I am not a big fan of wildcats, as all the gaps seem to be filled. However, running across a couple of posts about the 400 Whelen got me remembering Dave Scoville's articles in Rifle and Handloader magazines about the .411 Hawk. As I remember it, the .411 Hawk uses 30-06 brass necked up, but the base diameter of the chamber is based on the 9.3x62 chamber, which is a few thousandths wider than 06', and the shoulder is moved up to the same place as the 9.3x62 as well. For some reason, the 370 Sako (a.k.a. 9.3x66) case came to mind. I am a huge fan of the 9.3x62, and like most folks, I figured they were trying to improve on perfection with the 370. All they did was lengthen the case a bit and moved the shoulder up. While I turn my nose up at the 370, I think a larger bore version of this round has some merit.
So, given that .411" is the maximum practical bullet diameter with the 06's .465" case base diameter, is it logical to assume that .416" is the maximum practical bullet diameter to pair with the 370 Sako's .4776" case base diameter? Even at the 370's 62k psi pressure I doubt you would get a whole lot of improvement over the 400 Whelen, but you would think there would be some improvement. Plus, I think there might be a greater variety of .416" pills out there vs. .411". Transferring Michael Petrovs chamber spec recommendations to the .416-370 Sako might yield a pretty good round. Surely, someone else had of thought of this earlier.
I'm not a wildcatter, and I don't have or use any fancy software. Can some smart feller figure out how much of an improvement, if any, the .416-370 Sako might be over the original 400 Whelen? I can't imagine more than a 50 fps improvement, which brings me full circle to the fact that this rounds improvement over the 400 Whelen is much like the 370's improvement over the 9.3x62: Not worth the effort. Finding 370 brass might be difficult, here in the U.S., which is another strike against this wildcats practicality.






If I happen to be the first to come up with this round, I would like to name it after a certain Alaskan PH who sometimes moonlights as a gun and hunting writer. However, not being a seeker of attention, I think he would profusely object, so how does the "416 Cobler" sound? "416 Cordwainer" would be more precise.

I don't know it it has been done yet. If you have the time and dough it can be done.

You might consider the extremely narrow taper of the Brown Whelen to build up a slightly larger shoulder diameter.

35 Brown Whelen

Ok. Using Michael Petrov's original 400 Whelen specs as a guide, I've come up with some preliminary specs (no drawing yet, but you'll get the idea). This case should slightly best the 416/400 PDK, much like the PDK slightly bests the 400 Whelen. I don't see either of the newer designs offering any real world improvement over the 400 Whelen. The ability to use widely available .416" pills is a plus in the 416-370 an 416PDK columb. I do see the 416-370 Sako as being about the absolute maximum in performance in the 416/400 class utilizing a standard bolt face and 06' brass. One should be able to use 06' brass in the 416/370 Sako, much like you can in the 9.3x62, 370 Sako, and the entire line of Hawk/Scoville rounds up to the .411 Hawk. You just end up stretching the base diameter .006". Works just fine. Since 370 Sako brass is almost non-existent, 06' basic would be the best option. Using 9.3x62 brass would leave you with an awfully short neck. Buffalo Arms could stretch 9.3x62 brass, but who would bother. I also see the 416-370 as, possibly, the absolute maximum Power chambering compatible with the modern make Winchester/Browning 1895. I am not aware of the 95's max allowable O.A.L. though. Since the 370 Sako operates at 62k psi, and the modern 95 has been chambered in the 270 WCF, I see no reason to not load the .416-370 to this pressure.
I'm not in a good place in life to try and have a reamer and dies made, but who knows, maybe someday. The cost-benefit analysis doesn't look too good. Maybe some other sucker, with more time and money than I, will decide to take this up. Cheers!

Have you measured the actual 370 brass? I have not measured it against 06 at the base.

Matt if you do a search on the 416PDK (416 pdk) I've posted some of the results. I built it first using 280Rem brass. It worked fine as to fit and function. I lost interest and my buddy has been using the one and only for years in Alaska.

