Jim, with much love and respect -

"band slippage" is twist, not throat -- this aint the problem the short throat 500 accrel was created to fix.. the bands were stripped OFF ---

a .510 bullet was measured .500, no bands .. that is certainly something to be fixed..

that you can count 4 bands, with more or less square leading edges, detonates that there isn't band stripping..

we can agree to disagree on the cause of multiple groove engagement -- but it looks like "every" other banded bullet shot in a lott or capstick, etc...

or 458 winmag,/.

or 460 weatherby that has a LOT more speed than the cases we are talking about

10-4 Jeffe

Any reason not to rechamber a 475 Linebaugh Ruger #1 to 470 Accrel?

quote:

Originally posted by boom stick:
Any reason not to rechamber a 475 Linebaugh Ruger #1 to 470 Accrel?

Just be careful of bullets and plan ahead. There are sometimes inconsistencies in .474" bullets and barrels.

@ boom stick-

It looks like the Ruger No. 1 in 475 Linebaugh comes with a 1:18” twist barrel. That twist rate gives you a fairly good stability factor with even the longest bullet on the market, the 500gr Barnes Triple Shock. It would have no issue stabilizing all other, shorter projectiles. I love the efficiency of the 458-470 AccRel case (I own a 458 AccRel Mauser) but I think I would prefer a rimmed cartridge in a custom falling block, especially in this bore diameter. The 470 Nitro Express was made for it, although it is much less efficient. It’s a more volumous case and you would have no problem obtaining 2350fps with a 500 grain bullet in a No. 1 at relatively low chamber pressure.

Additionally, I have heard people complain about recoil management with the factory Ruger stock design. While not as comfortable as a properly laid out bolt action stock, I found a Ruger No.1 in 458 LOTT manageable with loads very near what you would expect with a 470AccRel (500gr @ 2300fps) and similar recoil (+/-80ft/lbs @ 22.5ft/sec) in a 10lb rifle. However, the No. 1 in Linebaugh comes in at only 7.5lbs. With no additional weight added, you will experience brutal recoil (94ft/lbs @ 26.6ft/sec). To put things in perspective, my 505 Gibbs is considered brutal by some, producing 94ft/lbs @ 23ft/sec. that recoil velocity will eat your lunch! But if you can manage the recoil, the compact No. 1 would be a dream to hunt with and carry with its 20” barrel.

Just a few thoughts,

RC

Thanks
I love the 470 Accrel and thought the small package would be a dream to carry. If you remove the stock for transport, it would make a small package as well. The rim of the Linebaugh is similar to the Jeffery/RUM so it seems all you need is a rechamber to go from a pop gun to an elephant gun. I figured 500@ 2250 with the short barrel. The concept seems like a fun one.

if the barrel shank is long enough, should be easy enough -- though pretty light weight!

How does it look Doc?

That is a nice length.

This one is 20", there were some 18" barrels, IIRC:



I thought about rechambering it, but took the quarter rib off and saw how deep they drilled the screw holes into the barrel shank.

Then I became very satisfied with the LongCOL loads for the .475 Linebaugh, using bullets for the .470 NE:
About 2000 fps with a 400-grainer,
and +1600 fps with a +500-grainer:

500-grain Barnes Original at 2.375" COL
LIL'GUN/WLR
30.5 grains >>> 1610 fps MV, Sd = 10 fps
31.0 grains >>> 1644 fps MV, Sd = 1 fps (A very uniform 3000.4 ft-lbs of KE at the muzzle.)
31.5 grains >>> 1661 fps MV, Sd = 10 fps
32.0 grains >>> 1673 fps MV, Sd = 4 fps
32.5 grains >>> 1690 fps MV, Sd = 3 fps (3170.6 ft-lbs of KE at the muzzle.) No pressure signs.



The fair to middlin' cast bullet load:



That is with standard factory Ruger No.1 throating.
The .475 Linebaugh is the .458 WIN of revolvers.

Rip ...

How does that shank look for a 470 Accrel or 470 Nitro conversion?

quote:

Originally posted by boom stick:
How does that shank look for a 470 Accrel or 470 Nitro conversion?

