7mm-375 build???

[BigDMT]

Howa actions are longer than 700s across the board. The 375 Ruger case by itself does not use long VLD style bullets so magazine length is not so much of a concern.

What bullets are you using in your 30-375? Can you seat a Berger 210gr VLD in the mag of the Howa?

 

[wwbrown]

Howa actions are longer than 700s across the board. The 375 Ruger case by itself does not use long VLD style bullets so magazine length is not so much of a concern.

What bullets are you using in your 30-375? Can you seat a Berger 210gr VLD in the mag of the Howa?

I was not aware that the Howa's were longer than the 700.

Yes I can seat a Berger 210 gr VLD and meet mag length. I had the reamer specced to handle 220 g Scenars at mag length, but could not find any when I wanted to some load development so had some 210 Berger VLD's on the shelf and went with those. I will finish up with the Scenar-L's as I have found those in other calibers to be a very easy accurate solution.

 

[wboggs]

What OAL length are you running in your .30-375?

 

[slm9s]

7stw?

 

[BigDMT]

Howa actions are longer than 700s across the board. The 375 Ruger case by itself does not use long VLD style bullets so magazine length is not so much of a concern.

What bullets are you using in your 30-375? Can you seat a Berger 210gr VLD in the mag of the Howa?

I was not aware that the Howa's were longer than the 700.

Yes I can seat a Berger 210 gr VLD and meet mag length. I had the reamer specced to handle 220 g Scenars at mag length, but could not find any when I wanted to some load development so had some 210 Berger VLD's on the shelf and went with those. I will finish up with the Scenar-L's as I have found those in other calibers to be a very easy accurate solution.

Good to hear. I was actually contemplating a Howa when I built my first 6.5 Rem mag because I wanted a long action that would give me more than enough room for the 140gr VLDs. The 700 seemed a little short to me for a LA, the Howa LA magnum action almost looked TOO long and I was concerned with feeding issues because of it, so I ended up building it on a Savage 116. Sold the Savage action when I shot the barrel out and built the same round on a TC Venture action and though it is shorter than my the savage by a hair, it's still just about right.

I believe the Weatherby's are the longest. A Weatherby LA is ridiculously long compared to a 700.

I will still probably build the 30-375 on an Ultra Mag action though. I like the extra seating options for tuning and so recoil doesn't slam the bullet tips in the mag.

With my 338-375 Ruger, the 250gr Berger VLD's are so long that I had to use the Ultra Mag version of the 700. Still have no chance of ever getting close to the lands with seating, but it shoots great so I'm not too concerned. Though when the time finally comes to chase the lands, I will be very limited and may just have to let it run until it comes time to turn the barrel back.

 

[JLDavid]

Scalloper,
PM or email forum member SuperiorRifles as he has built a 7mmLRM and has loaded 180's and is mag feeding it. He will have numbers for your throat. I have contacted him with questions and he has been quick to reply. FWIW, he built his on an old 270 Winchester Remington 700. Here is the link.
http://forum.accurateshooter.com/index.php?topic=3795988.0

Good luck.
David

 

[Scalloper]

Thanks guys. Great info here

 

[dkhunt14]

Why not build a 7LRM? I believe it is shorter then the 7-375 and has about the same velocity. I believe it uses less powder but does it more efficiently. Barrel would last longer. Matt

 

[BigDMT]

Why not build a 7LRM? I believe it is shorter then the 7-375 and has about the same velocity. I believe it uses less powder but does it more efficiently. Barrel would last longer. Matt

The 7 LRM is the same parent case with the shoulder bumped back a little to give a longer neck. I believe it was designed that way to get more case neck contact on the bearing surface of the 180gr VLDs when seated. But the 7 LRM and 7mm-375R are basically the same thing.

 

[dkhunt14]

If you loaded the bullet to the neck shoulder junction, wouldn't that make the OAL shorter? It would also be less powder and with the longer neck you would get better barrel life. They claim to easily reach 3100 and no pressure with 180 Berger. If that's true that would beat most 7MM cartridges. Matt

 

[hogan]

Winter craziness has surely set in among our crowd.

Best be buying barrels by the dozen, and get your smith a couple of new reamers and a rougher to work with. Bout the time you get a load worked up, the barrel will be gone, history...

Why not a 7mm Chey-Tac? Lots have done the 7mm/300wby ticket probably on the B list of several die makers. Might actually find a set on Ebay or on the shelf at Sinclair... But don't let me rain on the parade or rein-in them runaway hosses... Fun is fun, but after you sink about a grand into a barrel and die set no one else is ever going to want, it will dawn on you that this was folly.

Owned a .30-378wby for a few years. There's one for you to neck-down!
Your gunsmith will put his kids through college and give them BMWs on your work alone...
But, hey! Have fun!!!

 

[BigDMT]

Winter craziness has surely set in among our crowd.

Best be buying barrels by the dozen, and get your smith a couple of new reamers and a rougher to work with. Bout the time you get a load worked up, the barrel will be gone, history...

Why not a 7mm Chey-Tac? Lots have done the 7mm/300wby ticket probably on the B list of several die makers. Might actually find a set on Ebay or on the shelf at Sinclair... But don't let me rain on the parade or rein-in them runaway hosses... Fun is fun, but after you sink about a grand into a barrel and die set no one else is ever going to want, it will dawn on you that this was folly.

Owned a .30-378wby for a few years. There's one for you to neck-down!
Your gunsmith will put his kids through college and give them BMWs on your work alone...
But, hey! Have fun!!!

