I'm a leftie and as such have limited options to convert a suitable CRF action to 404. I already have a Walther Lothar pre-fit in 404 to suit a 98 and have some other parts for the conversion.

There are LH Zastava actions made in both standard length and 375 H&H length. I've never personally examined a 375 H&H length Zastava, but from pics on the net it does not look like the front or rear bridges are altered cf the standard length action, so I am not sure how Zastava have gained the extra length. Given that I am unlikely to be able to acquire any US made bottom metal, like Duane Wiebe's unit for the 404, I'm likely to have to have bottom metal made up locally.

I've often heard that when factories remove metal to convert standard length actions to handle 375 H&H length cartridges, more metal than is ideal is removed from the front lug area, weakening the action lock up. On the flip side I've never heard of any problems with factory converted 375 H&H length actions. There must be thousands of the same action in 375 or 404's out there as Zastava, Interarms, Whitworth and other variants.

My question is whether I should start with a standard length action and have it altered to fit the 404 (by biasing metal removal to the rear of the action) or simply use a factory 375 H&H length action.

Any insights would be appreciated.

quote:

I believe the Zastava magnum action is a regular length action that has been lengthened by removing metal, most likely from the front of the action.

They might thin the rear of the box but it is not moved back.

From the few standard length actions I have seen opened up for the 404 cartridge, or the 375H&H for that matter, some is removed from the rear of the magazine well but most is off the front feed ramp which is the lower locking lug recess. The great British gunmakers used to open up standard M98 Mausers without any issue and at least one standard action we know of was opened up for the 416 Rigby cartridge.

The pre-64 Mod70 Winchesters that came out in 375H&H were standard length actions opened up in the factory and in photos I have of one of these shows a lot was taken from the front feed ramp, very similar in fact to my own Oberndorf Mauser standard action which was a 10.75x68 but opened up to 404 at Harrison's in Rhodesia. A lot removed from the front feed ramp area but I have had no issues. Many a standard action opened up has quite severe notches taken out of the top of the receiver ring to facilitate loading of the longer cartridges like the 404 and 375H&H and this area is the top locking lug recess. One of the original Mauser models made in 30-06 had such a notch done in the Mauser factory.

Personally I don't see the need for a notch, my Mauser doesn't have or need one and the receiver ring has not been altered.

quote:

Originally posted by ramrod340:

quote:

I believe the Zastava magnum action is a regular length action that has been lengthened by removing metal, most likely from the front of the action.

They might thin the rear of the box but it is not moved back.

Some have been, and the bolt stop altered also

Just FYI...The 416 Rigby ammo as loaded by Hornady will fit just swell in a properly altered 98...The issue is that Hornady does not seat out to CIP OAL. So...if one happens to have access to only CIP length ammo, you'd be in a little touble

My 375HH Zastava (Rem 798) has had nothing removed from the rear and it is a regular Mauser 98 length action.

To clarify, did not mean to infer the Zastava'a had the back of the box and bolt stop lengthened. I know of a few original mauser conversions that had that done to them. Sorry if I confused some

I have a LH 375 Zastava Mauser. I will look at it tonight but I don't recall it having anything removed from the rear to open it up.
IIRC a member here opened one up for 404. I think it was Vol717. Might PM him an ask what all had to be done.

quote:

Originally posted by Duane Wiebe (CG&R):
Just FYI...The 416 Rigby ammo as loaded by Hornady will fit just swell in a properly altered 98...The issue is that Hornady does not seat out to CIP OAL. So...if one happens to have access to only CIP length ammo, you'd be in a little touble

That's interesting about Hornady ammo. Of course the standard M98 in 416 Rigby I was referring to was Harry Selby's and it was an original Rigby Mauser but I have never seen it confirmed whether Rigby did the opening up work on the action or someone else. Harry did not purchase the rifle from Rigby although somewhere he said he did have it rebarreled by Rigby as he wore out barrels. Not sure why Rigby would use a standard length action as they had sole import rights to the Mauser magnum action, supplied specifically to Rigby by Mauser to stop the practice of opening up the standard length actions!!

Obviously Harry was using standard length 416 Rigby ammunition, Kynoch in early days, so would be good to see just how Rigby, or whoever, opened up that action for the long 416 Rigby round (longer than the 404 and 375). Unfortunately the photo of Harry's rifle below doesn't show this sort of detail but does show a beautiful workhorse with a lot of history.

