Foobie
You are correct but you knew that already
45-70 SAAMI spec COAL 2.55"
Tip to crimp nominal length is .45"
Increase case length to 2.4"
Increase useable case capacity by .3" or roughly 10 grains.
If using 45-70 bullets under 400 grains I see this as a big gain.
At nominal rifle presure I see 300 grain bullets at 2,500 and 400 at 2,100.

Thinking along these lines I've been tossing around the idea of the belted 1.8" case. COAL with 45-70 bullets would be 2.25". Roughly the same capacity as the 30-06 think of it as a micro action 444. What platform? WSSM barrel swap conversions. Thinking it could achieve mild 45-70 performance of 300@ 1,800 and 400@ 1,500. Michaels 458 B&M super shorts would be superior but this would be interesting.

Boomie: Concur with the long throat adding life to this cartridge. Also, the increase from 42k to 60k pressure would enhance it.

FOOBAR: Yes, realize max length of 2.80-2.85. I really do understand about the NET volume being the key. They only reason I was even thinking about a longer case was for more case to hold the bullet. I will not worry about that, I guess.

I think using the RUM case, I can get a reasonable increase in volume for better velocity. That and trying for the maximum length in the magazine. Since I've never thought of using much more than the 450gr CEB bullets, both solids and the lighter Non-Cons, I should be OK. The rifle will be used for bears in Alaska and cape buffalo in Africa...along with some of the larger plains game. No elephant on the menu.

Maximum magazine length, safe but higher pressures, and limiting bullet weight should do the trick. Oh, and since I'm now semi-retired, counting shekels means something to me too!
Max

I think having a goal velocity for the project is good. I see 300 at 2500 and 400 at 2,100 being a good goal and still having lots of 45-70 bullets within their functional impact velocity envelope. Since we are talking about low BC bullets the impact velocity I see as 300's impacting at about 2,300 and 400's impacting at 1,900-2,000 fps. Over that and you have over expansion. Now those 325 grain solids at 2,200 would be my choice for bear.
With the longer throat there are just a few options for 400 grain rifle bullets that's why 45-70 bullets I see being the main diet for this monster.

I never know the level of understanding of the many people, whenever I'm waxing...ah, "profane" in some eyes. Hahahahah

It will be fairly easy to come up with a solid brass, well shaped bullet weighing ~300-350 about 1" long...basically swapping weight for velocity, as Boomie suggests. I'm guessing they are already available, and Michael's got his thing going on as you know.

I did some limited "testing" of 6 truncated nose design with different groove configurations. About all I can say is they went boom, didn't blow me or my NEF BC up, were accruate enough to hit the middle of a 30" lodgepole pine log at 25 yds, punched right through it and sailed off into the woods behind. They weren't hard to make, but time consuming. I didn't go any farther...some other project got in the way and I never came back.

I talked to a local CNC shop a couple of years ago, for the cost of an hours worth of machine time and doing the code...$75.00 machine time and the same for coding time, plus materials. He had 4 machines, 1 running and he was by himself. Cost boiled down to just over $1.00 apiece for ~250...a very short machine run...but online offerings cost more per unit but I didn't need more than 100 so....

I was back at his shop looking for a pin gauge, and he had 3 machinists and 2 girls working that day, product stacked all over the place waiting packaging and all the machines were running 2 shifts. What a difference 2 years can make...I asked him about making bullets for me...he said he would like to but he didn't have time to hardly sleep and no machine time for the foreseeable future...plus the problem of permits/licence. Glad he is surviving...this area is going downhill like a snowball headed for He**.

Your 45 cal 1.8" belted mag would be like a 458 A/450 M "short" and could be used like a 38/357 or 44 S/44 Mag...Cool.

I'm done for the year as far as projects are concerned(read "busted, broke POS), but I just might do some case trimming and play with that concept...that would give me ANOTHER case that would work in my NEF...pretty close to the 45-60 Win...

See how getting locked into a rut limits your options!!!! I pretty much always go for the max...turn my nose up as going the other way... ... never even thought about going short on the 45-70 or 458/450 M case... did think about using a WSSM case.

I think someone with his 458 B&M Super Short beat me to it. ... but THAT conversion/switch barrel, or a 375/416 cal is still rolling around in the little gray cells...just a neck down and the same....STOP IT.

