more reasons for the .338-06 A-Square

What are my other considerations for the .338-06 A-Square?

Well, there is brass available for it. That meas you don't have to either buy factory ammo and reuse the cartridges or fireform other cartridges. The first option leaves you with ammo you don't want and is expensive. The second option has problems when crossing borders as you are carrying ammo that has a different bottom stamp to the calibre of your firearm or to what it says on your licence.

And there is brass available from Norma, which has a very good name and does not have to go through any preparation stages before being loaded for the first time. This is not the case for the 3rd potential candidate: the .338 Ruger Compact Magnum (which is not in my version of quickload).

Saturday 26 September 2009

or maybe something a bit bigger? .338-06 A-Square

The fact that any kind of load that achieves decent speeds for the KJG leads to compressed loads in .338 Federal led me to looking for other options. Now I don't want a Magnum for 2 reasons.

1) I don't see any reason. I am not likely to shoot much further than 200m, so why would I need a Magnum?
2) I have found a full length moderator that basically looks like thicker barrel and has a diamter of 25mm, ie looks like a match barrel. This moderator at the moment can use a maximum of 30-06 Ackeley Improved, so I am hoping that the .338-06 will be usable. As that moderator involves drilling holes into the last 1.5" (make that 38mm) of the barrel the usable length goes down to 20.5", ie 520mm. Quickload still recommends Nitrochemie A/S 0300, so that is what I am using here.



**** Input data:                        Date: 26-Sep-2009     Time: 23:03:18
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)= 9.01       Groove calibre          (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)= 520.7 
**** Values calculated:
Seating depth          (mm)= 8.99       Volume displaced    (cu.cm)= 0.52 
Comb.chamber volume (cu.cm)= 3.96       Projectile travel      (cm)= 46.63 
**** Input data:
Propellant type........... = Nitrochemie A/S 0300
Charge weight...........(g)= 3.592      Load density......(g/cu.cm)= 0.907
Heat of Explosion   (kJ/kg)= 3950       Ratio of spec. heats cp/cv =  1.2401 
Solid density     (g/cu.cm)= 1.62       Weighting factor...........= 0.50
Burning rate factor Ba(1/s)= 0.675      Pro-/degressivity factor a =  0.94 
Burning limit ......... z1 = 0.5        Combust.Chamber Vb     (m³)= 3.962196E-6
Factor.................. b = 1.7        X-S.Area of Bore      A(m²)= 5.695E-5
Bulk density      (g/cu.cm)= 0.944      Projectile mass mp     (kg)= 9.007E-3
Loading ratio           (%)= 96.0       Projectile travel x     (m)= 4.6634E-1
**** Results calculated:
Maximum pressure ........  =  420 MPa     Way of projectile at Pmax=  41.4 mm
Muzzle velocity  ...... Ve =  981m/s      Muzzle pressure .......Pe=  64 MPa
Project. energy at muzzle =  4336J      Fraction of powder burnt  = 100  %
Projectile travel time from 10% Pmax to muzzle = 0.85 ms


KJG needs at least 750 m/s to open properly, so that needs to be achieved at whatever range one intends to hit. As the below ballistics table shows, this lets me do that to slightly beyond 250m:

 Muzzle velocity  : 981 m/s
 Crosswind speed  : 0 m/s
 Ballistic Coefficient(s) (G1):
 C1=0.362@V>800 m/s;
 C2=0.307@V>400 m/s;
 C3=0.335@V>340 m/s;
 C4=0.272@V>300 m/s;
 C5=0.253@V>0 m/s;


