Just purchased a hoyt dorado and looking at some beman classic carbons. 55lbs@ 28in. According to the beman arrow chart a 400's would fit the bill. When I put it in the Stu's Spine chart the 340 is closer. This is with the 75 grain insert and 125 grain tip. Anybody have any advice or am I going to have to buy one of each to try?

all arrow calculators will at best either nail the right shaft or get you into the ballpark.  at worst they will be way off the mark.  there are many dependencies that can't be intuitively part of calculating software.

i'd suggest getting a test kit of shafts and work out in real time a good arrow for both your bow and you.  that test kit will come in handy for your future bows, too.  good luck!

I shoot full length 340s with 125-grain tips on Winex limbs pulling 56# @ 32". If I were you, I'd start with the 400s and go from there. In the end, proper tuning will tell you exactly what you need.

I would try a 500 first, full length, insert installed and begin bareshafting.

It might not hurt to check your Dorado on a set of scales,they have been known to run heavier than marked.

With Beman classic MFX you have to do something special.  You should enter Zero for the insert and put the insert weight as a "footing" that extends to where the insert ends.  The "HIT" insert for those arrows acts as an internal footing and the shaft doesn't flex for about the first 2".  

If you are set on the point weight, probably you need a long 400 or possibly a short 500 could work.
Personally, I'd get 400's and make them work either by length or weight changes.

Well, I have basically the same set up as you and I ordered the 400 MFX Classics with the 75gr insert and a magnus 125 head. Works okay, BUT on a bare shaft my nock is consistantly to the left a good bit and my point was to the right...a testament to being underspined per all accounts.

I'm going to work on lowering the weight ( I really don't want to though)on the tip, but can't shorten my shaft very much if at all.

I may be going to the 340's pretty soon. My bow is centershot and so it treats the arrow with more energy and makes it act as if it's underspined.

I just set up a Hoyt Buffalo that is is with the light set of limbs pulling 52# at my draw

It liked a traditional only carbon shaft 400 spine with a 100 grain insert and a 125 grain head cut at 29 inches

No 2 bows are the same start with a test kit and cut them as needed it is the only way to be sure

QuoteOriginally posted by ArrowAtomik:
With Beman classic MFX you have to do something special.  You should enter Zero for the insert and put the insert weight as a "footing" that extends to where the insert ends.  The "HIT" insert for those arrows acts as an internal footing and the shaft doesn't flex for about the first 2".  

If you are set on the point weight, probably you need a long 400 or possibly a short 500 could work.
Personally, I'd get 400's and make them work either by length or weight changes.

That seems to put it within the 2#'s. Thank you. I only bought one arrow to make sure it was the correct spine. Had it cut @ 29 inches becasue the arrows at the shop were the same thing and seemed to fly good. I'm thinking I'm going to get the 400's and try them at full lenght and go from there.

A test set of shafts is the best and surest way to pick the correct size.  That said, Stu's calculator will often disagree with the standard tables because it also takes various riser center-cut variations into account that the tables do not.

My shrew is 55# at 28"( I pull just over 28") and bareshafts perfectly with an MFX 340, cut to 31" with a standard aluminum insert and a 250 grain head

All the charts have been on the stiff side for me and I find my setups usually works out better with a lighter spine shaft.  I use 100gr inserts and 125gr tips on all my arrows and shooting 54-56# at 27 I can shoot the Beman 500's at 28in and the 400's at 30in and get them to spine very well on my BW SA's and Hoyt Buffalo and Dorado bows as well.

QuoteOriginally posted by mark land:
All the charts have been on the stiff side for me and I find my setups usually works out better with a lighter spine shaft.  I use 100gr inserts and 125gr tips on all my arrows and shooting 54-56# at 27 I can shoot the Beman 500's at 28in and the 400's at 30in and get them to spine very well on my BW SA's and Hoyt Buffalo and Dorado bows as well.

I agree Mark, I have found the same.

Make sure your rest is set up for center-shot for the diameter of the arrow, and check your actual draw weight. The Hoyt's do pull 2-3 pounds heavier than marked.

I used Stu's calculator for my Bob Lee Classic, 55#@28".  My Beman MFX Classic 400's with 100 grain brass inserts, 145 grain broadheads, nock end weight of 23 grains, and 3x5" feathers came to and arrow lenght of 28 1/4......end result is they fly GREAT!!  Just like arrowAtomik said, you have to treat HIT inserts as a footing.