Do you really gain much over a standard 375 and how much more recoil does it have over the standard 375? Can you still use factory ammo if you were in a pinch?

Once you go to an improved 375 H&H, you are in a handloading mode for full power loads, and if you handload a factory 375 H&H case, you will be within 100 fps of the improved version. In addition, even the improved version will not match the velocities of the Federal and Hornady High Energy factory offerings in 375 H&H, so you may actually be limiting power and flexibility potential by going to the improved version.

Yes, you can still use factory ammo in a pinch, the velocity would just be a little lower. My .375 Ackley will chronograph loads higher than ANY factory load. Load data for this imp is similar to the .375 Weatherby. This imp holds about 10 more grains of powder, so the recoil will naturally be more.

The Federal and Hornady High Energy Factory rounds have 15 grains more powder, by weight, and chronograph 2700 and 2800 fps for 300 and 270 grain bullets. "The 375 H&H responded to this technology better than any other round it has been applied to" (Steve Hornady). Another bonus is that these velocities are achieved at pressures that are LOWER than regular factory rounds that are 150 fps slower. Although recoil is greater, it is more on the "push" side.

If you want to handload, definitely go with a 375 RUM and just use reduced loads to meet your requirements. This case is by far the best of all the RUM rounds in terms of flexibility and the ability to hold tight groups with reduced loads.

Other than entertainment and curiosity, there is no reason to fool with Improved versions of the 375 H&H any more. New technology factory loads duplicate them, with no changes to the rifle, and if you care to handload, the 375 RUM can do the same things at the same level of recoil and more if you want it to.

I have a .375 Improved and wish I didn't. It's almost impossible to fireform brass and not get a serious thinning on the case wall at the expansion web. The problem with this design is that nothing holds the shoulder back.

I tried seating bullets out but my throat is out there a ways and the only bullet that will reach the lands for fireforming is the 285 gr Speer. I am running out of them and the cases fireformed that way still have a small ring inside.

Otherwise the case looks nice and the rife feeds and shoots the standard .375 HH just fine.

I had this Sako made up before the 375 RUM came out but even now I would either get a 416 if more power was needed for a DGR or a smaller caliber if long range was the application.

I could make up cases for the .375 Improved from 416 Remingtons and get the headspace on the shoulder for the first shot. This is all way too much trouble.

As of the moment the standard 375 H&H is still the best deal in that bore.

My 375 Wby is running 2925 fps with the 270's, that is fairly stout and works great.

Not sure if the factory loads hit what they say or not, I've never personally clocked them and would want to b4 I said what they would run. (Sabot are those speeds you clocked or their specs?)

Personally, I do see a reason to do an improved, that is simply because it floats your boat. For me it has nothing to do with what speed a load will run, I just like to work wiht the cats. 100 fps doesn't mean much to me anymore at all, there was a time when it did but not anymore(I think that changed along with needing reading glasses an a lighter than naturaly color hair...grins).

I'd say do it if you like, you can always run the factory in the rifle if you like.

"GET TO THE HILL"

Dogz

Mark,
I just bought a Sako in 375 WBY (allready have one in 375 H&H). Can't wait to find out whether it likes 270 grain Barnes's or 270 grain Failsafe's more. Yee Haw!
JCN
Got any pet loads?

JCN--check out the newest Barnes book and take a look at R15, that is what I am using.

I shot some of the 260 Nozler Accu's in mine the other day, both groups were one small hole.

Barnes now has their TS available, I am for thinking that is where I am gonna head towards.

Good luck

"GET TO THE HILL"

Dogz

I have no trouble at all exceeding the heavy magnum ammo in my .375 Weatherby . And Weatherby factory ammo will also beat the heavy mags handily , chonoing right at 2800 fps (300 gr Nosler) at the 24 inch muzzle.

In addition , for the handloader , the Weatherby, or likely the other style .375 improveds , functions better at the upper pressure levels......you get less case stretching , better case life , and less chnace of sticky extraction.....

There is a Whitworth in 375 AI on Gunbroker with a fairly decent piece of wood: 375 AI

If it was a standard 375 H&H it would probably get more interest.

I did chrono the Heavy Mags when they first came out, but did not record the velocities...I do recall that they were a bit faster than the factory listings, but we were using a 26 inch bbl.

As for the weatherby and the other improved 375s, I just think a handloader entering the 375 bore market needs to become familiar with the 375 RUM as part of an informed decision process. Many are likely to see that the choice these days as between a standard 375 H&H or a 375 RUM.

The H&H still has a lot going for it given the decent and widely available factory ammo as well as the fact that one can get one in a CRF rifle from a factory. CZ may give the RUM a try in the near future, as it only involves the cost of a few reamers...they have the 375 bbls and there are no changes necessary to the 550.

IMHO, the problem is that the RUM has so much power that it falls in the DGR category...it matches up with the 416s in application and has commensurate recoil. If you handload this is not a problem, but the handloading market does not drive rifle sales.

I really do not want the 50+ lbs of recoil the 375 RUM has I think I will just build a standard 375 and use a 27 or 28 inch finish barrel on it. I am going to use it for Brown Bear, Moose and Elk so I think the standard 375 H&H would be fine. Thank you for the information everyone.

Sabot- to me the problem with the 375 RUM is not the power but to me it is the contour of the tube. It feels nice but I'd prefer it to have a fair bit more metal. Then it would be a much nicer round to have around.

Just my thoughts.

"GET TO THE HILL"

Dogz

That's a good thought, and insightful. An extra 8 OZ of steel in the tube would help all the way around. A heavier stock would be a good idea too. I have given some thought to a second stock for mine with more weigth AND recoil supressors. That would make the full power handloads a lot more fun to shoot and avoid the nasty issue of a brake.

As you know swapping stocks is a 5 minute proposition, at most. I am quite surprised it is not a more common practice. My guess is that an unscoped weight of 13 lbs is about right for the 375 RUM for the heavy stock, and around 8.5 pounds for the lighter factory stock. Just based on weight alone this will cut perceived recoil by 35% and make it a lot more like a 338 or 300 Win when you are not walking all day. The mercury supressors are good for another 15% if you want a couple of pounds of the heavy stock to be Hg.That gives you an '06 recoil level and you can still carry it a bit if you use a good strap.

Of course, if you have other long action model 700s with mag actions, it will go on them as well...I also have a 338 RUM and it makes sense.

The way we in the US deal with the trade off between weight an recoil is something of a mystery to me anyway...one does not need to be super strong to move around a bit with a 13 lb rifle and lets face it, the rifle is not only more stable but you can work more with the weight distribution to get exactly what feels good to YOU.

The most important and overlooked advantage to a heavy rifle is that it is far less sensitive to your hold, and in the field it is rare to get your exact sight-in hold when there is a serious time limit on getting the shot off. A bunch of us tried moving the hold and forend rest points at the range with several 1.0 to 2.0 MOA rifles and they basically go to 4.0 or more...the bigger the round, the more the impact point moves. A 40% increase in weight cuts this effect in half.