Interesting thought for VFS

[Charles E]

After shooting a couple groups in the 1's at 100 yards with a big .338 and the Berger 300-grain Hybrid, I ran some quick calculations on a somewhat milder chambering.

If you set them off with a MV of 1,700 fps, the drift at 100 yards in a 10 MPH wind is .3 inches less than with a "normal" score gun. At 200 yards, it's a full inch less drift. And it's still going 1,550 at 200. That's a few more Xs, guys, with the larger bullet and less uncertainly in the wind.

Now as to the recoil...

 

[ConRich]

Hello Charles, It may look good on paper, but I think that the approximate 40 % increase in recoil, and barrel time would negate anything that you expect to gain on the target.

JMO, Dick

 

[Wayne Shaw]

Maybe Mr. Robinette will make some light .338", or wait, why not some .375" bullets! That ought to punch a nice hole!

 

[Charles E]

I started thinking on this by contemplating a subsonic .338 with the 300 grain bullet. Everything looks just fine, but it was pointed out to me that subsonic cartridges are very hard to impossible to tune.

Keeping above the transonic region at 200 yards means yes, quite a bit stiffer than a .30 BR. Believe the recoil would be about 7 foot pounds in a 13.5 pound rifle. We're talking about something more or less equivalent to a .35 Remington, or a .308 with a 180 grain bullet at 2,600 fps, when fired in a 13.5 pound rifle -- not a sporter!

Now the barrel dwell time *might* be an issue, but it should be tunable.

One real issue would be torque. You could cut the twist needed considerably with a .250 Hybrid -- so less torque -- but the drift gets pretty close to the .30 BR. You would save about .5 inches at 200 yards in a 10 mph wind, but who shoots that if they can avoid it? Bullet still makes a bigger hole; not sure it's worth it. Recoil would be around 5 ft/lbs in a 13.5 pound rifle, which is not too much more than a PPC in a 10.5 pound rifle.

The looking good on paper part -- I did say I've shot this bullet at 100 yards. It was a 17-pound rifle with a brake, but the load was also equivalent to a .338 Lapua magnum -- 2750 fps. There are things more fun in life, but if you know how to shoot one, it's not too hard with rests, off a bench. I wouldn't want to shoot it prone or sitting.

Probably won't do this one, just too many other projects going on. Sounds like no one else is a believer.

Edit:

I did talk to Randy about this. I don't think he felt it had much promise, but he heard "That'll never work" too many times with the .30 BR to be dismissive. He believed it would be quite some time before Berger offered .338 jackets. I wouldn't expect him to make the bullets, either.

But the 300 Hybrids measure, and shoot, very well indeed. Fully the equivalent of a custom, given their size.

Edit No. 2:

Just to show prototype possibilities, I *think* a .338 Wolf Pup would do it. I don't have QuickLoad.

You'd need a special bushing to use an existing .30 Wolf Pup reamer in a .338 barrel, then take the neck out with a with boring bar, or even a twist drill. Yeah, I know, crude. Been done before. Skip the FL die at first -- we're not talking terribly high pressures -- and make a seater & neck die. Total tooling costs -- the bushing that fits the .30 Wolf Pup in a .338 barrel.

 

[mks]

After shooting a couple groups in the 1's at 100 yards with a big .338 and the Berger 300-grain Hybrid, I ran some quick calculations on a somewhat milder chambering.

If you set them off with a MV of 1,700 fps, the drift at 100 yards in a 10 MPH wind is .3 inches less than with a "normal" score gun. At 200 yards, it's a full inch less drift. And it's still going 1,550 at 200. That's a few more Xs, guys, with the larger bullet and less uncertainly in the wind.

Now as to the recoil...

Those are some very competitive groups, which counters what seems to be the prevailing opinion that big, long bullets won't group at short range. Wind is certainly a big factor in score and group, which such bullets can address. Recoil could be managed with stock design. I have too many projects and too little time, too, but I still keep thinking about a subsonic 510 Linebaugh.

PS. With no shoulder, the chamber could be made with a boring bar.

 

[Charles E]

Those are some very competitive groups, which counters what seems to be the prevailing opinion that big, long bullets won't group at short range...

Yes, that opinion can be wrong. I have a 6mm based on the 6.5 M-S case -- essentially a 2-inch PPC -- and fired 3 consecutive, like in a match, groups that agged a flat 2. This with 106-grain Clinch River bullets. I have no doubt the BIBs would do as well. I'd have fired 5 groups, but it was at the end of a session & I was out of bullets...

Now the long bullets probably aren't *quite* as good as their shorter brethren. But the difference can be small enough that you more than offset this in the wind.

PS. With no neck, the chamber could be made with a boring bar.

Unless you're headspacing off the case mouth, you'll want a 45-degree or so mean little shoulder. Speaking of boring bars, Phil (4Mesh) does his conventional chambers with a boring bar. If he chooses, he can just skip the reamer. But I believe you recently pissed him off?