I’m guessing this has been discussed here ad nauseam, but I can’t find anything in a search of AR. I’m ready to order a .423-424” bore barrel for a custom 10.75x68 Mauser project, and I’m wondering what folks who have “been there and done that” think. The plan is to load 400 grain bullets at mostly 450-400 Nitro velocities of 2100-2200 FPS from a 650mm (about 25.6”) barrel. There is a table in Jon Speed’s Oberndorf Commercial Mausers book indicating that original Mauser sporters in both 404 Jeff and 10.75x68 have 420mm (about 16.5”) rifling twists. I don’t need to shoot the long for caliber monometal bullets, or go any heavier than 400 grains, but if I had to shoot 400 mono’s, would they work OK in a 16” twist barrel? Thanks!

Matt,
I would always default to the faster twist. It will not hurt you and can only help in a situation you may not foresee.

Ludwig Olson's book "Mauser Bolt Rifles" contains very extensive information and data on both military and sporter Mausers and cartridges. The rifling twist for the 10.75x68 Mauser cartridge is listed in this book from early Mauser catalogues as 14.17". The barrels for the 404 were most likely the same as used for the smaller cartridge.
The 404 is not listed as it was not a Mauser cartridge but I have an Oberndorf Type A Mauser opened up to 404 from the original 10.75x68 and it shoots jacketed and cast up to 400 grain as accurate as the 347 grain bullets the 10.75x68 was loaded with.

My Kynoch and Parker Hale 400gr factory ammo and reloads with 400gr RWS bullets all at around 2100-2250fps all shoot great.

The 404 not a Mauser caliber ? Yes not Mauser designed but Mauser offered none the less, first in Standard action and later magnum action.

Odd this because Mauser built all Jeffery's Mausers for them.

What is more Mauser offered the 404 in Germany as the 10,75x73 and the rifles were sold in un- anglicized form.
Mauser listed the barrel specs in their 1926 summary sheet.

IMHO the 10,75x73 in original format on a Magnum Square bridge action the holy grail in Mauser rifle offering.

I always go with the faster twist.

quote:

Originally posted by ALF:
The 404 not a Mauser caliber ? Yes not Mauser designed but Mauser offered none the less, first in Standard action and later magnum action.

Odd this because Mauser built all Jeffery's Mausers for them.

What is more Mauser offered the 404 in Germany as the 10,75x73 and the rifles were sold in un- anglicized form.
Mauser listed the barrel specs in their 1926 summary sheet.

IMHO the 10,75x73 in original format on a Magnum Square bridge action the holy grail in Mauser rifle offering.

Yes Mauser did manufacture their sporter Mausers in many non-Mauser designed cartridges, 404 Jeffery, 250-3000, 30-06 etc., but much of the catalogue data contained in Olson's book, barrel and cartridge specs etc., doesn't list these 'other' cartridges. There are lists for British loadings of Mauser cartridges and likewise US loadings but again the lists only contain Mauser designed cartridges.

You are probably correct that later Mauser catalogues may have provided more information for the other cartridges and barrels.

I agree with you on the holy grail of Mauser offerings although a 404J on an opened up standard Oberndorf action makes a very nice light and reliable dangerous game rifle.

Um there are other infinitely more comprehensive works printed than Olson.
And though desirable than a opened up standard the Magnum actioned model A's are IMHO the holy grail.

quote:

Originally posted by eagle27:
Ludwig Olson's book "Mauser Bolt Rifles" contains very extensive information and data on both military and sporter Mausers and cartridges. The rifling twist for the 10.75x68 Mauser cartridge is listed in this book from early Mauser catalogues as 14.17". The barrels for the 404 were most likely the same as used for the smaller cartridge.
The 404 is not listed as it was not a Mauser cartridge but I have an Oberndorf Type A Mauser opened up to 404 from the original 10.75x68 and it shoots jacketed and cast up to 400 grain as accurate as the 347 grain bullets the 10.75x68 was loaded with.

My Kynoch and Parker Hale 400gr factory ammo and reloads with 400gr RWS bullets all at around 2100-2250fps all shoot great.

