How many gpi should I account for insert, nocks, and 3 blazers vanes?

What type of arrows are we talking about here? If I remember correctly the inserts and nocks on my ICS style carbons usually weigh around 25 grains total. I don't know the weight of the short blazers but would guess around 6 grains each. Check out www.bowjackson.com . I believe he has an arrow weight calculator on his site.

I am shooting a 8.2 gpi at 28 inches. The field tip is 100 grain and it is fletched with 3 bohning blazers. The nock and insert are teh ones that come with CX shafts. What would be a close weight?

Your talking about CX300's I would guess?
If so they are 8.1grs. per inch and finished as you describe would give you a total arrow weight of about 355grs and about a 12% FOC.

Do yourself a favor and put bushings and large Groove "G" nocks in those shafts.....they are very prone to cracking with the stock press in nocks both from shooting stress and rear end hits. This will only add a couple grains over the stock nock and will make those shafts last MUCH longer for you.

That is cutting it close to my 5 grain per lb!

Matt gave you a great recommendation. Those unibushings and nocks can definitely add to the structural support of your arrow. One thing with most ICS style carbons is that if you hit an extremely hard surface or if an arrow smacks the nock end of another arrow then they are prone to splitting at the nock end. This is really noticeable as the nocks tend to rotate very freely in the shaft.

What nocks and inserts do I get? Will all sizes fit?

I use a scale![8D]

Mike

Some people just suck all the fun right out of a thread.[8D]

A/C/C 3-60 bushings and large groove "G" nocks.