We have thanks to MileHighShooter a fun new wildcat project spawned on the great AR forum.

He wanted a "Poor mans 404" seen in This thread and liked this idea of an unimproved 375 H&H case necked to 404. this makes it the 404-375. There was the 424 By Keith but that was an improved case with a shoulder. By necking up the 375 to 404 you eliminate the shoulder. See photoshoped pic below.



As you can see the neck of the 404 is 2 thou larger than the 375 shoulder. so the necking up will take out the shoulder.

The Neck area that will give the bullet tension is .45" or just over a cal length neck.

so taper to 2.4" and 2.85" length.

I think 300 @ 2500, 350@ 2400, 400@ 2300 and 450's @ 2,200 would be a good goal for this case.






Thanks for all the comments and helpful info.

Should be a fun project. Keep us posted!

Yes, should be fun and easy.

I reeeely like the idea of the ability to pull 375 bullets from loaded rounds, expand and reload 404 bullets... this and the ease of forming cases beit necking up 375 brass or forming with Lott brass. That shallow shoulder of the 375 shouldnt give any problems at all. Basicly this turns the inefficient 375 into a more efficient larger bore cart. Another benefit would be the lower recoil compared to the 404 Jeffery for identical performance. This gun would weigh the same as a 404 Jeffery so recoil would be lessened. Would be quite a good hunting rig with recoil similar to the 375.

Assuming the same load of 350 grain bullet and 82 grains of charge in a 12 pound rifle and a 50 fps velocity advantage to the larger bullet the recoil would be 37 vs 39 ft lbs of recoil and identical 14 fps recoil velocity. Kinda neet.

The 375 H+H has a capacity of 97 grains so I fugure the 375-404 will be about 100 grains capacity. The 425 Express has 91 grains capacity so it seems the Express will be good for starting loads for the 375-404.

The 425 Express has loads pushing 400 grains to 2400. A bit too fast IMHO for the Express but this is a good indication that the 404-375 will be fine in duplicating the 404 factory loads

http://www.geocities.com/bw_99835/425_data.htm

I also found this thread helpful in the area of reboring the 375 to 423. It seems fine as long as there is at least .125" wall thickness at the end of the barrel. Reboring a 375 will save money if there are sights to keep.

https://forums.accuratereloading.com/eve/forums/a/tpc/f/...=489104777#489104777

cool
this cartridge sport a real ghost shoulder and should work well with a two set die's.
But the feact that one needs custom reamer and dies hardly makes it poor...

quote:

Originally posted by Bent Fossdal:
cool
this cartridge sport a real ghost shoulder and should work well with a two set die's.
But the feact that one needs custom reamer and dies hardly makes it poor...

There is some lore about ghost shoulder and accuracy...

There is a diferential on the custom stuff but the cheap brass, reloading and cheaper smithing bill will help make that up. Maybe the 375 dies could be opened up to work. Seems the conversion could be less than $600 for a new wildcat. That is impressive. We will see how it pans out. There is also the Catters sense of pride that is pricelesss

PS. Bent... this will be the big brother to the great 425 Fossdal

quote:

Originally posted by boom stick:
PS. Bent... this will be the big brother to the great 425 Fossdal

And by so wery welcome!
It hardly fills a gap...but every cat is a joy and pleasure for the maker!

Not a performance gap.
A belted no shoulder cheap, easy conversion 404 Jeffery duplicator and an advantage over a 375 in bullet weight and size.

Plus I think it will be a great feeder/extractor like the 375 parent case without feeding modification.

It does have some merrits that are worth while imho.

bent - i do see your concerns money wise on the reamer and dies, but thats a one time cost, and anyone who is interested will be more then welcome to the reamer! i am going to speak to some machinists i know as well as my smith to see how hard it would be to convert a 375 die set to the 404-375! I agree RUM brass necked up would be very easy, but look at the vast availability and cheap price of 375 H&H brass, and im sure we will speak to qual cart about proper brass in the future to make international travel easy. What i like is take a suitable action, and rebarrel with no feed work or magazine mods needed. I will be doing just the barrel most likely, as a switch barrel set to my 300 wby M70, so my costs are even lower....just need a barrel, dies and reamer.

