Reloading- What pressure signs do you stop at?

[gohring3006]

Some guys like to push the limits of everything they own.
I don't really push my guns hard, I use hex boron nitride to help me push past max loads.
I hot rod chainsaws that probably on the verge of exploding in my hand.
Same with car engines.
Same with my wife, I push the limits on her often, she blows up often too! Explodes into a rage if I really push it.

 

[memtb]

Well as you know there is no free lunch when pushing a cartridge to max pressures and beyond. It is not good for accuracy which is what I am after. People should understand this but many just do not care.

I completely agree with your statement with this possible exception.

While I certainly "do not" agree with exceeding max pressures…..often the most accurate load is "near" a max load. As max loads vary from firearm to firearm…..often the loader/shooter may venture into "over max" territory in search of the highest velocit, "accurate" load! It is then the loaders responsibility to recognize that they have exceeded a safe load and act upon this knowledge accordingly! memtb

 

[Rosebud]

Let's quit beating the poor horse, it's not getting up. Time for this thread to die from over pressure.

 

[comfisherman]

Forget that let's start doing bad advice but have some fun with it....


In that vein.. I stop when the primer Pockets blows so bad it sticks in my glasses, dial if back a half grain... brass life is for wimps. You're getting more than three firings from Lapua brass trade that camo for khakis.... sucked down another tall boy Monster Energy and get some velocity....

 

[Turpentine21]

Neither of these were " pushed too hard".

No they weren't. As pointed out in the last paragraph. They were negligence or ignorance cases. I Only used that term because the same can happen to a rifle that is pushed too hard.
In the pushed to hard category, I've had two shotguns come in. Young adventurous adults, term used loosely, decided they would roll their own heavy shells. They would open up a steel shot round and replace the steel with lead. They also used these to shoot ducks. One blew part of the barrel extension out through the side of the reciever. The other broke the bolt, destroyed the locking lug, destroyed the barrel extension, messed up the carrier dog, and galled the heck out of the receiver.
All of these folks were extremely lucky. Amazing examples of Darwin Award candidates at work but these guys were extremely lucky. A gun that has blown apart is an eye opener, regardless of how it happended.

 

[Turpentine21]

How to fire form bullets... yes bullets not brass... here is how to fire form a .308 caliber down to a .224.

You know the crazy thing is in both incidents i cited the deer was actually killed. 308 down to 270, 7mm-08 down to 270wsm. You might be on to something. On the spot fire forming.

 

[Turpentine21]

Everything ^^^^^ except primer flattening. Started ignoring that 25 years ago, and I'm still here.

You know, I pay a lot less attention to that now than I used to. With different cup hardness it really doesn't provide much in a definitive sense. But it can tell you some useful stuff. Headspace for one. Enlarged pockets. These are from slamming back into the bolt face with a bit of a running start. However, Flattening where you have brass flowing into crevices is an attention getter.

 

[baldhunter]

I used to run my loads up until I'd get a heavy bolt lift or ejector marks and back down if I did.These days I try to stay around book max for the type of powder for weight bullet.I'm also using a chronograph when I'm working up my loads as well.I don't rely on one data source,I pay attention to the pressure and velocity shown as well as barrel length.I don't have Quick Load,but I've had a guy run some data for me.If all the data is entered to exactly what you are using and the barrel length of your rifle,I find it to be quite accurate in predicting pressure and velocity.If your velocities are way beyond published data and you account for the barrel length difference,+ or- for each inch difference,your pressures are probably way up there too.Measuring case head expansion is a good way the measure pressure,but I question just how reliable that is because that depends on the brass hardness.I recently have been working with a new to me cartridge.I have three brands of brass for this cartridge,Norma,Winchester and Remington.The load that was shooting well in my rifle using all three of the brasses,was giving me loose primer pockets after first firing in the Norma brass.I backed off the load about one to two grains and the issue with loose primer pockets stopped on the Norma brass.I never had an issue with loose primer pockets on the Remington or Winchester brass.QL was showing the load I was getting loose primer pockets on the Norma brass at 63,250 pressure and my velocity was about 50fps higher in my rifle than the QL prediction.So really,Without the proper testing equipment,you really don't know where your at with your pressure.I more or less rely on about what velocity I should be running with the powder and bullet I'm using and the barrel length and focus on accuracy.

 

[Rich Coyle]

Well as you know there is no free lunch when pushing a cartridge to max pressures and beyond. It is not good for accuracy which is what I am after. People should understand this but many just do not care.

Blanket statements are often wrong. Some cartridges find the best accuracy at the highest velocity.

 

[xsn10s]

I agree some of the most accurate loads are at the higher pressures. I guess I should clarify how I load. I look for flattening primers, ejector marks, and stiff bolt lift. I consider a stiff bolt lift a pretty serious warning and rarely get there. Flattening primers can be causes by some case lube left on the brass so I pay attention to it, but don't always rely solely on it. An ejector mark is usually where I back down the powder charges. This is all while using a chronograph which I also gauge the pressures with by comparing with several "book" velocities. When I didn't have a chronograph I paid more attention to a flattening primer. These days I opt more for an accurate load with the highest velocities and still having a good radius on the primers. And this isn't a rule set in stone for me. I'll adjust the criteria depending on the job set for the ammo.

 

[VinceMule]

Most rifles may shoot their absolute best within 2.0g of a max load for that particular barrel.

So, start at the start, use good brass, establish first what is the max load, back off 2.0g, and work up carefully.

Crater'd primers mean the firing pinhole in the bolt is oversize. Every 257 Weatherby I have ever owned cratered the heck out of primers, and I ignored the crater.

Many do not realize that loading manuals are meant to show what pressures and velocities occurred with their test barrel, their components, which may not be an indication of what your barrel will do due to different components and possibly a much different chamber, bore dia, bore condition, and throat configuration on your rifle.

The loading manual is only a guide and is NOT an absolute, fixed in concrete indication of what may go on with your barrel. If you consult 5 different reloading manuals, you will get 5 different max loads with various velocities.

It is prudent to give some attention to all load manuals, and approach max loads with a degree of caution.

 

[waskow54]

I use a micrometer that measures to the .0001 to measure the case above the extractor groove. File flats on a new case rim so I can mic the case from the base end. First load is mild to form the brass a bit then work up in 1 to .5 grains until I see brass start to expand. I then back down to the last load that didn't have any expansion and fire a couple more times to make sure it's good to go. On some hunting loads I'll use .0002 expansion as the cut off. My thinking is I should get 4 to 5 loadings before the brass is junked. If brass lot is changed I do another work up of that brass. This process has served me well. Learned this from a book Bob Hagel wrote years ago.

Hogdon recommends using new brass when using that method of pressure estimation. I started using it because I have a CVA break action rifle in .35 Whelen. There's no ejector for the brass to flow into. For a 30-06 type round they say a maximum load should produce .0005"-.0006" of case head expansion. In my bolt rifles this level of expansion doesn't have a hard bolt lift or ejector mark, but my velocities are usually close to the maximum shown in the loading manuals. I never thought of filing a flat on the brass. I'll try that. It seems like it would be easier to get a good measurement that way.

 

[VinceMule]

I believe you are overthinking the process waskow54. Shoot what is accurate if you have no pressure indications of hard bolt lift and no swiping on the case head?

You know the pressure will increase as the temps go up, and likewise when the temps drop.

Keep in mind that some barrels are faster than others, and every now and again you will run into a slow barrel as bore dia. does vary.

I reload all kinds of wildcats for which no load data is available.

 

[6fatrat]

Large rifle primers that flatten in the pocket, small rifle primer cases that have an ejector swipe.
Steve Bair