Working with carbons for FOC

[handirifle]

#4472

OK as I mentioned in another post, I scored a good price on some Gold Tip Carbons, at 8.2 GPI. So today i got the chance to work on inserts for them and trying to bare shaft tune them to my recurve.

I made one insert (steel) and it turned out at 135gr, combined with my target tip of 165gr, I got them to shoot center (but STILL nock high) fairly quickly, and they measured approx 30 3/4″ from throat of nock to back of field tip.

The frustrating part is total arrow weight is only 570gr, without feathers, so I’d guess 600gr complete. A bit below the 650gr target weight. I have some grizzly heads (170gr) on back order at 3 rivers, and have 100gr steel inserts for them as well. That will bring total head weight of 270, up from the 165 of the target point I tuned with. So I know the arrows will end up a bit shorter than the current length. I think I need to make up a 270gr practice point until the broadheads arrive. I also know I cannot shoot bare shaft with the broadheads.

What would you guys suggest? That is a total tip weight of 405gr, and will put total arrow weight of approximately 700gr. Should I try to cut the insert back 50gr or make the insert heavier, to make my field point less than 270gr. That will end up being about 3″ long.

Thoughts?

[Troy Breeding]

#31305

700 grs. is a good weight. Don’t get locked in on hitting the 650gr weight. Another 50grs want hurt a thing.

As for the 3″ length. The futher the weight is in front of the insert the higher the FOC will be. Weight in front of the insert will yeild a higher FOC than the same weight located either in the insert or behind.

I’ll be pushing 425gr in front of the insert this year and really like the way it shoots.

Troy

[handirifle]

#31664

Well i used my 3″ guesstimate to make another field point with a goal weight of 270 or close to it. It seems 3″ is a tad too much. It actually came out to 388gr, juuussssttt a little high :D. This evening I will make another one. I want to keep the heavy one as is, cause ya never know. Besides I can always take weight off, but its a real pain to add weight back on.

So it continues on for another chapter.

[handirifle]

#32099

Well I am getting closer! There is either an inconsistency in the gr per inch of the steel, or in the machinist. Maybe a little of both.

Here is a pic of the three I have made so far.

from top to bottom,

388gr 3 1/4″

240gr 2 1/4″

175gr 1 1/4″

I also took the rasp to the shelf of the bow, to put a radius in the front and back, so see if that helps with this cursed nock high issue. Nothing else has cured it.

I sprayed it over with some clear poly, and will rework the way the shelf and pad contact the arrow.

[handirifle]

#32716

OK made another one. My wife is starting to wonder if I still live in the house:D. This one came out at 282gr, so I am not gonna push my luck. it’s 2 /34″ long and fits between the top two in the previous pic.

So it took taking another inch off the arrow (now 29 1/4″) to get the right spine, and lo and behold, I moved the target to 20yds and the nock hits straight, not high any more, I am a happy camper…..

Now I just need to get my broadheads in so i can weigh the setup. I figure if their numbers are accurate (170gr head, 100gr insert) that when I glue them up, it ought to be real close to 180gr.

Looking at the good Dr’s chart, with 29 1/4″ arrows, and balance point is 5 1/2″ from back of head, that puts the calculated point 9 1/8″ from actual center. That puts it right at 31% EFOC. Also, without the feathers (yes I am aware it will change the above numbers, but not enough to bother me) it weighed 660gr, so it’s about near perfect.

I also, tried a couple different setups on my compound (old Mathews Q2XL) and it shows weak spine, which is perfect, since due to the Whisker Biscuit arrow rest I use, I have a few inches I can play with. That way I can use the same broadhead on either bow.

Even with all the “extra stored energy” of the wheel bow I have had some shots on whitetail deer, that I felt penetration was less than stellar, with the previous setup. This ought to put it into a whole new category. In addition, even the wheel bow seems quieter.

I have never been a fan of the super lightweight arrows, even for compounds. Once it was explained to me, by a dealer, that the only useful purpose they serve is to quicken the needed repairs to bows, I decided to stick with moderate weight arrows to get the best of trajectory and hitting power. With the wheel bow, and sights, etc, that become pointless. I can set the sights for actual drop, and the rest, like shooting traditional, is up to me. I need to know the yardage or get closer. Closer is always better.

For now, I will go on the experience of others far better and more knowledgeable than me, and figure that when I get the shot, and make it good, the arrow will do it’s part, probably better than the one that loosed it.

I still need to get back in the shop, little at a time, and make a dozen or so inserts, and about 6 or more field points, so using the bow, this season is not very likely, especially, for this zone. The archery only time is long gone, and we are dead in the middle of gun season. VERY early seasons here in zone A of CA. Frustrating , but what do ya do? So for now it’s me and the ’06.

Sure I could most likely order them, but then I wouldn’t get any more badly needed experience with my lathe.

Once I get this all done, I will surely have to look at trying to make my own quality broadheads. might be a pipe dream, but no dreams, no advancement, right?

[handirifle]

#42741

OK I have made up a dozen inserts, and today I made up a 300gr field point. That was because I also changed my order from 3 Rivers. I had the 170gr griz on back order, and went ahead and changed that to the 200gr, which was in stock. They should be arriving soon. Combined with the 100gr steel tapered insert, that brings me to 300gr tip weight, plus the 135gr (I think) steel inserts I made, for a total of 435gr up front on the carbon arrows. Total weight was 687gr at 31% EFOC.

I hope the Griz heads fly to same point of impact the field points do, and fly well, otherwise it’s all for naught.

Now I need to make up 4-5 more 300gr field points so I can practice, without going to get the arrow after every shot.:D At least I work off my calories that way though.:D

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