Barrel speed up causing problems

[RocketM1419]

6.5x47, 26” Krieger barrel, 140 ELD-M, H4350, Oehler 35P

I went through a basic break in as normal and watched Chrono throughout. After settling I ran ladder test I got real solid node @2750 ft/sec. Went about 80 rounds with 4SD and 12ED and after playing with tuner, it was hammering. Went out second day to dial in scope and started to see barrel speed up so waited for it to settle in, about 20 rounds. Went out a couple of days ago, same temp, humidity up at about 85% and the barrel was holding at 2790 with 12SD and 22ED and groups started to open up. This was over 80 rounds. Virgin brass vs once fired was same.

Should I do speed test again? Local long range match cancelled due to weather so I have a couple weeks to mess with it or stick with it.

I have never had a new barrel speed up this much and wondering if I need to start over.

Thanks, T

 

[FeMan]

The level of speed gain seems pretty typical in my experience. It may not be finished either. You should certainly re-tune after speed up is finished, which is usually between 100 and 150 rounds for me.

 

[RocketM1419]

Thanks, I have never had one speed up this much before. And even when they sped up, the load stayed consistent . Just weird for me. Hate using up primers and powder if I don’t have to.

Typically, do people see a barrel likes a “velocity” vs some other variable? Just curious.

 

[lazyMlazyK]

Following...good topic, RocketM1419.

 

[gunsandgunsmithing]

Move the tuner a mark. I'd start by moving it in, toward the receiver.

 

[jepp2]

I have never had a new barrel speed up this much and wondering if I need to start over.

I typically see over 100 fps increase in speed with Krieger barrels.

 

[RocketM1419]

Move the tuner a mark. I'd start by moving it in, toward the receiver.

Once the speed settled in I ran another cycle with the tuner. Found 2 settings next to each other that shot one hole groups again. Let the barrel cool down and reshot to verify. Group stayed in similar pattern but velocity varied by 20 ft/sec on the string and opened up to .75”.

There was a front right quartering 10-12 mph wind, my least favorite. But usually the groups stay consistent.

I am thinking that I will load up 10 at that load and shoot in low wind and see what happens with speed. After a few, if it looks inconsistent I will run another ladder to see if I can get a speed node again.

 

[RocketM1419]

I typically see over 100 fps increase in speed with Krieger barrels.

My first Krieger, been shooting Hart barrels forever but club member had this one and I would not have to wait.

 

[swd]

I’ve seen it plenty of times. Just back it down. There’s no flies on a Krieger!

 

[FeMan]

I shoot a lot of brands but Krieger is the most common. 100 fps or even more is pretty standard. On match rifles I let them load up and speed up as quickly as possible. On hunting rifles, I tend to clean them after 20 or less rounds and can avoid the fouling accumulation and speed up.

 

[Steve Blair]

...the barrel was holding at 2790 with 12SD and 22ED...

The ED is the problem. The barrel is drooping.

 

[RocketM1419]

Loaded up a new series for speed testing. I assume I will find the node at 2750ish again but loaded up to max again. Might find a node at the faster speed...if not 2750 plenty fast with the 140s. Just want it consistent so it holds vertical at range, I can tune from there. Consistent speed is most important to me.

Thanks everyone, just never had a barrel speed up this much.

T

 

[paulT]

Loaded up a new series for speed testing. I assume I will find the node at 2750ish again but loaded up to max again. Might find a node at the faster speed...if not 2750 plenty fast with the 140s. Just want it consistent so it holds vertical at range, I can tune from there. Consistent speed is most important to me.

Thanks everyone, just never had a barrel speed up this much.

T

I re-adjust (decrease) The power charge when new barrel has finished speeding up to get back into tune.

 

[JEFFPPC]

I re-adjust (decrease) The power charge when new barrel has finished speeding up to get back into tune.

Now paulT, you know that is way to easy. Common sense not allowed.

 

[paulT]

Now paulT, you know that is way to easy. Common sense not allowed.

Yep, just doint forget to do the opposite at @500 round intervals along with re-adjusting seating depth to keep in the sweet spot or as soon as velocity starts to reduce.

 

[Liven The Dream]

My Barrel Man states Brux Barrels Speed up . I am seeing it Happen with my Newest Barrel .
Theses are HV 30 and 31" Barrels on F/Class Rifles .

Good Post

 

[JEFFPPC]

Yep, just doint forget to do the opposite at @500 round intervals along with re-adjusting seating depth to keep in the sweet spot or as soon as velocity starts to reduce.

Thats what tuners do.

 

[paulT]

Thats what tuners do.

I happy with my meathod
Leaves more money for Beer & Cigars.

 

[RocketM1419]

Just as a follow up. I loaded five rounds per load from 39.0 grains to 40.4 in .2 increments and shot them through the chrono. 40.4 was max that I wanted to load as it is getting a little too crunchy there. Barrel had 160 rounds through it before test.

The 39.2 and 39.4 both gave the 2750ish node with same exact same 12ED/4SD as before. I shot through the rest and steadily got worse then started coming back at 40-40.2. The last string of 5@40.4 gave me 7ED/2SD at 2823 ft/sec

Needless to say, I will be exploring that load further.

Thanks everyone for the guidance. Gonna have to make or buy one of the long neck funnels.

T