I want a bolt action 450 Marlin. Don't ask me why. I just do and I already have a couple of 45/70s. IIRC the case head size for the 450 Marlin is the same for the WSM size cartridges. So I should be able to take an action for a 300WSM and have it rebarreled for 450 Marlin. Maybe I would need some work on the feedrails and the ramp. Is there anything here I don't know about and need to consider?

I have a barrel already chambered for that cartridge, it is a stainless douglas and has a front sight. It was used for cast bullets and is threaded for a win mod 70. The case head is the same as the magnum as it is based on the magnum case. It should be a simple matter to adjust the feeding if needed at all.

Jim

I made one for a customer using a M98 action. Didn't take to much to get it to feed. Bill

A friend did it on a Yugo I believe. Says it works just fine.

I built one on a 700 short action. Had no feeding problems at all.

Clark built them in the past on a Ruger 77 IIRC.

No big deal looks to me to be a 458x2" plus .1".

Any .458x2 could just be reamed at the belt. You could set the barrel back on a .458 win mag and rechamber.

You can get a factory bolt rifle from Steyr in 450 Marlin if you want to go the readymade route and you like the SBS series.

hey,
i have thought about this very thing for awhile now. i have poured over my books and measured and put a lot of thought on this matter and i dont know of a reasson in the world why this will not work...matter of fact, ive just purchased a take-off barrel in 458wm for this very project. i have a 458wm in a 550 cz and it is a little overpowered for my taste,,,however i plan to set the barrel back into my ruger 77 action and have the headspace adjusted for the thicker band on the 450 so as to be able to chamber it. as for feeding,,,my m-77 feeds the 458 cases just fine even tho it will not completly chamber in the 375r chamber. the 458 cart. feeds well thru the rails and jumps into the chamber without any work on the rails. id like to know how your project is going as you proceed.

seems to me that a hot-rod 450 , in a bolt gun , should be just what the doctor ordered

good luck and good shooting

ted

Ted,
I'm wondering what the standard throat is on the 450 Marlin compared to the 458 WM. As I understand it, the SAAMI specs on the 458WM have a long throat, or freebore, then a long cone before the rifleing.

This means that setting back the 458 take-off barrel will give you a 458 WM throat, unless you set it way back. Maybe ok, maybe not.

I tried feeding 458 WM in my Ruger, which had a 300 WM barrel, and found that it feeds good. Then I tried some 450 Marlin and it didn't feed so good. Until I tried it, my logic told me there would be no problem, but logic didn't make it so in this case.

Incidentally, I have a PacNor stainless #5 barrel chambered in 450 Marlin, and threaded for the Ruger 77 MKII. The barrel is 20" long and has 20" twist rate, which is the standard rate for the 450 Marlin or 45-70. I would sell the barrel.

KB

i luv my 450Marlin bolt gun!! my gun started life as a 300wm savage 110 lh now has a Douglas 1/22 tight neck chamber Qtr rib, banded front swivel and front site all made by my brother and myself. the stock was reworked and with black spatter paint.when i get time i want to make a curly maple stock. at this time the metal is at the shop being blued. the idea as i worked on this was to make a 200yd cast boolit gun the load i found best is 330hp(457122)/55gr AA2230/wlr with a gas check upside down under the boolit. this load shoots at 2100fps and goes under 3" at 200yds. i think this will be a just rite for our mi whitetails Clint

I'm glad you guys started this discussion. I think I was about to make a mistake, another one to add to the list.

I have wanted a bolt rifle in 450 Marlin since the cartridge was introduced, and I spent the money to have one made. I bought a Ruger MKII rifle that was in 350 Rem Mag, with a butchered barrel. I figured since the action was already opened up for the magnum, it would be a no brainer to convert to feed the 450 Marlin.

I sent the barreled action to PacNor and they installed a barrel to it. They only installed the barrel, and did no action work. When I got it back, of course the feeding needed a little help. So, I sent it to my gunsmith, (not a member of this forum, and whose name I won't say) and after a long - long wait I got it back. The modifications he did to the ramp and feed rails to me appeared extensive. The feeding was better, but not slick, and not flawless. It would feed pointed bullets pretty good, but not always the flat nose bullets, and not the same from both sides.

To shorten the story - all I have left of that project is the barrel. I had made up my mind to ream it to 458WM, and install it on a longer Ruger MK II action. But I hesitated since what I really want is a bolt action 450 Marlin. This longer action is the same action that I tried the feeding of the 450 marlin cartridges. I tried just putting them in stacked to the rear of the magazine, staggered, and to the front as though the magazine was blocked off, and the cartridges didn't feed well no matter how I stacked them. This is the same action that feeds the 458 well. The extra cartridge length makes a difference.

Now I'm really interested in your thoughts and experience with this.

What I'm looking for is the perfect action to install that barrel upon. The barrel has plenty of shank length, so it could be re-threaded and rechambered to basically any receiver.

I'll say that I don't like Yugo actions, and I know next to nothing about Savage actions.

It is my opinion right now that this cartridge needs to be in a push feed action to enhance proper feeding, and avoid getting hung up as the rim trys to pop under the extractor at the rather sharp angle of entry caused by that short cartridge, as it comes up from under the feed rails. I can also see how a single stack from a detachable magazine could enhance feeding.

