Sticky for pressure signs?

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[Bustercluck]

That is why you don’t rely on one manual but several! That way you can cross reference to make sure things make sense!

For the record, I wasn’t asking for information for myself. I have some things to share and I think there’s probably quite a few people here who could teach me a thing or two

 

[Bustercluck]

You are getting the right answer. Reading pressure signs is not accurate and is only used by people who convince themselves they have it figured out. You are better off with a chronograph and a loading program than you are taking advice towards a practice that is not considered legitimate by anyone worth listening to.

This thread has only proved how many experts can’t be trusted on the internet. Yourself, myself and everybody else. I’ll carry on with what hasn’t killed me or blown up any gun parts and I should be good for the rest of my shooting career.

 

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[Gatehouse]

I gauge pressure when working up a load by watching the velocity. Once your velocity is in the speed max parameters you have probably hit top safe pressure. Quickload can give reasonably accurate pressure estimations if it has correct and adjusted data.

If you are experiencing even mild pressure signs - like a slightly sticky bolt lift- you are already considerably over maximum pressure.

I have tried measuring case head expansion with a micrometer in the past and found it's pretty unreliable. Mostly because you don't really have any true, consistent starting point.

Reloading manuals used to be written before most companies had any access whatsoever to pressure testing equipment which is why you see data changing. Also, powder changes over time, too.

 

[Hand Skills]

I have tried measuring case head expansion with a micrometer in the past and found it's pretty unreliable. Mostly because you don't really have any true, consistent starting point.

It helps if you measure WEB, not the HEAD there, Gate.

If yer still havin problems, ditch that mixed headstamp stuff and get yerself some new brass, eh?

Reloading manuals used to be written before most companies had any access whatsoever to pressure testing equipment which is why you see data changing. Also, powder changes over time, too.

Brudder, you give too much credit. There are some reloading companies publishing LOAD DATA straight from QL and GRT...

 

[DGY]

For the record, I wasn’t asking for information for myself. I have some things to share and I think there’s probably quite a few people here who could teach me a thing or two

Oh I wasn’t targeting you specifically, just giving my thoughts on the matter.

 

[Gatehouse]

It helps if you measure WEB, not the HEAD there, Gate.

If yer still havin problems, ditch that mixed headstamp stuff and get yerself some new brass, eh?





Brudder, you give too much credit. There are some reloading companies publishing LOAD DATA straight from QL and GRT...

I used the method that Ken Waters described. Ken Waters had as much knowledge on the topic as anyone else I would think. I liked the idea but so much of it is guesswork in the end. Ken Waters, Ross Seyfried among others recommended a micrometer and felt using calipers was pointless.

There isn't much point in trying to measure mixed headstamp stuff. Mixed headstamp brass is for range plinking ammo, loaded to a safe level and well under maximum pressure.

Ultimately using a chronograph is simpler and easier as I am going to be using it anyway when working up a load.

 

[Bustercluck]

I am interested in something if one of you guys wants to put a couple numbers through quickload?

6.5-284
H1000.
Cci large rifle magnum
156 Berger eol
Coal 3.210”
24” barrel

223 remington
Cci srm
Varget
85.5 berger
2.551”
29” barrel

6br
Varget
24” barrel
Cci srm
109 berger hybrid
2.371”

We’ll see how close quickload is to what I have for info.

 

[stubblejumper]

If there is excessive pressure, there will be excessive expansion of the case at the web. You can see this by measuring the web diameter, and you will notice that primers will go into the case significantly easier, if the web has expanded. To have any value, you need to use new or once fired brass of the same lot, not just the same manufacturer.
As for manuals, they are a good reference, but they aren't perfect, I have seen multiple instances when a published load was not safe in a specific firearm, and more often, I have seen instances, where a max published load produced over 200fps less than stated in the manual, and was actually a milder load, in a specific firearm.

 

[Smokinyotes]

I measure the case web just above the extractor groove. When I see expansion here I know I am approaching the material limit of the brass.

No pierced primers, stuck cases or heavy bolt lift... So long as I remember to bring calipers to the shooting bench (yes micrometer can be more precise)

Just stop when I see .001" growth at the web.

Took me 25yrs to figure this out, and seldom do I see this trick discussed.

If you are getting .001” CHE I suspect you are severely over pressured. Personally I use a mic and never exceed .0005”. Your call though.

 

[stubblejumper]

You are getting the right answer. Reading pressure signs is not accurate and is only used by people who convince themselves they have it figured out. You are better off with a chronograph and a loading program than you are taking advice towards a practice that is not considered legitimate by anyone worth listening to.

And judging pressure by velocity alone is not accurate, and neither are programs like Quickload. If those were accurate, the manufacturers wouldn't bother with actual pressure measuring equipment. I use a combination of velocity and case expansion. if the velocity is well above the normal published velocities, the pressure is also probably higher, but if I see excessive case expansion, I back the charge down, even if the velocity seems reasonable. Coincidentally, while there are exceptions, the velocity and case expansion usually are in agreement.

