Short Siberia Load Development Questions...

[ovenpaa]

I notice people look at me with interest (and scurry away) if I ever resort to safety glasses on the firing point....

[Christel]

Have fun and please report on the forum how it all went!

Pictures please

[dromia]

I always get Joe to shoot my handloads first.

[TattooedGun]

okay, so it looks like (using an old caliper and a steel rule... who'd have thought?) that its about .040" short of the 2.800" benchmark...??? I'm not great at reading rules... I really need to understand more if I'm ever to become an engineer! hahah!

photo above if you wish to dispute...

any ideas on any pressure problems i may encounter?

OAL 2.760" (ish)

[Robin128]

I always get Joe to shoot my handloads first.

:lol: :lol: :lol: :lol: :cheers:

[ovenpaa]

Cartridge : .308 Win.

Bullet : .308, 155, SRA HPBT Palma MK 2155

Cartridge O.A.L. L6: 2.760 inch or 70.10 mm

Barrel Length : 30.0 inch or 762.0 mm

Powder : ? Hodgdon VARGET ?, Temperature: 75 °F



Predicted data by increasing and decreasing the given charge,

incremented in steps of 0.632% of nominal charge.

CAUTION: Figures exceed maximum and minimum recommended loads !



Step Fill. Charge Vel. Energy Pmax Pmuz Prop.Burnt B_Time

% % Grains fps ft.lbs psi psi % ms



-06.3 97 44.50 2885 2864 53853 5630 99.2 1.327 ! Near Maximum !

-05.7 97 44.80 2902 2898 54961 5654 99.3 1.315 ! Near Maximum !

-05.1 98 45.10 2919 2932 56093 5677 99.4 1.304 ! Near Maximum !

-04.4 99 45.40 2936 2966 57248 5700 99.5 1.293 ! Near Maximum !

-03.8 99 45.70 2953 3000 58429 5722 99.6 1.283 ! Near Maximum !

-03.2 100 46.00 2969 3035 59636 5743 99.6 1.272 ! Near Maximum !

-02.5 101 46.30 2986 3069 60868 5763 99.7 1.261 ! Near Maximum !

-01.9 101 46.60 3003 3104 62128 5783 99.8 1.251 !DANGEROUS LOAD-DO NOT USE!

-01.3 102 46.90 3020 3139 63416 5801 99.8 1.241 !DANGEROUS LOAD-DO NOT USE!

-00.6 103 47.20 3036 3173 64732 5818 99.9 1.230 !DANGEROUS LOAD-DO NOT USE!

+00.0 103 47.50 3053 3208 66077 5835 99.9 1.220 !DANGEROUS LOAD-DO NOT USE!

+00.6 104 47.80 3070 3243 67452 5850 99.9 1.211 !DANGEROUS LOAD-DO NOT USE!

+01.3 105 48.10 3086 3278 68858 5865 100.0 1.201 !DANGEROUS LOAD-DO NOT USE!

+01.9 105 48.40 3103 3313 70296 5879 100.0 1.191 !DANGEROUS LOAD-DO NOT USE!

+02.5 106 48.70 3119 3349 71767 5892 100.0 1.181 !DANGEROUS LOAD-DO NOT USE!

+03.2 107 49.00 3136 3384 73271 5904 100.0 1.172 !DANGEROUS LOAD-DO NOT USE!



Results caused by ± 10% powder lot-to-lot burning rate variation using nominal charge

Data for burning rate increased by 10% relative to nominal value:

+Ba 103 47.50 3148 3411 77549 5593 100.0 1.151 !DANGEROUS LOAD-DO NOT USE!

Data for burning rate decreased by 10% relative to nominal value:

-Ba 103 47.50 2912 2919 54827 5911 97.1 1.313 ! Near Maximum !

[TattooedGun]

Oh dear, thats really not the news I was hoping to hear!

I guess I'll have to leave the 30 that I've done already and reload a bunch more without seating the bullet too deep this time! - leave these ones until I can get a bullet puller!

start at the top and work it in until its right, should have followed instructions better!

if its not too much trouble, what would that program say if they were at 2.800" OAL?

[ovenpaa]

Not a huge difference. One thing I will say is this is based on a max pressure of 62k PSI and I base mine on 65k PSI but even with the 65k limit at 2.800" QL is giving a Pmax at 47.80 - This is only an indication and your actual results may be different but it is a good starting point.