The photos I saw of his Rigby (A least purported to be) was opened up enough to scare me speechless.

what are the implications, safety-wise, of using the no magazine box solution? didn't 458win show us one like that? would you epoxy the insides of the wood for strength?

while we are at it, can someone comment on the stock above? that was built for iron sights only? how does the recoil flow on that? up and out or other?

quote:

Originally posted by eagle27:

quote:

Originally posted by Duane Wiebe (CG&R):
Just FYI...The 416 Rigby ammo as loaded by Hornady will fit just swell in a properly altered 98...The issue is that Hornady does not seat out to CIP OAL. So...if one happens to have access to only CIP length ammo, you'd be in a little touble

That's interesting about Hornady ammo. Of course the standard M98 in 416 Rigby I was referring to was Harry Selby's and it was an original Rigby Mauser but I have never seen it confirmed whether Rigby did the opening up work on the action or someone else. Harry did not purchase the rifle from Rigby although somewhere he said he did have it rebarreled by Rigby as he wore out barrels. Not sure why Rigby would use a standard length action as they had sole import rights to the Mauser magnum action, supplied specifically to Rigby by Mauser to stop the practice of opening up the standard length actions!!

Obviously Harry was using standard length 416 Rigby ammunition, Kynoch in early days, so would be good to see just how Rigby, or whoever, opened up that action for the long 416 Rigby round (longer than the 404 and 375). Unfortunately the photo of Harry's rifle below doesn't show this sort of detail but does show a beautiful workhorse with a lot of history.

Harry's rifle was made by Rigby and was originally for Don Bousfield. He didn't take to it and Harry picked it up at May & Co. when his double was damaged. Yes, it was rebarrelled later, and also checkered. Harry slimmed down the stock quite a bit and it went uncheckered for a long time.

I believe that the war interrupted the commercial arrangement between Rigby and Mauser, thus, no commercial actions. Selby's rifle was originally built and later rebarreled for him by Rigby.

If I recollect correctly, the Zastava M70 action chambered for the 375 H&H cartridge has the action opened solely by removing metal from the front - before the action is hardened.

I understand the commercial FN M98 actions factory chambered for 375 H&H had the actions opened in this same manner.

My two commercial FN M98 actions were originally chambered in 30-06 so my actions were opened maximumly to the rear with only a minor amount taken from the front lug area to accommodate a 3.615" COAL.

Hmmm ...taking off much more than 1mm to the rear gets into some major surgery. How was this done

You could always do like Jeffery and just cut out the magazine box altogether. I have a friend with an original Jeffery Takedown in .333 that has no magazine box to speak of. There's a piece of metal attached to the wood in the from if I remember correctly and the wood on the inside of the magazine well is all that is there.

I am currently restoring a Westley .318. The magazine box was extended .150 thou to the rear to accommodate the long cartridge.
Most of these Westley rifles I have handled have the magazine extended on the front end.

quote:

Originally posted by eagle27:
From the few standard length actions I have seen opened up for the 404 cartridge, or the 375H&H for that matter, some is removed from the rear of the magazine well but most is off the front feed ramp which is the lower locking lug recess. The great British gunmakers used to open up standard M98 Mausers without any issue and at least one standard action we know of was opened up for the 416 Rigby cartridge.
.

I have pictures of four original Rigby rifles built between the end of the war and 1955 that were all built on standard length 98 actions.

No need to over think this conversion. Buy one of Duane's bottom metal units and make the action fit the bottom metal, then work the rails and follower. I have done several using his bottom metal and they work great!

quote:

Originally posted by shikarafar1:
I am currently restoring a Westley .318. The magazine box was extended .150 thou to the rear to accommodate the long cartridge.
Most of these Westley rifles I have handled have the magazine extended on the front end.

The bolt stop should also be modified that same .150..just ain't enough material to do that

Thanks everyone for their feedback. There have been some very interesting comments.


skb - That would be a sensible solution but unfortunately your government has made it increasingly more difficult to source US made parts overseas. Hence the question and interest in how best to achieve the additional mag length required.

Duane - if you were in the same position that I am in, how would you tackle the conversion ? Would you start with a Zastava factory action in 375H&H or modify a 30/06 length action?

In your view what practical additional length can be achieved by extending the mag to the rear?

The other point is the 404 is not really that much longer than a standard length cartridge - I think CIP specs call for a 3.53" max length, making is a little shorter than a 375 H&H. However I'm not sure what length factory ammo is loaded to.

Start with an unaltered action that was originally a .30-06. The .375 actions were lengthened to the front.

quote:

Originally posted by JFE:
Thanks everyone for their feedback. There have been some very interesting comments.


skb - That would be a sensible solution but unfortunately your government has made it increasingly more difficult to source US made parts overseas. Hence the question and interest in how best to achieve the additional mag length required.

Duane - if you were in the same position that I am in, how would you tackle the conversion ? Would you start with a Zastava factory action in 375H&H or modify a 30/06 length action?

In your view what practical additional length can be achieved by extending the mag to the rear?

The other point is the 404 is not really that much longer than a standard length cartridge - I think CIP specs call for a 3.53" max length, making is a little shorter than a 375 H&H. However I'm not sure what length factory ammo is loaded to.