I tend to believe the factory table presented in Speed’s book over the info presented in Olson’s. However, it seems entirely possible that the twist rate was changed at some point and two twist rates exist. Have you measured the twist in your 404?

quote:

Originally posted by ColoradoMatt:

quote:

Originally posted by eagle27:
Ludwig Olson's book "Mauser Bolt Rifles" contains very extensive information and data on both military and sporter Mausers and cartridges. The rifling twist for the 10.75x68 Mauser cartridge is listed in this book from early Mauser catalogues as 14.17". The barrels for the 404 were most likely the same as used for the smaller cartridge.
The 404 is not listed as it was not a Mauser cartridge but I have an Oberndorf Type A Mauser opened up to 404 from the original 10.75x68 and it shoots jacketed and cast up to 400 grain as accurate as the 347 grain bullets the 10.75x68 was loaded with.

My Kynoch and Parker Hale 400gr factory ammo and reloads with 400gr RWS bullets all at around 2100-2250fps all shoot great.

I tend to believe the factory table presented in Speed’s book over the info presented in Olson’s. However, it seems entirely possible that the twist rate was changed at some point and two twist rates exist. Have you measured the twist in your 404?

Yes I did some years ago, it was as per the book, 14".

Olson visited the Mauser factory and got as much data as he could from them. Don't know why he should be any less credible than Speed. All I know is my 404 has a 14" twist and handles 350-400 grain bullets fine. The faster 14" twist would be better for the 450 grain Woodleighs too if you have a mind to use them, I haven't.

Big Bore Journal #22 has an article on the 404 "Still more on the 404" and it lists the Original Mauser barrel as having a 16.53" twist.

PM me your email and I will send you the two articles from the Big Bore Journals if you want. A lot of good historical stuff in these articles.

Click on picks at bottom for complete image. The pics show up cropped otherwise.

quote:

Originally posted by eagle27:

quote:

Originally posted by ColoradoMatt:

quote:

Originally posted by eagle27:
Ludwig Olson's book "Mauser Bolt Rifles" contains very extensive information and data on both military and sporter Mausers and cartridges. The rifling twist for the 10.75x68 Mauser cartridge is listed in this book from early Mauser catalogues as 14.17". The barrels for the 404 were most likely the same as used for the smaller cartridge.
The 404 is not listed as it was not a Mauser cartridge but I have an Oberndorf Type A Mauser opened up to 404 from the original 10.75x68 and it shoots jacketed and cast up to 400 grain as accurate as the 347 grain bullets the 10.75x68 was loaded with.

My Kynoch and Parker Hale 400gr factory ammo and reloads with 400gr RWS bullets all at around 2100-2250fps all shoot great.

I tend to believe the factory table presented in Speed’s book over the info presented in Olson’s. However, it seems entirely possible that the twist rate was changed at some point and two twist rates exist. Have you measured the twist in your 404?

Yes I did some years ago, it was as per the book, 14".

Olson visited the Mauser factory and got as much data as he could from them. Don't know why he should be any less credible than Speed. All I know is my 404 has a 14" twist and handles 350-400 grain bullets fine. The faster 14" twist would be better for the 450 grain Woodleighs too if you have a mind to use them, I haven't.

Big Bore Journal #22 has an article on the 404 "Still more on the 404" and it lists the Original Mauser barrel as having a 16.53" twist.

PM me your email and I will send you the two articles from the Big Bore Journals if you want. A lot of good historical stuff in these articles.

PM on the way, and thanks! Like I said it is entirely possible that the twist rate for 10.75mm barrels was changed at some point. Here is the original Oberndorf factory chart I was referring to, dated December 1926. It is from Page 275 of “Original Oberndorf Sporting Rifles”, by Speed, Schmid, and Herman:



420mm comes out to about 16.53, as the Big Bore Journal states, so it would seem that Mauser did change their twist spec sometime after this 1926 date!

Just to be clear:
There are a lot of unanswered questions regarding the 404 Jeffery and per usual the devil is in the detail and off course are usual timeline is everything.

Many Authors refer to a 1909 date as date of release and this has had my wondering was to why ?

