muzzle break and accuracy

[tiger49931]

So i have A GAP TEMPLAR 6.5 I took off the titan break and put on a YHM 7.62 break with qd for my suppressor. Using hornady match ammo i was getting .21 groups to .45 (shooter error im sure) but now with the new muzzle break i ran a satterly ladder 39.1 grains of h4350 to 4.9 grains. best group is like 40.3 grains that had a SD of 10.3 but my 40.9 had a 5.6 sd. but no one hole shots that im looking for. Max load according to sierra is 40.6 should i go higher looking for a better more solid node or is it the muzzle break? Do you guys look more at SD or group size? or will the lower SD get you a better group?

 

[Rocketmandb]

SD is less of an issue until you get out to much longer ranges. Group size is always important. How many in your group? I'm guessing 5 or less - if so, the SD value is fairly inaccurate.

 

[Greg Langelius *]

Muzzle brakes operate on muzzle pressure, which doesn't even begin to occur prior to the bullet fully exiting the muzzle. This should mean that group size is immune to the action of the brake.

But; the mass of the brakes differ, and in so doing, they alter the barrel harmonics. IMHO load development needs to be repeated every time one makes a change to barrel harmonics.

Greg

 

[Garvey]

So i have A GAP TEMPLAR 6.5 I took off the titan break and put on a YHM 7.62 break with qd for my suppressor. Using hornady match ammo i was getting .21 groups to .45 (shooter error im sure) but now with the new muzzle break i ran a satterly ladder 39.1 grains of h4350 to 4.9 grains. best group is like 40.3 grains that had a SD of 10.3 but my 40.9 had a 5.6 sd. but no one hole shots that im looking for. Max load according to sierra is 40.6 should i go higher looking for a better more solid node or is it the muzzle break? Do you guys look more at SD or group size? or will the lower SD get you a better group?

Published data is way too conservative. 140 gr in a 6.5 Creedmoor, loading H-4350, 41.5 gr is the start, headed toward 43.0 gr. You might find pressure before 43.0 gr, you might not, but look for it.

As Greg said, as soon as you change barrel harmonics, the load needs to be checked, and potentially tweaked. Pick a brake, leave it on, and perform load development.

 

[545riflefan]

I have had some really odd behavior out of my guns with different muzzle devices on the end. Range trips ending with me thinking I was having a bad day. Only to eventually learn that the latest best hotness muzzle device was the cause. Suppressed , un suppressed, FH, booster, brake, etc. Now I make sure to always shoot with nothing attached as a benchmark and go from there.

 

[hlee]

Set up the rifle how you want to shoot it. Tailor the load to that configuration. How the rifle shoots with a bare muzzle doesn’t mean piss if you are going to shoot it with a suppressor.