Boom - you rule! Without your help this may have never got rolling. I'll give you a holler tomorrow to discuss some more ideas on it. I think this will be a real winner, especially for someone that may have an extra 375 and wants something different. The added ease of emergency pull and stuff (lol) loadings in a foreing land far away from the loading bench makes it very flexible.

Time to email the smith

Thanks MHS!

I do think this is an interesting 375 conversion cat.
Please take pics of all the development of the gun for a future article here in cyberspace or in print.

The 375 dies would need to be opened up before heat treating.

Thought this was interesting since the 404-375 has a "Ghost shoulder". from Wikipedia.

"The Capstick has a ghost shoulder which allows the cartridge to achieve excellent accuracy. Use of a ghost shoulder, rather than a continuous taper on the case wall, helps the cartridge to line up concentrically with the bore axis, contributing to accuracy."

I also would be curious to see the efficiency difference with the same charge as the 375. Use the 375 charge for 300, 350, 400 and 450 grains to see what is the most efficient. I am guessing the 450 grain bullet will have the most energy for the least charge.

This is a recoil calculatuion that I just did but yet to be proven.

Assuming the same load of 350 grain bullet and 82 grains of charge in a 12 pound rifle and a 50 fps velocity advantage to the larger bullet the recoil would be 37 vs 39 ft lbs of recoil and identical 14 fps recoil velocity. Kinda neet.

that recoil doesn't seem too bad at all! of course my donor rifle is quite a bit lighter then that lol maybe I WILL have to just build a new one

Maybe have a heavy profile barrel but 400's dont kick much imho but hey... I love big boomers!

As for that Savage we spoke of, I read some accounts of extractor spring problems in the older 116's

I don't know why I was trying to find an action for a full length cartridge...when I remembered a lot of "standard" actions are long enough anyways lol. I have a feeling another M70 might be in my future...as 7RM M70's seem to be a dime a dozen on the used racks in the 400$ range. Not CRF, but, thats not super important to me. The hunt is on for a good donor action!

Boomie,
I think you finallly designed a good one.. very practical! it will easily outrun the taylor, and should be right there with the 416 rem

quote:

Originally posted by boom stick:
The 375 dies would need to be opened up before heat treating.

Perhaps, but probably not. I cut dies and recut various makes of dies frequently in my lathe, and I don't have any trouble doing so without annealing or using carbide tools. I just use HSS cutting tools, or some of the slightly harder cutting tool stock blanks available and the dies have all cut like butter so far, regardless of make.

Anyway, good on ya Boom. Looks like an inexpensive, useful, toy.

quote:

Originally posted by MileHighShooter:
As for that Savage we spoke of, I read some accounts of extractor spring problems in the older 116's

I don't know why I was trying to find an action for a full length cartridge...when I remembered a lot of "standard" actions are long enough anyways lol. I have a feeling another M70 might be in my future...as 7RM M70's seem to be a dime a dozen on the used racks in the 400$ range. Not CRF, but, thats not super important to me. The hunt is on for a good donor action!

Well the perfect donor will come around...

Have you checked the classifieds here or posted a "Looking for" thread?

quote:

Originally posted by jeffeosso:
Boomie,
I think you finallly designed a good one.. very practical! it will easily outrun the taylor, and should be right there with the 416 rem

Thanks El Jeffe

A compliment from such a discerning experienced wildcatter like yourself is high praise.

This is a great, easy and cheap way to jump in frontal area and keep recoil low.

quote:

Originally posted by Alberta Canuck:

quote:

Originally posted by boom stick:
The 375 dies would need to be opened up before heat treating.

Perhaps, but probably not. I cut dies and recut various makes of dies frequently in my lathe, and I don't have any trouble doing so without annealing or using carbide tools. I just use HSS cutting tools, or some of the slightly harder cutting tool stock blanks available and the dies have all cut like butter so far, regardless of make.

