High velocity

[Baboltin]

Hey everyone,
So I'm a little confused as to what is going on, I have been reloading for my CA ridgeline 7 mag for years I started with new nosler brass and now am using the same brass and so it's getting shot a second time. I'm shoot a Barnes ttsx bullet and manufacturer says 2998 velocity with a 24 inch barrel. When I first worked up the load I was at and around 3100 fps with a 26 inch barrel, that load shot well and I felt deadly with it even shot one shot kills at 440,480,492 and then lately the fps have increased to over 3200fps with the second shot brass and I am having a hard time shooting anything at any range. I'm loosing confidence in my shooting skills. I checked velocity a couple days ago it was an average of 3240 for 8 shots. I'm wondering if I should seat the bullets a little more and try and decrease the fps and maybe it would make for a more stable shot. What is your all thoughts ?

Details
H1000
67.0 grains
Seating depth .03
Nosler brass
150 ttsx Barnes bullet

Rifle CA ridgeline
7 mag
185 rounds through the rifle

Could the fps continue to creep up be causing the bullets to get unstable and open up at longer distance. I'm tempted to seat them to .05 (like Barnes suggest to start at and go to the range and see if the speeds come down. What is everyone's thought and will that bring my fps down by adjusting seating?

 

[lancetkenyon]

7RM virgin brass has a way shorter headspace than fired brass. Meaning you use a lot of energy during the burn to form the brass. Usually something like (using a .420 headspace comparitor), virgin will be 2.107, and fired will be around 2.121".
Now, the 2nd firing, if you bumped shoulders back correctly, will be taking that wasted energy and putting it behind the bullet, instead of blowing out the case.
Also, if you now have 100+ rounds down the barrel, your barrel is breaking in, smoothing out, and speeding up.

Drop powder charge by about 1.5-2gr, and your velocity should come back down to the original speeds.

 

[Varmint Hunter]

Any chance that you are using a different lot of powder? Have you stripped the bore of all fouling. Barnes bullets tend to build copper over time. This "may" lead to increased pressure and velocity. Just a few thoughts.

 

[Baboltin]

Same lot number of powder, I at the end of hunting season always clean and strip the barrel of all fouling material

 

[Baboltin]

Will changing seating depth decrease velocity?

 

[lancetkenyon]

Will changing seating depth decrease velocity?

Some, but not 100+fps.

 

[Baboltin]

Some, but not 100+fps.

Thank you for your information I guess I will be pulling bullets and dropping powder

 

[Mikecr]

This is why you should have load developed with fire formed brass.
Changing seating may or may not affect MV. Depends on land relationship and load density. What does seating of .03 or .05 mean?
Going up in velocity does not decrease stability.

You just need to start over

 

[MagnumManiac]

7RM virgin brass has a way shorter headspace than fired brass. Meaning you use a lot of energy during the burn to form the brass. Usually something like (using a .420 headspace comparitor), virgin will be 2.107, and fired will be around 2.121".
Now, the 2nd firing, if you bumped shoulders back correctly, will be taking that wasted energy and putting it behind the bullet, instead of blowing out the case.
Also, if you now have 100+ rounds down the barrel, your barrel is breaking in, smoothing out, and speeding up.

Drop powder charge by about 1.5-2gr, and your velocity should come back down to the original speeds.

^^^^^THIS^^^^^

Cheers

 

[skipglo]

7RM virgin brass has a way shorter headspace than fired brass. Meaning you use a lot of energy during the burn to form the brass. Usually something like (using a .420 headspace comparitor), virgin will be 2.107, and fired will be around 2.121".
Now, the 2nd firing, if you bumped shoulders back correctly, will be taking that wasted energy and putting it behind the bullet, instead of blowing out the case.
Also, if you now have 100+ rounds down the barrel, your barrel is breaking in, smoothing out, and speeding up.

Drop powder charge by about 1.5-2gr, and your velocity should come back down to the original speeds.

What Lance Says! X2

 

[WildBillG]

I would not pull any bullets just seat them a little deeper until you regain your accuracy. Is there any chance you may have shot a larger caliber rifle and picked up a flinch. This is just a thought of mine not meant to insult you. But deinetely try just seating bullets deeper about .010 at a time.

 

[Baboltin]

Well I went ahead and seated the bullets from .30 to .50 to give them some more jump and it made things worse. The group at a 100 yards opened up and also velocity increased. Doesn't make any sense to me but it's clearly not the right answer or bandaid to get me by. I very well could have created a flinch since I haven't shot much this year with the shortage of ammo and supplies.

 

[Baboltin]

I believe the best bet is to pull the bullets on a couple and adjust the powder and then go ahead and go to the range and see how they shoot and get my velocity down. Any other suggests or advice.

 

[Mikecr]

What got you where you were was just fleeting luck. New brass absorbs peak pressure energy to flatten it, making it forgiving, but that can never last. Brass cases change in many ways on firing that cannot be undone.
But now that your brass is closer to stable (hopefully), you can do the testing there is no shortcut for.

Back off a couple full grains and do Berger's recommended full seating testing with your bullets: https://www.longrangehunting.com/th...-from-berger-vld-bullets-in-your-rifle.40204/
Then with best coarse seating as tested, go to powder development.