I always felt the brass was too short. So when I decided to build another 400 (416) I elected to go 400 because of the bullets available. There are several posts of my cases and you will see that where you place the shoulder will have very little impact on case volume. S0 416-70 or 416PDK as long as the coal is the limit there is very little difference.

As to shoulder dia .458-.465 should work fine.

Last I checked z-hat didn't have any cylinder brass and had no clue when he would get some. Wayne at AHR has howell basic. I've used it I know some trying it with a 2 piece whelen die set had issues with the head grabbing their expander

if the 370 Sako had an actual 12 thou increase over the 06 then you could go to .423" bullet diameter and have a shoulder. Does anyone have Sako brass to measure? If that is the "Case" then there is a good case for the 416 and 423. 404 Sako? 10,7x66?

quote:

Originally posted by ramrod340:
Matt if you do a search on the 416PDK (416 pdk) I've posted some of the results. I built it first using 280Rem brass. It worked fine as to fit and function. I lost interest and my buddy has been using the one and only for years in Alaska.

I always felt the brass was too short. So when I decided to build another 400 (416) I elected to go 400 because of the bullets available. There are several posts of my cases and you will see that where you place the shoulder will have very little impact on case volume. S0 416-70 or 416PDK as long as the coal is the limit there is very little difference.

As to shoulder dia .458-.465 should work fine.

Last I checked z-hat didn't have any cylinder brass and had no clue when he would get some. Wayne at AHR has howell basic. I've used it I know some trying it with a 2 piece whelen die set had issues with the head grabbing their expander

Ramrod,
When the idea for the .416-370 came to mind a few days ago, I had not heard of the 400 PDK. The actual case capacity difference between the two would be trivially small. Your shoulder observation occurred to me, as well. This is why I noted, and I'm sure you have as well, that there is no practical difference in performance between the three rounds. Thanks to the 416 rem and the 416 Ruger, there are now several 416 caliber bullets available with shorter ogives that help meet 3.34" OAL requirements. In fact the 416 Ruger and the preliminary 416-370 spec have the same case length with very similar shoulder placement. Giving the 416-370 the same neck length as the 416 Ruger combined with the 400 Whelen's shoulder angle might prove to be the most efficient.

Boomstick:
I have not measured the base diameter of an actual 370 case. 370 base diameter specs are the same as for the 9.3x62. I have samples of new Hornady, PPU, and Norma brass up in my closet. When my knee heals up enough to allows me to go up the stairs again, I'll measure their bases for you. They should all be fairly close to spec. I can tell you that the PPU cases hold surprisingly more water than the other two. Very thin walled stuff, but still tough, can take pressure, and several firings.

From what I read the actual 9,3x64 case head is .474", spec being .476.
I think I might need to design a wildcat that is capable of head spacing on the shoulder with a 404 bullet on the 62 and maybe 64 case.
Maybe just a fire formed 62 case with the same shoulder position.
Does 10,75x62 sound too boring?
.4776" base .447" neck .470 shoulder.
Sorry for the partial thread hijack

quote:

This is why I noted, and I'm sure you have as well, that there is no practical difference in performance between the three rounds. Thanks to the 416 rem and the 416 Ruger, there are now several 416 caliber bullets available with shorter ogives that help meet 3.34" OAL requirements. In fact the 416 Ruger and the preliminary 416-370 spec have the same case length with very similar shoulder placement. Giving the 416-370 the same neck length as the 416 Ruger combined with the 400 Whelen's shoulder angle might prove to be the most efficient

Loaded to the same COAL I agree there is basically no difference. The longer case does allow you to use the cannelure and I "feel" the round looks better without that long bullet stuck out in front.

As to shoulder angle. When you compare the OD of the neck and shoulder you will find angle has little if any impact. Other than in my "opinion" something like a 35-40 deg makes me feel better.

quote:

Originally posted by boom stick:
From what I read the actual 9,3x64 case head is .474", spec being .476.

Do you mean 9.3x62. The base diameter of the 9.3x64 is .507". The 9.3x64 necked to .423" would be similar to the .423-300win a.k.a. 425 Express

Yes, sorry for the mistake.

