Author Topic: 375 Ruger Case Specs (Read 3866 times)

358Win · « **on:** November 19, 2006, 04:25:11 PM »

Hi All:

Just took a tour of the Ruger web-site. Very excited about the new 375 Ruger cartridge. Has anyone got actual chamber/case specs?

Also very excited to see the Frontier in both 338 Federal and 358 Winchester. I'm guessing that the short tube favors the 358, but I've never gotten a good explanation of how the trick powders used in the 338 achieve the quoted ballistics at the quoted pressure. I'm guessing that there is either a prolonged pressure wave or a secondary pressure wave. Either of which would hurt the 338 Federal in this short of a barrel. Anyone got any factual information on that topic?

358Win · « **Reply #1 on:** November 22, 2006, 08:53:39 AM »

Anyone?? I thought there would a couple of budding ballistic engineers out there just dying to answer this one. Oh well.

Have a Great Thanksgiving,
358Win

Graybeard · « **Reply #2 on:** November 22, 2006, 08:57:18 AM »

They've not yet given out the specs on it. I believe it is the .376 Styer case lengthened to about 2.5". At least that's what it looks like and the specs would back up that supposition. But it could be a bit shorter. I'm reasonably certain it will be that case and will be longer than it and not longer than 2.5".

skippermdj · « **Reply #3 on:** November 22, 2006, 12:22:06 PM »

If the speculation that the 375 Ruger shares a parent case with the 376 Steyr, then the parent case for both of them is the 9.3x64 Brenneke, which has a .496 rim diameter and a .506 dia at the base of the cartridge, with no belt. The 9.3 (36-caliber) Brenneke is supposed to push a 286-grain bullet over 2600FPS, so it seems reasonable that the same case could hold enough powder to push a .375 caliber 300-grain bullet to 2500 FPS+ and a 270-grain to 2650+.

CAse length of the 9.3x64 is 2.52" and oal is 3.37". The 375 Ruger should be close to those dimensions, I'd guess.

Just speculation, but seems reasonable.

- Mark

Coyote Hunter · « **Reply #4 on:** November 23, 2006, 02:52:57 AM »

358Win -

My understanding is the .375 Ruger uses a new case the diameter of the rim on a belted mag or about 0.532".

The explanation for the .338 Federal is that it achieves .308 velocities with a heavier bullet because the .338 bullet has a 20.4% larger base for the pressure to act against. The circumference of the .338 is only 8.9% greater, so given similar bullet profiles (surface contact with the barrel, which in part determines friction) and similar construction, the gain in in base area outweighs the increase in friction.

376Steyr · « **Reply #5 on:** November 28, 2006, 04:54:33 AM »

The Hornady website has some drawings of the 375 Ruger in the "ammunition" section. I assume these are drawn to scale. I did some embarrassingly primative measuring of the 375 Ruger and 376 Steyr cartridges shown. Again, assuming these are to scale, the 376 Steyr case rim is significantly smaller than the 375 Ruger. I strongly suspect the Ruger rim is around 0.532 inch, which makes sense as every standard length belted magnum action can be used for the Ruger round and all the rounds which will soon be developed from it. Too bad, as I was hoping Ruger would chamber the M77 for the Steyr and help keep a fine cartridge alive.

Questor · « **Reply #6 on:** November 30, 2006, 03:30:12 AM »

What makes the 375 Ruger exciting?

Coyote Hunter · « **Reply #7 on:** December 01, 2006, 03:38:18 AM »

Quote from: Questor on November 30, 2006, 03:30:12 AM

What makes the 375 Ruger exciting?

Questor –

Currently available .375’s tend to be fairly expensive and/or heavy. The least expensive is the CZ Safari at $875 and weighing in at 9.4 pounds with a 25” barrel. Next is the Remington XCR at $1056. The Remington is a lightweight at 7-5/8 pounds, has a 24” barrel and comes in H&H and RUM flavors. If you want a Ruger in H&H, the list price is $1975 as it is only available in their “Magnum” model, which weighs 10 pounds. The Weatherby and Dakota .375’s cost considerably more, well beyond what I can afford.

