Re: Easton FMJ 340 or 300? Need some help.

[JJB2]

I have a new bow comin' soon and I'm going to be shooting 55# at my draw and want to shoot a 625-650 grn finished arrow, shaft cut to 29 - 29 1/2".  Not sure which shaft to go with to get the correct spine with the FOC I want to achieve.  On the 340 I'd have to go with 300 up front to get to my target arrow weight and on the 300 I'd probably go with the dangerous game version and shoot a 175 or 200 grn head.

I'm thinking that the 340 with 300 up front should spine out about right but don't have much first hand experience loading that much weight on the front of one of them.

Thanks in advance for the help.

[TDHunter]

is the bow a recurve or a longbow?  I shoot a 30" arrow and have a 29inch draw and I've got a bunch of .340 spined arrows and I've been having to really drop my weight up front to get them to fly. I shoot the 100gn inserts and I've had to go down to a 125 grin point to get really good flight which is making my arrow lighter then I want. I'm in the process of getting rid of my 340 spined arrows and switching to .300 spine so I can put 275+ up front. not sure if that helps but for my set up and draw etc I need the 300 spine

[JJB2]

I'll be shooting a zipper recurve.  which of your bows are you shooting the 340's out of and having trouble?  Thanks.

[JimB]

You should start by reading the tuning information at bowmaker.net

When you increase point weight,you weaken the dynamic spine.You can't just arbitrarily change point weight to get the overall arrow weight you want,without regard to tuning and good arrow flight.

It would take close to 400 grs of weight on the front end of a .340 spine shaft to get proper arrow flight.Those are heavy shafts.that would give you close to an 800 gr arrow.

The .300 spine shafts are way stiffer than the .340's and using lighter weight heads than you proposed for the .340's,you make them even stiffer and way,way too stiff for your bow.You are focusing on an overall arrow weight and totally ignoring proper spine for your bow.

The only shaft in that range that I know of that would make an arrow that weight is a .350 spine Victory V Force HV.I built a set recently for a 55# bow.30" shaft,100 gr insert and 325 gr point.Total shaft weight 650 gs.The Victory shafts are 4.4 grs per inch lighter than the FMJ's.If I used the FMJ's,the total arrow weight would be 132grs more-782 grs.

Proper arrow tune is more important than a certain arrow weight or FOC.If the arrow is not tuned,your broadheads won't hit where you look and poor arrow flight will lose a lot of your bow's energy and poor penetration will result.

Read that tuning information and learn how to do that.The bow will tell you what the arrow length,point weight and overall weight will be.It is hard to predetermine those things before shooting and tuning.

[ozzyshane]

jjb2 i use 340 2219 @ 29.5 with 300 up front out of a 50lb curve but it is cut 3/16 past centre if your bow isnt cut past centre u wouldnt need that much spine a 400spine mite do Thanks Shane

[JJB2]

JimB, I understand all about dynamic spine and the physics involved in adding, subtracting weight from the business end of the arrow.  I've set up, bare shaft and paper tuned dozens of bows.  On a new recurve, cut past center, with a skinny diameter arrow like the FMJ, there's no reason to expect a .340 29" - 29 1/2" shaft with 300 grn up front to act stiff.  I didn't suggest that I'd use the 300 spine shaft with so little weight up front, I just commented that's what it would take to get me into the arrow weight I would like to shoot.  

What I said was "I'm thinking that the 340 with 300 up front should spine out about right but don't have much first hand experience loading that much weight on the front of one of them."

I've not done much experimenting with this much weight FOC.  I've always used a more closely spined heavier aluminum or hickory shafts and a lighter head weight.

Sounds like TDHunter's experience with them is in line with what I was thinking.  He's shooting a bow of roughly the same poundage, an arrow that's an inch longer with 225 grn up front and their acting weak...so he's going to the 300 spine and throw 300 grn up front to see what kind of flight he gets.

I'm going to order full length shafts and experiment with them when they get here.  Just trying to get in the ballpark before I plop down the money on the shafts.

[stickem1]

I don't know if this will help you but I shoot a pretty fast R/D longbow cut to center. It's 55# and shoots a 29.5" legacy 2020 with 200gr up front very well. The total arrow weight is 652gr.

[Bill Carlsen]

I'm shooting a DAS bow with Border HEx 5 limbs at 55#. My  340 arrows are 29". I was shooting them from my 60# Winex limbs perfectly with 200-225 grains up front. When I got the new limbs I thought that I would have to go to a 400 spine but found that with 250 grains up front they flew just great. I think the 340's with 300 will be just fine the way you describe your set up.

[MarkE2006]

I have run full length Easton Full Metal Jacket 340's with only 125 grain points out of a 50 pound recurve with no problem. The stiffer heavier arrow keeps the weight up and the full length softens the spine.  As configured these arrows only come to around 525 grains.  The degree of center shot on the bow makes all the difference.  The same arrow out of an agressive longbow of 56 pounds requires 200 grain points.

[Easykeeper]

JJB2 - I'm shooting ACC 3-60s which are rated at 340 for spine, 30" length, 175 grain point out of a 64" 54@28 Blacktail recurve.  The arrows weigh around 500 grains.  To get the kind of arrow weight you want, the 300's with heavy tips might be the way to go.  You could start with them long and cut back until they bare shaft tune right.