Boomer,

A 9.3x62 print:

Thanks.
Keeping the shoulder in the same place might be easier but I like the idea of a long neck.
Fun to ponder...

quote:

Originally posted by boom stick:
Thanks.
Keeping the shoulder in the same place might be easier but I like the idea of a long neck.
Fun to ponder...

Boom Stick,

You might try a .423-370 Sako, using the 416 Ruger neck length as described above. If the 416PDK can headspace reliably with a .460" wide shoulder, Then a .467-7" wide shoulder on the 370 should hold a .423" bullet just fine. .423" bullets should have shorter ogives, on average, than .416", so OAL won't be much of a worry in 06' length mags.

It seems obvious that, even if shade-tree gunsmiths had not ruined the 400 Whelen's reputation by causing headspace issues with narrower shoulders than Whelen's specs, factories would be hesitant to pick it up due to the fact that they would have to be super vigilant with their reemer specs. There is just no room for the grossly over or undersize chambers that you can see in mass produced rifles. The .416" on the 06', and the .423" on the 9.3/370 seem to push the absolute outer limits of headspace control.
Matt

Being that the .423" bullet would eliminate the shoulder, one could play with the shoulder position. If using formed 9,3x62 cases getting rid of that neck/shoulder wrinkle is a pain. One could eliminate one part by keeping the same shoulder position. Wanting to clean up the 9,3x62 chamber for a rebore job, the shoulder position might have to be the shoulder/body junction for maximum neck length. I think that would be the best option. Rechamber and rebore an existing 9,3x62 for ease and cost reduction. Maybe have a matching pair of 9,3x62 and 10.75x62. One for PG and one for DG but could replace each other on a pinch.

Sako writes 55m/s beetween 9,3*62 and 66 some of must be higher pressure.

http://cdn.sako.fi/sites/defau..._cartridges_2015.pdf

Using QL you the velocities are basically the same. Actually load the 62 to 66 OAL and pressure it wins by a few fps.

Both are too close to call.

Found out Qual Cart .411 Hawk brass can be special ordered through Midway:

quote:

Found out Qual Cart .411 Hawk brass can be special ordered through Midway:

Interesting. The z-hat website doesn't even list brass. Appears to be an overhaul and mostly about loading manuals and his book.

But unless you had to have a head stamp I would simply roll my own. Get some Whelen brass and blow it out.

I have 2 boxes of Federal Premium 370 SAKO's. The head diameter of cases from both boxes is .4735 and the rim diameter is .467.

Thanks Jgrabow!

Thanks for measuring
Those cases could be fire formed to .476" if need be. Maybe more?

quote:

Originally posted by Jgrabow6493:
I have 2 boxes of Federal Premium 370 SAKO's. The head diameter of cases from both boxes is .4735 and the rim diameter is .467.

quote:

Originally posted by boom stick:
Thanks for measuring
Those cases could be fire formed to .476" if need be. Maybe more?

I think you can go a little more, but not a lot. I briefly posted a link to a post where a fellow was using fireformed 375 H&H brass in 404 chambers. Lots of criticism there from AR members. I recall, but could not find, a post where a South African fellow demonstrated the same thing, and indicated that it is commonplace in SA. I'm not advocating such things, but surely a few thou past .476 is safely doable. However, don't blame the armchare wildcatter when thing go south in your rifle

Large bore with no case taper?

Thought I was pushing it with .46"

quote:

Originally posted by ramrod340:
Large bore with no case taper?

Thought I was pushing it with .46"

I took it that boom stick was referring to base diameter.

quote:

I took it that boom stick was referring to base diameter.

You are probably right . I read it as a max shoulder.

I think you could squeeze out 6 or 7 thou body taper on a fire formed case based on the wider 9,3x62 for the .423" bullet.

Just looked through the newest edition (14th) of "Cartridges of the World". J.D. Jones has apparently come up with a 416-06 round utilizing a 60 (Yes, SIXTY) degree shoulder. Interesting. The same old dribble about the 400 Whelen being useless and having no headspace control is still there.