I'm thinking about switching from carbon to aluminum arrows. My current setup is 60" recurve, elevated rest 47#@28, and 64"longbow, off the shelf,44#@28". I have a 28 inch draw. I'm currently shooting GT3555,30.5" with both bows different weights up front. Stu Miller helped me set my arrows up.I have tried to research my questions on here and other sites but some questions I can't find any info. So here goes:
1. On Stu Millers calculator he has Gamegetters listed with spines and Alum #'s with X7 after them. Does the X7 stand for XX75 easton arrows?
2.What is the difference between arrows that start with 19, 20 and 21? I believe this is wall thickness but can't confirm.
3. With me currently shooting a 500 spine carbon arrow should I stay with a 500 spined aluminum arrow?
4. Are the XX75 Gamegetters and the XX75 Camo arrows the same with the exception of price and weight tolerances?

I appreciate any help on this. Thanks.

The 19, 20,21 as the first two numbers represent how big around. 19/64 20/64 etc the other two are thickness.

You can start with 500 (2016) alums and will end up close to where you are now with 500 carbons but the true beauty in alums is that if you want to shoot a 29" or 28.5" arrow with 125 up front there is a combination out there that will work, where as with carbons you will find the general spine you need I.e. 500 and then you end up with the length you want but maybe not the point weight and vice versa.

Game getters and the camos vary in tolerance but they are both fantastic shafts.

Real world example . My 2018. Fly great with 175 point at 30", but I wanted a shorter arrow with less tip weight so now I have some 28 7/8" 1916 with 145. I could go to a 1913 if I wanted shorter. Alums give you a ton of options to play with

just dont shoot at at pigs, they break off as they run through the brush.....  

I agree with Brianlocal3 on the 2016. That is a great choice for your set-ups. rat'

The first two numbers are shaft diameter in 64ths of an inch the second tow are wall thickness in thousanths. 2016 is 20/64" diameter with 16 thousanths wall thickness.

To compare the different shafts go to Easton's website. There you will find the difference in the shaft materials. Not sure what Stu means about X's. there are XX75, XX78, X7. The Gamegetters is XX75 but the specks are not as close as the camo shafts. The Gamegetters donot have as much tensile strength as well. They are good shafts and great for hunting as well as any other shaft.

I think the X7 is a target arrow.

X7's are the blue ones. Good arrows as well, easier to find than the camo ones! The autumn orange ones are still my favorites. I snap up 2117's in those every time I find them

I shoot in the same weigh range & have found the game getters with the 400 spine & 100gn up front work out well - I think the gpi on both 500 & 400 are both around 10 so not a big difference unless you want to up your FOC - if that's the case then the 400 would be a better bet I'd think  - if you're shooting a plunger & want heavier arrows for indoors stuff you should be OK too- I've shot the 400s without complaint at 32# as well - M

MODERN "GAME GETTER'S"  ARE  xx75s.   The older ones  WERE NOT >( Older ones Game GETTERS were dark "LODEN" green and GAME GETTER II's  Brown and tan CAMO)  The older ones   were  SLIGHTLY less in aluminum quality ( really not that much to worry about ) and the straightness factor  was less also.   MODERN  ones are  xx75 quality .    xx78s were a SLIGHTLY better quality aluminum from xx75's and   SLIGHTLY better in straightness.      xx78's were  Super Slams , and some of the quality , Target and specialty shafts like the ECLIPSE and PLATINUM'S

for the money gamegetters are the best bang for the buck.(no pun ment)

Oops update re my earlier post on game getter gpi - from 3Riv - 500 spine= 2016= 10.6gpi & 400 spine= 2117= 12 gpi - explains why those 400s I've got have lasted so long

Anyone know where the old Easton arrow chart is posted???

I believe somewhere it is available

Here it is Gator, click on the "true specs" tab.

http://www.eastonarchery.com/arrows/alloy-xx75-camo-hunter/0/2

Thank you I appreciate it a great deal.

2016 should shoot good out of that setup