Thread: Short fatties vs long slender ones...

Originally Posted by Stocky

Out of pure interest i just ran a 20 inch barreled 7SAUM against a 20 inch barreled 280AI in quickload with capacities being averaged to the same 73Grains and seating depths of the 180 eld m to the same depth to keep useable capacity identical. The results where all the same powders and same loads to reach identical pressures however interestingly the Saum alway leads in velocity at that pressure by 19-20fps. Im guessing this if due to the extra half inch of effective barrel length.
Obviously this isn't a real test but its based on a program based on lots of testing.

The issues (not to discredit it but maybe why they cant be taken as gospel) I see with the 300wsm vs 300H&H test are as follows:
-There is higher case capacity (a few grains) on the 300H&H.
-We dont know what seating depths were and whether they where kept consistent.
- How was the extra barrel added?
- Without seeing the test there appear to be quite a few uncontrolled variables including how to determine actual pressures etc as by feel isn't accurate at all.

I feel there may be an advantage by shorter cases but i imagine its minimal. The consistency of burn leading to a more efficient burn appears to be true so wouldn't a more efficient burn lead to more velocity? Also your half inch shorter the second you drop to a short action anyway so could run a half inch longer barrel for same overall length.

I dont think we will ever see a proper answer but velocity probably shouldn't be the only factor.

Yes most people dont realise that for the exact same barrel length a saum or wsm type cartridge will have a greater length of rifling compared to a longer case such a a 7RM etc.

This has to give a slight increase in velocity for the powder burnt.