 

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[DGY]

There is a few things worth noting here I think, older chambering like 9.3x62, 8x57, 7x57 etc, with the new powders, stronger actions, these cartridges can be loaded a lot hotter than what the book generally suggests, those rounds were developed with loads that were quite conservative due to the possibility of running them into older weaker actions. Or in the case of the 8x57 using the wrong bullet diameter! If a certain action is able to sustain 65000psi with lest say 270, 7rem mag or what ever, then it should be able to sustain the same psi with 8x57 or 9.3x62! John Barsnes did quite a bit of testing and had access to a pressure testing device and showed that those older chambering when loaded to 60,000psi can and will be fine! I load my 9.3x62 286gn Aframe at a velocity of 2450-2470 and have no issues whatsoever so ever, and that is out of a 20” barrel! I’m still slower than what John publish in his book.
Also book value is from there barrel and there components so you can have a slower barrel or faster barrel than them, temperature will carry your results where those guys don’t have to worry about that in there “lab”.
So start low and work up and it’s not because you loaded it that you have to shoot it! It happens to me when shooting a ladder that I stop when I’m happy or if something doesn’t do what I want it to do, I just pull the bullets and dump the powder and start over!
I’m far from being an expert lol, but so far so good! And the best thing that happened to me is to find a mentor(Whynot), a guy that have been reloading for 50+ years that still have both eyes and all 10 fingers, that man have saved me a lot of troubles and made things a lot easier!

 

[stubblejumper]

While modern strain gauge instruments are more accurate, the deformation of a copper disc used to be the standard means of measuring pressure. Measuring case web expansion, is actually using the same basic principle as the copper disc.

 

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[Bustercluck]

The is a big difference between cartridge brass and the copper blanks used for CUP measurements. I doubt you are bothering to gather as much information about the specific composition and/or elastic limits of your brass. That is also ignoring the fact you aren't using the same setup. Even if you did no two pieces of brass are be exactly the same. Copper is copper, brass is copper and zinc and not always in the same amounts, let alone precisely. You think you have it figured out but that doesn't change anything. It's a guess at best. Your addition of a chronograph is the biggest benefit to your process.

Do you mind running the above info I posted through your quickload? I’m interested in seeing the results compared to my findings. I’ve shot all of those loads alot and proved their competence at distance and brass life. One is quite a bit off from most published data.

My problem with a computer generated data is it might limit you from the maximum performance and if you’re looking to swing next to the best in the country(or world) than you’ll be at a complete disadvantage to someone who’s pushing the boundaries of pressure. I know some people who push the 200.20x berger out of a 308win case with varget at 2710fps and they say there’s no issues with pressure or destroying brass.

 

[Bustercluck]

So I just did some measuring on brand new lapua 6.5-284 brass and also some trashed lapua 6.5-284 brass on it’s last firing. I measured 10 pieces around the web of new brass and every piece was bang on the exact same size, roughly 1/4 thou under .499”. I think it’s safe to say the entire box is probably the same. My outside mic doesn’t measure 1/2 or 1/4 thou, but I can say the line was in the exact smae place.

The trashed brass varies from .499 to roughly .49975, but I didn’t measure it when I bought it so we’ll never know what it was originally, but it was probably the same lot as my new brass. I had some brass forming a crack and was ready to separate so i tossed it, but I’m wishing I would’ve kept it now for this. I found one piece with the crack forming and it measured about 3/4 of a thou over .499”. I did push some of this brass fairly hard until I had ejector swipes and a tight bolt lift so some was abused. I was going to toss the entire lot, but I’m thinking I might be able to sort through it and pick out the bad pieces and get a few more firings out of the good stuff. I normally try and keep my brass in batches of 100 and I toss the entire lot when I start seeing issues with a few pieces.

 

[Unholysavage]

Its hard to make a guide when high quality brass like Lapua, Peterson etc masks overpressure compared to brass like Hornady.

Is the amount of force the lugs see the same at the point where brass of different quality starts showing visible overpressure signs? I'm not an engineer, but am guessing no. Rightly or wrongly I've always considered visible pressure signs in my Lapua brass as being much closer to danger than similar signs in Hornady brass in the same rifle. I'm sure smarter people than me could educate us here.

When I go through load development I have a chrono and a pile of manuals to bookend loads. I also get a buddy with QL to check things ahead of time.
Ultimately - brass isn't cheap and I value my face. If I want an extra 100fps I'll build/buy something bigger.

 

[Bustercluck]

Brand new lapua 223 rem brass is almost the same. Bang on .375” with 2 or 3 roughly 1/4 thou wider.

Lapua 6br brass came out the exact same as my 6.5-284 brass at 0.469” and every piece was identical

I found some new lapua 308 palma brass on my shelf so i measured ten pieces of that too. Exact same results as the 6br and 6.5-284 0.469” perfect every case.