Loaded 300 gr. TSX's over 72 gr's of Reloader 15 in my .375 H&H cz550. Barnes says use X bullet data for the TSX but might be able to go a bit higher with the TSX. This is the max X bullet load. Probably the third reload in Federal brass using WW primers.

On one of 20 rounds I got a dark ring around the entire primer and had a little smoke escape from the action. Another round showed a little darkness around part of the primer but not a complete ring. Didn't notice any smoke on that one. Normal bolt lift, no sticky extraction, no flattened primers.

Can anyone explain? I've heard some federal brass can be soft. Got this brass from economy priced Federal cartridges I've bought through the years.

Forgot to mention, the other 18 rounds were fine, as were the 10 factory Federal loads fired.

What type of throat do you have in your rifle?

How far off the lands are those bullets?

How easy did those primers seat?

Buy some Winchester brass.

Drop back to 68 grains for now.

What was your velocity? How far from the muzzle? How long is your barrel? How fast do your factory 300 grain loads go from your rifle?

The Barnes manual gets out there on some loads.

Thanks,

LD

Throat- Don't know
Off lands- .05"
Seating- easy
New brass- doing it
Will reduce but likely to 70grs
No chrony to check velocity
25" barrel

Remember,

It will likely be significantly hotter at your destination.

Often times our rifles don't read the load tables from our manuals.

The velocity tells the pressure.

Sticky extraction is not desirable when shooting a large animal with a bad disposition.

Have a good hunt.

LD

In my Whitworth, I use 72 grains with the 270's and they chronograph 2770 fps. I sure wouldn't want to stuff a 300 grain bullet on top of it in my rifle, and if I did I wouldn't want it to be a TSX. Some people have used 72 grains of RL15 with a 300 Swift, etc. but i'm positive it is too much in mine. Also Winchester brass will handle a grain of so more than Fed, more difference than that with Remington. I'll bet 68 grains with the TSX is over 2500 fps in your rifle.

Thanks for keeping me out of trouble guys!

Is Winchester the best US brass?

I've never used Lapua or Norma. Is it worth the extra money?

I don't know about feds rifle brass but their handgun brass seems to have looser primer pockets than some others.

I have the best luck with Winchester brass, but I've never had a problem with Federal either. I don't think brass is your problem, mine won't handle your load either. That's why you sneak up on that max load.

quote:

Originally posted by citori:
Loaded 300 gr. TSX's over 72 gr's of Reloader 15 in my .375 H&H cz550.

Alliant has a max of 66.5grs for a Hornady 300MC. But maybe those TSX's are a softer bullet. I'd back-off a bit though if it were me. J

Check out Fjold's reply on this thread. See that nice .247" group? 66.5grs. 4064, a powder almost if not identical burnwise to RE15, and he's using the same bullet as you.

https://forums.accuratereloading.com/eve/forums/a/tpc/f/2511043/m/638106374

My last batches of 5000 WSRs and 5000 WSRMs just drop into the primer pockets compared to other brands. It's worse when I put them into Winchester cases. This Winchester loose primer thing seems to have started about the time they went to the brass colored cups. This has been discussed a number of times. roger

I have a loadbook from Midway USA that aggregates all load data from various powder and bullet manufacturers by cartridge. In reviewing other 300gr. bullet loads, most top out at 68grs. of RL-15. One goes to 70 grs. I went to the max X bullet load because Barnes said the TSX'x could likely go a grain or two higher. In reviewing the data it appears the Barnes manual really is aggressive. I'm so used to conservative loads in manuals that I may be forgetting the basic rule of working up to max loads. Thanks to all for your responses.

Compare your books to other books.
Never cease's to amaze me how much difference there is in written data.

Typo's do occur, that's why I have three books minimum.

What bug's me most is blowing primers on a cool day in a cool gun that's fired thousands of the same loads. Yesterday, and it jammed the ejector on my Sako on the third shot. Was gonna play some hell on p/dogs. Nice drive 20 miles out in the country though, guess that's supposed to ease the pains.

Second load in .45 colt seems much better though. Sure made a p/dog dive several feet from a close miss at 75yds with the .45. First time I've seen one make a dive from that distance.
Just barely missed on the first shot with this gun/load. 20gr H110, 230 Hornady RN's.

Was told a few yrs ago: "IF you can't do it with a .45 Colt in a Ruger, you need to use a rifle". Good heavy blast and recoil, I'm happy with it now.

George