See how you are Boomie...doesn't take much to run me off chasing "wildcats".

Luck

FOOBAR:
The problem is, when we get our age, we get sort of set in our ways. It takes a mere youngster like Boomie to get off our duffs and thinking! All that learning must not go to waste (or is that waist?).

THAT'S fore, four, for, phoar, f-f-f??? certain...hahahahahah.

I just couldn't let it go...I HAD to fiddle with the 1.8" case, just in case something good popped up.

FWIW...24" bbl SMLE conversion

458 WM trimmed to 1.8", case volume 62 gr H2O...45-70 trimmed to 1.8", case volume 67 gr H2O. Started with the 458 "Shortstuff"...RL7 powder - 40 gr, Sierra 300 gr seated to cann - 2.25" COAL - 1600 fs...increased 2 gr each round to 48 gr - 2054fs...primers still had rounded edges, EZY extract.

Cases trimmed to 1.802" actual, shortened to 1.795" to 1.797" each firing...and lengthened back to 1.804-5" at each resizing then trimmed...

Base new case and sized 0.5085" - fired size 0.5105" first firing, increased ~0.0003" per firing to ~0.5121" last firing...belt size remained at ~0.5288" throughout...only fired one round per powder increase.

I ran the 45-55? and 458 x 1.8" through Load from a Disk for informational purposes ONLY...I haven't trusted LD's pressure/velocitiy numbers for a VERY long time...QL need looking at with a cocked head also...but in some cases it seems to be much closer.

LD listed ~250fs higher velocity at 55KCUP with 48 gr RL-7 than what my Oehler 33 indicated. My load at 48gr RL-7 at 2054 fs sure the heck wasn't anywhere near 55KCUP...I'm guessing it was somewhere in the 40-42KCUP range.

I also ran it through a Powley online calculator and Winload, which came up with 3031 and 4227 powders...3031 would work as it's just slightly slower than RL-7, 4227 is faster and might work. 48 gr RL-7 is right at 100% density. H and IMR 4198, AA 2015 and 5744, N130 were all useful powders...RL-10 might work in the 45-70 x 1.8"

I have enough 300 gr Sierras to run the 45-70 x 1.8" maybe tomorrow in the NEF BC 30" bbl...might give a nice comparison...5 gr more capacity should move the powder selection around a bit...

In this case there IS an additional 5 gr more volume because the internal shape of the 45-70 case is different and larger...a 5 gr volume kick AND 6 more inches...THAT'S what I'm talking about...hahahahah

I hit OVER 2600 fs with that same bullet in a 45-70 case with H4198 when I first started reloading the BC...that sure stirrup up the troops...DIRE warnings abounded and I could hear a rope party approaching in the middle of the night - I swear - but turned out to be just some stray cattle trimming my yard hay...and I used a load right out of the 2006 Hodgdons reloading manual for Marlin Leverguns, exactly as printed...same load is in the Hodgdons #27 manual...60 gr H4198, Sierra 300 gr HP, 24" bbl, 2424 fs, 40KCUP.

I plan to try that H4189 load starting at about 50 gr to try to get some kind of pressure guess/comparison in the SMLE as I can fire both 45-70 and 458 cases in it...I MADE it that way...for a purpose and for kicks... Hahahahaha

Luck

Wow!
300@ 2,000+ in a micro bolt action is sweet!
Seems this 458 belted Super Sort is getting modern 45-70 performance. Thanks for testing Foobie!
Case capacity was a few grains off my estimate but at 60K psi this is one potent efficient bastard. Looks like the same capacity as the 458 SOCOM but the SOCOM is shorter and lower pressure for AR15 guns. Seems like a cheap micro bolt action 45-70 duplicate.

Ry-ton...Gives new meaning to the term "wildcat" doesn't it.

The weights were slightly less than what LD case design program came up with by about 1 gr or so, and I could have been off a bit with the meniscus...water is HEAVY and a grain of weight ain't so very much. Doesn't really matter, this isn't life or death brain surgery...and even NASA gets to fiddle the trajectories on all the flights.

Recoil wasn't much either, at least to me firing offhand...more of a firm push rather than a slap...and a heck of a lot less than say a 338 WM, 250 gr bullet at 2800. I was whacking the pinecones behind the chono, right and left and causing mighty dirt eruptions...hahahahahah

A few more bits...

