People who make up their own loads

[15meter]

In a word, "DON'T!". There are so many sources for load information, why would anyone risk their safety by trying to work up a load without a solid reference??

Because there are cartridges still in use that there is little or no data available for.

8x50R, 280 Ross, 8x56R, 318 Westley Richards, .350 Rigby No 2 and a few hundred more that you can't look up on Hodgdon's website and get nice tidy pressure tested load data.

Now go even further and try and find cast boolit data for the (almost)obsolete and you'll find even less data.

I extrapolate data, but very cautiously.

It's that or have more wall hangers then there is wall.

[mehavey]

Because there are cartridges still in use that there is little or no data available

^^^^ THIS ^^^^

I am not a believer in the chronograph telling you much about
how safe a load is. In fact, not a believer in using one at all...

Intelligent use/adjustment of QuickLoad plus a Chronograph is an excellent
source of pressure/performance data... short of a strain gauge/transducer.

Use either alone however, you're flying blind.
(See Post #11)

[para45lda]

I'm anxious to hear back from you. My presumption is you have a limited powder selection and are trying to figure it out. A common problem I imagine for quite a few folks if the truth was told.

Do you have an end use you can share and we could make a SWAG at it. Otherwise it's just WAG.

Wes

[todd9.3x57]

i WAG'ed some alliant 2400 loads in my 35/30 and 444 marlin.

[DougGuy]

There is also a comparative approach. Let's say for example 44 Special or 45 Schofield in a New Model Vaquero or Flattop Blackhawk.

These are two anemic factory loads made for older guns that SAAMI will NEVER adopt a +P rating for, and there is absolutely ZERO published data that goes any higher than the factory loadings and factory pressures.

Working with just H110, we know this powder works well with 80% and above load density. You can sorta compare case volume and boolit weight for Ruger Only 45 Colt loads and 44 Magnum, and when you reduce the case volume for 44 Special and 45 Schofield and figure 80% of the new reduced case volume, you will arrive at generally a safe +P load for the modern guns not the antiques. Lighter boolits will yield more case volume, because there is less boolit down in the case which doesn't really create a dangerous load, because the boolit is lighter. This works. Heavier boolits will reduce case volume, and therefore 80% will be a LOT less powder, and then again, the load won't be dangerous because of the reduction in powder charge.

[MT Gianni]

Look at the parent case. Examine other cartridges with a similar bore to case capacity ratio. In one of my reloading manuals there are 19 combinations for 270 with 130 gr bullets. There are 22 combinations for 30-06 with 150 gr bullets. There are 11 combinations for 280 with a 139/140 gr bullet. Do we really believe that the 280 will detonate if used with a start load of one of the combinations listed for 270 or 30-06 but not listed for 280? Same story with the 7/30 Waters. Some cartridges are so obscure there is little data out there.

[M-Tecs]

Look at the parent case. Examine other cartridges with a similar bore to case capacity ratio. In one of my reloading manuals there are 19 combinations for 270 with 130 gr bullets. There are 22 combinations for 30-06 with 150 gr bullets. There are 11 combinations for 280 with a 139/140 gr bullet. Do we really believe that the 280 will detonate if used with a start load of one of the combinations listed for 270 or 30-06 but not listed for 280? Same story with the 7/30 Waters. Some cartridges are so obscure there is little data out there.

Yes, but that relies on common sense. That seems to be very rare nowadays.

Also contacting the loading manual ballisticians can be very helpful. They tend to have thousands of loads on file that are not in the books.

I have done a couple of self-designed wildcats and your method has worked very well. Same for the other folks I know that designed their own wildcats.

I am not aware of anyone using carefully interpolated data that has had any significant pressure issues.

One the other hand I have seen a lot of blown firearms due to careless loading techniques with number one cause being using pistol powder believing its rifles powder.

With a little common sense it's actually quite difficult to damage a modern firearm. The less common sense the easier it gets.

[gifbohane]

You gotta have a starting point or some parameters. You get them in a manual.

If you are dealing with an obscure bullet, well, you just don't know where to start. If I absolutely, positively had to try, I would put some quantity of powder in the case, set up a Chrono, a lead screen and pull the trigger with a string from six feet away and behind the screen. Only Idea that I have and I am not recommending this.

[Tar Heel]

In doing so you are taking on an assumptive risk. Propellant companies have a lot of test barrels. I have one barrel on a firearm that I would prefer not losing. I have done it simply because there was not a lot of load data for the 226-JDJ. Years ago J.D. Jones taught me the golden rule which is that ballistic pressure curves are not linear and do not necessarily track proportionately with load weight or density.

