Effect on recipe when components are altered

[Dirtlaw]

It is a temptation when some of the ingredients are unavailable. But I find myself too cautious to gamble; particularly with primers. Like the shooting sport itself, reloading needs to be treated with great respect.

[Epaphroditus]

It depends.

Particularly on exactly which components but also on the cartridge.

Highly tuned magnum rifle loads meant for accuracy - critical.

Plinking loads - hardly worth worrying about for most any component.

[TomReloaded]

I'll sub out a small pistol primers for a small rifle magnum primer without so much as blinking. Or changing my powder charge. Done it for tens of thousands of rounds.

[smoothy8500]

But I find myself too cautious to gamble; particularly with primers.

Whenever switching primer brands for years I used to drop down and work back up, only to find that it didn't matter. Switching powder or projectile weights; yeah, no-brainer there. Work back up.

[JackEllis]

I'm aware of at least one article in a shooting publication that experimented with both single stamp and mixed stamp brass for .223 and found no material difference. So...

I didn't think about it when practicing with .30-06 rounds using something other than the brass I would normally load for hunting. Had I not noticed the difference in POI I might have missed a deer last fall.

Where it counts (hunting and competition), it's worth checking.

[NapalmCheese]

In general if I swap a component I'll work up a few loads to make sure whatever charge I wanted doesn't seem like a problem. If the velocity is the same or less, no problem.

I read pressure signs on brass, but I don't use it as the ultimate sign of anything. I've had factory ammo in factory chambers that flattened primers, had ejector imprints, or on the other end of the spectrum blew soot back over the shoulder of bottleneck cartridges. I do know that in my main hunting rifle and loading with Fed 210 primers, the bolt will start to stick before the primers look really flat. I was working up to a book max load when I noticed the velocities were going ballistic. I didn't think anything about the velocities until I noticed a hard bolt lift and realized I was way over. From then on I let the chrono do the talking.

In my book though, velocity = pressure. So I don't mind not following the recipe, especially when components are hard to get, but I sanity check against the velocity listed in the book.

[divingin]

I read pressure signs on brass, but I don't use it as the ultimate sign of anything. I've had factory ammo in factory chambers that flattened primers, had ejector imprints, or on the other end of the spectrum blew soot back over the shoulder of bottleneck cartridges.

Other things (besides purely pressure) will cause "pressure signs". To wit, solvent in the chamber or remaining case lube will decrease the cartridges "grip" on the case wall under pressure; a shorter-than-normal case will generally get pushed forward by the firing pin, and can slam back into the breechface when pressure ramps up; the primer will push out and against the breech and flatten as the rest of the case catches up.

[Fjold]

If I change any component, I back the load down 5% and then work my way back up to check for acceptable performance.

[Capybara]

I think this is also an experience thing too. Since the "Event", primers have been nearly impossible to get or so ridiculously expensive until recently so I have read and heard about a LOT of primer substitutions that probably wouldn't have been attempted in "normal" times when we could all get what we needed. If you look at it objectively and think about pressures and stay on the powder puff side of things, most of these subs are probably relatively safe. Some good advice here, especially about velocity and pressure and strategies to look for overpressure signs.

It can become confusing also cross referencing published data sources (books) as they definitely do not always match up as far as loads, pressures, even COAL sometimes.

[Dirtlaw]

If I change any component, I back the load down 5% and then work my way back up to check for acceptable performance.

I'm conservative. I was considering 10% and checking everything out after each test round. I'm actually focused on 209 style primers which I'm told require greater care.

[BIGOX]

What brands for 209 are you thinking of substitute?

[Dirtlaw]

I have Fiocci primered hulls (Fiocci 616) and W209 primers. I may have some additional primers but I am still in the process of taking a complete inventory.

[Dirtlaw]

Cheddite 209s seem most widely available, but I believe they may be a bit oversized for American hulls. I believe Fiocci is oversized as well.

[Dirtlaw]

I don't have an oversize reamer, but I do have a BPI reforming tool. Common sense would be to avoid reaming because that gives more future flexibility.

[Dirtlaw]

My present goals are basically defensive with a potential side branch into hunting. BPI's thug slugs, AQ slugs and DGS slugs for now. Next up would be non-lead.