Was at the range today when a young friend showed up with his .375 Ultra Mag. He was there to chronograph loads using the Barnes .270 gr. TSX.

His loads ranged up as far as 102 grs. of RE-19. Although he did chrono that load, it showed no sustantive difference from 101 grs of the same powder with the same bullet, so I won't dwell on it here.

Anyway, I could hardly believe my eyes. The 101 gr. loads showed an extreme variation of FOUR fps for the few rounds chrono'd, and were grouping at 5/8 or better for 3 shot groups at 100 yards. Of course, I know that was at least partly a statistical anomoly & luck, even though that 5/8" or less group size was repeated several times.

I know, I know, four 3-shots groups really tells us nothing much in terms of what to expect over the long haul.

But I'm not mentioning this to brag on the accuracy of that combo.

What really impressed me, at least for the moment, was the velocity of that load along with its very small extreme spread. Believe it or not, average velocity with that 275 gr. TSX load was 3,168 fps!! Geez, that's only 11 fps slower than my normal working .300 Wby load with 180 gr. Nosler Partitions...

I'm still mulling over a bunch of questions:

1. Is that velocity level common for that weight of bullet from the .375 RUM?

2. Does 101 grs. of Re-19 sound like a dangerous overload? (I kinda suspect it may be, though the brass and primers "looked" fine.)

3. Would that velocity actually be too HIGH for practical field use at relatively close ranges? (We recovered a couple of bullets from the sand bank at 200 meters, and they looked like the pictures I see in ads, showing "perfect" mushrooming, while losing NONE of the bullet.)

I know I haven't been keeping up with the really modern cartridges, but Yumpin Yimminy, it really makes me feel a bit like my old .375 H&Hs are antiques....

Any comments from Y'all??

.

quote:

Originally posted by ALF:
What rifle was he shooting?

To tell you the truth, ALF, I don't know if it was a factory gun or not...very few of his are. But it WAS on a Remington 700 action...not what I would have picked, but what he has used pretty much ever since I've known him and he has shot a BUNCH of bears with them, never any reported problems so far. (Bear hunting is pretty much what he lives for.)

It has a muzzle brake made by a friend of mine (Chuck Engelking of Chuck's Chambers & Barrels), and really is rather mild to shoot compared to my original standard non-braked .375 H&H Magnum Mauser, and not noticably noisier than my .375 either. Of course, that is with my Tac-7's on. Don't know what the noise would be without them and don't plan to voluntarily find out when standing under the range roof.

That should make a great long range elk load.

My SWAG is that he was shooting a 26" barreled Rem 700 factory rifle with a load that was way over max.

93 grains of RL-19 and about 2900 fps would be a max with most 270 grain bullets and .375 RUM rifles, so the TSX might handle a few grains more, but still max out less than 3000 fps.

101 grains is too much! That I am sure of.

My .375 Lapua seated out to to Rigby length with TSX's would have a greater case capacity, and greater bolt thrust, so I sure as hades will never try to equal that stunt.

quote:

Originally posted by RIP:
My SWAG is that he was shooting a 26" barreled Rem 700 factory rifle with a load that was way over max.

93 grains of RL-19 and about 2900 fps would be a max with most 270 grain bullets and .375 RUM rifles, so the TSX might handle a few grains more, but still max out less than 3000 fps.

101 grains is too much! That I am sure of.

That's what I thought too! Could it be he accidentally just said the wrong powder when he said Re19? I know he also uses lots of Re22 and Re25 in other guns. Could that maybe be a correct load (but still probably absolute max) for, say, Re22?

That kind of velocity with that kind of charge of RL-19 is the only think that would be consistent, and crazy!

Actually, your comment has confirmed my worst fears for him. He has always used loads I would NEVER touch, let alone fire in my own rifles...in all his rifles. Never had a problem, YET. He hangs around with three other guys who all say "If they didn't intend (me) to use that much powder, they wouldn't have made the case that big."

I've tried to warn all of them that their "logic" is an accident waiting to happen, but have been starting to think maybe I am an old fuddy-duddy still trapped mentally in the last century. In a very real way, I thank you for your comment. Makes me feel much better about my own experience and loading approach.

Seems that if a 300 can go 2850 per nosler load data. A 270 should get 3000+. At least to me anyway.

I had a 375 ultra SS syn rem 700. My starting load of 95 grains IMR4350 with a 270 gr bullet was 2950 F.P.S. This matches 375 H-H improved velocity from what I understand.

No way I could ever get 2950 from my 375 AI and a 270 gr bullet. Maybe others have but that is at least 100 fps faster than my best.

Perhaps it is because I am a bit timid, or that I shoot a great deal of the time in Tucson where it can get hot, but I thought I was doing well with the following:
260 gr Nosler partition
73.5 gr. Reloader 15;
Rem. 9 1/2 primer; WW case
3.615 OAL
MV2803 3/4" @ 100 yds 1 5/8" @ 200 yds
With custom built pre 64 Mod 70 action and a 24"
Douglas barrel.
I have been anxious to try the TSX but will start more modestly.