I am currently shooting Beman ICS Bowhunters 340 @ 9.3 gpi.
These arrows have been absolutely perfect and I have 100% pass throughs.

I want to get slightly faster, mainly for longer shots, to lessen the drop at those distances.

I'm wanting to switch to Easton flatlines at 8.2 gpi.

I assume I'll lose some KE Im hoping this will be a change for the better but...
What if any problems may this cause?

I'd say the biggest problem is that you're messing with a set-up that is "absolutely perfect". But that's just me.

That is my hesitation, but I would like a little more speed. Not sure if it is worth it or not.

Why faster? Faster only means you miss quicker! Like Primitive Hunter asked why mess with a good set up?

I'm shooting at 260 FPS, but then again I'm shooting almost 600 gr's. Faster is not always better. When the Bowtech came out with the Black Knight and the Pro 40 dually I was sponsored by Bowtech, shooting competition in ASA tournaments I had to work real hard to slow the bows down to 280 FPS to comply with ASA rules, I realized then that speed wasn't all that it was made out to be.
Take it from someone that's been there, don't mess with what is working for you.

I am shooting very fast but due to the lighter arrows I haven't gotten a pass through yet. 80ft/lbs of energy at 325fps.

I went ahead and ordered some to try out. If I dont care for them, I'll order another dozen of the Bemans and not have to switch anymore. I just have to test it out as I have never tried different arrows.

While I would not disagree with you bjanowski, as you have probably forgotten more than I know about archery, but I would submit there are in fact benefits to getting faster arrow speeds.

Less drop with flatter trajectory
Less windage affects at distance
Capability of shooting through tighter spaces
Less chance (very small) of string jumping

But I do understand the tournament aspect of shooting lighter draws with line cutting arrows.

For every benefit of a faster arrow there is a trade off. Yes you have a lower chance of them beating the string, however you bow will be noticeably louder so there is a higher chance of them hearing it.

Also you bow will feel less smooth. The penetration issue is the major one. While a heavier arrow does drop more if you try to shoot longer distances a lighter will hold less momentum.

However, if you have to shoot unknown yardages then yes its nice not to have to worry as much about the larger drop.

I am running lighter arrows, I do not think the super heavy is the answer but the bemans are right in the middle and a good compromise of both. THey seemed to maximize KE on my last bow in the 430gr range.

Remember speed if fine but accuracy and penetration are final.

Im guessing here, but your arrrows around 28-29 inches so your new arrow will weigh about 28-29 grains less. Do you know how many FPS that will translate into?

I'm shooting two weights of arrows. 340's and 400's. I shot two pigs last weekend one each with each arrow. Both got full penetration. I like how the bow sounds with each arrow but it does cost me 25 to 30 fps.

You've already gotten some of the best advice I've seen on this forum so I'll just address the items in red.


Less drop with flatter trajectory - Arc of trajectory is a non-factor if you know the range. Today, there's no excuse for not knowing the range.
Less windage affects at distance - How far are you planning to shoot? Unless you're hunting in a West Texas gale, it's not that much at archery ranges.
Less chance (very small) of string jumping - The increased noise from your bow will negate this advantage.
Capability of shooting through tighter spaces - Perfect recipe for a wounded and lost deer.

No, I don't. I've shot the same arrows for three years. This is one of the reasons I would like to try out some different arrows.

All very good points. I'm sticking with the same spine, just lessening the weight a little bit. I know there are a lot of guys that shoot in the 8gpi range. I'm not trying to get some super speed arrows and under spine, but if I can get faster with a small trade off, it is pretty much win-win IMO.

I get it. I've been there. When I shot 3D competition, I shot 5 grains/lb. In reality, the best thing for you to do is to do whatever you want. If something doesn't work, at least you can check it off your list. I was a curable tinkerer. I can't count how many good set-ups I screwed up. But it was my choice. Now I shoot a stick and a string. The circle is complete.

there is a 1.1 grains per inch difference. assuming your arrows are around 29" long you are looking at 31 or 32 grains less. i am guessing that you will be shooting 12fps faster give or take. i read a good article once that said the perfect balance is around 400 grains of arrow weight total. more than 400 you gain kenetic and loose speed. less than 400 you gain speed and loose kentic. to each his own. i shoot a maxima hunter at 394grains and it has worked great for me. shooting the flatlines you are going to get about as much speed as you want out of the bow you are shooting. i wouldn't go any lighter than that though. no matter how fast it shoots! good luck

Thanks for the info. Math adds up to about:

Arrows are cut to 28.5".
Bemans= 410
Flatlines=379

Saying 3g = 1fps should yield 10.3 fps increase
Saying 6g = 1fps should yield 5.1 fps increase

Seems about 9gpi would give me that 400g arrow.

Look at the CX Maxima Blue Streaks