Enter the .375 Ruger. It fits any standard length action that can chamber a .300 Win Mag. It will be a SAAMI standard cartridge, meaning you can expect other rifle manufacturers to chamber their rifles for it. Savage/Stevens and CZ come to mind as likely candidates. In other words, expect very affordable rifles to be available.

The 20” barrel on the Ruger “Alaskan” will make it a very handy rifle. My Ruger in .257 Roberts has a 22” barrel and it has become my favorite rifle due to its handling characteristics.

From a performance standpoint, the .375 Ruger Alaskan offers better than H&H performance but with a 20” barrel. Weighing in at 7-3/4 to 8 pounds (depending on which spec sheet you look at), the Ruger Alaskan and African will be much more comfortable for mountain work than rifles weighing 9-10 pounds and up.

One of my rifles is a Marlin in .375 Winchester. It pushes a 220g bullet to 2230fps. For some time I have wanted a .375 that would provide additional performance, including higher velocity, heavier bullets and better ballistic coefficients. RUM and WBY performance (and recoil) was not part of what I was looking for – a fat, heavy bullet at .308 velocities or better would have sufficed, and I considered building a Ruger for chambered for the .375 Dakota. The .375 Ruger fills the bill nicely by pushing a 270g to 2840fps and a 300g to 2660fps.

What’s not to like?

Questor · « **Reply #8 on:** December 01, 2006, 03:45:41 AM »

Thanks Coyote Hunter. That does make it exciting. I wonder if it's legal for use in Africa on cape buffalo and other game that have traditionally required 375H&H as the miniumum cartridge.

358Win · « **Reply #9 on:** December 01, 2006, 09:29:31 AM »

Hi All:

Ruger is letting us all get worked up with speculation about the dimensions of the new 375 Ruger cartridge that they are working on with the folks over at Hornady. I just read a piece on the new cartridge in this month’s issue of Handloader.

Same basic prognostications as given here; A rimless case with a length between 2.4 and 2.6 inches, and a head/rim diameter of either 0.532 or 0.500. Given that the leaked ballistics are about 100 fps faster than the 375 H&H with the 270 grain bullet, I’d have to lean towards 0.532 at the rim and base, then 0.512 at the shoulder, and 0.408 at the neck. Taking a wild guess I’d think that they would want about a 25 degree shoulder angle and a neck at least bullet diameter long. So to get the shoulder length we resort to the old machinist saying “A Happy OldHeap Of Apples” ->
A/H = cos <, O/H = sin <, and O/A = tan <. The Opposite length = (0.512 – 0.408) / 2 = 0.052, and tan 25 degrees = 0.4663. So the run of the shoulder = 0.052 / 0.4663 = 0.111514 ~ 0.112 inches.

My wild guess for case dimensions would then be:
Diameter at Rim & Head: 0.532
Length to Primer Cup Face: 0.200
Length to Shoulder: 2.100
Diameter at Shoulder: 0.512
Length of Shoulder: 0.112
Shoulder Angle: 25 degrees
Length of Neck: 0.408
Diameter of Neck: 0.408
Length to Neck: 2.212
Case Length: 2.620

Now all I need to do is wait until New Years to find out how close my guess is.

jrkrk · « **Reply #10 on:** December 01, 2006, 02:11:24 PM »

Hey guys case specs for 375 ruger are in GUNS magazine jan. 2007 issue page 38. Overall length with 270gr. bullet is 3.315" it is rimless and beltless with head diameter of .529" and case length is 2.580" hope this helps.

376Steyr · « **Reply #11 on:** December 05, 2006, 03:33:42 AM »

And the Jan 2007 issue of Rifle magazine, page 8, gives the measurements at 0.522 at the base and rim, and the case as 2.568 inch long. Neck length is 0.310 inch, shoulder diameter of 0.510 inch, base to the shoulder is 2.178 inches. Curiouser and curiouser....