Just when you think you are pretty smart and have it all figured out with your Quick Load (or other software) data in hand, you may experience a "pressure excursion" which at best is an eye opening experience and, at worst, a barrel/appendage destroyer. My 411-JDJ was my humbling experience. I was expecting about 1500fps and after my hand registered an ungodly recoil. I looked at the chronograph which displayed 1900fps. Fortunately my barrel/frame/hand survived the excursion.

That is the assumptive risk. Are you willing to sacrifice a barrel and/or a body part? I prefer to let the powder companies blow their stuff up. They can easily pull another test barrel of the wall.

But we are guys. Hold my beer.

[Winger Ed.]

Curious to how y'all go about it and your thought process. Thanks

It'd be different if I loaded for some old and obscure cartridges,,, but I don't.

I just use loading book data for the few cartridges I load, and they are old, well developed, and super common.
Basically, I work in and on 'well plowed ground'.
I figure they've been researched and developed by folks with a whole lot more test gear than I'll ever have.
For me and my purposes, there's no great need or desire to go off into uncharted waters.

[TurnipEaterDown]

If you go about developing your own loads, without some cartridge/powder data, something WILL bite you at some point. I have had a couple experiences, while working with wildcats, surplus powder, or oddball cartridges where data is Very limited, but never a horrifyingly bad experience. My worst was a blown primer in a Rem 700 with a case that had to be pried out of the bolt face. Would the next person have a worse experience? You be the judge. I tend to work in what I think is a very careful manner when I do this type of thing, and it still involves risk.

There are many things about powder beside burn rate that needs to be known to make good guesses, and even when making good guesses you had better have a way of measuring pressure or at least Comparative Pressure.

Velocity off a chronograph is a good thing to have, required even, but it is certainly not sufficient if your criteria is to be completely safe.

Example:
I used 4895 in a wildcat 416 caliber I did on a moderate capacity case. 300 gr bullets Jacketed & Cast GC, easy, reached expected ENERGY levels with ease, great groups, and no indication of pressure in heat or cold. Same gun & Cartridge, same said for a 370 gr CAST GC bullet.
Then, same cartridge & gun, went in between with a 340 gr jacketed bonded core bullet. 44.5gr, all good, and 420 ft*lbs short of energy target, so I load 46 gr (~ 3.3% more powder) and the energy jumped 800 ft*lbs, or ~40%. Changes like this Do NOT occur without sudden pressure jumps.

One notable powder metric beside burn rate is Specific Impulse. Rarely is this ever found by the consumer.

Making up loads comes with risk. Possibly serious risk. You accept it or not. I don't recommend this practice to anyone, but have done it. There is no way to judge another person's knowledge level.

Closing note: There is NOTHING Mystical about some pet cartridge. Case capacity is Directly related to potential bullet energy IF the correct powder is employed, and operating pressures are normalized. If you think you have a miracle cartridge, it is not. With the enormous spread of commercial and proprietary cartridges out there in common calibers, re: capacity to bore ratio; whatever you have has Very Likely been done before, and the potential bullet energy will be governed by case capacity and operating pressure. You might have something with a different shape, but capacity and pressure govern the ability to achieve target projectile energy levels.

[Mk42gunner]

Back when I was messing with high velocity wildcats; I compared same case capacity similar bore vs. same bore similar case capacity. Then I started with the slowest powder I had and the heaviest bullet.

This may not be the best way, but I still have all ten fingers and both eyes. The rifles are still shooting fine too.

Robert

[M-Tecs]

If you go about developing your own loads, without some cartridge/powder data, something WILL bite you at some point............................................. .......................
Closing note: There is NOTHING Mystical about some pet cartridge. Case capacity is Directly related to potential bullet energy IF the correct powder is employed, and operating pressures are normalized. If you think you have a miracle cartridge, it is not. With the enormous spread of commercial and proprietary cartridges out there in common calibers, re: capacity to bore ratio; whatever you have has Very Likely been done before, and the potential bullet energy will be governed by case capacity and operating pressure. You might have something with a different shape, but capacity and pressure govern the ability to achieve target projectile energy levels.

I concur 100%. For the most part data is available for a very similar cartridges so you really do have to lack common sense to randomly select truly dangerous combinations. That being said lots of folks do some very strange and dangerous things.