Jeffery refers to the 404 as their 1905 rifle and in the 1910 catalog we see this.
The 1904 catalog does not list this and the 1904/1905 season catalog also makes no mention of it. The big question is when did the first 404 actually see the light of day in the hunting fields of Africa.
Many 404's by "other " makers such as FN and Parker Hale are actually relatively modern and often short lived releases. ( the Parker-Hale with its Spanish Santa Barbara action and barrel of undetermined origin as recent as 1984 )


We have a Eley drawing ( the first known drawing of a 404 ) dated 08/10/1905 submitted for proof which puts its design likely somewhere in 1904 / early 1905 ( we assume)

But now this 1909 date ? Why ? Did Jeffery only release it to coincide with the 1910 catalog ?
In Speeds date lists the earliest date cited for a 404 is 1908 ?

So the question begs when did Mauser produce their first 404 and if that date is after Jeffery's release who built Jeffery's 404's ?

We know that Jeffery used H Leonard as finisher for most of their bolt actioned rifles and given that the action surface treatment ( stippling etc) on the bridges are all the same it had to be done by one person or group of persons.

Jeffery used Le Personne ( Liege Belgium) as importer.

Now here is the anomaly.

Early Jeffery Rifles were built 7 groove Krupp Barrels with nominal twist rates given as between 1: 15.625 " to 1:16.000"

Mauser Barrels on the other hand were 6 groove barrels with a nominal twist rate of 1: 16.530"

Vickers Armstrong rifles had a 6 groove barrel with twist similar to the Krupp barrel but the bore / dimension of the Vickers was a a.4220 to .4225 as opposed to a Mauser's .423 and Krupp's .4224 to .4230

When I was young urban legend had it that one had to be careful of Vickers 404's because they had .419 groove barrels? Gun shop tyre kickers bandied this about like it was some disease.

Access to Jeffery's remaining ledgers would be a huge help !

Alf,

I believe Mauser was well aware of the 404 by 1907-1908, and I believe the 10.75x68 was created as a competitive response to the 404. Speed believed that the 10.75x68 was developed by at least 1907-1908, as rifles were made at least as early as 1908. The cartridge was “Normalized” in conference at Erfurt in 1909, along with several other rounds.

Mauser "aware of " the 404 ? well they had to be because they supplied the actions for the rifles.

But here is another conundrum: Did Mauser actually design the 10,75x68 ?

The 10.75 cal was around for some time and DWM lists the 10.75x68 as being produced in 1909 case # 515A
it was preceded by the 10,75x63 DWM # 515 of 1908 Mauser listed the above at based on the G case

But this was preceded by the 10,75 x 57 by Roth for Mannlicher in 1907 and the 10,75 x 61 For Haenel ( also a Mannlicher type action ) in 1908.

And there is a link between Mannlicher and Jeffery in that Jeffery imported and sold Mannlicher rifles as per their 1904 catalog.

Rigby was the exclusive importer of all things Mauser during the time the 404 was developed, and I understand all other British firms, including Jeffery had to get their actions through Rigby until after 1912. If I am wrong in this I will happily stand corrected.

I suspect DWM’s 1909 515A case design was a result of the cartridge being normalized at the 1909 Erfurt conference. Speeds book has pics a 10.75x68 rifle with “1908” stamped on the receiver ring along with the Mauser provenance. I have run across two more similarly date stamped Oberndorf 10.75x68’s.

The 416 Rigby is traditionally offered in 16.5" twist. The traditional load is marginally faster than the 404Jeffery.

However, the relatively recent offering of the 416 Ruger comes in a 14" twist.

Personally, if I were building a 41 or 42 caliber, I would have a barrel made with a 12" twist. The 12" twist will shoot any standard ammo and bullet out to 400-500 yards accurately. Extra stability never hurts up close. It is only long range, 400-700 yards +, where a modest, slower twist is useful.

A second reason for the faster twists, you may change your mind and desire to shoot some 450 grain bullets and/or some long, high-BC bullets. People change every few years, at least leave these options open.

For comparison, consider the developments in the 223. Today there are 223's that come from the factory in 8"-twists, though a few years ago people were content with 12" and the 222 used to come with, shudder, 14" twists. the 6.5 Creedmore is getting a lot of press because it typicallly uses 8" twists and can shoot high-BC bullets should the shooter desire. I think that the same is true for 416's and 423's. My own 416's have all had 16.5" twists and they have worked, but I would have tried some different loads and bullets if I had a 12" or even a 14" twist.

