Lightweight 375 Ruger project (I might be crazy)

[colorado]

My Rem XCR II (TriNyte) coated in 375 Weatherby with a 24" barrel weighs 7.5 lbs with a Leupold 2-7x Firedot scope. Recoil with 375 H&H 300g A-Frames at 2500 fps is mild. With Weatherby ammo (300g Partitions at 2800 fps) it's a bit sporty.

 

[Never Been]

I spent over an hour with Rick on the phone yesterday. I have an A-Bolt in .375 I'm trying to decide what to do with, and it sits at 7lbs 8.9oz bare with its 26" barrel. I think if I were to go ahead with it I would do 18.5" to keep it legal in Canada, and the contour is between a 4 and a 5 so I don't know how much I would lose there, but the stock is 1lb 14.4oz so Rick was confident we could lose close to a pound there. What weight did your stock end up at?

 

[Never Been]

My Rem XCR II (TriNyte) coated in 375 Weatherby with a 24" barrel weighs 7.5 lbs with a Leupold 2-7x Firedot scope.

What work did you have done to the rifle? I'm seeing facotry weight listed as 7lbs 10oz, which have lost faith in as it seems they always end up coming in over. My Browning is a good example-- listed weight of 7lbs 3oz and actual is almost 6oz more. Good looking bear by the way!

 

[Alaska Luke]

I spent over an hour with Rick on the phone yesterday. I have an A-Bolt in .375 I'm trying to decide what to do with, and it sits at 7lbs 8.9oz bare with its 26" barrel. I think if I were to go ahead with it I would do 18.5" to keep it legal in Canada, and the contour is between a 4 and a 5 so I don't know how much I would lose there, but the stock is 1lb 14.4oz so Rick was confident we could lose close to a pound there. What weight did your stock end up at?

I think my stock is in the 24 oz range. Lighter is possible but I wanted it stronger so it has an extra layer or two in the wrist.

 

[Never Been]

Fascinating, so the balance of the rifle is in the 4lbs 12oz range. My barreled action with the bolt, trigger group, and sights come in at 5lbs 2.5oz, and I can see that difference being made up with my barrel length. Between yours and @colorado 's posts I'm beginning to wonder if the A-Bolt action is actually any lighter than the others. That was always my understanding but it could be easily explained by Browning understating their weights while other makers are overstating.

 

[Riflecrank]

My factory rifles, Ruger M77 Hawkeye Alaskan Stainless,
stocks removed and barreled actions with factory iron sights weighed:

.375 Ruger with 20" barrel: 5 lbs 12 oz = 5.75 pounds (0.675" muzzle diameter)
.416 Ruger with 20" barrel: 5 lbs 8 oz = 5.50 pounds (0.755" muzzle diameter)

Rebarreling to .458/.416 Ruger Winchester-Magnumized-Throat aka .458 WMR (not a rimfire)
would be a way to reduce weight: Bigger bore hole.

That .375 Ruger Hawkeye Alaskan barrel contour could work for .458 WMR.
Can't just rebore any of them though,
whether .375 Ruger or .416 Ruger, because of the rear sight screw holes on all of them.
All of them are 0.875" diameter at 6" from breech face, and JES has found screw holes too deep to re-bore to .458.
Nutz !!!

 

[Never Been]

Wow, bore diameter makes a larger difference in weight than I assumed. Too bad about the screw depth, that .458 WMR looks like a lot of fun!

I keep being tempted to wack my barrel off with a cutoff wheel just to see how the rifle would feel but I want to gather some chronograph data before then.

 

[Riflecrank]

The advantages of firearm weight reduction by re-boring a .375 caliber to .458 caliber:

24" No. 5 Sporter
.458-caliber barrel weight = 3.34 lbs
.416-caliber barrel weight = 3.53 lbs
.375-caliber barrel weight = 3.71 lbs

20" No. 5 Sporter
.458-caliber barrel weight = 3.02 lbs
.416-caliber barrel weight = 3.19 lbs
.375-caliber barrel weight = 3.33 lbs

 

[Alaska Luke]

Here are some better pictures. It is a really nice rifle. I handloaded a few rounds t chec the iron sites. Recoil was pretty brisk with lighter 250 gr loads. My Trijicon scope will add weight and help.

 

[CoElkHunter]

I spent over an hour with Rick on the phone yesterday. I have an A-Bolt in .375 I'm trying to decide what to do with, and it sits at 7lbs 8.9oz bare with its 26" barrel. I think if I were to go ahead with it I would do 18.5" to keep it legal in Canada, and the contour is between a 4 and a 5 so I don't know how much I would lose there, but the stock is 1lb 14.4oz so Rick was confident we could lose close to a pound there. What weight did your stock end up at?

