Barrel harmonics

[Esw0001]

Glad to be here.. not my 1st Grendel, but glad to be back in it and get to finding the sweet spot on mine. I currently have 24" stainless heavy 1-8 barrel with a muzzle brake as offered when I bought it. My question would be, after reading into barrel harmonics, ladder loads, nodes, etc.. what are your thoughts on the add-ons such as muzzle brakes, etc and their effects on harmonics, accuracy at longer ranges? I'm not really concerned about the effectiveness of a brake with the Grendel, and I would only assume that it would affect poi.

[ricsmall]

It’s hard to pinpoint this. Few months ago a buddy of mine came over with a new suppressor. We hung it on a couple of my Grendel’s and the POI didn’t change out to 400 yds. That was as far as we shot. Fast forward, I built a form 1 suppressor with the same baffle design and spacing. Tested yesterday, same results. Yet, I can hang my magnetospeed on some barrels and it changes POI. Other barrels it doesn’t. I’ve mounted brakes on light barrels, some change and some don’t. Same goes for heavy barrels. Conclusion? I can’t come up with one other than it’s consistently inconsistent in my experience

[Esw0001]

Interesting.. I've heard varying reviews using a suppressor, but the magnetospeed was going to be one of my next purchases. I may stick with my old chrony for a while lol.

[HuntTXhogs]

Johnnys Reloading Bench on YouTube did extensive testing you should check it out

[Esw0001]

Will do, thanks!

[CaptnC]

Interesting.. I've heard varying reviews using a suppressor, but the magnetospeed was going to be one of my next purchases. I may stick with my old chrony for a while lol.

IMO...Magnetospeed is a mandatory tool for loading gas guns. The possibility of over pressuring your platform out weighs any possible negative of changing POI or even group size.

I try to stay as close as I can to published max velocities. And an accurate chronograph will help you stay as safe as possible!

Sweet rig with a 24"...I have an 18 and 20, but a buddy has a 24". He reaches higher velocities with having to push the powder charge.

WeLome to the forum!

[Double Naught Spy]

Harmonics are a funny thing. The additional or subtraction of a muzzle device may improve or unimprove group size as may changing muzzle devices. Adding a significant muzzle device such as a suppressor usually results in impacts that are lower and usually a tad left, but once in a while they go higher or may stay in place. Same rifle with a different model of suppressor will often have a different result.

As for the use of a Magnetospeed, obviously if you don't shoot for groups when getting your velocity assessments. Maybe it costs you a few more rounds.

[Bfglowkee]

[FW Conch]

Barrel tuners have really started to get popular in long range competition. One competitor told Me that changing his tuner by the thickness of one scribe line changes his POI.

[LtDan]

Last November I played around with barrel harmonics after realizing that when I strapped on my Magneto Speed the groups got tighter. So I measured the weight of the Mag Speed wand and turned out a piece of Al round stock the slipped on the barrel. I took 3 shots at a 100 yard 1" spot and then slid the weight on and took another shot and damn what a difference. The only problem I can see is that it only worked for that bullet and powder selection and another powder bullet combination it didn't seem to matter. I did some research on barrel tuners and found that Browning in the late 90's put a barrel tuner on a hunting rifle. The theory is that hunters will use a particular round to hunt with and it would be tunes for that round. On Grendel I have at least 9 bullet types and 5 or 6 powder choices. So tuning did work for a particular charge. The barrel I used in the pic was a 24" White Oak. spot #1 was the 3 rounds without weight, #6 was with weight but the point of aim was at #2.


Barrel WeightGB.jpg Bare weight gb.jpg

[CaptnC]

LtDan...my experience is the same...the load I have that has single digit SD and a low ES shoots tighter with it at 200yds than it does with it off. If they had any color other than red I was thinking about trying the Bossman donuts. Maybe if the get some black ones in stock I will spend the $14.00 just to see.

I'm also trying to get away from so many different 6.5 bullets...I currently have 16 different 6.5 bullets in stock!

And I just finished my box of 140gr RDF's this morning! I'm feeding 7 rifles, in 6 different 6.5 chamberings....

[kmon]

For a while I had two rifles in 7mm-08 one Browning with the BOSS and a Remington 788 that shoots very nicely. I tuned the BOSS so the Browning shot my pet load for the Remington so both could use the same ammo

[Esw0001]

That difference in poi is impressive, but certainly did tighten it up.. and thanks for all the input! I now have some hornady black in hand, and hope to get some rounds ready by the time weather breaks.

[LtDan]

That difference in poi is impressive, but certainly did tighten it up.. and thanks for all the input! I now have some hornady black in hand, and hope to get some rounds ready by the time weather breaks.

That did surprise me also, especially after the first shot expecting it to hit the POA after the second round I though dang, and after the third round I was kinda smiling.

[Javman]

I've been messing around with one from Limbsaver and what I did notice that it improved my 85gr load. But it did tighten up other loads but with different POI. So on my next go around I'm thinking of marking the barrel with a marker for that tuned load, tune the next load and mark that one and so forth to see if it is repeatable.