What, If Anything, Can Be Learned From One Tuned Load to Another?

[CharlieNC]

I have found using Quick Load or the free Gordon Reloading programs to calculate an optimum barrel time, OBT, load will be very close to a node based on stable poi. The resulting fine tuning is much less involved vs otherwise starting from scratch. Any combination of powder, bullets, etc can be evaluated to calculate velocity, pressure, etc as well to generate significant insight.

 

[Fast14riot]

I have 3 loads for one gun and barrel. Its an AI chambering so I have a fire forming load, developed on its own, a 140gr formed load and a 153gr load. Different bullets and powder for each. But based on my notes I knew about what velocity I needed for each and used GRT to figure out about where thats going to be.

 

[miningshawn]

I tried something very similar once...

I wanted a hunting and a target load for 30-06. I chose Berger 185gr Juggernauts for target, and 185gr Classic Hunters for hunting. Similar profiles, ogives, and bullet OAL. The biggest difference was seating depth, and that only varied by .007.

Results were significantly different with the same powder, primer, brass and distance to lands.

I believe the results of one will get you close, but a new work-up is needed.

Good luck!

 

[RegionRat]

After you have tuned two loads from scratch on the same rifle and you get what you are looking for, have you ever seen any similarities on the target as to what the rifle likes?

Yes, but....
My answer is based on using barrels of high quality, chambered by good folks, using good components, and...
These barrels have good heavy sections and sit on good actions in good stocks. It is what you should expect for heavy section match barrels cut with a well designed reamer.

Within your question, you would see more strange behavior with thinner/lighter barrels in lighter stocks.

Those rigs have important second harmonic modes that need attention and luck to tune, not to mention their recoil brings the issue of how it is held/driven to the forefront.

With standardization around good barrels/actions/stocks using good components, you will get fewer weird behaviors. Bring in a bunch of different types of barrel methods and sections, different reamers, mounted in different ways in flimsy stocks, and you are off to the rodeo....

 

[Doom]

I ran across this again and a different answer, actually approach struck me. What you can carry from one load to another is what your rifle may or may not like in general terms. It is also about the things that you learned that didn't work. If a VLD bullet works then staying with that style is probably a good idea. If it didn't you should probably stay away from that style. Same with seating depth.

 

[gunsandgunsmithing]

I'm not even sure this is what you're referring to but yes, you can learn a lot. We've all seen charge "windows" and good powder options for most any given cartridge out there. Very often, very near the same load does work in different bbls/guns of the same chambering, particularly if the same reamer was used. That often gives a good starting spot for seating depth. Sure, you may well need to adjust any or everything a bit but sometimes not at all, too.

Examples..30BR and 34.5gr h4198 112-118gr
6PPC and 29.5 of n133 68gr
6BR 30.0 varget w a 105
22-250 and 36.0 IMR 4064 52-55 bullet.
The list goes on but you don't know if you're getting the full potential unless you tweak even a good combination.

Also, none of those are starting loads. So, work up before going straight there.

 

[Doom]

I'm not even sure this is what you're referring to but yes, you can learn a lot. We've all seen charge "windows" and good powder options for most any given cartridge out there. Very often, very near the same load does work in different bbls/guns of the same chambering, particularly if the same reamer was used. That often gives a good starting spot for seating depth. Sure, you may well need to adjust any or everything a bit but sometimes not at all, too.

Examples..30BR and 34.5gr h4198 112-118gr
6PPC and 29.5 of n133 68gr
6BR 30.0 varget w a 105
22-250 and 36.0 IMR 4064 52-55 bullet.
The list goes on but you don't know if you're getting the full potential unless you tweak even a good combination.

Also, none of those are starting loads. So, work up before going straight there.

There are several cartridges and loads that are "standard" meaning they work well in that cartridge in almost any rifle. In fact one factory load is kind of a benchmark for accuracy in 308Win and that is the 168 FGMM. BUT, there have been cases where this wasn't the most accurate.

Sometimes you will see reports on the internet of people trying to clone a factory load by deconstructing it and trying to guess the powder by observation and weight. Sometimes this can work but more often than not it doesn't because without some help we never know if the powder is canister grade (likely not) and often it is impossible determine even the supplier.

What is usually a good guide with factory ammunition is bullet selection and velocity range, and in some cases knowing whether the powder is Ball or Extruded can provide some assistance.