Anyway, good on ya Boom. Looks like an inexpensive, useful, toy.

Hey AC! Thanks for the input. If we can convert 375 dies that would be great in keeping with the "Poor mans 404" concept.

Once the reamer is made and the first one goes boom I think the reamer might get passed around a bit.

Calling all catters...

I dont have any 375 brass or the expander. If you have some old used up lose primer pocket ect 375 brass and have the ability to and the give a dang...could you help out with necking up to 423 and letting us know what the neck diameter is and maybe the grains of water capacity. I am guessing about 100 depending on the brand. I think Winchester has the largest volume.

Thanks!

Boomie,
i'll make you an expander for next week

Coolio!

Now I need some used 375 brass and some 423 booolits.

i got the brass, too

OK... Jeffeosso had the briliant idea that I did not think of in anealing the dies in order to open them up.

So if you have a 375 the expenses are a little do it yourself, reamer that can be passed around, chamber and a rebore.

The naming is a quandary... But whatever it is a cool round!

404-375 Bastardization due to ease of understanding
375/404 English and most correct but laymen will get confused.
423-375 American. I can hear it now..."What is a 423?"
10.75x73 European. Easy to understand but I am American and proud of it damnit!

Being that we are bastardizing two English carts together 404-375 does not seem that bad.

Boom -

Just because I know the various African game rangers from the first 65 years of the last century would have loved this cartridge, and their departments would have loved the cost compared to the .404s many of them DID use,
I vote for either the .404 Game Ranger, or the .423 Game Ranger.


(And if a guy likes puns, he can always call it the Game Ranger Rifle...as in Grr!)

quote:

Originally posted by Alberta Canuck:
Boom -

Just because I know the various African game rangers from the first 65 years of the last century would have loved this cartridge, and their departments would have loved the cost compared to the .404s many of them DID use,
I vote for either the .404 game Ranger, or the .423 Game Ranger.


(And if a guy likes puns, he can always call it the Game Ranger Round...as in Grr!)

Well basic Hornady brass could be bought that just says Hornady on it and if a stamp is made it could have a "Sub title" but just adding a 404- to a rebored 375 to say 404-375 on the barrel is a big deal.

So it could be a 404-375 ???

I thought PH's would love the round and thought of "404-375 PH"

Alter the H+H to to PH wont be too hard.

Not a lot of room on the case to get too creative but an acronym is possible.

404 GRR lol I love it. I still put my vote towards simplicity, which is what this whole idea is about. 404-375 just works, keeps things clean and easy to identify.

Girlfriends xmas gift is gonna run more then planned, so donor action will have to wait til after the new year. I have been searching the classifieds and GB though.

quote:

Originally posted by boom stick:


Not a lot of room on the case to get too creative but an acronym is possible.

True, limited space on cartridge heads. That's why I suggested the .404 GRR...and it's not likely to get confused with anything else when grabbing shells in a hurry.


I know if I make one for myself, that's what I'll stamp on my barrel. I don't really care if the next owner knows what case he has to reform to feed it, just like Chatfield Taylor didn't care whether people knew HIS rifle shot .458 brass necked down (or .338 brass necked up). .416 Taylor worked out just fine for a name.

If it prooves popular, everyone will know what to use anyway, and "Grr" describes the cartridge in action, a potent fighting rifle, adequate for taking on the big 5.

Will still be a fine round whatever we each call it....and a perfect fit for a genuine pre-War M70 action wearing a nice Lyman Alaskan with post (no crosshair) reticule in a G&H sidemount. I had a .375 H&H pre-war with a 20" barrel I wish I had saved. Would have been just perfect for a real "using" gun & cartridge like this. (Mine spent its life in Alaskan bear country hunting camps and was on it's third barrel when I got it.)

Glad to hear there is some interest in other building one!

Boomie you're a genius!!! I have an older Ruger 375 with the heavier barrel. What great gun for a rebore. How about "404 Boomer" for a name?

