The Accurate Reloading Forums
404-375 Now with pics!
02 April 2010, 04:50
boom stick404-375 Now with pics!
Thanks Oscar.
Made some great friends here in 5 years.
Hopefully God will not subtract from my life spent on AR. He might take off the time spent in the political forum though
Was thinking 404-375 might be enough but you should never underestimate the stupidity of the TSA I guess. Hope that using HH will not get us in trouble with Holland and Holland
Could stand for another HH acronym. Maybe I need to make a DBA with the initials H&H

What say the rest?
04 April 2010, 04:18
capowardquote:
Originally posted by boom stick:
Hope that using HH will not get us in trouble with Holland and Holland
I doubt there'll be issues with H&H regarding the 404-375 H&H Magnum nomenclature as US wildcatters have been using that type naming convention for close to 100 years now.
Jim
"Life's hard; it's harder if you're stupid"
John Wayne 09 April 2010, 03:48
oscarHello Gentlemen,
I put in an order for a box of Hornady 400 gr. solids.It may be a week or two before they are in stock though.The same for new cylindrical brass.
I have on hand Win. & Rem .375 cases I will use to neck up and the cylindrical to neck down. This should give some reasonable averages for the outside neck diameter.
I have been using a turned brass tapering rod for expansion measured at .423", but I will be more comfortable using a standard bullet with a long full shank for the final measurements.
I will give a report as soon as the packages arrive. Oscar.
09 April 2010, 08:40
boom stickAs my dad says... Measure twice, cut once.
30 April 2010, 10:15
dfcjrLakelander
Pleasesend me your address re 424 OKH
03 May 2010, 02:56
foxhoundHey BoomS
Thanks for the great welcome! Let me know when it gets to the point where money is needed to order. Then, hopefully, you guys can recommend someone to do the work on my .375 that is just sitting and waiting! No one around my way that I would trust.
thanks
Rick
DRSS
03 May 2010, 07:52
boom stickGlad you are aboard

Oscar, any update on the reamer specs?
Thanks!
quote:
Originally posted by foxhound:
Hey BoomS
Thanks for the great welcome! Let me know when it gets to the point where money is needed to order. Then, hopefully, you guys can recommend someone to do the work on my .375 that is just sitting and waiting! No one around my way that I would trust.
thanks
Rick
09 May 2010, 15:07
boom stickHi Oscar... Any news on the reamer? I know you are busy. Would like to see the reamer ordered soon for everyone involved. If you need money to order let's send you some.

24 June 2010, 06:06
foxhoundGuys
Just to let you know up front, I have to bail on my request. I decided to go a more expensive route, and am waiting on delivery of a 450/400 double, and have sold the gun I was going to redo with this neat wildcat. Sorry I'm going to miss the fun. Thanks for allowing me the chance.
Rick
DRSS
I made a dummy sample yesterday using a fired SPEER case necked up to .423" without any other change.
This results into a case with a ghost shoulder.Resulting neck diam is .446" while parent shoulder measures .451" .
IMHO the 375 H&H can be loaded with .429" without changing the taper of the case.
Cool round ,anyway
24 June 2010, 15:27
boom stickPivi. The fired case would be at lest 5 thou larger than a sized case so no ghost shoulder from necked up unfired or sized cases.
The reamer and dies will be taper to neck without a shoulder.
Glad you like.
Yeah,I had no time to look at the 375 H&H dimensional data. The reported shoulder diam is .448" so this will eliminate the shoulder.Will try with a resized or new case when I will have some
06 July 2010, 07:57
MileHighShooterBit of an absence, sorry! Summer is hell in pest control lol
Boomy, my M70 will be going in for 375 H&H treatment soon. Cheaper to have this done first then it is for me to find a good 375 stock. Had my friend at Gander Mountain do a company wide search for a bolt action 375 and came up empty handed several times. 80$ for a barrel, I'm trying to get the thread/chamber/install done rather cheap, and I'm likely ordering the laminate stock next week.
Unfortunately I won't be able to jump on the band wagon just yet, as with my recent move I am no longer in a position to reload, plus the guys whose land I used to shoot has been sold so I'm up the creek without a paddle as far as ranges. Everything around here is expensive and super strict on rules....no chronos, no field position, no exceptions

So it'll be a 375 for at least a year or so until I'm in a position to reload and develop again.
Still, good to know things have been progressing! Oscar and Boomy you guys RULE!
If you think every possible niche has been filled already, thank a wildcatter!
Here's my sample.
As Boom said, dies will eliminate any evidence of the parent shoulder ( I used a fired case)
Anyway , Boom's wildcat should be almost identical to a very scarce british cartridge designed by BSA and called .400 or .40 BSA .It had a straight case made by necking up the 375 H&H mag case.Actual bullet diam should had been .412" so the two cartridges actually differ for their bullet diam.
There was also a belted pistol cartridge also called .40 BSA, in two words a belted .40 S&W very similar to the wildcat .40 G&A belted magnum
07 July 2010, 01:35
boom stickThanks for the pic Pivi
Yes I mentioned the 40 BSA in the thread earlier. That is one rare collectors item.
Something I have been getting a finer appreciation for lately is reliable feeding. It would be easy to get this round to feed reliably in a 375 rebore/rebarrel conversion.
Once you neck it up and have the case in hand you just think to yourself "hmmm... I like this"
Been thinking I might need a matching set of 300 HH, 375 HH with a 404-375

