3200 fps-300 smk

[Long Time Long Ranger]

Kirby, that 338-378 custom I am confident was a custom reamer that somebody designed. The neck was so short I don't think it was the kahn or the Baer. Looked like something rocky gibbs would do with the short neck. I checked the bore and it definitely had at least the standard wby freebore if not more. His bullets were not seated to the lands. I wrote some of his loading data down for future refference. The best loads were 118-124 grains of H-870. He had some T-5020 loads up to 127 grains. All these were with the 300 smk. My best accuracy loads in my 338-378's are around 110-115 grains of H-870 for comparison.

You were right on with what you said about those rounds like the 257 stw, lapua's and such in that earlier post in this thread. My results are identical to yours. There was a guy on here last year talking about the 4100 fps with the 257 stw. I have two now and they will average 3850 with the 100 grain bullet and best accuracy. I would blow the primer pockets out of them at 4100. Like you say though with the proper freebore somebody might get that but it is all give and take. For a good shooter in that cartridge 3850 is about where a guy will end up.

 

[Fitch]

Fitch,

There are several 338 wildcats based on the 408 CT parent case.

<snip>

You are correct, they are truely amazing precision instruments.

Kirby,

Thanks! You filled in a lot of blanks for me.

I was impressed with a 4" 800 yard group because it was an "unload, set up, fire 4 shots beginning with a cold clean bore" group. I'm convinced this group of guys can unload that rifle in Colorado, haul it to their stand, set it up and be pretty sure of taking down the elk at ranges they talk about, with as much certainty as ever applies to a real hunting event. It was a good rifle in competant hands.

I don't have any practical use here in PA for a piece of man carried field artillary like that .338 Baer, but I was sure impressed with it's capabilities in good hands.

My very first long range hunting rifle, a 10 lb 7mm MAG (a pea shooter by comparison to what many here shoot) will arrive in PA a week from tomorrow if all goes according to plan. I'm really looking forward to making friends with it.

Fitch

 

[Fiftydriver]

If the neck is that short its certainly not a Kahn. With the added body length the round would gain quite a bit of capacity and if the freebore is as long as you say, it puts a whole different light on things.

I would be curious what kind of accuracy the rifle is producing with these +3200 fps loads.

 

[Autorotate]

LTLR

Thanks for sharing. I'd be interested in learning:

1. How much freebore/throat this rifle was chambered with.
2. The water case capacity of the fired cases.
3. Maybe you have a picture of the case as compared to a standard 338-378 Wby case you could post...or email it to me, and I'll post it.
4. Same interest as posted above on the accuracy at these velocity levels

I was able to achieve 3100+ fps before pressure signs with the rifle listed below:

Weatherby Mark V
338 Excalibur w/.285 worth of freebore/parallel throat
31.25" Brux 9.8 twist
COAL was approx 4.185
(I'll get a more recent pic with the optics mounted and some more load development here a few weeks)

Accuracy came in around 122 grains of H50BMG at 3075-3082 fps with the 300 SMK.

The once fired cases hold right at 140 grains of water with a spent primer seated in reverse.

This case/bullet COAL combination starts to see powder compression at the 123.5 to 124 grain levels....with a 140 grain case and a long COAL.......this 338-378 Wby must be absolutely maxed out regarding case improvement...and have a bunch of freebore to boot.

Thank you very much for sharing, and am interested in hearing more about this rifle.

L-R....338 Norma, 338 Lapua, 300 RUM, 338-378 Wby, 338 Excalibur, .540 bolt face/staggered feed Wby mag box, .580 bolt face/center feed Wby mag box.