Author Topic: 45/70 conversion? (Read 698 times)

tanoose · « **on:** November 17, 2005, 12:48:49 PM »

I would like to know if one could convert the handi or BC 45/70 to 470 Nitro Express. I dont know if my shoulder would hold up but I would think the action is stronger then the double barrel actions and the 470 only works at 35,000 CUP Do you guys think this could be done

quickdtoo · « **Reply #1 on:** November 17, 2005, 01:01:45 PM »

I think it would be possible only if you kept loads on the light side, full loads are 90-100grs of smokeless powder and 500gr bullets at 2100fps, are a bit too much for the SB2 frame and design. Starting Ruger loads in the 45-70 are about tops for it in a big bore caliber.

tanoose · « **Reply #2 on:** November 23, 2005, 09:21:32 AM »

Quick i see most factory ammo loads the 500 grain bullet to 2150 and have seen handloading data go to 2260, the saami specs for the 470 Nitro is 35,000 now the 45/70 is at 28,000 but we know the handi can handle 44,000 with the 45/70 (maybe even higher) So with the 470 are there concerns other then the 35,000 pressure

quickdtoo · « **Reply #3 on:** November 23, 2005, 10:24:17 AM »

Well, if you look at the 45-70 Ruger load data, you'll see 1800fps as the max for 500gr bullets. The .470 NE is apparently an obsolete or wildcat caliber, it's not listed in any of my manuals, so I dunno. All the online data I found for it lists 80-100grs of powder behind 500gr bullets for 2000-2150fps. That's almost double the powder capacity of the 50gr ruger 500gr 45-70 loads. That tells me that it ain't gonna work in an SB2 frame unless you load squib loads for that big cartridge. :wink:

Edit: Just looked in the Hodgdon Annual, it shows the .470 NE using 100 to 120grs of powder for 500gr bullets, but no pressures.

safetysheriff · « **Reply #4 on:** November 23, 2005, 11:09:43 AM »

tanoose!

i swear, i can finally, after posting on this site all these months, hold my head high! finally we have somebody on this site who recognizes the REAL potential of converting the .45-70. when i think of how many guys have asked about recoil, eye-relief for scopes, comp'ing of barrels, etc.etc. etc. ad nauseaum.....i finally feel relief with someone who is willing to go where no handi-holic has ever gone before! i mean it, tanoose. nobody has ever posted about a real hot-rodding of this rifle.

i am asking you please, no, dagg-nab-it, i'm Begging you, however, to consider the 450 watts magnum in place of that 470 nitro conversion :-) you see, the 450 watts mag' is capable of putting 500 gr's of lead 'downstream' at 2500 fps which makes the .470 nitro at 2150fps' look rather anemic. it's academic, really. the .450 watts is the only answer.....regardless of any reaming, chamber insert, etc.etc.etc. that may be involved.

astly, i beg of you: don't spoil it with safety glasses or goggles, no face-shield, no flack jacket/vest, NO LIFE INSURANCE, and for damn sure, no tying the rifle to a tree to test it. i'm begging you to test it from the prone position, shooting over concrete or asphalt like none of these other guys has ever done, and filing a report with us as soon as you get back from the hospi.................back from the range! :wink:

yep, i'm finally feeling real good about being a part of the 'GBO' team of posters.

thank you, tanoose,

ss' in n.e. ohio

ps: i think you spelled your town wrong! it's not Bellerose! it's spelled Bellicose!

pps: heaven be praised for you, tanoose!

quickdtoo · « **Reply #5 on:** November 23, 2005, 11:16:27 AM »

Hmmm......gettin a little bored again, eh SS??? :wink:

safetysheriff · « **Reply #6 on:** November 23, 2005, 11:24:25 AM »

Quote from: quickdtoo

Hmmm......gettin a little bored again, eh SS??? :wink:

tim'

is it really showing that much?

:eek: :eek: :eek:

i guess that with me taking a depo medrol shot for asthma, and an antibiotic to ward off any pneumonia, i've kinda' lost sight of the important things :-D

maybe a little red wine will help :shock:

take care,

ss'

quickdtoo · « **Reply #7 on:** November 23, 2005, 11:39:10 AM »

Maybe the wine or the drugs but not together, we need you here as part of the GBO Team!! :grin:

Have a Happy, but thankful Thanksgiving!! :wink:

tanoose · « **Reply #8 on:** November 23, 2005, 01:04:08 PM »

Glad i made your day with my post safety. after all that said i guess you dont really know the answer to my question and the question was about pressure not powder capacity unless the same powders were used then double charges would be a factor. the 470 has been a factory load for years now Federal puts it out as does A- Square. My question was about the handi action and if pressure was the only thing to worry about and if not what are the other concerns, as i stated the working pressure for the 470 is 35,000. If anyone knows the answer to my question please post about it if you dont then dont . Thanks Tanoose Bellerose NY

quickdtoo · « **Reply #9 on:** November 23, 2005, 01:42:50 PM »

Tanoose, I haven't found the dimensions of the .470 NE yet, but looking at it compared to a .458 win mag and the .458 Lott(aka .458 Watts), I'd say that at that case head diameter, you're looking at more to consider than just the pressure at 35kcup, that diameter is going to have much more affect on the frame at that pressure than it would on a smaller case head.

http://www.gunsandammomag.com/reloads/458winmag_122804/

Cottonwood · « **Reply #10 on:** November 23, 2005, 02:19:19 PM »

Hey guy's heres what your looking for... BTW Tim great picture of those 3 cartridges.

