Reloading- What pressure signs do you stop at?

[59FLH]

Published data when available and all the above mentioned when it's not.
All methods backed up by recorded velocities entered Into computer models.

 

[Pdyson]

If you have a stiff bolt lift you've already gone too far…however I have had some seriously FALSE pressure signs in my 28 Nosler when using over-priced and Uber-soft premium brass I bought from Nosler. Twice I went home and pulled bullets after having to knock the bolt open with a rubber hammer on loads that the chronograph showed 7mm Mag velocity and over 2 grains below published manual maximums. I don't know if it was a fluke, both boxes of brass were the same lot number. I threw it all away.
I treat book maximum charges as the gospel and back away when I see any ejector marks or smears on the case head. I typically find wider speed nodes below max anyway.

 

[hankle]

Usually will drop .5-1gr below ejector mark assuming no heavy bolt lift. Then will reload a couple cases over and over and make sure they last at least 4-5 firings.

However I did this with an absolute hammer load in my 30-06 that was sizzling fast but seemed ok by the above parameters. Using Varget so very temp stable.

Hunted in the snow and got pretty wet. Fired a round just to see what would happen…blew the primer. Not sure if the outcome would have been different with even factory loads but it does raise some concern on the validity of my methods.

Thanks for your honesty! This is the kind of info that is so valuable to safety. I love theory as well as the next guy, but these are the experiences at the limits that people need to hear.

Thank you again!
HW

 

[TRG65]

I've had batches of lapua 6.5x47 brass that had a series of light ejector marks all around the case head. It still lasted 10+ firings. That case seems to have a very high pressure tolerance. I have found that ever gun is a bit different. So like others I compare what I see to the velocity and pressure in QL. I have one gas gun that shows bad ejector marks at 58k. But for bolt guns, I load for accuracy at the velocity I can achieve. I don't mind having a load that says it is in the mid 60k according to QL/GRT of if I get light ejector smears I'm ok with that IF the load doesn't have hard bolt lift AND the load passes a water test for a few rounds in the summer.

 

[jessej]

For me, it depends on what the rifle is used for. For a general purpose plinking/hunting/ higher shot volume rifle, I'll be far more conservative, but if a rifle won't shoot good at max pressure, I don't want it.

For a low volume hot rod hunting rifle, flat primers and ejector marks are the norm. I work it up to the starting of heavy bolt, then back off a 1/4 grain. These are for local to me shooting and hunting.

If I'm loading for a long range trip where I'll leave the gulf coast and and travel 1k-2k miles and 5k-10k elevation change, all the above goes out the window. Accuracy and precision is all that matters then.
For that I want stable predictable rounds that put heavy projos exactly where I want them. Even if I sacrificed 100 fps.

 

[dblman]

I think the absolute best method for safely working up loads is to use a chronograph from the start.
Check each progressive load. If increases are consistent then speed should be also. When you hit a different result. STOP!
You just passed the sweet spot. Been doing this for 30 years now, it works and it is safe.

 

[Cberndt]

I load one each in .3g increments up well above book specs. I then shoot each logging speed and monitoring brass as I go. Once I identify pressure signs I discard anything above that point and start developing test loads from the loads up to that point.

The exception for me was years ago with a .308/178 A-Max/Varget. It shot significantly better with flat cratered primers. Remington 9 1/2s so they were soft. I'll never find the hot accurate load again though. I just don't go there.

 

[memtb]

I use a slightly heavier bolt lift as my indicator. As others have mentioned, different cases have different degrees of hardness as do different primer cups…..so, I don't lose sleep over flattened primers or an extractor mark on the case.

I'm just guessing that I'm not extremely over-pressured as my primer pockets are still tight after 10 reloads! If I didn't get violently I'll when I have to throw away cases…..I might push them a bit harder! memtb

 

[DoneNOut]

Some additional thoughts on the matter:

Loading 3gr under max published data is the easy button for starting out. To save on components I read the bones & ornaments in the black magic brew:

Case capacity consideration.