I'm not sure I would do anything to it? My blued steel/walnut A Bolt in .338 WINCHESTER MAGNUM has a 26" barrel and weighs 8.5lbs. scoped. Recoil is mild(er) and I've hunted elk here in the mountains with it since the mid '90s. Remember, the Ruger cartridges like their now defunct .300 and .338 Ruger Compact Magnums, along with their .375 and .416 were designed to use shorter barrels unlike the .458/.375 belted magnum cased cartridges as the Rugers' have fatter cases. I think there would be a significant velocity loss with the belted magnums using really short barrels?

 

[CoElkHunter]

My factory rifles, Ruger M77 Hawkeye Alaskan Stainless,
stocks removed and barreled actions with factory iron sights weighed:

.375 Ruger with 20" barrel: 5 lbs 12 oz = 5.75 pounds (0.675" muzzle diameter)
.416 Ruger with 20" barrel: 5 lbs 8 oz = 5.50 pounds (0.755" muzzle diameter)

Rebarreling to .458/.416 Ruger Winchester-Magnumized-Throat aka .458 WMR (not a rimfire)
would be a way to reduce weight: Bigger bore hole.

That .375 Ruger Hawkeye Alaskan barrel contour could work for .458 WMR.
Can't just rebore any of them though,
whether .375 Ruger or .416 Ruger, because of the rear sight screw holes on all of them.
All of them are 0.875" diameter at 6" from breech face, and JES has found screw holes too deep to re-bore to .458.
Nutz !!!

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Great idea! Too bad factory Ruger barrels won't work because of the sight screw hole depth, because now you have the added expense of finding a new chambered barrel with the additional expense of adding sights.

 

[Riflecrank]

Alaska Luke,
That NECG Ghost Ring peep on the rear integral base of the Ruger is the way to go.
Very nice rifle indeed.

 

[Riflecrank]

CoElkHunter,
More of my kuhnoodling on barrels on Rugers:

Barrel contours on the Ruger Hawkeyes, closest fit to Pac-Nor Sporter Contours: Pretty close !

.375 Ruger 23" African with muzzle diameter 0.700": Pac-Nor No. 4 cut to 23" >>> 0.680" muzzle diameter
.375 Ruger 20" Alaskan with muzzle diameter 0.675": Pac-Nor No. 3 cut to 20" >>> 0.685" muzzle diameter
.416 Ruger 20" Alaskan with muzzle diameter 0.755": Pac-Nor No. 5 cut to 20" >>> 0.760" muzzle diameter

Ruger No. 1-H
.416 Ruger 24" Tropical/Stainless with muzzle diameter 0.750": Pac-Nor No. 6 cut to 24" >>> 0.770" muzzle diameter

Yes, too bad the re-bore to .458 is made impossible by the rear sight screw holes on the Hawkeyes.
Any of the muzzle diameters on the factory Hawkeye rifles would be OK otherwise,
with the 20" .375 Ruger being at the minimum of acceptability,
ditto the slick .300 WinMag Hawkeye barrel cut to 20" and re-bored, for 0.680" muzzle diameter.
I got cold feet on that one too now.
Not building needle guns anymore.
Virgin barrel it shall be.
At least I am a simple gunnut, not something more expensive like a womanizer.

 

[Riflecrank]

Pac-Nor Barrel Weight Calculator for .450-bore/.458-caliber, 1.200" shank diameter

No. 5 Sporter

20" barrel length
Muzzle diameter 0.760"
Weight = 3.02 lbs

That would look (aesthetics of external barrel dimensions) very like the .416 Ruger Hawkeye Alaskan with 20" barrel.
It would be 0.17 lbs or 2.72 ounces lighter than same barrel contour and length for .408-bore/.416-caliber (3.19 lbs).
The .458 WM/WMR Ruger Alaskan would be a little lighter than the factory .416 Ruger Alaskan

But hey, the mightier .458 WM or .458 WMR deserves a subtle visual indicator of its greater power than the .416 Ruger.

Back to the calculator ...

No. 6 Sporter, .450-bore, 1.200" shank diameter:

21" barrel length
Muzzle diameter 0.800"
weight = 3.43 lbs

Only 0.24 lbs or 3.84 ounces heavier than the approximation for the .416 Ruger Hawkeye Alaskan 20" barrel
Slightly longer, fatter and heavier barrel befitting the step up in power.

No. 5 Sporter, .450-bore, 1.200" shank diameter:

21" barrel length
Muzzle diameter 0.750"
weight = 3.11 lbs
Just a wee bit lighter than the 20" .416 Ruger barrel on the Alaskan.
That would be about 7.5 pounds for a No. 5, 21"-barreled .458 WM or .458 WMR
and easily under 8 pounds for a No. 6, 21"-barreled .458 WM or .458 WMR.
with iron sights in a B&C stock.

 

[Riflecrank]

The latest corrections for properly loaded ammo, sized with .416 Ruger dies and
a workable neck expander/seater/crimper from cut-off .460 WbyMag, dies, etc.
Criticisms of brass maximums versus chamber minimums welcome, before I pull the trigger: