grains per pound

[Mr Green 740]

I currently shoot a 59# Morrison longbow and my arrow weight per pound is 7.5 grains per pound. Everything is tuned correctly with the length and point weight and I shoot it well but my question is do you think 7.5 grains per pound is too low? I shoot Beman classic 500 and was wondering if I should upgrade to the 400's.

[McDave]

I don't know about your Morrison longbow, but the Black Widow warranty is void if the bow is shot with arrows less than 8 grains per pound.  Most recommendations I've heard are for arrow weights of 9-10 grains/lb.

[Lonewolf Jim]

I'll second McDave's comment.  No less than 8gpp.

[Alsea]

Man I bet them arrows are smokin'!

I guess you're borderline, your limbs may not last as long as they would if you were shooting 10 grains per, but what the heck? You can always get more limbs...lol!

[longbowguy]

I expect the bow will hold up, but I expect it will shoot sweeter with heavier arrows. The reason to shoot a heavy bow is to ensure deep penetration, especially if large bone is struck. Dr. Ashby's extensive studies, posted on this site, indicate that 600 grain arrows are at the minimum threshold for really reliable penetration. I'd consider about 650 grains out of your bow for general purposes and sweet shooting. For large and dangerous game I'd go higher.

[Lonewolf Jim]

I guess it boils down to how much money you have.  For me, I'd be saving the bow.  We didn’t have much money when I was growing up and my dad raised me to not knowingly tear things up.  I still feel that way today.

[Big Sneaky]

I would say you are too light.  Try going to a 400 spine arrow and use the 100 gr brass insert.  Should be able to shoot 125 gr point and it should bareshaft good for you.  I'm shooting a 58# Morrison shawnee Dakota with this setup.  I draw 29" and my arrows are 30".  Total arrow weight for my Axis is about 530 gr.

[Chris Wilson]

Talk to Morrison about recommended arrow weights for his bows.  Most bowyers do have a minimum arrow weight associated with their warrenty.  7.5 gr/# shouldn't hurt your bow, though it may make it feel more harsh when shooting, depends a lot on the bow design.  The arrows I use for target shooting/3D are in the 7.5-8.0 gr/# range on my bows.  Haven't had one blow apart yet and I shoot a lot of arrows in a years time.

[cjones]

My hunting arrows weigh 392gr. Out of my 56# hunting bow that makes for 7gpp. Most will think that is too light but they sink into the ground on the other side of the animals just fine.  :D   Plus i shoot snuffers and never have any trouble with penetration.

[Orion]

I shoot 600-650 grain woodies out of a 60# Morrison Dakota.  Quiet the bow nicely and still moving plenty fast.

[Big'n]

That seems light to me. I prefer 10 grs. per pound of bow weight. It sure will make your bow quieter and aid in penetration.

[strick9]

Recently had this conversation with Bob Morrison, I shoot at 60lb at 29" out of morrison td 57lb at 28" and tuned my beman 400 mfx classics bareshafting.
  I wound up with true spine at 29.5 bop, standard inserts and 100 grn point=441 grn, man what a dart 210 fps and 43 psi KE, but only 7.35 gpp so I was worried about limb damage, Bob said, gotta go heavier so I bumped up point weight to 125 grn, this gives 466 grn arrows and 195 fps = 40 KE and 7.76 gpp and still spines fairly well , bumped up to 145 grn point and lost spine, wouldn't have thought that that the Ke would increase with lower gpp. I am now upping to 340 series with 100grn inserts to: 1.Quiten bow, 2. increase penetration, and 3.decrease chance of limb damage. Bob was fairly adamant about incresing arrow weight for my set up. BTW these 400s will hopefully be for sale soon.

[Pinelander]

I personally prefer 8.5 - 9.5 gpp when hunting, wil go a bit heavier on certain bows, it all depends on how they shoot, how quiet they are, nd how they "feel". If shooting a rather lightweight arrow such as your setup, I would definitely use a string that has plenty of padding in the string loops. Also, wouldn't pay much attention to so-called minumum arrow weights for penetration on deer. Most heavy setups are mainly for two things...
1) Hunting big animals with unusual bone structure found in African/Australian species.
2) Insurance for when you have a bad hit on bone and maybe get enough penetration, but I wouldn't count on it.

I think your bow would probably "feel" much better and be much quieter if you went up to 9 gpp.

[Snakeeater]

Mr Green,

The mass (or weight) of your arrows affects a lot of things.

1. The heavier the arrow the more arc it needs to get to the same point. That is the light arrow/fast arrow discussion. Since the lighter arrow has a flatter trajectory errors in range estimation are less critical.    

2. The heavier the arrow the more energy it can absorb from the bow. This increases (up to a point) the efficiency of your setup, allowing you to get all that you can from your bow. It also means that since more of the energy is transferred into the arrow less is left in the bow and string. This translates into less hand shock and less noise. All three of these things are good things.    

Having said that, I use a heavy 2219, averaging more than 10 grains per pound of pull and when I shoot folks only know it when they see the arrow going down range. I also like the low pitch "thunk" they make when they hit something.  

[RamiusEng]

I agree with Mr. Snakeeater.  I like the thunk too and making loose 3D targets at the range dance.

[katman]

Another agre with snakeeater. Heavy arrow, quieter bow, more energy to arrow, less potential damage to bow.
Chad, glad the light combo works for you, you must hit the lungs consistently, probably miss ribs to, wish I could. I go with a heavy hunting arrow 650+ from 55# to help when my shots are not so well executed.

As stated earlier, read Dr. Ashby's information, threshold lies somewhere between 625 and 650 for getting to the vitals on off hits on heavy bone with a two blade broadhead.