Is this trend you observed at 2% from the listed max, or 2% from the max load determined from that particular gun and that set of components? Very interesting trend that would make for a good target zone to expect good accuracy when doing either method. Thanks for sharing.
- Thread starter spife7980
- Start date
D
Deleted member 113831
Guest
It was from that particular gun and set of components where they started seeing pressure signs.
You can test it for yourself pretty easily. Just take note of where you saw pressure, and multiply that number by 0.98. You can see just how close you are to the load you actually picked. It is very often spot on, or within 0.2 grains.
Last edited by a moderator:
D
Deleted member 10043
Guest
This thread is a perfect example of mindless load development. Like yesterday I watched a Law & Order marathon. Sort of like that.
I don’t know what I was thinking when I said this and I guess didn’t really think about what I was seeing. The pitfalls of netflix.
I used to have them at 2.120 which was .020 off for touch at 2.140 a couple hundred rounds ago. They are now touching at 2.150 and .20 off gives me the 2.130 which you could see on the 500 target. That’s about what I saw in erosion the first ~1-1200 rounds. I don’t know why speeds are increasing but I do see that it looks to be growing more quickly then I expected all of the sudden. Dang six burners.
so this is more in line with what ive seen in the 6mm...the first 1000ish rounds not a lot lost off the lands once you hit a 1000 1200 they go fast....in a 6.5 up to about 1500ish then past that the same thing...which makes it hard for me to believe some of the "accurate" barrel life/round count claims i see posted on the web.
as far as it speeding up when was the last time you REALLY cleaned the barrel? im sure you know but the throat probably looks like a dry lake bed and will start traveling down the barrel so all the fire cracking will pick up more copper/carbon...that would be the only expiation i can think of why its picked up speed as long as everything else is the same.
I cleaned it three weeks ago, let wipeout sit in it for a couple hours and then I ran some boretech c4 and c2 patches. I put 20 rounds trough it before I resumed with these tests for a good fouling and the only obvious outlier was my first shot. I’ll track this barrel a bit longer. If I just have to set the micrometer .005 longer every 100 rounds then that’s fine if it will keep shooting well enough.
That's an interesting observation that I think I'm going to try to replicate soon. I just ran the numbers on a cartridge I've been working on and it seems to work out on paper and with the ladders I've already shot. I landed .2gr over the 98% of the lowest pressure load but after chronographing a larger sample (25) I am not satisfied with the results.
I'll have a brand new barrel and new cartridge to load soon, my plan is to do single shot ladders to pressure, then the 98% load and .2gr above and below. It should be interesting.
I wish I knew why my barrel has sped up but oh well. Shooting well enough though.
As you can see it was a bit wet today... tough to get the marker to show up well.
As you can see it was a bit wet today... tough to get the marker to show up well.
Last edited:
D
Deleted member 113831
Guest
At what distance was this shot at?
500
I guess so. It matches the velocity of my prior chosen load.
Also, 39.7 was getting hot. All rounds over 3030 fps had heavy bolt lift and that 3050 one had smear around the primer and a good amount of force/clicker to open the bolt. There may be accuracy for Sheldons hypothesis but I’m not going to play there.
Last edited:
D
Deleted member 113831
Guest
39.3 has the best vertical, 39.1 is fairly round and not too bad vertically, 39.2 has 4 shots in about an inch with just that one landing out. I don't think you would do bad with any of them.
39.1 for the win 
D
Deleted member 113831
Guest
This another nugget for my 2% hypothesis. You saw pressure at 39.7 on this particular day, 2% backed off from there is 38.9 grains. You chose 39.1 grains.
The trend I have been noticing is that either 2% or 2% + 0.2 grains off of the place where you find pressure is a sweet spot in a very wide spectrum of calibers and loads.
Just an interesting side note. Thanks.
Just wanted to vet that area around 39.1
Im just going to keep loading my 39.4-39.5 load I always have used and chase the lands til it quits.
Im just going to keep loading my 39.4-39.5 load I always have used and chase the lands til it quits.
Similar threads
