Cheap Way to Increase Arrow Mass

[bigchiefj]

I don't know if this has been posted before, but I cut some 0.093" string trimmer line to the same length as my arrows and shoved it inside the shaft. It added about 40 grains and maybe dropped my impact 2" at 30 yards.

It works, but you may not be able to find trimmer line that's as heavy as the weight tubes they sell.

[TxAg]

Yep, works well.

Another thing to try is poly rope....you can about 100 grains.

[bucsfan69]

Nice suggestion

[Deer Destroyer]

How does that change the mass? Wouldn't that only change the weight? I think that might jack up the arrow flight. If arrow companies go through all that trouble taking out as many deviations as possible, wouldn't shoving a Lenght of plastic inside kind of defeat the purpose?

[bigchiefj]

I just used the term mass to sound more scientific than saying weight.

It didn't affect the arrow flight other than making my arrows hit about 2" lower at 30 yards. I shoved 2 arrow-length pieces of 0.093" trimmer line inside the arrows to increase the mass (weight) by about 80 grains. My total arrow weight is now 500 grains.

I just did it for a cheap test instead of buying heavier shafts.

[TxAg]

How does that change the mass? Wouldn't that only change the weight? I think that might jack up the arrow flight. If arrow companies go through all that trouble taking out as many deviations as possible, wouldn't shoving a Lenght of plastic inside kind of defeat the purpose?

While mass and weight are technically different, they're basically the same thing for our purposes. As for arrow flight, there is a significant difference between dynamic spine and static spine. Adding rope or weedeater line won't change static spine, but could change dynamic spine....although rarely enough to notice.

The reason for doing such is increasing momentum. Momentum is what we all strive for (not kinetic energy).

[JW]

How does that change the mass? Wouldn't that only change the weight? I think that might jack up the arrow flight. If arrow companies go through all that trouble taking out as many deviations as possible, wouldn't shoving a Lenght of plastic inside kind of defeat the purpose?

.

[bigchiefj]

What I like is there's a louder thump when my arrows hit the bag.

[Bill]

I've been a believer in the momentum being more important than KE for penetration for years. Recently I bought a dozen CT Cheetahs (around 360 grains finished arrow) for 3d having shot CT Rhinos (around 510 grains finished arrow) for 3d and hunting. I was really surprised to see how much deeper the lighter arrows penetrated into slightly wet hay bales. The 2 diameters are the same so that's not the reason.

Bottom line is they both pass through and come out the back side of animals I shoot.

[Deer Destroyer]

I've been a believer in the momentum being more important than KE for penetration for years. Recently I bought a dozen CT Cheetahs (around 360 grains finished arrow) for 3d having shot CT Rhinos (around 510 grains finished arrow) for 3d and hunting. I was really surprised to see how much deeper the lighter arrows penetrated into slightly wet hay bales. The 2 diameters are the same so that's not the reason.

Bottom line is they both pass through and come out the back side of animals I shoot.

You can achieve penetration in two ways, speed or weight. The arrows that weighs over 500 didn't penetrate as well for you because it was to far on the heavy side of the spectrum. If you shot a, let's say, 400gr arrow it would penetrate about the same as your lighter arrow. This is because the lighter arrow is moving faster. And the momentum you talk about is KE. KE does not truly exist until impact. Personally I prefer a lighter arrow because it will have a flater flight, which means if you miss judge the distance a little it will less of a difference.

[JW]

You can achieve penetration in two ways, speed or weight. The arrows that weighs over 500 didn't penetrate as well for you because it was to far on the heavy side of the spectrum. If you shot a, let's say, 400gr arrow it would penetrate about the same as your lighter arrow. This is because the lighter arrow is moving faster. And the momentum you talk about is KE. KE does not truly exist until impact. Personally I prefer a lighter arrow because it will have a flater flight, which means if you miss judge the distance a little it will less of a difference.

.

[TxAg]

You can achieve penetration in two ways, speed or weight. The arrows that weighs over 500 didn't penetrate as well for you because it was to far on the heavy side of the spectrum. If you shot a, let's say, 400gr arrow it would penetrate about the same as your lighter arrow. This is because the lighter arrow is moving faster. And the momentum you talk about is KE. KE does not truly exist until impact. Personally I prefer a lighter arrow because it will have a flater flight, which means if you miss judge the distance a little it will less of a difference.

Not to be argumentative, but KE is not the same as Momentum. And I seriously doubt 500 grains is the point of diminishing returns for the Bill's set up....although I haven't done the math

[Niko]

Pretty neat stuff here.

[Deer Destroyer]

Not to be argumentative, but KE is not the same as Momentum. And I seriously doubt 500 grains is the point of diminishing returns for the Bill's set up....although I haven't done the math

KE is derived from "momentum". The speed and weight of the arrow make up the KE. Just like a truck driving down the road, the speed of the truck and the weight of the load and truck(it's momentum) give it KE. When the truck hits something it transfers some or all of its KE to what it hits.

[jmm83164]

there is an arrow ballistic chart you can get as free phone app that will help you figure the optimum arrow set up for you and your rig . For Android it was listed under hunting apps.
The set up it recommended for my rig kicked asp