10 July 2010, 03:49
MileHighShooterA matching 300, 375 and 404 set? Sounds like a trio ready for the world right there boom stick. I like it! In barrel length order to increasing bullet diameter, 26", 24", 22"

If you think every possible niche has been filled already, thank a wildcatter!
13 July 2010, 05:51
boom stickHeck a 6.5-300HH, 300HH, 375HH and 404-375HH on a savage with ease of barrel swap would be interesting and the same taper to feed all carts well.
06 October 2010, 09:18
dfcjrIs this idea dead? I thought it was a great idea.
07 October 2010, 06:30
boom stickHell no!

A good idea never dies.
Some start up guns being done but have not heard from Oscar lately. Probably just need to order the reamer myself.
31 October 2010, 17:01
Rae59quote:
Originally posted by dfcjr:
Is this idea dead? I thought it was a great idea.
Boomy, I sent you a PM asking the same thing. Just wondering if you ever got the PM?
(I still havn't mastered navigating around here at the forum - not ambitious enough, I guess)
"The right to bear arms" insures your right to freedom, free speech, religion, your choice of doctors, etc. ....etc. ....etc....
-----------------------------------one trillion seconds = 31,709 years-------------------
01 November 2010, 21:39
boom stickHmmmm never got the PM Rae59
I'll pm you
12 December 2010, 02:09
dfcjrHas anyone made up a rifle in this chambering? I am anxious to hear about any progress. Hope this good idea doesn't die before birth.
12 December 2010, 17:36
metricWhy don't you use the perfectly good 404???
If you've got an action long enough for the 375H&H, it will be a nice 404 Jeffery

m
18 January 2011, 08:10
MileHighShooterquote:
Originally posted by metric:
Why don't you use the perfectly good 404???
If you've got an action long enough for the 375H&H, it will be a nice 404 Jeffery

m
You obviously didn't read the entire thread! That question was answered a dozen times at least.
Short version - just because its long enough for the 404 doesn't mean its WIDE enough. All actions available in the USA, except old Model 70 300RUM's, will take extra work in order to house the 404 properly and feed it. This all adds up to extra money, and it takes a good experienced smith to do this, which costs even MORE money.
This is all about a quick, simple conversion with readily available parts and tools. In the 3 years or so we have been planning this, we all have many, many times, looked into the pricing of just either buying a 404 Jeff, or building one. Our plan ALWAYS comes in between 1-3,000 USD cheaper.
If you think every possible niche has been filled already, thank a wildcatter!
18 January 2011, 08:12
MileHighShooterquote:
Originally posted by dfcjr:
Has anyone made up a rifle in this chambering? I am anxious to hear about any progress. Hope this good idea doesn't die before birth.
It ain't dead! 9 pages of thread here on this one, someone WILL build this.
By the way my 375 barrel ships next week

If you think every possible niche has been filled already, thank a wildcatter!
17 March 2011, 19:45
Cross LBOOMY,
the 400 H&H thread reminded me of this one. Any progress ? still thinl it sounds like a fun idea.
SSR
Nothing so sad as the demise of a great idea!
10 July 2011, 03:18
boom stickHi
Thanks for thinking it is a great idea. I and others think it is pretty good. No demise. Anyone can make it. For me to make one I'd have to start from scratch since I have no 375 H&H to start with the cost would be about $1,500. Life as it is other things have taken financial priority. This will get made sooner or later. A good idea never dies. There are a handful of people who want to make one but I understand going first can be daunting. I guess an easy start is to order the reamers so a standard is set. If a few people want to go in on the cost of the reamer set I'll be happy. Six guys say $50 a piece and use of the reamers.
MHS is correct. Width of action is a key reason to go this route.
10 July 2011, 03:20
boom stickDfcjr, love the Kenai peninsula. Was there a couple years ago and had an amazing time. Whereabouts are you there? Homer?
10 July 2011, 07:41
Cross LBoomy
I have a thing for Pre-64 m70s and this idea crossed a thread i saw about rebores. Can you think of any reason a Pre-64 in 375 could not just be rebored to the 404-375? Shouldnt need any feed work and you get at least 4 down.
SSR
10 July 2011, 08:26
boom stickAn existing 375 HH rebore should have minimal feeding issues if at all. Posted earlier on the thread it fed dummies without issue. Thats a major inherent design value. Load some dummies and see how your rifle feeds them. Granted they won't fully chamber unless you rebore and rechamber.
25 July 2011, 15:35
kiwiwildcatCan you neck down the .458 Lott case to 404-375?
Well done guys on a well thought out wildcat. While this isn't my own personal cup of tea, as I am going to be building a .404 Jeffery, I can certainly see the merrits of what you are achieving which is throwing .423 calibre projectiles to duplicate the .404 Jeffery, but from a case that requires way less action work than the original .404.
She was only the Fish Mongers daughter. But she lay on the slab and said 'fillet'
30 July 2011, 11:30
boom stickThe Lott is 2.8". I was thinking 2.85" the same length as the 375 HH. It won't hurt to use Lott brass and load to the same length. Forming brass with the dies should be easy. Simplicity and cost effectiveness is a great thing. The great 404 was 400 @ 2,200 so that should not be a problem getting that velocity.
Yes there should be no or minimal work to get it to feed. Rebore a 375 HH and you have a moderate pressure 404 duplicate in performance at half the cost.
14 August 2011, 20:33
DArcy_Echols_CoHas anyone actually chambered and shot one of these 404/375 H&H's yet ?
15 August 2011, 00:51
boom stickHello DArcy Echols.
None has gone boom yet but I think I just need to order the reamer on my own and after that maybe it will rock the fence and get some made. I'll order a rough and finish reamer so we can get dies made. I have the reamer and dies for my other project the 500 kill All but maybe this one should come first.
16 August 2011, 21:46
Kabluewyquote:
Originally posted by MileHighShooter:
quote:
Originally posted by metric:
Why don't you use the perfectly good 404???
If you've got an action long enough for the 375H&H, it will be a nice 404 Jeffery

