Home Forums Hunting & Shooting Hunter's Campfire unsafe loads?

Recently I have been thinking about unsafe loads. If one is working with a wildcat how does one know when he exceeds a safe load?

You need to read several good reloading books. There are few wildcats, or very similar wildcats, that have not been well documented in various places by some very dedicated and technologically sophisticated reloaders.

Terry

When someone has to call 911.

No matter how your load compares to one listed in a manual the second you experience hard bolt lift you need to stop and reevaluate things. Trying to "read" primers is not a reliable indicator of pressure signs. Hard bolt lift is trying to tell you something.

If you have dial calipers you can measure case head expansion as well but with some sloppy chambers I've seen that can be misleading.

A chronograph and some reasonable expectations regarding velocity.

Does anyone still make the Powley?calculator?y The one where you put case vlume, powder, and bullet into a chart and ti gives a starting place. Other than that, look at any similar sized things in the books.

Hard bolt lift, like said,, you can tell SOME from primers, case expanding. Is the velocity reasonable for the scenario?

Almost always, there is some info on the internet, you just have to remember that free advice is worth what you pay.

Post what you are doing, someone will chime in.

I am a chikken about this. I will let others, more knowledgeable than I, lead and then I may follow... At a distance.

Be safe and always start 10% under a max load
Patty

I don't know it they still give out that info, but I used to call Sierra's ballistic lab.

The variation between loads iin the Hornady and online Hodgdons reference info id pretty dramatic, at least for the last time I looked at 45-70 rifle loads. The upper end of H4198 was a way higher...

I go for accuracy rather than just speed. Both is good if attained at something well under max for me.

Safe velocity is purely a function of case capacity vs bore diameter vs bullet weight.

Short and fat case vs long skinny case, it does not matter. If the internal volume with a bullet seated is similar, you may well expect similar velocities with the same bore diameter and bullet weight/construction.

I use the cartridge designer feature in "RCBS Load version 2.88" to compare the internal capacity of my wildcats to a known cartridge. That gives me a good clue as to what I should expect from my chronograph as I start shooting.

I have found "Mule Deer's" rule of halves to be of much help when looking at cartridges of slightly dissimilar capacity.

If cartridge #1 has X percent more capacity than cartridge #2, then you may expect to get X/2 percent more velocity from cartridge #1. A six percent increase in case capacity will net a 3 percent increase in velocity at similar pressure with the proper powder and equivalent bullet.

After reading of such in the reloading manuals I took careful measurement of "PRE" pressure ring expansion and "CHE" or case head expansion. But I found the numbers had so much variance as to be nearly useless.

Denton has written extensively on this matter, and has discussed the "noise" associated with these measurements. I am not the mathematician he is, a far cry from it, but my observations certainly lend credence to his claims.

I study the capacity of the cartridge and determine what velocity I should expect based on other cartridges of like capacity.

I shoot work up loads over the chronograph and plot curves of powder charge weight vs velocity.

I look for a spike in the curve or a plateau. Either can indicate a high pressure situation.

I look for the traditional pressure indicators, such as ejector marks, and flattened primers. But I do not depend upon them. I especially look for loss of radius at the edge of the primer. One can usually correlate advancing loss of radius with increasing velocity. That feat gets much more difficult with advancing age and deterioration of eyesight.

But my bottom line indicator is the primer pocket.

Brass becomes more brittle each time we fire it, and less malleable. Therefor a brass case which has already been fired five times is a poor choice to indicate pressure.

After I have worked up to what I think is a proper load I will take a virgin hull and stoke it up, and shoot it.

Seat a new primer. Does it seat firmly? Yes? Load it and shoot it.

Repeat with the same empty case four more times.

The acid test!

Does the primer still seat firmly after five loads????

Or does the primer fall out on the floor when you handle the cartridge case??

With my maximum loads, the primer does not seat quite as firmly after five loads as it did in the virgin hull. But it is in no danger of falling out of the primer pocket either.

Yeah, I know, that is pretty subjective. But I find acceptable results for the load work I do.

Rich,

Forgot to mention but Art Alphin's book "Any Shot You Want" is a great resource, much more than just a reloading manual that has tons of good info on pressure signs and safe handloading.

What he said!

I always see how it chambers afterwards, how it chambers after neck sizing ( which is indicative of lower pressures) and finally how difficult it is to full length resize....

I usually live with the neck sizing test...

if I go much over that, then if it is difficult to resize full length... then I figure the pressure is a lot higher than it should be...

loose primer pocket when reinstalling a new primer is also a good indicator...

Thanks, guys, for the input.



In the past I discovered if you measure new brass then measure it after the second and third firing making no changes, each measure has less increase.

I don't want to see any ejector mark on a fired case. Also I want the bolt to open as easily after I fire it as it opens with nothing in the chamber.

Seafire,

Now that I switched from Imperial sizing wax to Hornady One Shot full length resizing is a breeze.

So my having to open a bolt on a ruger with a piece of 2x4 was a sure sign of an overload then, just like I thought.
I know my late brother was impressed at how well the Ruger in 300 win mag handled it.

Cause once I got her opened, the primer fell out as the pocket was much enlarged, even brass in the head had extruded into the slot in the bolt head and the firing pin hole, that is when I knew for sure, cause after using a piece of wood to open a bolt if a primer falls out of the pocket, you know it was too high pressure, at least for that one rifle.
I know, I am a freakin genius.

Ejector marks can also be due to brass softness.

I've never fired a factory weatherby without the mark on the brass. But that brass is known to be soft.

Same wiht FC match in 223 for sure, they all give marks but run over a pressure tester are not over....

Thats the problem with signs, you can't be looking just for signs, you have to have an idea of what produces them or can produce them.

Combo of all IMHO is most reliable.

And by doing different things, with the same round you come to different speeds and pressures with the same bullet and case and powder combo. IE coat the bullets makes a difference. Throat makes a difference. Odd or even rifling makes a difference. Depth of lands and grooves and bore diameter can make a difference.

Not to mention the lots of powder, primers or bullets and even cases.

A wildcat cartridge shows the same pressure signs as any other cartridge. Bolt lift, primer signs, marks on the case head, case head expansion, all can tell you something. I use all of the above, but the one that I don't ignore is bolt lift.

If you are looking for a load for a new cartridge, someone else has probably already done it, and some data is probably on the internet. Compare the data as much as you can, average a starting load, and watch for pressure signs. You can also compare it to cartridges of like capacity.

Just curious, what cartridge is this? Good Luck, Lightman

Yes, this is a good indication of how quickly the brass work hardens in the case head area.

Mule deer used CHE to determine pressure when he wrote about new powders in the 264 about ten years ago.

Since we have no standard to tell what is an acceptable amount of CHE with any given lot of brass, M D fired factory loads and measured expansion, and used that as a standard.

Then, if I remember correctly, he pulled bullets and powder and used that lot of brass to do load workups. When he measured CHE on the handloads which matched factory loads, he determined that was a maximum load.

lightman,

The funsmith called last week to tell me the barrel had shipped. My experience told me I will get the rifle late this month. It is a .257SLR. It is like a .25-06 Ackley with the shoulder moved forward leaving .200" long neck. I have a bunch of G.S.Custom HV 85 grainers. They claim a B.C. of .383. The Barnes TTSX 100 grainers claim a B.C. of .357. I should be able to get about 200 feet per second more velocity using the lighter bullets and similar amount of powder. Well, I'm hoping.

Now I need to learn to shoot from shooting sticks.