I identify the case being used in the load books and compare to what I'm loading.
I'll use 308 WIN for example. Winchester brass holds the most water of all the brands. Lake City NATO brass has the least. There is a general 4gr of water capacity difference between the two. This equates to a couple grains of powder charge I've found.

H20 capacity of case - explained above
Seating depth of bullet - I load .050" longer than the books
Length of base to shoulder - new brass is 1.608-10", fired brass in most factory chambers grow shoulders to 1.620".
(I recently started putting together my own rifles and can set headspace to only allow 4 thou stretch of shoulder)
Nosler load data is accommodating by listing H20 capacity of brass used to develop load data!

Brass composition consideration:

Federal and Nosler brass is softer and can show false ejector/bolt parts smears. (CRF I have don't have ejectors, so look for other stuff making shiny smears on case head)

Lapua, Lake City, older Winchester brass aren't joking with their case head smears.

Atmospherics

Hornady states their data is collected at 59 F. I do most of my load developments in winter because cabin fever and such. I factor the temp difference. I don't expect to get book velocities in 25F temps. If I am getting book velocities in cold temps then I'm over pressured. Even with the Hodgdon Extreme line of powders.

 

[Mike D Texas]

When working a ladder, I run until I get stiff bolt. Typically by then I'm getting ejector swipes or even plunger marks in the brass. Depending on the case capacity I will back off anywhere from .5 to 2 grains. As long as a I don't see any visible swipes, plunger marks, etc and assuming the grouping seems decent I'll work around that with seating depth to fine tune.

 

[Dean2]

I will echo what many have said, I use a Chrono on all load development. First I find the COAL the gun likes best with a load 3 grains below max. Then I start adding powder to move up the velocity curve, as soon as velocity quits going up as powder increases, or shows a larger than normal spike, that is it. I back off from there and work on the load. This usually happens very close to the average max published velocities. Sometimes a little under, sometimes a little over but usually within 100 FPS.

Excessive fouling, extremely hot weather, I have also seen velocity spike in very cold weather, uniformity problems with components, oil in the chamber, or a snow or rain storm can all lead to a condition which will produce unsafe pressures. If you are already running right at the ragged edge, you leave no margin of safety for things that are often way outside your realm of control.

If you are getting ejector marks, or hard bolt lift, pierced or black edge primers, or expanded primer pockets using Lapua or WW brass, you are already WAY over max pressure. Not a place I go. If I want 200 FPS more speed, I will move up in case capacity rather than push a smaller one too hard.

 

[dblman]

Dean2;
It's scary to me to hear of all the guys who use stress signs as limit factors. Stress signs, as you say come way above max., no matter what the book says, too much is too much and you are not only taking a chance with your eyes of even your life, but you rifles are taking beating too. not good...

 

[randy86314]

You have set interesting rules. Who is Steve?
Ejector wipe is a sign of pressure too high for that brass. Try better brass.
Heavy bolt lift is a sign to avoid.
Flat primers are a headspace situation.
I stay within published data.
Thanks for asking.
Here is a good link:

Understanding Pressure :: Primal Rights, Inc

Reading pressure is a required skill that all shooters must have. Whether you are shooting factory ammunition or your own handloads, you absolutely must be able to detect and interpret pressure signs on your fired brass.

www.primalrights.com

 

[Rosebud]

Most reloading manuals have been lawyered down in resent years. But do not jump on me yet! Powder changes and brass has become better. I,ve got loading manuals frrom1960. They put in on average about two grains of powder more than todays manuals. Friend shoots 54. Something , in his 30-06 with 168 Hornady Amax. About two grains of IMR 4064 over book max. Been doing it for 40 years. Still has all his fingers and both eyes. That being said , stiff bolt is what I look at first. Loose primer pockets is a dead give away.