The 458 case topped(~100%) out at 48gr, light compression with RL-7, the 45-70 x 1.8" topped out at 54 gr, but heavily compressed...top loads went 2196 fs with H4198 and 2255 fs with RL-7...velocity in the NEF BC 30" bbl went 2196 fs and 2155 fs in the 22" SMLE with the same 45-1.8" load and same case.

This is telling me that the burn rates for those powders have an optimum barrel length somewhere around 20-24"...anyone with QL can work out that data and maybe post it...all the needed information is contained in these last few posts.

Also shoots all that "XX fs more per inch of barrel hoohaa that keeps getting bandied about, but I can't seem to convince anyone and it turns into another "I can't believe this BS..." endless argument. This "increase" amounted to about 8fs MAYBE...could just be nothing more than the velocity spread deviation playing with me.

Might gain a bit more velo going to a slightly faster powder, or happen to hit just the right conditions...2300 to 2400 fs is probably attainable with the right powder, barrel, chamber, throat, etc. I don't have access to Norma 200, but I can cadge some AA1680 next time I'm in town.

The SMLE has a 458 WM chamber and the NEF BC has a 45-120 chamber PLUS a longer throat, both of which will lower the pressures and velos, considerably in the BC. Lots of things going on here so NO GENERALITIES can be generated from this small amount of data...unless it is "Generally speaking...EVERYTHING gets taken out of context and mucked about".

Getting a fat lady(or gentleman) to sing sometimes requires a but of coddling and cajoling.

Luck

300 @ 2,200+ is nothing to sneeze at
Over 3,000 FPE
What a cool cat!
I'm quite curious about what the 1.8" case could do with 400 grains. This case is obviously more well suited for 300 grainers though. Could you post pics of the dummies?
Thanks!

Sure....doesn't look like much more than a slightly short cased 45-70/belted cartridge tho'. Didn't use dummies...just trimmed the cases and started loading, but these are the fired cases with bullets stuck in them to the 2.25" length...the 430



430 gr TS on left side. To keep the same NET case volume as the Sie 300 at 2.25" it needs to be seated to about ~2.58"...Sierra 300 HP is 0.775" long and the 430 TS 1.100". Position of the cann impacts case volume AND length.

LD gives ~1800fs??? with the 430 TS...plenty of whack for deer sized game within 150 yds or so.

I would also probably go with a tempered hard cast bullet rather than the jacketed and something in the 350-375gr range and try to find an optimum bullet weight/case capacity/COAL zone...might gain a bit more case volume to boot.

TOTAL PITA to get the dies set up and I had the seater stem screwed down as far as it would go to hit 2.25". Use specific case sizer for each type but used the 45-70 dies to seat and a Lee factory crimper. I probably would have faired better if I had a set of 450 M dies but the 458 WM set works for all except the crimp and the Lee takes care of that.

My interest in this case has been satiated, and it doesn't fit my milieu, plus if I want less performance than I get in my other 45 cals, all I have to do is download a bit, and I'm not know for doing that. No getting crazy with the pressures...at either end. Hahahahahah

Still an interesting proposition for something in a SA, but I would step up to the RCM, Ruger or WSM case and get away from that HUGE rim and even the belt. Seems more appropriate in todays "new" world.

I still have a 416 cal 2.65" max OAL cartridge for another swap barrel on my Marlin 336...designed around the Speer 350gr Mag Tip...little brother to my 416 Talor, but using either the RCM or Ruger case, the WSM is TOO big in my estimation for the Marlin without having to do a BUNCH of mucking around with the receiver and barrel threads...

It combines the handyness of a levergun, the BC of that bullet and higher velocity. Perfect for that long woods shot when it comes along.

Luck

Thanks Foobar!
The 1.8" case is for 45-70 bullets and 2.25" COAL in the WSSM rifle or AR15. With flat nose rifle bullets cycle in a 450 Marlin lever gun at 2.6" COAL or less.

OK guys, since the rifle should be here soon, I need to pick up brass and dies. Will be getting RCBS dies, a Lee factory crimp die in 45-70/.450 Marlin, and Hornady brass (as if I had any choice). What do you recommend for bullets and powder in the .450 Marlin? Load data? I'm going to do some testing before the rechamber to .458 WSM.