358Win · « **Reply #12 on:** December 05, 2006, 09:33:58 AM »

Hi Guys:

Well it looks like they are going with pretty much a standard belted boltface diameter only with a beltless case for more capacity. Good idea! The length of the case at 2.580 which is about what I had guessed at when you account for the shorter neck length they actually used. You can bet I'll be hunting down a copy of GUNS magazine tonight. I've wondered for a long time why a standard rimless design had never been built with the standard belted case head/rim diameter.

Now I may as well stir up the mud and design a 35 Caliber Wildcat rifle around this case shortened enough to fit in a short action. The New Ultra Light Arms short Action with Magnum Boltface has a 0.532 inch boltface diameter and an Overall Cartridge Length limit of 3.00 inches and weighs 28 ounces and will hold 3 in the magazine and 1 in the chamber. I'd want about a 19 or 20 inch barrel so that the overall length of the rifle is just under 1 meter at 39 inches. The goal would be to have the scoped rifle weigh in at about 6 3/4 pounds.

So the cartridge length would be 57mm in length or 2.244 inches, with a neck length of 0.332. The rest of the specs fall out at:
Diameter at Rim and Base: 0.532 inches
Length to Shoulder: 1.800 inches
Diameter at Shoulder: 0.510 inches
Length of Shoulder: 0.100 inches
Angle of Shoulder: 25.0 degrees
Diameter of Neck: 0.388 inches
Length of Neck: 0.344 inches

This is close I'll have to fix it tonight at home, back to work.

358Win · « **Reply #13 on:** December 05, 2006, 11:05:37 AM »

As stated above I was just winging this design on my lunch break at work. But my initial calculations are that this would be just a bit more than the 35 Whelen in a short action. Seems like a good idea.

jw4570 · « **Reply #14 on:** December 05, 2006, 12:46:34 PM »

I just came here and looked around saw the excitement of the Ruger 375

I'd say the only 375 that comes close in weight is the Remington 700 Classic in 375 H&H, I have one, and it is an excellent shooter. It's got a thinner tapered barrel than Remington normally uses on the 375 I believe, it's pretty light, 7lb range without the scope, so a little over 8 with. And I got mine a a really right price, probably not fired 20 times (probably only once).

Now, don't get me wrong, a beltless cartridge would be nice. This seems a much better idea in new cartridges than what has been coming out in recent years, actually worthwhile in a real sense. The 375 is a good caliber and could be used to hunt nearly anything. I hope a good selection of light to heavy loading would be available from Hornady.

As much as I actually shoot mine, I'm probably sticking with what I have.

358Win · « **Reply #15 on:** December 06, 2006, 09:00:58 AM »

Those reading this thread might want to follow my similar thread in Medium Bore Rifles about a 358 x 57mm wildcat especially the last note about a 358/375Ruger x 57mm as a pretty good idea for adding 150 fps or so to a 250 grain bullet over what is possible in the 35 Whelen and do it in a short action.

358Win · « **Reply #16 on:** December 07, 2006, 12:12:56 PM »

Quote from: Coyote Hunter on November 23, 2006, 02:52:57 AM

The explanation for the .338 Federal is that it achieves .308 velocities with a heavier bullet because the .338 bullet has a 20.4% larger base for the pressure to act against. The circumference of the .338 is only 8.9% greater, so given similar bullet profiles (surface contact with the barrel, which in part determines friction) and similar construction, the gain in in base area outweighs the increase in friction.

