[shep854]

Shooting with Hobie
The writer's main point is that current "+P" loads are actually milder than old "standard" loads, and that he has no problems shooting them through older steel revolvers.
I've read several times that loads have been reduced for liability concerns, but this was new to me!

 

[t-star]

part of the reason i RELOAD from OLD manuals is that the new ones are actually DOWNLOADS - i.e. their top ends are somewhat lower than the old manuals , and the powder charge is lighter for a given bullet, but the velocities are faster- this amounts to DOWNRIGHT LYING- you just can't change physics like that

 

[Patrick Sweeney]

No, you can't change physics, but you can use more-precise measuring tools, and find that what you were doing before wasn't exactly what you thought you were doing.

I take all old data with a grain of salt. If a modern piezo system tells me I'm getting 20,000 PSI, I'm getting 20K, no more, no less.

If a copper crusher system tells me that I'm getting 20,000 CUP, well, I could be getting anything from 17K to 23K, and maybe both in alternation.

The way some people gripe, you'd think the ballistic labs were sneaking into their houses and stealing fps from their gun safes in the middle of the night,.

 

[Retmsgt.]

They do!!! I caught two of them one night! Only real experience I have with this is with 357magnums. Back in the late 80s I was happily loading 158grain hardcast SWCs with 14.8 grains of 2400 and CCI mag primers in my Model 28s. No obvious pressure-signs( don't have and never did have a fancy piezo system, Is that Italian?). Shot that load for years,didn't hurt either gun. I did get to shoot it over a guys Chrono once(Very rare to have one back then) and they were doing an honest 1425fps(Six-inch Barrel). Killed a lot of Deer with it.

Now, that is considered an over-max load except for, I believe, Alliant, who shows 15.3 grains as max. For reference, I settled on 14.8 grains because 15 locked up the Cylinder. Wild and crazy days of youth.

 

[William R. Moore]

Crap, had to retype this.

I noticed the writer got all his velocity "data" from old ammo catalogs. Back in them thar days, those velocities were produced in very carefully made pressure barrels a lot longer than most of the commonly used barrels in use and with no attempt to compensate for any barrel/cylinder gap. IIRC, the SAAMI .357 Magnum test barrel was 10 inches long.

In addition, since chronographs were very scare and expensive gadgets, the data could be ''carefully sampled" to produce desired results. Who was gonna know? I've got an old Lyman loading book and one of the most interesting parts was the chart showing what factory ammo did in their test weapons. Seems like the velocity thieves Patrick mentioned have been at it a long time.

Finally, there's the CUP vs Piezo thing. If you look at new load data, you'll note a lot of the rifle loads we thought were 50K PSI are actually 60+K PSI. Oops!

 

[shep854]

Hey, the backstory we're getting through the responses is as interesting (for me, at least) as the article I linked to!
Thanks!!

 

[William R. Moore]

Speaking of back story......

Back before chronographs there was a velocity thief at some installation. Seems the velocity was mathematically derived from how far the round knocked some weight that absorbed the bullet. After a series of extremely bizzare results someone else studied the issue and realized the original folks weren't compensating for the additional weight of all the stored bullets!

BTW, this type of thing does work. I've got a ballistic pendulum from the early days of IPSC. After calibration with a load of known velocity, the pendulum could be very, very close so long as bullets of roughly the same hardness were in use. It's not what the 'power meter' was intended for, but it could be done.