Cartridge Dementions

.450 Watts and .450 Lott Cartridge

I'm droolin over these cartridges, because they are a true Buff Buster Now with the belted cartridge I would make one off of the .450 Marlin barrel.

quickdtoo · « **Reply #11 on:** November 23, 2005, 02:29:39 PM »

Thanks Jon!! Hmmm, I looked at Steve's Pages twice for the NE cartridge, I must be goin blind!! :oops:

I was gonna link to the .458 page, but since it's way too much for a Handi, didn't wanta get Tanoose all excited about it!!! :-D :-D :-D And I certainly didn't wanta put any wind in Safety Sheriff's sails!!! :grin:

safetysheriff · « **Reply #12 on:** November 23, 2005, 02:53:26 PM »

Quote from: tanoose

Glad i made your day with my post safety. after all that said i guess you dont really know the answer to my question and the question was about pressure not powder capacity

as i stated the working pressure for the 470 is 35,000. If anyone knows the answer to my question please post about it if you dont then dont . Thanks Tanoose Bellerose NY

tanoose'

in all honesty, i was wound up/bored i guess, just like tim observed. i can sincerely say that No insult was really intended. i'd hoped that on a night when so many of us are being snowed-in that we could enjoy it. i say, "i'm sorry" if i offended anybody. i'd like to say more about the effectiveness of the present ammo' and calibers available to us tonight in these Handi's; but i guess that such reasoning is not welcome at this time.

No, i am not at a loss for an answer. if you think about it, the 35,000psi times the area of the 470 nitro cartridge base against the front of the frame (the standing breech, as it's called) is going to give us the thrust against the rifle.

here goes: the .572 diameter section of the case that bears against the frame (because the larger diameter of the beveled rim does not bear against the frame and could flex anyway) is divided by 2 and then squared. that equals .081796. multiply by 'pi' which is 22/7 = .2570731! multiply that times 35,000 psi gives you 8997.5585 lbs of thrust.

consider this, however! the Handi' in .308 Win' has a working pressure of 60,000 psi allowed to it. at .473" 'rim' diameter the case-head thrust should come to approx' 10547.214 lbs! if we reduce the rim to a diameter of .470 we achieve approx' 10,400 lbs of thrust from the case head.

i'd say that your 470 nitro is 'do-able' as my guess. the .067" difference in the diameter of the sidewalls between the .45-70 and the .470 nitro is probably tolerable...... a good gunsmith could better answer that question, but i'm reasonably certain of my guess. i'd do it myself, except i'd have no use for one. i can tell you in all honesty, i'd do it myself if i had 'money to burn'; but i don't at this time.

i hope you can see the reasoning behind my answer.

good luck,

ss'

ps: my reference for diameters of cartridges is Cartridges of the World, 10th Edition, Revised and Expanded, by Barnes and Skinner.

Mac11700 · « **Reply #13 on:** November 23, 2005, 07:25:49 PM »

tanoose...want some advise..? Don't do it...there is a-lot more to this than trying to figure out the case head formulas on pressure...a simple answer is ...no...you really shouldn't do this ...a couple of reasons...

You can't load to 458 Winchester mag velocities..the action won't take it..even to the lowest levels of the 458 data provided..The 470 NE can achieve the same velocity as the 458 can...and uses as much as 2x the powder...Do you honestly think this would be safe????A 10 lb gun and the 500 grain load at 2150 would give you 85.13ft.lbs of recoil...I doubt seriously the action would stay closed for #1...and #2 most likely would stretch...

I seriously advise you talk actually talk to a qualified gunsmith who has experiances working on the Handi..as to this conversion...or bettr yet...find a bolt gun or a Ruger or Encore..if your wanting a single shot...

Mac

tanoose · « **Reply #14 on:** November 24, 2005, 12:20:00 AM »

Thanks for all the replys guys you gave the answers i was looking for . I just wanted to know if it could be done. My 45/70 is doing fine for me and i plan to purchase in January a cz550 in 458 Lott as far as the 470 goes , if i ever hit the lottery i would like one in a fine double rifle. I think if i did find the need for a single shot 470 i would lean toward a ruger #1 action.I guess that if it were do be done with a handi rifle it would have to be with nef getting envolved in making a new heavy duty action stronger wood for stock and forend , but then we wouldn't have a handi rifle anymore. Again thanks again and Safety no insult taken you and everyone else have a great thanksgiving. Later Tanoose