 Optimum trajectory information :
 Optimum sight-in range (X) = 190 m
 with max. ordinate above LOS at range (M)= 113 m
 and max. point blank range (P)= 220 m.
-------------------------------------------------------------------------------------
 Sight-in clicks, 1 click = 1.0 cm/100 m or 0.394 in/100 m
 Height of sight above bore axis = 3.6 cm or 1.417 inch
 Gun is zeroed-in at 200 m,
 by sighting-in at level firing
-------------------------------------------------------------------------------------
 Range  Velo Time of  Energy   Path    Deflection    Total  Sight correction  Target
        city  flight            to    at crosswind    drop   for setting new   lead
                                LOS    of 0.5 m/s              zero range     10 m/s
-------------------------------------------------------------------------------------
·Meter   m/s     s    Joule     cm     cm      MOA     cm    Clicks     MOA      m  ·
-------------------------------------------------------------------------------------
|    0   981  0.0000   4336    -3.6    0.0   -----     0.0   ------    -----    0.00
|   25   958  0.0258   4132    -0.6    0.0    0.02     0.3     +2.2    +0.76    0.26
|   50   935  0.0522   3936    +1.8    0.1    0.04     1.3     -3.6    -1.25    0.52
|   75   912  0.0792   3749    +3.5    0.1    0.06     3.0     -4.7    -1.61    0.79
|  100   890  0.1069   3569    +4.5    0.2    0.08     5.4     -4.5    -1.53    1.07
M  118   874  0.1273   3444    +4.7    0.3    0.09     7.6     -3.9    -1.36    1.27
|  125   868  0.1353   3396    +4.6    0.4    0.10     8.6     -3.7    -1.27    1.35
|  150   847  0.1646   3231    +4.0    0.5    0.12    12.7     -2.6    -0.91    1.65
|  175   826  0.1947   3072    +2.4    0.7    0.14    17.6     -1.4    -0.48    1.95
X  200   805  0.2255   2919     0.0    1.0    0.17    23.4      0.0     0.00    2.25
|  225   782  0.2570   2754    -3.3    1.2    0.19    30.1     +1.5    +0.51    2.57
P  229   778  0.2621   2727    -4.0    1.3    0.19    31.2     +1.7    +0.59    2.62
|  250   758  0.2892   2590    -7.6    1.6    0.21    37.7     +3.0    +1.05    2.89
|  275   735  0.3224   2433   -12.9    1.9    0.24    46.4     +4.7    +1.62    3.22
|  300   712  0.3570   2283   -19.5    2.3    0.27    56.3     +6.5    +2.23    3.57
-------------------------------------------------------------------------------------
M = Peak vs. L.O.S, X = Set Zero, P = Max. Point Blank Range
Elevation above Angle of Site (0.0 deg.)  = 0.0772 deg.





Thursday 17 September 2009

.338 Federal

The .338 Federal is a nice "against the trend" development by Federal. All tests seem to agree that it is quite a deadly little cartridge, which is basically a necked up .308 Winchester. I had a few doubts about usability with KJG, which demands rather high speeds, but it looks good:

**** Input data:                         Date: 17-Sep-2009     Time: 01:21:09
Cartridge................. = .338 Federal
Projectile type........... = 8.58, 9., Möller 8,5 mm KJG S with boattail
 
Max.avg.pressure(Piezo Wil)= 415 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)= 3.73        Length of projectile   (mm)= 30.48 
Length of barrel       (mm)= 560 
**** Values calculated:
Seating depth          (mm)= 10.52       Volume displaced    (cu.cm)= 0.61 
Comb.chamber volume (cu.cm)= 3.13        Projectile travel      (cm)= 51.94 
**** Input data:
Propellant type........... = Nitrochemie A/S 0300
Charge weight...........(g)= 3.04        Load density......(g/cu.cm)= 0.972
Heat of Explosion   (kJ/kg)= 3950        Ratio of spec. heats cp/cv =  1.2401 
Solid density     (g/cu.cm)=  1.62       Weighting factor...........= 0.50
Burning rate factor Ba(1/s)= 0.675       Pro-/degressivity factor a =  0.94 
Burning limit ......... z1 = 0.5         Combust.Chamber Vb(m³)= 3.126347E-6
Factor.................. b = 1.7         X-S.Area of Bore A(m²)= 5.695021E-5
Bulk density      (g/cu.cm)= 0.944       Projectile mass mp(kg)= 9.007E-3
Loading ratio           (%)= 103.0       Projectile travel x(m)= 5.1936E-1
 
**** Results calculated:
Maximum pressure ........ =  400 MPa     Way of projectile at Pmax =  32.7 mm
Muzzle velocity  ......Ve =  949 m/s     Muzzle pressure .......Pe =  48 MPa
Project. energy at muzzle =  4053 J      Fraction of powder burnt  = 99.8  %
Projectile travel time from 10% Pmax to muzzle = 0.92 ms


This looks like a nice starting load for this cartridge and it only slows down to < 750 m/s beyond 225 m which strikes me as OK. The BC of the short 8.5mm KJG are not overwhelming but still the ballistics look sufficient. Wants!



1st moves

Ok, I have become a member of a rifle and shooting club and thus fulfill the necessary requirement to procure a gun. I have had a look around for gunsafes and will talk to the landlady about putting one up. I know which gun I want and will soon put down a down payment on one. A freind of mine who owns land has agreed to sign for me that I can shoot on his land. Things are coming together ... Rabbits here I come!

I will go with the Savage mentioned further down with a moderator and work on getting the licence for hares as well. That should prove entertaining, since it may well be the first licence in the state that says that. I hope my super can be talked to. I have contact persons I can name for him to ring ...

Time for a rant

OK, there is a German term "Waidgerechtigkeit" which is nearly impossible to translate, but encompasses doing things so that one's prey animals don't suffer needlessly and in general be humane and fair about one's sport. It has taken on a major flavour of tradition and "the way one does things".