Cartridge : .308 Win.

Bullet : .308, 155, SRA HPBT Palma MK 2155

Cartridge O.A.L. L6: 2.800 inch or 71.12 mm

Barrel Length : 30.0 inch or 762.0 mm

Powder : ? Hodgdon VARGET ?, Temperature: 75 °F



Predicted data by increasing and decreasing the given charge,

incremented in steps of 0.632% of nominal charge.

CAUTION: Figures exceed maximum and minimum recommended loads !



Step Fill. Charge Vel. Energy Pmax Pmuz Prop.Burnt B_Time

% % Grains fps ft.lbs psi psi % ms



-06.3 95 44.50 2869 2832 52235 5660 99.1 1.342

-05.7 96 44.80 2885 2865 53293 5686 99.2 1.330 ! Near Maximum !

-05.1 97 45.10 2902 2899 54372 5711 99.3 1.319 ! Near Maximum !

-04.4 97 45.40 2919 2933 55474 5734 99.4 1.308 ! Near Maximum !

-03.8 98 45.70 2936 2966 56599 5757 99.5 1.298 ! Near Maximum !

-03.2 99 46.00 2953 3000 57748 5779 99.6 1.287 ! Near Maximum !

-02.5 99 46.30 2969 3034 58922 5801 99.7 1.276 ! Near Maximum !

-01.9 100 46.60 2986 3068 60120 5821 99.7 1.266 ! Near Maximum !

-01.3 100 46.90 3002 3103 61344 5841 99.8 1.255 !DANGEROUS LOAD-DO NOT USE!

-00.6 101 47.20 3019 3137 62595 5859 99.8 1.245 !DANGEROUS LOAD-DO NOT USE!

+00.0 102 47.50 3036 3171 63872 5877 99.9 1.235 !DANGEROUS LOAD-DO NOT USE!

+00.6 102 47.80 3052 3206 65177 5894 99.9 1.225 !DANGEROUS LOAD-DO NOT USE!

+01.3 103 48.10 3068 3240 66511 5910 100.0 1.215 !DANGEROUS LOAD-DO NOT USE!

+01.9 104 48.40 3085 3275 67874 5925 100.0 1.206 !DANGEROUS LOAD-DO NOT USE!

+02.5 104 48.70 3101 3310 69267 5939 100.0 1.196 !DANGEROUS LOAD-DO NOT USE!

+03.2 105 49.00 3117 3345 70691 5952 100.0 1.186 !DANGEROUS LOAD-DO NOT USE!



Results caused by ± 10% powder lot-to-lot burning rate variation using nominal charge

Data for burning rate increased by 10% relative to nominal value:

+Ba 102 47.50 3132 3375 74921 5638 100.0 1.165 !DANGEROUS LOAD-DO NOT USE!

Data for burning rate decreased by 10% relative to nominal value:

-Ba 102 47.50 2894 2882 53034 5939 96.9 1.330 ! Near Maximum !

[ovenpaa]

I should add that these QL dumps are purely and indication and not 100% accurate so I strongly suggest you start off a good bit lower and stop at the first signs of pressure, especially as this is a new to you rifle.

[Dougan]

haha, last time I went to fultons i spent over £2k on an RPA

Though I'd seen that rifle before....

I don't know if you've paid for a marker or you've got your future MIL butt marking for you ( ), but if there are 'markers' in the butts, then there will be a shared NRA radio down there, and another at the point. Check in the office when you book in (or phone the day before to make sure), and they'll sort you out.

The same goes with the target, as Ovenpaa said, the standard 100 yd target should already be there...but check with the NRA office.

At Short Siberia 100yrd point, the point is divided in two, with covered benches (set back from 100 yrd), and 'prone points' to the right (which are 100 yrd) - if you want to shoot prone, again call the office to make sure you're 'on the right'.

With the advice you've already been given, I'm sure you can make some safe (COAL) rounds, but without calipers to measure there's not much point - because small differences will affect the accuracy. Personally I'd buy some RUAG or other good ammo (your rifle was built to shoot these rounds), and sort the 'zero' out (on and off the sand bag). Then take a few live ones home to measure, and copy the COAL - then make your loads to match.

There's loads of info on this forum about reloading, including how to take a cast of your chamber, to work out the perfect COAL. But to begin with you can't go wrong by copying the ammo you rifle (and a nice one too ) was designed to shoot.