FMJ spine???

[mountain lion]

Are the 500 spine different than the mfx classic 500? Now that they aren't making the mfx anymore I'm going to the FMJ because the are heavier gpi and I'm shooting a widow so they say to stay at around 10 gr per pound.  The reason I ask is because I have some FMJ 500 that have the standard inserts in them with 125 gr point and they are tuned good for my 51# bow and they are cut pretty short. But I have some classics that are 5oo and I have the 75gr inserts in them and 125 gr point and they are tuned for my bow and the are like 30 1/4 ". So what's the deal, will I be ok to get the 400 FMJ because I'm going to put the 75 gr inserts in them with either 125 or 150 gr point.

[gonefishing600]

It’s looks like you have bottomed out on your FMJ's, so you don’t have much room to shorten up to increase tip weight, so the only other option would be to move up to the 400’s. But FYI, the MFX Classic has been replaced by the Center Shot shaft. I’m not quite sure why Beman did this, but only time will tell.

As far as the difference in the MFX and the FMJ having different profiles, the MFX acting stiffer than the FMJ, but both having the same spine number printed on the shaft. I have a spine tester and most shaft’s in the same spine, don’t gauge the same on the tester, so I’m not so sure your comparing apples to apples.
 
Two questions:
1.What’s the actual difference in length of the two shafts?
2.Do both shafts have the same length feathers?

Here’s my opinion, I could be wrong: MFX’s has the 75gr insert which is longer then the standard FMJ insert, and could cause the MFX to act a little stiffer, hence the longer shaft. And from your observations I’m quite sure the FMJ’s shafts are a little weaker than the MFX’s. So, the combination of the two differences is probably why the two have such different profiles. And if the MFX's have longer feathers, that would also cause the MFX's to act stiffer.  

Hope this helps!

[mountain lion]

It does help, thanks

[Shane C]

The centershot is NOT the direct replacement for the Beman Classics. The Easton Traditionals are the direct replacements, though they are a little lighter. The Centershot is a bigger diameter arrow.

[gonefishing600]

I didn't know Easton owned Beman!

MFX Classics and the Centershot are both 9/32.

[Shane C]

Yeah, I guess you're right. But, the Easton traditional are the direct replacements. The guy at the archery shop told me the center shots were bigger. They do use a different nock and insert compared to the traditional and classics. Here's some more info I found from another old trad gang post.

Axis Traditional Carbon Shafting Specifics Spine Point GPI Length Insert Nock Carbon Collar Nock Collar
600 9/32" 7.9 30 ½" 75-50gr X E --
500 9/32" 8.9 31" 75-50gr X F --
400 9/32" 9.8 31 ½" 75-50gr X F --
340 9/32" 10.3 32" 75-50gr X G --
Straightness ±.003" Weight ±2gr Adjustable 75-50gr brass HIT inserts

Beman MFX Classic Arrow Specs:
340 - 11.2 gpi., uses 9/32" diameter field point, BAR6 Broadhead Adapter Ring
400 - 10.4 gpi., uses 9/32" diameter field point, BAR5 Broadhead Adapter Ring
500 - 9.7 gpi., uses 9/32" diameter field point, BAR5 Broadhead Adapter Ring
600 - 8.0 gpi., uses 17/64" diameter field point, BAR3 Broadhead Adapter Ring Adjustable
75-50gr brass HIT inserts

Beman CenterShot™ Carbon Shafting Specifics Spine Point GPI Length Insert Nock Carbon Collar Nock Collar
600 9/32" 7.1 30 ½" 75-50gr H A A
500 9/32" 8.3 30¾" 75-50gr H L --
400 9/32" 9.6 31" 75-50gr H B B 340 9/32" 10.3 31½" 75-50gr H CC C Straightness ±.003"
Weight ±2gr Pre-installed H Nocks

HP 75/50 Brass Break-Off Inserts- included

[Hoyt]