That load and that velocity do not suggest high pressure. And primer flatness is the least reliable indications of pressure, anyway.
The Chrony is the best evidence. you are not over the speed limit.
Shoot and enjoy.
Pressure at minimum load?
- Thread starter TikkaWSM
- Start date
That load and that velocity do not suggest high pressure. And primer flatness is the least reliable indications of pressure, anyway.
The Chrony is the best evidence. you are not over the speed limit.
Shoot and enjoy.
- Location
- Iroquois Falls ON
I've read somewhere recently (perhaps in a book by "George C. Nonte, Jr.") that to light a load may cause flattened primers due to the fact that the pressure is not sufficient to get case obturation. Because the case does not grip the walls of the chamber, it is driven back against the bolt face. I'll try to find this reference tomorrow.
I dont know if anyone has looked up the load data for this for you but Hornady doesn't seem to list a varget load for the 50gr V-MAX. The 55gr hornady bullets have a suggested max load of 26.4 gr of varget so you could have just loaded it too hot. I know Hodgdons' site say to start at 26.5 but that is with Speer 50gr SP. I like to with the bullet manufacturers info and build for there as ever rifle is different.
In my opinion I'd start a few grains lower (than the bullet manufactures suggestion) and ladder test until you see pressure signs. Then drop it back a bit.
From the little bit i know about reloading a ladder test will also help you find the most accurate load for your rifle as well. Other things like barrel oscillation and harmonics come into play. Food for thought.
In my opinion I'd start a few grains lower (than the bullet manufactures suggestion) and ladder test until you see pressure signs. Then drop it back a bit.
From the little bit i know about reloading a ladder test will also help you find the most accurate load for your rifle as well. Other things like barrel oscillation and harmonics come into play. Food for thought.
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Polar_Hunter
Read my post 18, and remember this, my 30-30 primers always protrude because the chamber pressure at 38,000 cup or 41,000 psi is not great enough to cause the brass to stretch to meet the bolt face. This is called headspacing on the primer and this brass never stretches and thins in the base web area.
At higher pressures the primer is pushed out of the primer pocket and then seated flush by the case stretching to meet the bolt face. If the head clearance is too great, meaning the shoulder is pushed back too far. The primer as it is pushed out of the primer pocket bulges and again is seated by the bolt face but it becomes mushroom shaped. This then looks like high pressure and flatten primers. And this is why measuring the case just above the extractor groove for expansion is the best method for determining excess pressure.
The pressure signs were at the published minimum and a few grains above that, at 26.0 gr my primer is fine and looks just like the primers on factory loads I've shot (I found 27 grains as minimum from a few sources). That load (26 gr) is giving me 3200 ft/ sec and the accuracy is fantastic. Best group I managed so far was 0.38'' at 100 yards which suits me just fine. I am thinking the velocity would have been higher than recommended at the loads I tested before getting a chrony. Considering each grain is almost a 4% increase in powder in such a small case so I would think I was above safe velocities when I was seeing the flat primers. I'm not planning on trying the "hotter" loads again as I'm happy with the performance I have now. I will be starting at lower charges for future reloads and consulting a few more info sources if possible though. Learned a fair bit here.
skneub
CGN Ultra frequent flyer
Interesting , I quit shooting Grandpas 30/30 years ago because it was pushing primers
skneub
Normally with any cartridge when you start at the suggested starting load and work up, your first loads will have the primer protruding and lots of soot on the neck. As you increase the load you reach a point where the primers are flush with the bottom of the case. If memory serves me this is approximately 43,000 psi and from there the pressures increases and at the high end the primers start to flatten.
This is not written in stone and components vary in hardness and visual inspection of the primers is only a ball park guess on pressure.
And what Ganderite stated above about a chronograph is 100% correct, I bought the costly Quickload software only to find out you need a chronograph to calibrate Quickload to get accurate output from it.
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Tikka, you have described one of the best applications of the chrono while testing loads. You established a consistent velocity increase per grain increase in charge, from minimums up. If that relationship changes, then you are likely over pressure. Including if you see a diminished increase in velocity, as excess pressure may alter the burn rate of the powder such than you are no longer getting an efficient pressure curve.
It can also appear after the first firing of a brand new case due to slightly larger chambers. Probably 99% of my brass used in my older guns show a ring or line of some kind....doesn't mean the case is about to fail. You need to get a feeler wire in there or separate a case.
I don't think you will ever see detonation from a min start load with normal velocity rifle powder selection. You get that from using "reduced loads" with fast burning pistol powders usually combined with cast bullets. It's easily remedied with some filler to keep the powder in place over the primer.
skneub
CGN Ultra frequent flyer
Cool
next purchase is a chronograph , I noticed the soot.
depending on accuracy , I may not up the loads on the old girl .
just to save wear on the action and brass.
but I plan to reload for others.
may even buy a 22/250 (as I scooped a pile of brass for that) cheep to load for