Hi Coyote Hunter:

Very true about larger base area. I picked up that bit of info from P.O.Ackley's book back about 1975. My question is how are they getting higher velocities and energies in the .338 Federal than is possible in the 358 Winchester which in theory should win the contest between them hands down. My understanding is that the SAAMI spec for both cartridges is 52,000 CUP or approx. 60,000 PSI. So my question is how are they breaking the laws of physics here? The only theory I've heard that makes much sense is that Federal is using some trick powder that is not available to handloaders. What this means to me since I only shoot reloads is that my 358 Winchester will still out perform the 338 Federal since I won't be shooting any factory ammo. The same issue applies to the Hornady LeverEvoultion (sp) ammo. As far as I know the bullets with the soft tips are not available to handloaders and they state outright that they are using a "special" powder to achieve those ballistics. Which again makes them almost worthless to me, since I really only shoot reloads.

358Win · « **Reply #17 on:** December 07, 2006, 12:22:13 PM »

Quote from: Questor on December 01, 2006, 03:45:41 AM

Thanks Coyote Hunter. That does make it exciting. I wonder if it's legal for use in Africa on cape buffalo and other game that have traditionally required 375H&H as the miniumum cartridge.

My limited knowledge of the legal cartridge situation is that it varies from country to country. Some countries simply require a bore diameter of 0.375 or greater. A few others add an energy level to the requirement. At least one requires a bore diameter of 0.400 or greater. Since the energy of the 375 Ruger > the energy of the 375 H&H, the 375 Ruger should be ok except where the bore diameter requirement is not meet. Hope that helps.

crash87 · « **Reply #18 on:** December 08, 2006, 02:33:01 PM »

The latest issue of Rifle magazine, an article by Dave Scovill, also states the cartridge can be formed using 8x68s brass. The same as the .30 & .35 Newton. CRASH87

CaptOnion · « **Reply #19 on:** December 12, 2006, 01:01:53 PM »

The 375 Ruger was based on the30 Newton case.Impressive IMO.All that and a bag of skittles.

Coyote Hunter · « **Reply #20 on:** December 12, 2006, 05:29:24 PM »

Quote from: crash87 on December 08, 2006, 02:33:01 PM

The latest issue of Rifle magazine, an article by Dave Scovill, also states the cartridge can be formed using 8x68s brass. The same as the .30 & .35 Newton. CRASH87

Actually, here's what Rifle Magazine has to say:

"Since no one at Ruger or Hornady is talking, details of the case design have not been released, which pretty much leaves everyone hanging until the “official” unveiling. We now know, however, that the .375 Ruger case is essentially the same as the .30 Newton, or if you prefer, the .35 Newton, albeit necked up to .375 inch."

"Measurement of the .375 Ruger shows it is .522 inch at the base and rim and 2.568 inches long. Neck length is .314 inch. Shoulder diameter is .510 inch. Length from the base to the shoulder is 2.178 inches."

"Research suggests the only reasonably available case from which to form the .375 Ruger is the 8x68S and 6.5x68." [Owing to a lack of Newton cases]

"The hitch is the .375 Ruger is a 60,000+ psi case, whereas those pressures might be stretching the upper limits for the basic 68 case. And, the 8x68S, like the 6.5, has a diameter at the base some .008 inch less than the standard Ruger/Newton and a rebated rim at .509 inch."

Sounds to me like the x68 brass is too small. Don't know the exact dimensions of the Newton cases but consider it irrelevant anyway since I doubt many will be forming brass instead of buying new.

nomosendero · « **Reply #21 on:** December 12, 2006, 05:35:29 PM »

Besides, the Hornady brass will be cheaper than 8X68s brass anyway.

Coyote Hunter · « **Reply #22 on:** December 14, 2006, 04:03:05 PM »

In the January 2007 Guns & Ammo, Boddington says the .375 Ruger has a .532" rim and base.

358Win · « **Reply #23 on:** December 14, 2006, 04:52:07 PM »

I had completely forgotten about the old Newton cartridges. Great to have a standard rimless case on the Magnum boltface diameter. I'm sure that this will be wildcatted in every possible direction in the next few months. But I'm thinking the Ruger Hawkeye Alaskan in its standard format would be close enough to perfection for me.

