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Main Boards => PowWow => Topic started by: TRAP on July 10, 2013, 12:29:00 PM

Title: What alum footing size for FMJ 400?
Post by: TRAP on July 10, 2013, 12:29:00 PM
Will a 2020 work?? A 2018 seems too big?  

Thanks, Trap
Title: Re: What alum footing size for FMJ 400?
Post by: JimB on July 10, 2013, 12:33:00 PM
Do you have any idea what the actual shaft diameter of the FMJ is?
Title: Re: What alum footing size for FMJ 400?
Post by: RLA on July 10, 2013, 12:37:00 PM
I think I remember reading they take 1916 but I could be wrong? I wish I had the right size as I just built some myself & would try my hand at footing.

Here we go,

 http://tradgang.com/noncgi/ultimatebb.php?ubb=get_topic;f=2;t=000098
Title: Re: What alum footing size for FMJ 400?
Post by: Tater on July 10, 2013, 02:36:00 PM
I foot mine with 2018's and have no problems makes a real durable arrow.
Title: Re: What alum footing size for FMJ 400?
Post by: Jakeemt on July 10, 2013, 05:27:00 PM
wouldn't footing be somewhat redundant on an fmj? As I understand it is a carbon fiber shaft with an aluminum sleeve.
Title: Re: What alum footing size for FMJ 400?
Post by: iohkus on July 10, 2013, 05:55:00 PM
The FMJ 400 is .261" O.D. 1914's with an inside diameter of .2689" would be very close to ideal.
Title: Re: What alum footing size for FMJ 400?
Post by: TRAP on July 10, 2013, 05:56:00 PM
I suppose it would be redundant, but I'm gonna foot it to reduce the chance of mushrooming and to make a better head to shaft transition.

Trap
Title: Re: What alum footing size for FMJ 400?
Post by: iohkus on July 10, 2013, 06:11:00 PM
Just measured the FMJ 500. It has an O.D. of .255". Didn't realize there was a difference. Those are the only two sizes I have, so can't say about the other sizes' O.D.
Title: Re: What alum footing size for FMJ 400?
Post by: JimB on July 10, 2013, 06:18:00 PM
If .261 is the OD,1916 may also work at .2649 ID and 2020 is .2725,
Title: Re: What alum footing size for FMJ 400?
Post by: iohkus on July 11, 2013, 04:57:00 PM
The 1916 may work, but it would be pretty tight. I don't remember where I got this recommended tolerance list, but it was on this subject:
    .0073 perfect
    .0052 too tight
    .0129 too sloppy
Title: Re: What alum footing size for FMJ 400?
Post by: JimB on July 11, 2013, 05:04:00 PM
That may be right.I've made some work that were awfully close but it does help to have a little clearance.If cutting with a tubing cutter,the ends get pinched in a little,no matter how careful you are or how well you deburr the piece.

You sometimes just have to try a sample.I've found some to fit that shouldn't,according to Easton's figures and vice versa.

The tolerance list could come in very handy.I had not seen that before.Thanks.
Title: Re: What alum footing size for FMJ 400?
Post by: proprod on July 12, 2013, 06:21:00 AM
You may want to consider the broad head adapter ring they offer for the FMJ. BAR3 is the size spec'd out on the FMJ website.
Title: Re: What alum footing size for FMJ 400?
Post by: DarkTimber on July 17, 2013, 09:30:00 AM
Dayrl,  Not sure if you've already bought your footing material or not but I just got some 1914s to foot my Axis 340s and I checked them on some FMJ 400s I have and they fit very well.