Thanks for the interesting discussion.
Surely this all means that the +40-cal of '04 was concieved by W. Jackman Jeffery in 1904, for his Model 1905 rifle, proofed in August 1905.
The German version of that was the 10.75x73, following their 10.75x68.
After Jackman passed, his heirs modified the .500 Jumbo of Richard Schuler, to produce the .500 Jeffery, yep, pretty certain.
Blame the World Wars for all the confusion, but as Wonder Woman said, love will prevail.
The 404 Jeffery was the first and the greatest magazine-repeater, DGR. Thank you Jackman.

I agree with .416Tanzan's recommendations.
George Hoffman used 14" twists on his .416 rifles, but opined he would choose 1:12" for the one he never got to build.
The CZ 404 Jeffery rifles used 1:10".
That twist worked great on my M70 Winchester, 330-grainer to 400-grainer.

CIP spec as of 2002 was

1:16.5" (420 mm) for the "10,75 x 68"
1:16.5" (420 mm) for the "404 Riml. N.E."

I do not know if that is any different now.

As to bore and groove diameters and throats, use modern common sense.

I'll take a 1:12" twist on any rifle from .358-cal to .510-cal. for jacketed bullets and smokeless powder.

Rip ...

I used a 1 in 10 for my 416 shoots very nice one hole groups and with several different bullets to the same point of aim

My last 416, a Rem Mag with a McGowan barrel had a 1 in 10 twist and was quite accurate with 300 gr Hawk up to 400 gr Super Solids .
The only reason I've never owned a 416 Rigby is the 1 in 16" or there abouts twist.
I've never had a realistic accuracy problem from too fast a twist. But I have from too slow a twist.
I've wondered if the reason Pondoro reported the 10.75×68 had a penetration problem, was due to the slow twist. Combined with too malleable a bullet construction.
The factory 416 Remington has a 1 in 14" twist. It seems to work fine. The 458 Win and Lott have 1 in 14" twist.
The increased chamber pressure from a faster twist is more than offset by today's powders , compared to Cordite.

Yep, doubling the twist rate from 1:14" to 1:7" causes less than 1/2 of one percent (< 0.5%) increase in pressure.
That is according to artillery research, a source I read once, don't remember exactly where.
The rotational kinetic energy of a bullet is very tiny compared to its linear-translational kinetic energy. That is why.

Rip ...

The belief that a faster twist increase pressure enough to be a concern is false.

quote:

Originally posted by RIP:
Yep, doubling the twist rate from 1:14" to 1:7" causes less than 1/2 of one percent (< 0.5%) increase in pressure.
That is according to artillery research, a source I read once, don't remember exactly where.
The rotational kinetic energy of a bullet is very tiny compared to its linear-translational kinetic energy. That is why.

Rip ...

Rip (or anyone else who knows)

How much velocity differenc might one see between 16” and 14”? Thanks!

quote:

Originally posted by ColoradoMatt:

quote:

Originally posted by RIP:
Yep, doubling the twist rate from 1:14" to 1:7" causes less than 1/2 of one percent (< 0.5%) increase in pressure.
That is according to artillery research, a source I read once, don't remember exactly where.
The rotational kinetic energy of a bullet is very tiny compared to its linear-translational kinetic energy. That is why.

Rip ...

Rip (or anyone else who knows)

How much velocity differenc might one see between 16” and 14”? Thanks!

There is a negligible difference, maybe 2-3fps, and not measurable with our tools and limited testing.

quote:

Originally posted by ColoradoMatt:

Rip (or anyone else who knows)

How much velocity differenc might one see between 16” and 14”? Thanks!

Matt,
You will have no problem with a velocity difference between the 2 twist rates. I shoot a lot of NRA long range matches and the old stand by with the 308 WIn. was a 1-13 using the mandated 155 gr. bullets. Over the years there has been a shift to 1-11 and 1-10 barrels. Same with the AR 15 and some of the heavy bullets we use, some going to a 1-6.5, though my favorite has always been a 1-7. As I said earlier I will always go to the faster twist as in my mind there are many benefits and no real downsides. With the popularity of the mono metal bullets that tend to be longer for their weight compared to lead core bullets, the faster twist will always be a benefit.

I have not seen any scientific studies of effects of twist rate on velocity, just that thing about < 0.5% increase in pressure with a 2-fold faster twist rate,
which is just about negligible.
About the same with velocity change, negligible, is my guess.
I have certainly never seen any reason to blame faster twist for slow velocity.
Any difference would probably be swallowed up by the difference between two rifles built as identically as possible.