358Win · « **Reply #24 on:** December 30, 2006, 02:02:30 PM »

They have resurrected the old Newton case so this is NOT based on any of the standard dimensions used since 1940 when production of Newton cases stopped. Still a great cartridge even with the odd 0.525 rim diameter and the 0.522 base diameter. This should be fantastic news to anyone who has one of the original Newton rifles as there is now a source of brass which hasn't existed for 67 years. I'd surely have the old Newton checked by a competent gunsmith before running out and shooting it.

Coyote Hunter · « **Reply #25 on:** December 30, 2006, 04:05:40 PM »

Quote from: 358Win on December 30, 2006, 02:02:30 PM

They have resurrected the old Newton case so this is NOT based on any of the standard dimensions used since 1940 when production of Newton cases stopped. Still a great cartridge even with the odd 0.525 rim diameter and the 0.522 base diameter. This should be fantastic news to anyone who has one of the original Newton rifles as there is now a source of brass which hasn't existed for 67 years. I'd surely have the old Newton checked by a competent gunsmith before running out and shooting it.

Boddington, who has actually used the .375 Ruger with Steve hornady and others involved in its development, has stated in Guns and Ammo and Sprts Afield that the rim and baqse are 0.532", not 0.522". If correct, it would not be a resurection of the Newton but a new case.

Ratltrap · « **Reply #26 on:** January 09, 2007, 09:54:26 AM »

Quote from: Coyote Hunter on December 30, 2006, 04:05:40 PM

Boddington, who has actually used the .375 Ruger with Steve hornady and others involved in its development, has stated in Guns and Ammo and Sprts Afield that the rim and baqse are 0.532", not 0.522". If correct, it would not be a resurection of the Newton but a new case.

Too bad. I wish they had simply ressurected the Newton case. Then we could have seen new 30,33, or 35 Newton chambered rifles along with the 375 Ruger.

One thing I noticed was that the Hornady loads only used a spire point in 270 grain. Both 300 gr. loads are round nose. Anyone care to comment on why that might be? Does that have anything to do with the short neck or the overall length of this cartridge?

Coyote Hunter · « **Reply #27 on:** January 11, 2007, 03:04:34 AM »

ratltrap -

The new Ruger case has more internal volume than the Newton case could provide. I think Ruger has done the right thing, maximizing case volume by dumping the now useless belt and using the belt diameter as the case diameter. Too bad for people with Newton rifles, perhaps, but they are no worse off than before. The new Ruger case provides an excellent basis for a whole new generation of small and medium bore cartridges that are not handicapped by restrictions imposed by old case designs. (Read useless belts and excessively large or unnecessarily small case diameters.)

As to the Hornady decisions on choice of bullets, the 300g bullets include the FMJ and InterBond RN, both of which predate the .375 Ruger. Good choices, IMHO, as these are DG loads not long distance loads.

deltecs · « **Reply #28 on:** April 10, 2007, 05:45:20 PM »

I did an extensive search for the 375 Ruger case dimensions. I found out that the case is an 06 length standard belted rim case before swaging the case to create the belt. Think of the .338 Win case with the base the same as the rim at .532, plus or minus a .001 or two. The case capacity then is about 10-15 % larger than the same case with a belt. So, with the .375 H & H having substantial case taper for such a long case and the new Ruger case being fairly straight, the case capacity should be the same or greater. The .375 Dakota case based on the 404 Jeffrey has a case capacity of 98 gr. This is just 2 gr more than the H & H according to Handloader's Manual of Cartridge Conversions. The new Ruger case should be extremely close capacity wise. So, ballistics are going to be nearly identical with the same pressures. The Ruger case is interesting because one can rebarrel without a bolt face alteration to the .375 bore from a .264 Win Mag. or similar case in an action that won't take the long 2.850" cartridges. I plan to have one made up for .375 Ruger along with one from the Dakota lineup. The 404 Dakota. I plan to test both in Alaska and Africa, soon. We'll see what happens.
Greg