Too early to do load developement?

[corsteve]

all you are doing is getting the burres of the rifling cp donnaly told me had a 300wby made by him an you all know who is was great barrel maker shoot 1 rnd run a patch everytime for first 10 rds w/out gettin warm then clean it an start shootin did that w/1/ dozen barrels an no problem so do what ever u want

 

[MagnumManiac]

Brass does not elongate in the neck upon firing...it shortens as the case fills the chamber pulling brass from the neck as the body expands.
Brass elongates in the neck when you SIZE it excessively.
Cases after firing may have expanded in the neck by .008", .006" on a SAAMI chamber is more common, then your sizing die, typical FL non bushing die, pushes the neck back .010" and then the expander returns it .002" under bullet diameter or whatever. It is this squeazing down and xpanding back that causes necks to lengthen.
If you don't believe this, I suggest you measure your cases prior to firing, after firing and again after sizing them.
Also, another example, belted cases are anywhere from .015"-.025" SHORT in the shoulder area prior to firing. Upon firing the shoulder is blown forward by this amount, the neck shrinks in length. So, if the case flows by .025" where is the brass going?
Too many myths are still believed, cases do not flow. Cases also spring back after firing, if they flowed it would stay the shape of the chamber and never come out.
Think about it.

Cheers.

 

[Rooks]

With a number of different rifles and cartridges, my experience has been that once you're through the short break in, attention to detail regarding components tells more about load development. I am sold on the ladder test method. It works perfectly if your brass prep is perfect and the components are top shelf. Look for info early and often. Test test test, and read the info without bias.

 

[Greyfox]

In my experience, barrel break-in in terms of seeing a difference in the ease of cleaning, or carbon removal generally occurs within the first 10 or 20 rounds. Velocity stabilization, which is an increase in velocity over shot count, an can vary by barrel, and a separate effect. The average for my barrels over a dozen years where I have recorded shot count and velocity and consisting of factory, semi-custom, and custom barrels have increased 50-100FPS, ultimately stabilizing after the first 100-200 rounds. For serious competition and LRH, I generally complete this process before applying long range ballistics. I will still work on accuracy tuning during this run-in period and adjust for velocity, or any fine tuning when it stabilizes.

 

[matt_3479]

I'm doing load development on my latest build as we speak. Once fire brass wasn't enough to fireform perfectly to the chamber but twice fired was as a heads up. I still do load development on once fired brass but I won't do final measurements on brass till twice fired as far as shoulder bump goes.

I fire 100 and then start load development just so all brass is once fired. My 6 creed the second previous build did continue to speed up until about 240 rounds then I had to back off my charge. I'm hoping this 25 creed settles in a bit faster

 

[Alex Wheeler]

New brass can change speed, but we see it in the BR rifles and have cases with a lot of firings. They dont wear out and you use them on the next new barrel. Its not the throat breaking in either. Pay close attention to the lapped finish and how it changes early in a barrels life and you will see.

 

[vancewalker007]

I've got a new C.A. In 280ai. The barrel has 75 rounds through it after the C.A. recommended break in procedure. I've got a couple different powders loaded up for some ladder tests but am starting to wonder if these will be conclusive. Any opinions on if the performance will change once there are 200 rounds down the tube (for example) compared to now?

All I can tell you about is my recent experience with a 6.5 PRC in. Proof Carbon barrel. I was monitoring velocity on everything I was shooting up to around 300 rounds as I was shooting different bullets and powders on ladder tests. I did noticed a 45-48fos increase around 253-255 rounds. It's had stayed fairly consistent after that one jump.

 

[milo-2]

All I can tell you about is my recent experience with a 6.5 PRC in. Proof Carbon barrel. I was monitoring velocity on everything I was shooting up to around 300 rounds as I was shooting different bullets and powders on ladder tests. I did noticed a 45-48fos increase around 253-255 rounds. It's had stayed fairly consistent after that one jump.

Getting a barrel through the speed up is a minor inconvenience. But at 250 rds when it happened, that is a disruption.
I have had 2-3 Hawk Hill barrels that took around 120 rds, too much, but were so good after I didn't let it bother me. But 3 Proof carbon barrels that I broke in, had to be the most unruly for some reason, one taking 47 shots to settle in, it was back and forth, 40 fps spreads. I chrono each shot through the speedup myself also.

 

[greenejc]

I've got a new C.A. In 280ai. The barrel has 75 rounds through it after the C.A. recommended break in procedure. I've got a couple different powders loaded up for some ladder tests but am starting to wonder if these will be conclusive. Any opinions on if the performance will change once there are 200 rounds down the tube (for example) compared to now?

Its never too early to do load development. Some rifles will shoot tighter as you get the first 2 to 3 hundred rounds through them. Some don't change at all. They're all a little different.