Home Forums Hunting & Shooting Express Rifles and Big Bores Only 375 AI Fireform?

Hey Gents, I have a Bud with a 375 AI, he doesnt want to follow my fireform procedure, i use 235 Speers seated long and a medium charge of RL-15, has always worked very well for me.

Bud wants to load his 375 H&H hulls with RL-15 and the 270 gr TSX, question is, whats the proper powder charge for this combo?

He wants to hunt and shoot with these loads while fireforming, I advised him he may loose around 100 fps doing this, but we surmised that at even 2650 fps the 270 TSX's should still take care of all NA game animals inside 300 yards.

Thanks for all replies and opinions.

Gunner

With the info you've given I'd load 76 grains of RL-15 with the 270 TSX and call it good. I'd expect that load to reach 2700+ at a minimum.

Many Thanks 406, I'll pass the load info on over to my friend.

Gunner

Using TSX for fireforming? He's wealthy. I used cheapo Speer 235's.

I use the Speers to, he doesnt want to "waste ammo" , and will hunt his fireform loads provided the accuracy is there.

Gunner

Personaaly, I'd get a box of commercial cast cheap nongascheck bullets from someone like Midway, load with something like Unique or 2400. Look for a 375H&H book load for cast, and try it out. You may have to increase it.

Cheap, easy, and fun plinking with a fun rifle at the range This would normaly be hard to do with a 375 AI. These big belted rounds are made for reduced loads. Think ground squirrels at 1000 feet per second.

Just saying... not an expensive waste of ammo. Fun practice day. Maybe later get some gascheck bullets and shoot a deer at 38-55 velocities.?

his plan of hunting with FF loads will work fine. i've done it both ways. side note, nothing feeds quite as slick as a H&H round going into an AI chamber... he should get fine accuracy too.

Thanks Gents, and as the 375 H&H hull head spaces on the belt, I can assume he will have no case stretching issues at the web?

Gunner

no issues. i do ignore the belt and headspace on the shoulder once i have fireformed brass though.

Thanks Toad, and me too on the shoulder headspace, I also do that on the gentle sloping 300 H&H Mag.

Gunner

The .375 Weatherby brass will fit in my .375 Improved.

I've often thought of that, but have read the gun-rag BS about proper headstamped cases while traveling abroad.

Gunner

One more option. Hornady"s basic belted case. I make 375Wby cases by running them through a 416 taylor die (backed out to just form the shoulder in the proper place) then run them through the Wby die. Should work the same with an AI. As for the proper headstamp, they have no stamp.


8mmwapiti

Thanks for the tip Wapiti.

Gunner

I made my first 375h&h brass out of 300wby brass. The thickness of the brass was enough that even minimum charges over pressured.....bad. Measure first when using odd brass.

On improved cases I just load my full boat improved load (as long as it will fit) and fireform while I use it. The cases are only a bladder to contain the pressure within the chamber. Much like an inner tube in a tire. The brass is at full capacity long before peak pressure occurs. This give the same effect as using fully formed brass.

A recent observation on a couple customs recently built. A max charged 22-250 will loose 300 fps when fired in a 22-250AI chamber.

Well, as I remember back in the days when I had a Ruger No 1 Tropical chambered to the 375 Mashburn (just another flavor of improved 375 H&H), I loaded "full tilt" H&H loads and sallied forth. Worked well; any reloading manual can get you there.