I only have a 45-70 and not a 450 Marlin. I'm sure you can find a few sources for good loads.

Do an online search for 45-70, 450 M and 458 American/458 x 2"...the beginning loads for all cartridges will work across the board as the case volumes are within 10% of each other.

There is literally millions of pages of online data and EVERY reloading book I ever read has data for the 45-70...Hodgdon online reloading data is a good place to start.

Time to do your own homework.

Luck

Ooooh, homework. The word my students hate. I've done research and have loads for both the .45-70 and the .450 Marlin from various sources. Just thought you might have several pet loads from your lengthened COL magazine.
Max

I can relate to the HW thing...but soon found out it was MUCH easier to get an A by just doing it and a bit more, than it was to get a C and try out all the shop worn BS the Profs heard a thousand times already...one Prof even had a small fish tank full of numbered slips...when you need an excuse you just reached in and grabbed one...that was your excuse, entered into the grade book. He was cool.

He did give you many ways to half way reclaim your embarrasment doing grunt work in the lab, cleaning equipment the janitors wouldn't touch, give a class lecture(full credit if you could hold their attention for half the class period), setting up experiments and being "substitute teacher for an hour" and various other undignified activities depending on the level of your disgrace.

Guess he figured you might learn SOMETHING doing those onerous chores and it was worth some credit anyway.

Best way to get involved with wildcatting if you go to the WSM is to spend the buck and a half for QL...at least it will show you many of the nuances of reloading a cartridge not available...SAFELY...I don't trust net data, or anyone much for that matter and I quit giving out anything but published data from established, trusted sources a long time ago, but I slip now and then.

No way to know how the data is being used or WHO is using it, or if they have enough brain power not to hurt themselves. REF: Marlin Cowboy blow up in Leverguns.

Luck

FOOBAR,
I hear you, that is why I own an Oehler Ballistics Lab. Worked in small arms R&D and training for the Air Force for 5-1/2 years. Just spent the cash for the QL.

If you been there, done that and have that equipment, you should be GIVING answers, instead of ASKING them...that's like hiding in the shadows and shining people on...not cricket, Ol' Boy.

Luck

Never meant to shine anyone on. I try to give answers when I have them, but am not an ego freak who needs to spout off on everything. I try to be a quiet person. The reason I ask questions is to learn. I've learned a lot for this project from you and Boomie.

Have received my Browning BLR Take-down in .450 Marlin! Bought bullets, brass, dies, and powder. Awaiting QR Leupold bases and rings, and a 1-4x VX-R scope. Will be able to start testing in two days. First will be as it is, next will require the gunsmith to mill the magazine spacer for longer OAL.

Got the scope mounted and bullets loaded. Friday will try to see how this thing shoots with the bullets seated out in newly modified magazine. I'm hoping the Lee Factory Crimping die does what it is supposed to.

Did load the .450 Marlin case with 52gr of AR2200 powder (bought 8 lbs surplus for my .223s) and the 325gr Hornady LeverRevolution bullet to zero the iron sights. Cloverleaf group at 50yds and no pressure signs. Cartridges were singly loaded and not worked through the standard magazine. This load is with the bullet LOADED TO AN OAL OF 2.85" for anyone thinking of using it. I would not use it at the 2.55" OAL, or in any rifle but a Browning BLR.

Isn't this basically a 450 Alaskan minus the rim?

quote:

Originally posted by Idaho Sharpshooter:
Isn't this basically a 450 Alaskan minus the rim?

and that would be the basis of a lawsuit ...

HEM claims they did exactly that, derimmed the 450 alaskan, long before jamison "invented" the WSM.. sorry, lamison mags...

Nope, no lawsuit. All I'm doing is loading the .450 Marlin case to a longer OAL. Have increased the throat and modified a BLR magazine to allow it to feed without a hitch. Also, the Browning BLR is currently chambered in cartridges well over 60,000psi. All I'm doing is attempting to use the OAL and increased pressure capabilities to produce power in my rifle. Still fires factory .450 Marlin cartridges.

Oh, later add-on: Depending on how the OAL lengthening works, may or may not rechamber to a .458WSM, lengthened neck, and using the longer throat. Recoil in the 7lb rifle is going to be the limiting factor...and my left shoulder.