Marginal or no good,
depending on the factory job of drilling those holes for mounting the quarter rib.
They may be highly variable in depth and should be measured on a case-by-case and rifle-by-rifle basis.

I have heard of horror stories where the holes went all the way into the bore.

The knoxform is only about 1-1/8" diameter maximum to start with.
That means:
(9/16" maximum radius of knoxform) - (radius of chamber under the hole) - (depth of hole) = chamber wall thickness nearest breech

Hole e molie!!!
That is crazy
They need to learn how to tap a hole.

Hey El Jeffé
How fast can a 9,3 Accrel push 320 grain pills? 320’s @ 2600?
Plenty of 9,3 guns out there to put a reamer into.

no clue--- didn't build one... it's a medium

Lol, yes. The “M” word. I just thought it would be interesting to have so many DGRs in 9,3x62 that could be supersized. Having a 375HH/375 Ruger+ power twins but in 9,3 would be a temptation to some.

Boomie,

There's always room for a little tweek here and there, but you have to admit that the 375 Ruger has carved quite a niche into the heavy medium area. I just picked up an inexpensive Mossberg Patriot in 375 Ruger earlier this year so that I could do some bullet testing and load development in the US. It's a light rifle, yet pleasant to shoot.

El Jeffé has said the same thing about the 416 Ruger lessening the need for a 416 AccRel on more than one occasion. The 416AccRel may be a slightly more efficient design, but it isn't worth all the time and expense, especially when looking for a hunting rifle.

The big plusses for the AccRel line come in the 458, 470 and 500 areas where the commercial offerings are sparse, expensive, or bulky. RIP showed in his meandering thread that the 458 could be loaded to Lott levels safely, if someone had a long magazine.

But Jeffeoso's designs work in standard length rifles, and plain vanilla models like the Ruger Hawkeye.

So if someone were looking for a hunting rifle in 9.3mm with the punch of the 375H&H, I would say get a 375 Ruger. It is a great medium caliber rifle for elk or bear and can handle buffalo.

PS: Excuse this post, I just re-read yours and now see that you were intending to rechamber existing 9.3x62s (with the necessary rail and bolt work), pure and simple.
My comments only apply to someone buying or building a new rifle. Yes, a 9.3x65 Magnum (9.3AccRel) would be a nice rechambering and a significant power increment. (I'd like to see a 338 PRC, but I wouldn't want to hassle with the brass issues when I have an accurate, functioning 338WinMag.)

Getting a potential 300 fps increase for the heavy 320s and a bit more flat shooting with some mods to an existing DGR like the CZ with its factory cross bolts etcetera could be tempting. I would want to pair it with a true big bore but that is some good whallop power and reach out to some distance with lighter bullets for PG.

If I had a 9.3x62 rifle that I liked, with a barrel that I wanted to keep, but that I want to increase power—
I would first look at chambering for a 9.3 B&M with a "458-slow leade throat" so that bullets could be seated long, almost duplicating a potential "9.3AccRel". Brass might be available from Michael McCoury.

If one uses the 1 to 4% velocity to volume increase rule, then a B&M would yield about a 5% velocity increase. A full 9.3 AccRel might yield a 7.5% increase. Would that extra 2.5% velocity be worth the trouble of a full wildcat development? Certainly to some with time and money to invest. To hunters with an inclination to make practical compromises, maybe not so much. I would probably spend the time and money on a new 375 Ruger. Both the African and Guide Gun Ruger Hawkeye models are very attractive, although they now run about $1100+. Still that would be faster and cheaper than a wildcat.

Any thoughts on the 550 Accrel? 2.5” version of the 550 Magnum and the 550 Express? Same idea to turn 7mag Ruger MkII into a pachyderm perforator. 700@ 2,000 for 6K FPE? Should be fun in a 9lb gun. Big fat brother to the 458 Win Mag. I know there is not that much difference between 2.65” Express and the proposed 2.5” Accrel, but it would still be a potent package like the 577 Nitro. If you don’t like it Jeffeosso, I will just call it the 550 Warthog (both short, stout and ugly)