Need reloading help

[asd9055]

What is the MAP for the 257 AI?

 

[sierracharlie338]

What is the MAP for the 257 AI?

I was only able to find a MAP of 500 for the Roberts +P. Couldn't find an Ackley drawing yet either.

 

[Tripodmvr7]

48200 CUP according to Quick Load = 55K psi

 

[Tripodmvr7]

SC338. I can only do as well as the info supplied. With case volume and COL as shot I can make a much better prediction. The calc I have now done might be way off.

 

[Tripodmvr7]

Calc with present data and default COL and case volume.

 

[asd9055]

I don't think QL was right, that is why I was asking.

 

[Tripodmvr7]

The above calculation shows a pressure of 53K psi. With modern actions a 60K psi limit is usually safe. I prefer a band of 50-55K psi as that ensures good ignition and burn of most propellants. Case should then also be close to 100% fill.

 

[sierracharlie338]

I don't think QL was right, that is why I was asking.

The above calculation shows a pressure of 53K psi. With modern actions a 60K psi limit is usually safe. I prefer a band of 50-55K psi as that ensures good ignition and burn of most propellants. Case should then also be close to 100% fill.

I appreciate the help guys. I am being kicked out of the house regularly for the house to be shown to potential buyers so my schedule changes at the drop of a hat. It's really starting to **** me off. I will be loading some more tonight and will work on getting y'all some info. All of your help is much appreciated!

 

[sierracharlie338]

I don't think QL was right, that is why I was asking.

The above calculation shows a pressure of 53K psi. With modern actions a 60K psi limit is usually safe. I prefer a band of 50-55K psi as that ensures good ignition and burn of most propellants. Case should then also be close to 100% fill.

Ok I finally have some info for yall to work off of.

COAL -2.954
CBTO - 2.441 loaded .020 off the lands

Average water capacity 62.54 (from 10 cases)

Reloader 19
110 Accubond
22 inch barrel with 1:7 twist.

49.9 grains provided about 2882 FPS

I hope this helps. Thanks again for all the help!!

 

[sierracharlie338]

48200 CUP according to Quick Load = 55K psi

52000 CUP was the only number I have found so far and that was not from an official source.

 

[Tripodmvr7]

52K CUP = 60K psi
Your loaded COL is not correct - should it not read 2.941?

Using 2.941 the prediction now is 51.6gr for 2987fps. Pressure calcs at 53K psi.

 

[sierracharlie338]

52K CUP = 60K psi
Your loaded COL is not correct - should it not read 2.941?

Using 2.941 the prediction now is 51.6gr for 2987fps. Pressure calcs at 53K psi.

The case base to ogive is 2.441

The case overall length is 2.954 (base to tip of bullet)

Guess I didn't need to put both measurements haha

 

[Tripodmvr7]

Base to ogive is a measurement you can relate to and does not give total length from tip to base as QL needs.

With COL of 2.954 as shot the charge ups to 51.7gr and speed is the same.

 

[sierracharlie338]

Base to ogive is a measurement you can relate to and does not give total length from tip to base as QL needs.

With COL of 2.954 as shot the charge ups to 51.7gr and speed is the same.

Awesome I have some rounds loaded up to 51.9 to test. Thanks again for all your help!!