KB

im also glad to see this discission on a bolt 450m.

the reasson i wanted the 458wm barrel in the first place is the long throat. i will want to feed 500 and 530 gr cast bullets and wanted a long throat to acomadate them. the overall length of cart will be longer then factory 450 but now i dont know if they will be long enough to feed well in my ruger long action.

i also tryed the 458wm cart in my action and it feeds very well in all positions. i just figured [ silly me ] that the 450 would feed as well. thanks for the heads up before i got too much $ involved in this project.

the only reasson i wanted a 450 over a 458 is that i dont want nor need the extra power the 458 developes. incidently...i have a current 458wm and download it with very satisfactory results. it runs a 400gr bullet at around 16-1700 fps and will print three into one ragged hole at 100yds. the thing i dont like about my cz550 458wm is the bulk of the action area and its a bit like carriying a 2 by 4 thru the woods. however i like the accuracy and the recoil is very managable. maybe i just need to figure out how to make my cz into a more friendly carry and cosmetic.

id still like to develope a 450m tho and will continue to investigate this as i think it would be perfect combo...bolt action with 450m that has a long enough throat to handle the longer 500's +.

lets keep this one going and hopefully someone who has figured this out will chime in and share the wealth of their knowledge and how to tips.

ted

Ted,
The things you said make good sense to me, and encouraging.

Knowing that you intend to use long heavy bullets, makes sense with the long throat. Also the 14" twist should be right.

Since your loads will be longer than factory loads in 450, that should help with feeding. Since your action has already proven to feed good with the 458, of course that's encouraging. It's really a simple matter of trying the 450, preferably with the dummy loads you intend to use, and see how well it behaves. It should be reasonably easy to see if it's going to take a lot of tweeking or hopefully no modifications.

I understand how you feel about the big CZ. It's a great Safari rifle, with the heaviest cartridges, loaded heavy and full blast, but I got rid of the one I had for the reasons you mentioned. I just didn't enjoy using it or carrying it around.

I'm looking for a short, light and handy carbine with lots of thump, but also suitable for reduced loads.

The encouraging thing is what you said about the accuracy of your 458. I have no problem with the 458 as long as I can be relatively sure that it will give the accuracy I want with loads in the velocity range you mentioned.

Since I intend to use bullets no heavier than 400gr, it's the throat of the 458 that has me concerned. Using the 458 would actually simplify things somewhat, since I know it will feed well in an action I already have, and brass is no problem, and good light loads are extensively tested and well known. Getting the velocity wanted from 900 fps to 2400+ fps is no issue. So to me it's all about slick feeding, and accuracy, and the right combo to make it light & handy.

KB

thanks kb. ive been wondering whether to continue with the 450 project , or to just build a 458wm as is and continue to download it like i already do. i havnt tryed the cast bullets yet but cant imagine they will not perform at least as good as the 400's ive been shooting.

my pursuit began when i realized that my 338wm and the 375ruger are so close to the same balistics. and i always have had a fondness for the 458 caliber but the lever actions and the sharps i have do not lend themselves to a scope. my ol eyes need help anymore so this is the main reasson i started the 458 search for a ...as you stated....light weight, short, easy to carry bolt gun in this caliber that wont tear off my shoulder.

so i have decided to convert my 375r to a 458 and just hadnt decided whether to use the 450m or 458wm chamber. i think that becouse the 458wm cart feed so well ill settle for this and the 458wm ruger take off barrel i already posess.

i like the long throat it already posess's and the thing should be almost a drop in conversion.

also another thing i like about the 458wm is the meassurments for it are within just a whisker of the old 45/90 which i will use for a cast bullet guide for my cz. dont know why the ruger wont perform the same. one ragged hole at 100 when i do my part. i intend to develope a cast load in 500 or 535 gr lead wheelweights for it as i believe this should be the medicine for the moose and bear i hunt here. this and without tearing up too much meat.

thanks guys for helping make up my mind for this project. i still would be interested in what the conversion to 450 marlin will do if any of you guys continue with it. i still think that this would be spiffy in a light short easy to point bolt gun.

ted

KB,

i wonder what the diff is in the throat length between the ruger and the cz. it would be a shame to build this and figure out that i needed to copy the throat length before i have it mounted.

do you know maybe if there is a difference?

ted

IIRC Winchester actually chambered the M-70 short action in .450 Marlin but through the custom shop!

I don't know if this will be of any help at all,but will throw it in just in case...

A friend and I both have had .458 Win Mags built into carbines on Springfield '03 actions using Bill Atkinson barrels. Both fed very well indeed. As to weight, the thing to be careful about was to keep them heavy enough.

I don't know if the Marlin cartridge would feed well through the Springfield actions, but it might. And those actions are still relatively inexpensive, CRF, and all steel. The late Paul Marquart did the fitting, chambering, and action work on ours, and the action mods appear very minor.

I am currently building another "project" .458 exactly the same as the first two. (Paul chambered this one just before he passed on, and it may well be one of the last .45 barrels Bill made in his own shop before he went to work for Ruger....late 1980s)

I built a .458 x 2.2 on a pattern 14 action. Its a 2.2 because I used a 45-70 reamer and then cut the belt relief with a common reamer. It likes the 500-550 bullets. This thing is my first big bore, and the most fun I've had shooting in a long time.

rolltop,

Winchester's Custom Shop did offer it but I don't know if they ever built any. I have the proto-type "THUMPER". It is a fun little rifle.

Headache