With the advent of heavy for caliber bullets for the subsonic, long range and extreme long ranges applications lots of cartridges do not have data for the heavy for caliber bullets so there is still lots of uncharted territory in those applications but these cartridges will require quicker twist ie customer barrel to stabilize the long bullets so that limits the amount bubba's going babba things.

I was at the range last summer when a gentleman could not understand why is 12 twist 223 would not stabilize his 90 grain bullets since they shot in his buddies' rifle. I tried to explain the why but he basically told me to take a hike since they worked in his bud's rifle and they should work in his rifle also...................

[justindad]

A couple of things I’m wondering about:
1) How do I identify the design pressure range of a powder, and compare that to my intended application? I know there are burn rate charts, but I expect burn rate to be variable and actually a function of pressure.
2) Is this powder designed to be compressed? Fill the case halfway? Barely fill the case? Then what happens if my guesstimated powder charge moves too far away from one of those? How far away from that intent can I go? - probably depends, and likely some powders go up while others go down. This may not be reliably accounted for in software tools.
*
A phone call to the powder maker is probably the way to answer those questions. Until then, I consider it good to take stock of what I don’t [fully] understand.

[Bigslug]

Whenever somebody comes up with a new edition of their loading manual, buy it, and keep your old ones.

Whenever a new edition of Cartridges of the World comes out, buy it.

Do some online searches for "powder burn rate chart", and study a few different ones to see where your particular powders lie.

Study all the online load data sites you can find.

When looking at your manuals, study the cartridge blueprint diagrams to see what out there is similar to what you are proposing to play with.

If you're playing with historical things, look to historical sources.

[BMW Rider]

When you get to where you think you know it all, you have reached the point where you are probably just dangerous. You need to get to the point where you are always a bit worried if you are doing everything right.
.

^^^THIS^^^

[Rcmaveric]

Invest or source out an internal balistic program. The only two i know of is Gordons Reloading Tools (free) and Quickloads (Windows Only, expensive, buy or borrow (due to liabilites and legalities i wont mention it being available on P2P which is how i got it)). Understand that these programs are just estimates and only as accurate as the info you out in it.

Next justify to yourself why you need to create your own recipe and justify endangering yourself. My case I have a favorite powder (Tight Group) and wanted plinking loads in all my cartridges. It just so happens I use it for shotgun and 9mm.

Under stand pressure CURVES and how it affect your accuracy. Just because the gun is rated for 60k psi doesnt mean your bullets be accurate at 60k.

Then I run a simulation to find my max charge. Max charge is dictated by either max safe pressure for the gun or max pressure for the bullets (i dont want to start that debate we can start a new thread on that one). I write that one in red (red your dead). Then i drop 20% and call that min and write that in blue. Some times i just start at the min pressure needed for obturation snd go up from there. I create a shot test of 4 shot groups in 1g increments from max to min.

Then i go shooting. Depending on how i feel i might check my wills. Pray. That first shot always makes me nervous and hesitant. I have rolled lots of unbuplished loads with powders and i always get uneasy. Depending on what my targets tell me depends on what i do next.

You may find some powders just dont work. I never got any accurate loads out of BLC-2. They were all 2 MOA. Fine for plinking but i like .5 moa to 1. Anything less than .5 is bragging and deserves pictures. Needs to be pictured and reproduce 5 times to prove its repestable and not a fluke.

There is an art and science. Like determining at which pressures to start at. It is dangerous, powders act different when they have space and as pressures go up. Study the pressure curves. Know your bullets and their pressures. There have been times i found accuracy when i shouldnt ie over pressured the lead.

Sent from my SM-G991U using Tapatalk

[Tar Heel]

Here is my last propellant determinant equation. You can either use this equation and spend 73 hours making calculations or you can look up a load in a manual and then go to the range and have fun.

Attachment 295443

[tmanbuckhunter]

I compare multiple data sources figuring out their minimum and maximum loads, and go from there. The hottest max I find is true max, and the lowest minimum I find is true low, and then I find a starting place and work my way up until I either start running into pressure or I hit target velocity/group sizes.

[farmbif]

my first thought is, why
these days with computers and internet, there is more load data available online from the powder and bullet manufacturers than ever before and there are more powders available than ever before .

and some things just plain work and work really well, like the 4350's in 30-06 and 3031 in the 30-30 and bullseye in many handgun loads.
I tend to eer on the side of safety and many years ago realized that in order to reload many different calibers and experiment with many different bullet weights and try to get the best accuracy many different powders were just a good thing to keep in the reloading room. and back then before everything was online having as many different reloading books was a very good thing to keep for reference.