I'd agree that you might as well start with a 30-06 length action….Jim Wisner feels 1mm is about as far as you should go because of he bolt stop. I think that's reasonable maximum.

quote:

Originally posted by Duane Wiebe (CG&R):
[QUOTE]Originally posted by JFE:
Thanks everyone for their feedback. There have been some very interesting comments.


skb - That would be a sensible solution but unfortunately your government has made it increasingly more difficult to source US made parts overseas. Hence the question and interest in how best to achieve the additional mag length required.

Duane - if you were in the same position that I am in, how would you tackle the conversion ? Would you start with a Zastava factory action in 375H&H or modify a 30/06 length action?

In your view what practical additional length can be achieved by extending the mag to the rear?

The other point is the 404 is not really that much longer than a standard length cartridge - I think CIP specs call for a 3.53" max length, making is a little shorter than a 375 H&H. However I'm not sure what length factory ammo is loaded to.

I'd agree that you might as well start with a 30-06 length action….Jim Wisner feels 1mm is about as far as you should go because of he bolt stop. I think that's reasonable maximum. Trouble is that you still have an issue with width (for proper stack.) And...yes, our politico's do a real good job of fixing what ain't broken.

quote:

Originally posted by JFE:
Thanks everyone for their feedback. There have been some very interesting comments.


skb - That would be a sensible solution but unfortunately your government has made it increasingly more difficult to source US made parts overseas. Hence the question and interest in how best to achieve the additional mag length required.

Duane - if you were in the same position that I am in, how would you tackle the conversion ? Would you start with a Zastava factory action in 375H&H or modify a 30/06 length action?

In your view what practical additional length can be achieved by extending the mag to the rear?

The other point is the 404 is not really that much longer than a standard length cartridge - I think CIP specs call for a 3.53" max length, making is a little shorter than a 375 H&H. However I'm not sure what length factory ammo is loaded to.

I'll measure some factory Norma and Kynoch 404 cartridges when back home tonight, it is about 90mm while the magnum cartridges for standard length actions are about 85mm. We are not just talking of a millimeter or two, 5mm is a lot to find from a standard length action but it does seem relatively easy to achieve.

Irrespective of what ammo you acquire, when handloading you need to be able to seat to the cannelure on the range of jacketed 404 bullets available. I have RWS 400gr solids which when crimped in the cannelure sets the cartridge length to the same as factory ammo (as you would expect from RWS who provide loaded ammo for the 404).
The 404 has a long neck and crimped jacketed bullets occupy the full neck length and don't intrude into powder space in the body. Similarly my own cast 400 gr bullets occupy the full neck to produce factory length cartridges and can be crimped at this length if needed. Shortening the 404 cartridge case (neck) as some suggest to better fit a standard length action would only see the bullet intruding into the case body and powder space, then of course factory 404 ammo wouldn't fit so kind of defeats the purpose of having a 404.

With what Duane mentioned about the Hornady 416 Rigby being on the shorter end on the spectrum and Eagle27 measuring out some Norma and Kynoch...

Does anyone have a Hornady 404 Jeffery cartridge they could measure as well?

I am curious how 3the length compares to other factory loaded 404 Jeffery ammunition.

404 Jeffery:
CIP = 90.93mm
Mauser original magazine dimension = 92mm

RWS Solid ( 26 gm ) = 88.7mm
Kynoch 410 Soft = 90mm
Kynoch 400 gr solid = 89.66mm

416 Rigby
Original Mauser mag dimension = 97.5mm
CIP = 95.25mm = 3.750 inch
Hornady book COL = CIP
Norma book COL = CIP

Original Kynoch 416 Rigby = 94.5mm
Federal 416 = 94.5mm

Hornady 416 rigby 400 gr = 90.93mm
this length is determined by the position of the Hornady bullet crimping groove.

404 Jeffery

RWS case and 401gr RWS solid (reload with bullet seated and crimped in cannelure so same as factory RWS) 89.6mm COAL.

Early Kynoch 400gr soft nose 89.3mm COAL.

Parker Hale (Norma components and loading - Norma's own bullet made just for a special production run of ammunition for Parker Hale 400gr solid) 89.6mm COAL.

Jim Wisner wrote an excellent piece on converting a 98 action to except 404 with his retro fit magazine for that case design. I think he does make this magazine configuration now and then as well as the follower and the correct bolt stop.

I would look into it and go through the pain in the ass import requirements and start off in the right direction to begin with.

By the time you go through all the other dead ends you'll be money ahead with the proper parts and a map on how to do it.

404 Jeffery

Correction to my RWS cartridge length with 400gr solid. I remembered that factory RWS cases, of which I still have a packet of unused ones, are 72mm in length as opposed to the normal 73mm and I have allowed my RWS case lengths to grow to 73mm to match Kynoch and Parker Hale when reloading hence the measurement I gave was not correct.

The RWS factory loaded cartridge with their 400gr solid is 88.6/88.7mm same as ALF has reported.