LJS reboring a rifle like that was one of the big thoughts behind this cartridge! YOU'd be right on the money. Keep your sights, most likely no feed ramp work...just rebore, put a stamp on the barrel and go to town

Let's just keep it at 404-375 for the simplicity but if you want to put a special stamp on your barrel I wont hold it against you.

LJS all you need is .125" thickness left on the barrel so you will be fine it sounds like. It can have the same recoil too if you want.

Let's get a reamer ordered... that will take 3 to 4 months.

quote:

Boomie you're a genius!!!

Can I quote you on that?

LJS yours would be a rebore unlike MileHighShooters that will most likely be a rebarrel.

You doing this would help show how (Fingers crossed) easy it would be.

OK so far we have 4 possible users of the reamer... so in going with the "poor mans 404" does anyone who possibly wants to use the reamer want to chip in? I would chip in a portion.

Expand 375 dies and share the reamer.

I posted this in the original thread but thought I'd post here also.

I like the cartridge idea and I think it would have been a better cartridge for H&H than their .400 H&H with its .411 caliber bullet. Also, had H&H produced this round I believe they'd have used the UK norm of identifying the parent case first followed by the caliber, the inverse of the USA norm that you've used - in naming this cartridge. I also doubt that H&H would have given Jeffery, their competition, any credit in this cartridge by using the .404 designation in its nomenclature.

So I perceive that they'd have named the cartridge one, or all, of the following:
.375/.423 H&H Magnum, or
.423 H&H Magnum, or
.423 Belted Rimless Nitro Express (.423 BRNE)

Thanks Capoward!

Back in the day I think H&H would have named it the 423 Belted Rimless Nitro Express but would have shortened it to 423 H&H

I think most conversions will be from reboring existing 375's to keep the sights so the 404-375 H&H stamp on the barrel is an easy conversion.

Being that H&H is still in business they might take issue at naming anything H&H except in variance of their 375.

Calibers do not all the time equate actual diameter and some equate the 404 as a caliber but the actual diameter being .423"

I agree Boom, it would have been 423 BRNE shortened to 423 H&H and adding the .404 in front of the .375 is definitely the easiest way to handle the rebore job, perhaps that's why we use the caliber then parent case designation for many of our non-factory cartridges vis-a-vis the Brits' parent case then caliber designation.

The 40-bores have been interesting in the USA running from just shy of .400 groove to just over .438 groove but all identified as a 40-caliber.

I like the idea of a mutual chip in for the reamer! 4 or 5 people and we're not talking a very big commitment. Plus, it would really make it an Accurate Reloading born and bred cartridge!

Who does everyone here prefer for reamers? 4-D, PGT, someone else?

OK, I'm real green in the wildcat game so I need a little hand holding here .... Heck, my 338-06AI is still a work in progress since I've been recovering from having my Grand Marquis totaled (rear ended by someone in a hurry).

I do not have a 375 H&H donor rifle so, should I be looking for a 7mm/300/etc. Magnum or do I need to find a specific 375H&H or 458Win Mag to avoid feeding issues? What is the cost difference between a rebore and rebarrel (assuming no barrel mounted sights)?

What sort of costs am I looking at to get a complete rifle? How much am I looking at to get what I need to reload (I already have an RCBS Rockchucker, scales, powder measure, etc.). I need to figure out how much I need to save to build one of these rifles.

I have toyed with getting a CZ Safari model in 458 Lott or 416 Rigby and briefly considered a 470 Capstick. Harsh recoil has kept me from buying one of these. It looks like this wildcat will be a good trade-off in terms of recoil and hunting ability.

I won't ever take a game animal in Africa but, an Elk is very likely in a year or two when/if my back heals completely (or at least enough to tolerate heavy recoil). I know this rifle will be overkill for most North American game but, it should be good for American Buffalo, Elk, Moose, and large Bears. With good shot placement, meat damage should be minimized and the kill should be very humane. It also should be a fun "range day" rifle if recoil isn't too severe for experienced riflemen/women.

What is the cost of the reamer? If we have 5 or 6 guys splitting the cost, am I looking at a $50 or $100 contribution to the reamer kitty?