How much am I likely to notice removing 3.6oz from the front end of the gun?

[Sry0fcr]

In chasing after the handiness of the 6720 I'm considering going to a 10.75" URX 4 in lieu of the 13.5" URX 3.1 currently installed on my SR15. I'm wondering if the change in overall weight and moving the balance point rearward will be noticeable enough to justify the cost. My lack of handling other configurations is showing.

[MistWolf]

Change in CG between the two handguards will be about 1.5 inches. Difference in weight is approximately 4 oz.

4 oz x 1.5 inches = 6 in/oz, or .375 in/lbs. Difference in moment between the two handguards is less than a half inch-foot

[GH41]

Am I correct in assuming that you still have the factory FSB and handguard on the rifle? Just trying to establish a starting point.

[Sry0fcr]

It's a bone stock SR15 Mod 1 with the pinned gas block and 13.5" URX 3.1.

Mist Wolf reminded me why I decided not to be an engineer.

[Waylander]

Not worth it especially for the expensive wrench you'll need to remove the URX 3.1 or pay someone to remove it. I doubt you'd notice much difference if at all.

[HighDesert]

Not worth it especially for the expensive wrench you'll need to remove the URX 3.1 or pay someone to remove it. I doubt you'd notice much difference if at all.
I have a standard 16" BCM and a lightweight 16" BCM. Identical except the barrel profile. That - 4 oz at the end makes a pretty decent difference in the balance and feeling.

Go tape 4 oz of quarters to the end of your barrel and report back. That is TWENTY quarters, or half a roll.

[gaijin]

My sense is you'll notice little, if any, appreciable improvement in handling.

[MistWolf]

I have a standard 16" BCM and a lightweight 16" BCM. Identical except the barrel profile. That - 4 oz at the end makes a pretty decent difference in the balance and feeling.

Go tape 4 oz of quarters to the end of your barrel and report back. That is TWENTY quarters, or half a roll.

He's changing the weight of the handguard, not the weight of the muzzle. 4 oz at the muzzle has more than twice the moment of 4 oz at the center of an 11 inch handguard.

4 oz gives 5 in/lbs at the muzzle (assuming the muzzle of a 16 inch barrel is about 18 inches from the CG of the rifle) versus 2 in/lbs at the center of the handguard (about 8 inches from the CG of the rifle).

I didn't think through my earlier calculations. They were based on the change in the handguards alone, not how they would affect the rifle itself

[Waylander]

I have a standard 16" BCM and a lightweight 16" BCM. Identical except the barrel profile. That - 4 oz at the end makes a pretty decent difference in the balance and feeling.

Go tape 4 oz of quarters to the end of your barrel and report back. That is TWENTY quarters, or half a roll.
He's shortening his rail from 13.5" to 10.75" not taking 4 ounces off the barrel, chief.

According to the published weights the BCM lightweight barrel, assuming the same profile under the HG, has the 5 ounces removed from the last several inches of the barrel which is farther away from the center of gravity. So the barrel weight will affect the balance of the rifle more than the rail weight removed.

[556BlackRifle]

He's shortening his rail from 13.5" to 10.75" not taking 4 ounces off the barrel, chief.

According to the published weights the BCM lightweight barrel, assuming the same profile under the HG, has the 5 ounces removed from the last several inches of the barrel which is farther away from the center of gravity. So the barrel weight will affect the balance of the rifle more than the rail weight removed.

So in other words, it might be hard to tell the difference. ;)

[Beat Trash]

So in other words, it might be hard to tell the difference. ;)


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