Carbon arrows from an old Bear K-Mag - dangerous?

[GingivitisKahn]

Not sure if I got sales pitched today or what but we were in a local shop that does some archery stuff and the guy there was telling me that it was dangerous to shoot carbons from my son's old Bear KMag.

For what it's worth, he's shooting an old Bear K-Mag 45 @ 28 (he overdraws it a bit).  His arrows are Gold Tip Hunters (3555) 30" long (not counting insert or knock).  

They seem to me to fly just fine from that bow but this guy is telling me they are way too light and that my son might as well be dry firing his bow.  Is this guy right or full of it?

Thanks in advance

[JBiorn]

Whats the rule of thumb? 8gr arrow weight per pound of draw weight I think.

[MI_Bowhunter]

As long as you have 8-10+ gr/inch I think you will be OK.

If the arrow is too light, it would be like dry firing it.

[DaleinOhio]

I don't think it's dangerous to shoot carbons from it at all...as lon as they are heavy enough like MI_Bowhunter said.  Weigh them with broadhead, insert, etc and see how heavy they are.  If they meet the 8-10+ gr/inch rule of thumb you are okay.  Does this shop sell much trad stuff?  If not, I'd take his advice with a grain of salt.

[GingivitisKahn]

Just to be sure I'm calculating this correctly...

The shaft itself is 30 inches long.  According to Gold Tip's web page, that's 7.4 grains per inch or 222 grains.  Add to that 125 grains for the head (forget the feathers and knock weight) and that's a total of 347 grains.  Call the arrow 31.5 inches long (figure an inch for the head and half an inch for the throat of the knock and I get a bit over 11 grains per inch.

Hoot if I calculated that wrong, but I should be good right?

[Hot Hap]

Adding the feathers-nock-insert would put you right at 380-385 gr. 47# draw weight would put you at 8 gr. per pound of draw weight. Might be a bit light, but should be ok. Hap

[Whitetail Chaser]

The grain weight "safety zone" is based on pounds of draw, not inches of arrow.  

If he draws 47#, you'll need 47 x 8 = 376 grains to be "safe."

Brett

[Danny Rowan]

Yep, total gr weight of the arrow with everything on it. For a 45# bow 10gr per # would be 450 gr total arrow weight,8gr per # would be 360 gr total weight. if he is pulling farther than 28" then you would need the weight to be up a little more.

Danny

[mahantango]

The very best arrow I have found for my 1967 K-mag, 53# is Gold Tip 55/70 with 100gr. insert and 145gr. points, cut 29.5" BOP. Absolutely flawless flight, about 10gr. per lb.

[BamBooBender]

I agree with Hot Hap the arrows should weigh about 380-385 with a 125gr point. So they would probably be dangerous to the deer. lol

btw here is a good site to calculate arrow weights and such.    bowjackson.com

[Billy]

I shoot the GT 35-55's from my 50# at 28"  Red Wing.
 I draw @ 26.5 and the GT's are great shafts. Depending on your son's draw....
full length, with a 125 head and a 50 grain insert will get you to 386grns. That will be 8 grns at 48#,roughly.

[JBiorn]

And with carbons-----remember to flex before you shoot. A hairline crack in the arrow could be really bad.

[George D. Stout]

Let's really think about this for a second or two.  During the 60's and 70's we routinely shot 40 to 45 pound target bows...many hundred shots per week, using arrows that were between 7 and 8 grains per pound of bow weight.

Target arrows were generally 1816 (for me) with a 50 to 70 grain target point...about 340ish grains. Add some feathers and nock and you have about 360 grains.   We shot these repeatedly with no string silencers and light strings (12 strand).

You will not hurt that bow easily, unless you really do dry-fire it.

I've even used 1913 out of a 45 pound target bow and they are even lighter.  Never had a bow blow-up and I shot a lot of arrows through them.

[joel smith]

George is right---and if you take the time to weigh some of those cedars we used to (and sometimes still do) shoot, you'll be surprised to find how light some of them are---and carbons are way tougher as a rule than wood.

Got a couple guys come in the shop that are shooting closer to 5 grains per pound on recurves and, though noisier than a heavier arrow, they haven't experienced any problems. I personally wouldn't shoot that kind of arrow weight but it's being done

[NDTerminator]

Don't guess, weigh them...

[GingivitisKahn]

Excellent info guys - super helpful.  :-D