Please could you pm me quick load's calculations for this load.

.243 win
23.75" barrel
1 in 10 twist
load
44.5 gr H380
85gr interbond ie G1 bc 0.395 sec den 0.206
cic large rifle primer

Many thanks to anyone that could help

It's right at 65k. Certainly not a starting load, and I wouldn't go any hotter.

Cartridge : .243 WSSM

Bullet             : .243, 85, Hornady Interbond 22539
Useable Case Capaci: 50.172 grain H2O = 3.258 cm³
Cartridge O.A.L. L6: 2.360 inch = 59.94 mm
Barrel Length      : 23.8 inch = 603.3 mm
Powder             : Hodgdon H380

Predicted data by increasing and decreasing the given charge,
incremented in steps of 1.136% 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

-11.4   83    39.00   3019    1720   44228  10233     97.2    1.238
-10.2   84    39.50   3055    1762   45834  10351     97.6    1.217
-09.1   85    40.00   3091    1804   47494  10465     98.0    1.197
-08.0   86    40.50   3127    1846   49212  10574     98.3    1.177
-06.8   87    41.00   3163    1889   50990  10678     98.6    1.158
-05.7   88    41.50   3199    1932   52830  10777     98.9    1.139
-04.5   89    42.00   3235    1975   54734  10871     99.2    1.120
-03.4   90    42.50   3271    2019   56705  10959     99.4    1.102  ! Near Maximum !
-02.3   91    43.00   3306    2063   58746  11042     99.6    1.084  ! Near Maximum !
-01.1   92    43.50   3341    2107   60860  11119     99.7    1.067  ! Near Maximum !
+00.0   93    44.00   3376    2151   63048  11190     99.8    1.050  ! Near Maximum !
+01.1   94    44.50   3411    2196   65316  11255     99.9    1.033  !DANGEROUS LOAD-DO NOT USE!
+02.3   95    45.00   3446    2241   67665  11314    100.0    1.017  !DANGEROUS LOAD-DO NOT USE!
+03.4   96    45.50   3480    2286   70101  11366    100.0    1.001  !DANGEROUS LOAD-DO NOT USE!
+04.5   97    46.00   3515    2331   72625  11414    100.0    0.985  !DANGEROUS LOAD-DO NOT USE!
+05.7   98    46.50   3549    2377   75244  11460    100.0    0.970  !DANGEROUS LOAD-DO NOT USE!

Results caused by ± 3% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 3% relative to nominal value:
+Ba     93    44.00   3419    2206   66360  11081    100.0    1.026  !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 3% relative to nominal value:
-Ba     93    44.00   3328    2091   59743  11248     99.3    1.076  ! Near Maximum !  

It looks like a good combination of components. If you've shot this load I'd be about how it groups.

quote:

Cartridge : .243 WSSM

I believe it is a 243Win not 243wssm. That makes it even hotter.

Thanks for that AS Only shot a three round at 100m they were all touching I will post back here once I've shot it properly over the chrono interestingly I had a PM with the same details in quick load and it flashed up dangerous at only 42.7
There are no pressure signs on the cases at the moment.
After your post I feel a bit easier as its way over max on any of the listings I have in my old books! Before anyone shouts I have worked up to this from 37gr.

Ramrod, thanks for the catch.....
Yea, .243 win makes it way hot.
Forest if you are using Winchester Cases you water capacity is probably a little more then what QL list, which would reduce your pressure.

 Cartridge          : .243 Win.
Bullet             : .243, 85, Hornady Interbond 22539
Useable Case Capaci: 49.907 grain H2O = 3.240 cm³
Cartridge O.A.L. L6: 2.710 inch = 68.83 mm
Barrel Length      : 23.8 inch = 603.3 mm
Powder             : Hodgdon H380

Predicted data by increasing and decreasing the given charge,
incremented in steps of 1.149% 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

-11.5   82    38.50   2942    1634   45186   9783     98.0    1.249
-10.3   83    39.00   2977    1673   46858   9886     98.3    1.228
-09.2   84    39.50   3012    1712   48588   9984     98.6    1.207
-08.0   85    40.00   3047    1752   50378  10076     98.9    1.187
-06.9   86    40.50   3081    1792   52230  10163     99.2    1.168  ! Near Maximum !
-05.7   87    41.00   3115    1832   54148  10245     99.4    1.148  ! Near Maximum !
-04.6   88    41.50   3149    1872   56134  10321     99.6    1.130  ! Near Maximum !
-03.4   89    42.00   3183    1912   58189  10391     99.7    1.111  ! Near Maximum !
-02.3   90    42.50   3216    1953   60318  10455     99.9    1.093  !DANGEROUS LOAD-DO NOT USE!
-01.1   91    43.00   3250    1993   62522  10513     99.9    1.076  !DANGEROUS LOAD-DO NOT USE!
+00.0   93    43.50   3283    2034   64806  10565    100.0    1.059  !DANGEROUS LOAD-DO NOT USE!
+01.1   94    44.00   3316    2075   67172  10611    100.0    1.042  !DANGEROUS LOAD-DO NOT USE!
+02.3   95    44.50   3348    2116   69625  10653    100.0    1.026  !DANGEROUS LOAD-DO NOT USE!
+03.4   96    45.00   3381    2157   72167  10695    100.0    1.010  !DANGEROUS LOAD-DO NOT USE!
+04.6   97    45.50   3413    2199   74802  10736    100.0    0.994  !DANGEROUS LOAD-DO NOT USE!
+05.7   98    46.00   3445    2240   77536  10775    100.0    0.979  !DANGEROUS LOAD-DO NOT USE!

