Velocity changes with different brass manufacturers?

[JFrank]

Sounds good’
I know I damn sure don’t have it figured out. lol

 

[Tesoro]

When doing a sweep for depth/jump... as often as anything else, you will see a decrease in speed with deeper seating, until you get to where things get really really deep.

A picture is worth a thousand words, so here you go. Below is an example of a 6 Dasher running Varget.

View attachment 1516102

Yes I did recall this phenomena with my 6br. The Garmin gadget is so easy and handy that I find myself looking at velocity data 10x more than before. I only had a magnetospeed and never shot with it on as I was convinced it would interfere with precision, so I just wasted ammo getting samples of my loads.

As someone mentioned, 25fps is a miniscule increase when at the 3000fps range +/-. It really dosent matter but in my case it bumped me over to the 3000's from the 2900's which really just looks nicer. on the screen!

I heard back from Mr Tubb and he didnt give it much thought other than maybe case capacity. I found my notes this morning and case capacity was 1% less or 1/2 a grain less h20 in the Lapua.

 

[RegionRat]

Correct me if I'm wrong but if running light neck tension, Primer impulse can pop the bullet into the lands prior to powder ignition thus creating a larger powder capacity. GRT has a setting for just such a situation. Is this what we are seeing here?

These run roughly 60 - 70 pounds seating force, which isn't considered light.

 

[RegionRat]

I heard back from Mr Tubb and he didnt give it much thought other than maybe case capacity. I found my notes this morning and case capacity was 1% less or 1/2 a grain less h20 in the Lapua.

All is well that ends well...

Like the rest of us, you know the bottom line. We end up testing.
In for your range report and good luck!

 

[RabbitSlayer]

My suspicion is the hardness and resulting neck tension.

Im just a hobby reloader for a few years so take it with a grain of salt...I don't get wild on weight sorting cases, because in an eric cortina interview I think with lou murdica or jack neary they said the problem with weight sorting cases is you don't know where in the case the variation is. The neck, the web, the base? Who am I to disagree with hall of fame benchrest shooters? Also Johny's reloading bench I believe it was tested case weight vs capacity and found there was not always a correlation. I do weigh new brass just cuz its easy and im bored. One member here said to figure out if it's worth the effort to sort shoot 5 or 10 or the heaviest and lightest and see if there is any difference over the chrono. I did that with brass for 3 rifles and it was not enough difference for me to bother. However, before these tests there were a couple outliers that were so far from the rest of the cases I culled them and just use them for fouling or setting up dies.

 

[Tesoro]

Dont discount your knowledge in reloading because of your newness. Look at Cortina for an example of someone who is a relative newcomer to shooting. He gave himself an accelerated phd program by picking the brains of the super accomplished, and thankfully passing it on via his podcasts. I am also a hobbyist who got his first rcbs jr kit in a box at age 15. 48 yrs later am still at it but like most but I didn't get to the 4th decimal place until the internet got rolling, and co-incidentally around the time when the hunter population started exceeding the animal population out west. Now I primarily shoot steel and paper and eat beef!

Conclusion: Tougher brass lasts longer and shoots insignificantly faster. With the cost of brass these days it is also more cost effective to shoot the best brass!

 

[JEFFPPC]

Not to dispute anyone else’s tests or findings, but just for something to ponder I’ll post a couple things.

One) a difference in .015 bullet jump with virtually no variation in point of impact at 300 yards.

Two ) While sorting brass by chrono it’s easy to see quite a variation in speed within the same lot.

Three) Even with such a variation you may still not see a point of impact change once in tune.

For myself the target is King..

The only post in this thread that's worth reading. JFrank has it correct.

 

[Tesoro]

The only post in this thread that's worth reading. JFrank has it correct

Sorry for wasting your time

 

[JEFFPPC]

Tesoro....No, your entitled to how you spend your time and effort. I just get frustrated seeing guys chasing what will not make them more competitive. But shooters shoot for different reasons. Good luck chasing whatever that is.But, the best way to get out of the proverbial rabbit hole is do not enter it in the first place.

 

[Tesoro]

Tesoro....No, your entitled to how you spend your time and effort. I just get frustrated seeing guys chasing what will not make them more competitive. But shooters shoot for different reasons. Good luck chasing whatever that is.But, the best way to get out of the proverbial rabbit hole is do not enter it in the first place.

Did i say I was competitior? No. Was just an observation for a curious mind looking for an explanation, no different than for many other aspects of reloading oddities.

 

[Old Navy]

Did i say I was competitior? No. Was just an observation for a curious mind looking for an explanation, no different than for many other aspects of reloading oddities.

If it was not for a new topic like this we would not have anything to talk about. We have covered all the basics a hundred times over.