Can someone break down the meanings of the number sequence for arrows, for example:

300/70 0.350 9.4 433 278

exactly what do those numbers mean? I got the gpi (9.4) but cant seem to find out the other numbers meanings. And how to I figure total arrow weight. if these are tipped with 100 grain arrows what would the total weight be? The arrows are 28.25" Any help would be greatly appreciated!

Your total arrow weight would be around 380 grains (with vanes nock and inserts) .350 is the diameter and as for the others i don't know.

I'd have to know exactly what you are referencing here, such as is this what someone said or is this from a manufacturers web site or are these numbers that your pro shop gave you?????

But I'll give my best shot.

300/70 - the label on the particular arrow.
0.350 - the actual spine rating of the particular arrow
9.4 - the weight of the bare arrow shaft in grains per inch with nothing installed on or in the shaft.
433 - total finished weight of the arrow with vanes, inserts and tip installed.
278 - the speed of the finished arrow in feet per second.

Each mfg puts a different label on their shafts. Some put the actual spine, those look like .300-.340-350.-.400-.500 The .300 is the stiffest in that range of numbers. Aluminum shafts had a number like 2216 and the first two was the outside diameter in 64ths. the second two was the thickness of the tube, in this case sixteen thousands of an inch or .016. Some companies like Gold Tip and some others use the 5575 or 3555 and 7595 and has no spine corelation. Now to figure the weight of your complete arrow: gpi + vane weight X how many + nock + insert + tip weight. For 2" vanes I use 21grs total, inserts usually around 15grs and the nock 8grs. or just 40-45grs added to the tip and the shaft weight.