m
You obviously didn't read the entire thread! That question was answered a dozen times at least.
Short version - just because its long enough for the 404 doesn't mean its WIDE enough. All actions available in the USA, except old Model 70 300RUM's, will take extra work in order to house the 404 properly and feed it. This all adds up to extra money, and it takes a good experienced smith to do this, which costs even MORE money.
This is all about a quick, simple conversion with readily available parts and tools. In the 3 years or so we have been planning this, we all have many, many times, looked into the pricing of just either buying a 404 Jeff, or building one. Our plan ALWAYS comes in between 1-3,000 USD cheaper.
I really agree with MHS on this great idea for a wildcat.
This is the kind of thing that makes me relate to wildcats better. For examples, a few years ago, I decided that I wanted a 8x68S and a 9.3x64, and started accumulating the parts to have them built. At that time dies and brass were not a big problem, but that has since changed, which thankfully now isn't an issue for me, since I went with wildcat equivilents.
So, instead of forcing the issues of building the metrics, and the associated gunsmith costs with action and magazine modifications, I went with the 323 Hollis and the 9.3x338, which basically clone the ballistics of the 8x68S and the 9.3x64. The standard actions I have were factory rifles in 7mm Rem Mag and 300 Win Mag, so the followers, magazine width and bolt faces are correct with no mods for the wildcats. To me that's a big factor and relief. Dies, reamers and brass for the wildcats were not a big problem nor great expense since both Redding and PTG had the chamber drawings and specs and tooling already on hand, and perhaps very importantly the two companies reconciled in the specification of the chambering and the dies for both cartridges. That impressed me significantly that I was on the right track, and it certainly saved a bunch of time money and perhaps grief over mismatched chamber/dies.
This 404-375 is basically the same principal, and is an excellent idea, if one wants to shoot a .423 bullet.
However, I'll ask the questions: What is gained over the 416 Remington? What is gained over the 458 necked down to .423? After all the 416 Rem is a factory cartridge, and not very popular, and the 458 brass works in more readily available actions.
Also, I recall that H&H came out with a 400 H&H (.411) a few years ago, which has already faded into obscurity.
PacNor has the reamer. Look under .411
http://www.pac-nor.com/standard/KB
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16 August 2011, 23:40
boom stickThe .423" bullet is ideal for eliminating the shoulder of the 375 HH not that a lot is gained over the 416.
The lack of feeding Issues with conversion. Of the existing 375 rifles is part of the beauty not to mention keeping the slick feeding properties of the taper so thats an advantage over a shouldered case. Keeping slick reliable feeding over eeking out another 50 fps and not having to mess with a shoulder. Shoot 404 bullets at half the cost of a factory 404 is a possible cost advantage not to mention cheap brass.
17 August 2011, 00:46
KabluewyI would surely enjoy having and shooting one of these 404-375s built on a CZ 550 Safari action.
That would just have to be fun.

KB
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20 December 2011, 23:23
BwanaColeBoom stick,please edjamacate me on something here as I'm just getting started understanding all this wildcat business. If I understand it right, the bullet your going to use is slightly larger in diameter than the stock .375. So what has to be done to the bore of the barrel to make it fit?? Does it get honed out, rebored, replaced??
I like the sound of this, has there been any progress??
H. Cole Stage III, FRGS
ISC(PJ), USN (Ret)
"You do not have a right to an opinion. An opinion should be the result of careful thought, not an excuse for it."
Harlan Ellison
" War is God's way to teach Americans geography." Ambrose Bierce