The problem is now that this tradition of course will get in the way of progress, even if that progress might improve the chances for a humane kill. A couple of days ago I read on the German hunting forum on which I hang out two comments from the same experienced hunter:

  • He would never let anybody hunt on his hunt who used a rifle with a thumbhole stock. When questioned why he said "because this shows a mindset of wanting to push the envelope and trying to do things that are not good for the prey" - basically I think he meant wanting to shoot too far.
  • He said that he had never been on a shooting range since he took his hunting exam in 1973!
So let me get this straight mate. Not only do you not practice, you also refuse to allow others to use things that increases their chance for a good kill? And that is "waidgerecht" how ?!?! I honestly cannot believe this. In a lot of other areas the man talks sense but the bigottry displayed here is beyond belief.

Monday 14 September 2009

And again cartridge ...

Well, i spent the last few days looking around and reading and I found that there is company in New Zealand that makes over the barrel moderators. Now this I consider very useful since it keeps the length of the rifle at a reasonable level and also they can be made quite thin if the cartridge is not too massive. So I talked to the guys at JMS Arms (warning, use IE for this link) and they suggested that .338 WM needs a 32mm wide over the barrel moderator. I asked about .338 federal and 8.5x63 Reb and he said he'd ask. I have been looking at .338 federal, which is a necked up .308 winchester where he said he was reasonably sure it would work with a 25mm over the barrel mod.

Now that would be nifty :)

.338 federal means that i should likely not over 250m with KJG but from my current shooting I am not convinced that i shoud shoot that far anyway ;)

Sunday 13 September 2009

sighting in a rifle

There appear to be two schools in sighting in a rifle:
1) sight in your rifle to the optimum sighting-in distance, which assumes that your targets don't care whether you shoot them 4cm higher or lower than what you are aiming for.
2) sight in your rifle to 100m and use a ballistics table or a ballistic tower on your scope for adjustment of distance according to what you have measured.

The problem that I see with 1) is that you are basically adding those 8 cm to your own errors, so that your shot distribution is not going to look like this:



with the half circle at the top being your margin of error at the shorter range where you will be @ +4cm and the larger circle on the bottom your margin of error when you are at the longer range where -4cm applies. Whether you are prepared to accept that is IMO dependent on how good a shot you are and whether you'll be able to keep this in mind when you are shooting at a fox for instance where even the 8cm may be slightly pushing it.

For myself I have decided against this and am planning to get myself a Leupold scope with the bullet drop correction dials, which they will custom make for your load. This requires a rangefinder, but hey, that is a sensible thing to get anyway.

Saturday 12 September 2009

More on powders

Well, it turns out that the 8.5x63 is actually reasonably loadable with Norma 201. Not quite as fast a bullet, but I think trading 20 m/s for a huge fireball sounds like a good deal. I also had a look at the .270 Winchester, which I might have to get as a second barrel if I fail in arguing the 8.5x63.

Friday 11 September 2009

Powders

I have been remiss in my updates

I have done a lot of thinking about shtuff and I am getting clearer on what I want.

This first update will deal with powders. Reloading is not legal in Ireland, and the new firearms law has provisions that make the import of guns and ammunition impossible for a private indivudual, it has to be done by a licensed firearms dealer. But: This part of the law has been passed but not yet scheduled andI am having my doubts that it ever will. It would be just like the Irish to react to the public's comments by not scheduling part of a law that was passed. An example I can think of is the German law on cheques which has crossed cheques but those 2 paragraphs never got scheduled. So for the time being I will assume that one can import one's own ammunition. If that changes I'll have to talk to a dealer.

Why is that important? oh, sorry forgot to mention that. KJG is mostly a reloaders bullet, the is no mainstream manufactured ammo with it. And as it happens the guy we are moving next door to in Sweden is a reloader, so I'll be able to work with him.

So from what I can see from Quickload is that one gets the best results from dual base ball powders like the Winchester W748 or Hogdon BL-C2. These are prone to creating big fireballs since the nitroglyicerin contained in them leaves spare hydrogen when burning which of course will burn when in contact with air, ie. after leaving the muzzle. So for hunting at night (boar) this would be unuseful. At the moment I am trying to find out what the story is with moderators swallowing that fireball. i know they can swallow the fireball from not 100% combustion in the barrel, the question is quite simply how big the fireball from the hydrogen is ...

I'll report back when i know this.



Hmmpf. So much for 8 x 64S

Well, here goes that idea. Lutz Moeller just declared that he is discontinuing the  KJG 8003 which puts paid to havign a 9g bullet in 8mm from him. This drives the necessary calibre up to .338" or 8.5 mm. There is a new German cartridge there, the 8.5 x 63 Reb by Werner Reb. About the same amount of energy as the 8x64 S, so no big deal really. And actually a modern development.

More on the subject to follow.