Sounds like you need to find a more affordable gunsmith ;D

The 375 Ruger wildcats are gaining popularity quite rapidly actually. I personally think one of the 7mm, 30, or 338 versions has the appeal to be picked up as a commercial round by one of the major manufacturers. Hornady already makes the brass, just have to neck it down. All perform extremely well at long range with excellent accuracy and tremendous energy that is all manageable without a muzzle brake.

I push the 250gr Berger VLDs in my 338-375 Ruger at 2925 fps in a 26" barrel and don't need a brake. The gun weighs just under 13 lbs with scope and rounds loaded in the magazine so that helps, but I think it would still be manageable without a brake at around 10 lbs total weight.

 

[M14AMU]

I'm thinking about necking my thermos jug down to a phonograph needle! What action will I need??

 

[wboggs]

I'm interested in how a .338RUM compares with the .338-.375 Ruger. Any opinions out there?

 

[BigDMT]

I'm interested in how a .338RUM compares with the .338-.375 Ruger. Any opinions out there?

I know that the 338 RUM has about one gran less H20 capacity than the 338 Lapua. 113gr vs. 114gr respectively.

Now the 375 case has a capacity of 99gr. So it is a bit smaller, and loses a little more capacity when necked down and using High BC bullets seated to magazine length.

In my tests I was able to get to 3000 fps with a 250gr bullet, but was starting to see slight pressure signs around 2975 fps. Primers were not flattened, but ejector marks were starting to become very visible on the brass. Now keep in mind that I am only using a Brux 26" 1 in 10" twist barrel

Many claims you see for speeds on the 338 Lapua are done with 28"-30" barrels.
But the 338 Rum speeds are often based on 24"-26" barrels as well because it is often used as a hunting rifle cartridge.

So the beauty of the 338-375 Ruger is that it may not be quite as fast, but it will hold it's own on performance when pitted with the larger more main stream 33's and do it with less powder.

As far as accuracy, my 338-375R shoots excellent. I built it in a hunting/tactical rifle format and it will print groups under 1" at 300 yards with ease. Of course the other 33s mentioned will do the same if built properly.

 

[wboggs]

If one looks at Berger's ballistic tables the effect of velocity differences is educational. Start a 250gr with a G7 of .349 at 3000 and 2800 and compare at a reasonable hunting shot at 400yds. Velocity changes 180fps from 2467 to 2287, energy changes 3378 to
3224, drop with a 275 yd. zero changes -10.89 to -12.77, wind deviation 7.25 to 8.06. It would seem to me that these won't make a lot of difference. Now the long range target shooter is a different matter. Inches make a difference between 9's and 10's and 10's and x's. There is very little difference in all these cartridges for hunting at usual ranges. If you are trying to make a shot at extreme range, game or target, velocity is important and the usual measures to increase it are necessary. As always, there is no "free lunch"
and you make your choice.
Having said this, I will add that the fast .338's are some of the very best rounds ever developed. This thread reminds me of the perpetual argument when I was young of whether the .270 or ..30-06 was better. These discussions do force one to look at the facts and make a choice depending on his needs and desires and this is a source of great satisfaction, myself included.
Bill

 

[dkhunt14]

I guess by the remarks of some they think the 375 Ruger case is enormous. They better go look at the facts. It is way smaller then most of the cases they are talking about. It should have a lot better barrel life then they are thinking. Both the 7-375 Ruger and 7LRM are available as ready made rifles. Yes they are not available from the big Manufacturers but I think they may be picked up by some of them in the future. Especially the Ruger. They are both good chambers for the 7mm. Matt

 

[BigDMT]

Right. Its not that big of a case. Its shorter than a 300 win mag case and thinner than an Ultra Mag case. Definitely not an "overbore" like the Ultra Mags. In 7mm form, the 375 case is right on that overbore border line, but still pretty efficient. In 30 and 33 cal it is just about perfect with bullet weight to powder spent ratio on any given speed that is achieved. The original form of 375 is very efficient as well and easily duplicates 375 H&H speeds.

But like I said before, my favorite thing about tue 375 case is that it gives me speeds very close to the bigger 33s and I dont have to fit my barrel with one of those God forsaken ear busting muzzle brakes.

My 250gr Berger is doing 2925 fps from a 26" barrel with only 72gr of RL-17. Thats not a very heavy charge at all when compared to like speeds in bigger 33s. Now dont get me wrong, she kicks pretty darn good, more than a 300 win mag, but it is definitely manageable.

 

[wboggs]

Agree, that is a small charge for 2900+ fps and it is a very efficient case. The bigger ones really pull ahead when seated to a long OAL in a modified magazine and are propelled by a large charge of Retumbo.
Definitively something to consider in a new build. Could be useful in the .284 and .308 cals. also, especially in a 3.6" magazine.
The good thing about a hunting rifle is that you never are bothered by the recoil when a trophy is in your sights.

 

[BigDMT]

Exactly right. Recoil is never an issue when hunting, but its not too bad at the range either with a 1.5" deceleartor pad on the stock. Though you will definitely want to have a good scope with a solid 4" of eye relief or better and tough enough to handle the punishing recoil. I have a Bushnell Elite Tactical 4.5-30 x 50mm on my rife and I am very happy with it so far. Holds zero extremely well, tracks perfect, has excellent eye relief through the whole power range. The 4.5-30 power range is also extremely versatile for taking all kinds of shots in just about any hunting situation and at any range the rifle is capable of making.