Results caused by ± 3% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 3% relative to nominal value:
+Ba     93    43.50   3322    2082   68148  10445    100.0    1.035  !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 3% relative to nominal value:
-Ba     93    43.50   3239    1980   61465  10654     99.7    1.085  !DANGEROUS LOAD-DO NOT USE!
 

Ramrod your right it is a 243 win!! I did't spot that makes it a bit wrong does't it?

yea, it makes about a 5k difference if pressure. But just because QL predict that pressure, that doesn't mean that's what it is in YOUR gun.

Thin brass, such as Winchester, or a long throat can reduce pressures.

What brass, and what make of rifle are you using?

tikka t3 varmint and win brass
H2O 55.9gr
COL 2.77" seated on the lands

Here it is with your case capacity and your OAL. It dropped you 7k PSI, but since you are on the lands, your pressures could be higher then reflected.

 Cartridge          : .243 Win.
Bullet             : .243, 85, Hornady Interbond 22539
Useable Case Capaci: 52.510 grain H2O = 3.409 cm³
Cartridge O.A.L. L6: 2.770 inch = 70.36 mm
Barrel Length      : 23.8 inch = 603.3 mm
Powder             : Hodgdon H380

Predicted data by increasing and decreasing the given charge,
incremented in steps of 1.149% 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

-11.5   78    38.50   2875    1560   41488   9819     97.4    1.305
-10.3   79    39.00   2909    1597   42962   9931     97.8    1.284
-09.2   80    39.50   2942    1634   44484  10038     98.1    1.263
-08.0   81    40.00   2976    1672   46054  10141     98.5    1.243
-06.9   82    40.50   3009    1709   47679  10238     98.8    1.223
-05.7   83    41.00   3043    1747   49356  10331     99.0    1.203
-04.6   84    41.50   3076    1786   51087  10418     99.3    1.184
-03.4   85    42.00   3109    1824   52875  10500     99.5    1.165  ! Near Maximum !
-02.3   86    42.50   3141    1863   54723  10576     99.6    1.147  ! Near Maximum !
-01.1   87    43.00   3174    1901   56631  10647     99.8    1.129  ! Near Maximum !
+00.0   88    43.50   3206    1940   58603  10712     99.9    1.112  ! Near Maximum !
+01.1   89    44.00   3238    1979   60640  10772    100.0    1.095  !DANGEROUS LOAD-DO NOT USE!
+02.3   90    44.50   3270    2018   62746  10825    100.0    1.078  !DANGEROUS LOAD-DO NOT USE!
+03.4   91    45.00   3302    2058   64922  10873    100.0    1.062  !DANGEROUS LOAD-DO NOT USE!
+04.6   92    45.50   3333    2097   67172  10919    100.0    1.046  !DANGEROUS LOAD-DO NOT USE!
+05.7   93    46.00   3364    2136   69498  10964    100.0    1.030  !DANGEROUS LOAD-DO NOT USE!  

quote:

+02.3 90 44.50 3270 2018 62746 10825 100.0 1.078 !DANGEROUS LOAD-DO NOT USE!

I think your program is way off. Mine calculated a pressure of 62747

I think I will back off a bit Unless I can get this load measured for real.
Thanks a lot both of you.

quote:

I think I will back off a bit Unless I can get this load measured for real

Measured how?

Key thing to remember is QL is only a calculation based on the data in the system. I never take the data as fact. I allow my rifle to give me an idea of what is happening. If I have no pressure signs and my brass is giving 5-6 reloads with no primer pocket issue I feel safe in using the load. Simple different burn rates in the same powder within normal ranges can give you a +/- 7000psi swing.

Like wise I've had QL caculations saying a load is well below max but in my rifle with my lot of powder I get significant signs.

If you feel more comfortable backing off then please do but I sure wouldn't simply based on a QL calculated pressure. QL also has basically 60,191 as the max so anything over that raises the danger flag. I've also felt is a 6mm can be loaded to 65,000 why not the 243.

You're in good hands with Rammers and 'Sniper New Forest, They've covered the important bits but I have couple of observations that may be relevant.

Firstly as Paul explains QL is not be taken as gospel, if you supply an OAL, a measured case capacity and the burn rate in the simulation matches the burn rate of your lot of powder the predicted velocities and pressures will be very close.

The only way to test this, again as Paul points out, is to let your rifle tell you what is going on, with reference to the QL data.

If QL says your load is producing x psi at y fps, then because we can only measure the velocity and velocity being proportional to pressure the best way to find out if the assumptions are correct is to chronogrpah the load at different chargeweights and compare them to the QL predictions.

IMO, you can then adjust the charge weight to match the velocity you're seeing on the chrono. When I have done this I have found that QL is pretty darn accurate, I mean to a few percent, but the acid test of the pressure of a particular load is how well the brass holds up.

I have Privi brass in my 30.06 that will give hard extraction at around 55-56Kpsi, whereas norma brass seems to take around 62Kpsi and Lapua even higher ( not sure how high as I haven't finished playing with it yet ), in those circumstances the absolute value of Pmax is irrelevant, it's how much pressure can a particular brand take.

The consequence of this is basically that the best way to find out if a oad is reasonable in terms of pressure using QL is to see how long your brass lasts...

I hate having to be honest with my self about the actual utility of new toys...

Do two things, the first is chrono a work up at 1grain increments from say 40-44.5 and post up the velocities and secondly load the same piece of brass on the firing line again and again until you feel the primer pocket starting to come loose.

Best,

Amir

quote:

I've also felt is a 6mm can be loaded to 65,000 why not the 243.

That's probably because at one time the .243 was chambered in the Savage 99, where the 6mm was not. SAAMI specs are set to the lowest denominator, so it was prbably this, or some other non-bolt rifle that lowered the specs for the .243.

65K is pretty much what I load all my modern bolt rifles to.