Like others here, I have only been dissatisfied by twist rate when it was too slow,
like with a 1:12" .308 that was improved in accuracy, with a broader range of bulletweights, by switching to a 1:10" twist rate.

Too much of a good thing might be a bad thing in some cases like use of cast lead bullets, which might skid on the fast twist rifling.
There are compromises to be made sometimes.
That is why Riflecranks need more than one rifle.
Beware to the man with only one gun, its versatility is not unlimited.
Especially if it is a Scout Rifle!

Rip ...

Bryan Litz go check it out.
Also tests using gas guns and different twist rates measuring velocity. Keeping the gas mass constant and only changing twist rate.

Rule of thumb; tighter twist keep all else constant = decrease in velocity

is this enough to make a huge difference at big bore ranges . I dont think so

is it a issue for loooooong range shooting perhaps ?

Thanks for everyone’s comments! I’ve decided to with a 1 in 14” twist.

Thanks for the suggestion, Alf, goaded me out of my lethargy.
Just as I suggested, the effect of twist on velocity is very small, according to Bryan Litz, tested in a .308 WCF with 6 different barrels:

1.33 fps loss of MV for a 1" twist rate change,
5 fps loss for a change from 1:12" to 1:8" in a .308 WCF!
That is less than 0.2% velocity loss for going from 1:12" to 1:8" twist rate.
That is on the same order as the less than 0.5% of pressure increase that I was referring to,
with a two-fold bullet spin rate increase by going from 1:14" to 1:7" twist rate.

Indeed, that trivial pressure increase might contribute to the exceedingly small velocity loss seen with increasing twist rate.



http://bulletin.accurateshoote...-velocity-litz-test/

"We proceeded with the testing in all 6 barrels from 1:8” to 1:12”. After all the smoke cleared, we found that muzzle velocity correlates to twist rate at the rate of approximately 1.33 fps per inch of twist. In other words, your velocity is reduced by about 5 fps if you go from a 1:12” twist to a 1:8” twist. [Editor: That’s a surprising number — much less than most folks would predict.] In this case the math prediction was pretty close, and we have to remember that there’s always uncertainty in the live fire results. Uncertainty is always considered in terms of what conclusions the results can actually support with confidence."


"Above, data shows relationship between Twist Rate and Muzzle Velocity (MV) for various barrel twist rates and rifling types. From fast to slow, the three 1:10″ twist barrels are: 5R (canted land), 5 Groove, 5 Groove left-hand twist."

The least-squares fit of that line shows some correlation alright, but not the strongest of r values.
The variation of the 3 barrels all in 1:10" twist is almost as much as the entire range from 1:8" to 1:12" twists!!!!
The 1:10" 5R barrel beat the 1:12" 5R barrel by 1 fps.
Another 1:10" 5-groove (standard) barrel equaled the 1:12" 5R barrel for average velocity, but had a lower standard deviation.
Anecdote or statistically significant?


It all boils down to the tiny amount of rotational kinetic energy in the bullet compared to the linear kinetic energy of the bullet,
conservation of energy, chop chop.

Rip ...

RIP

You must have read my mind

One can actually deduce it mathematically

If the total energy is held constant then a increase in energy due to angular velocity would by necessity mean a reduction in linear velocity, the magnitude is very small though.

But one tends to forget how relatively slow a point on the surface of the bullet actually rotates at when compared to linear velocity ! and this increase or decrease in angular velocity is very small for every incremental change in twist rate.

The very same reason why bullets do not act like Buzz saws

I'm surprised that Litz was able to partially verify such a tiny difference. And I'm also gratified to see that his 2.7fps result for a 2" twist difference fit my gut extrapolation of 2-3fps.

More obvious using a two stage gas gun.
Used in some experiments where single factor changes are observed and studied.
The reduction in velocity to change of rate or twist is not linear. At very large angles of twist the drop in velocity is greater than at small angles of twist. Again mathematically obvious.

Whilst more than likely a non issue in our ballistics system when dealing with load bearing projectiles in long range cannon twist angle and projectile dimension becomes critical in design and long range precision. The point being that just enough stability is preferable to high stability numbers at projectile egress.