New toy!

[Jim]

I found a 1916 Spanish Mauser that has been rebarreled to .308 Win. It's been sporterized( more like bubbarized), but it shoots decent.

[Jack Stanley]

Any plans for it ? Other than try to wear the steel out of it using lead .

Jack

[Jim]

Plans? Yeah, I plan to SHOOT IT![smilie=w:

[arjacobson]

is it a fr8 with the flash hider? I sure miss the one I had......

[jcwit]

Happy to see you backon board!

[WILCO]

I found a 1916 Spanish Mauser that has been rebarreled to .308 Win. It's been sporterized( more like bubbarized), but it shoots decent.

Pics????? Congrats too!

[missionary5155]

Good morning
Bought 3 of the same years ago. 2 are still in the family. Mine is the only 308 Bolt gun I have up north there and I hapilly keep it fed when stateside.
The RCBS 180 gr FNGC is a good boolit in it.

[Jim]

Pictures (http://fgsp.wordpress.com/2010/12/05/1916-oviedo-armory-spanish-mauser-7-62x51-nato/)

Here ya' go.
Thanks for the welcome back, JC! Nice to know somebody missed me.

[Jim]

Pictures (http://fgsp.wordpress.com/2010/12/05/1916-oviedo-armory-spanish-mauser-7-62x51-nato/)

Here ya' go.
Thanks for the welcome back, JC! Nice to know somebody missed me.

[oldhickory]

Pictures (http://fgsp.wordpress.com/2010/12/05/1916-oviedo-armory-spanish-mauser-7-62x51-nato/)

Here ya' go.
Thanks for the welcome back, JC! Nice to know somebody missed me.

I noticed you weren't around in a while too, Jim. Good to see you again.

[oldhickory]

Good morning
Bought 3 of the same years ago. 2 are still in the family. Mine is the only 308 Bolt gun I have up north there and I hapilly keep it fed when stateside.
The RCBS 180 gr FNGC is a good boolit in it.

Hi Mike, I just got one of those molds last week and cast around 200 of the most beautiful boolits with it I ever saw. To say I'm impressed with that mold is a gross understatement, I can't wait to load it my .30's and give it a try. :lovebooli

[Multigunner]

These converted rifles are fine for carefully taylored handloads, and most factory ammunition with bullet weights of 150 grains or less, but I'd be leery of any heavy bullet loads. The chamber pressure of 7.62 NATO and .308 can rise drastically when hevy long bullets are loaded, due to the restricted OAL heavy bullets intrude on powder space.

7.62 NATO Ball of the time frame when these rifles were converted was restricted to 48,000 CUP/50,000 PSI. More modern .308 long range match loads push the 62,000 PSI SAAMI limit for the .308.
M118 Long Range Ball normally generates 52,000 CUP but acceptable max deviation per lot is as high as 57,000 CUP.

M80 Ball sticks to the earlier NATO interchangability standard of 48,000 CUP/50,000 PSI.

[Jim]

.....but I'd be leery of any heavy bullet loads. ....

I quit tryin' to prove anything years ago. No, I have no intention of tryin' to turn this rifle into a Howitzer.

[Larry Gibson]

Multigunner

Not arguing but just interested, where is your information coming from? I ask because I use numerous refferences and specifically TM 9-1305-200, Small-Arms Ammunition, dtd June 1961. I've also measured the psi of the various types of ammuntion you mention with an Oehler M43 in several .308W/7.62 NATO rifles. My sources and actual tests differ from your posted figures. Perhaps you are misconstruing the older CUP "psi's: as compared to modern "psi's" as measured with modern piezo transducers?

Larry Gibson

[Multigunner]

Multigunner

Not arguing but just interested, where is your information coming from? I ask because I use numerous refferences and specifically TM 9-1305-200, Small-Arms Ammunition, dtd June 1961. I've also measured the psi of the various types of ammuntion you mention with an Oehler M43 in several .308W/7.62 NATO rifles. My sources and actual tests differ from your posted figures. Perhaps you are misconstruing the older CUP "psi's: as compared to modern "psi's" as measured with modern piezo transducers?

Larry Gibson

I downloaded a document that was published to correct errors in previous SAA manuals.

MIL-P-3984J
AMENDMENT 3

found at everyspec.com

I know the difference between CUP and PSI readings, thats why I included both when the document gave both figures.
Figures for M118 are given in CUP only.
The figure for M-80 Ball should be 48,000 CUP/51,000 PSI, the Indian Ordnance Factory gives it as 50,000 PSI. Figures for chamber pressures are rounded to the nearest thousand. If the chamber pressure read as 50,400 then it will be listed as 50,000, if the pressure is 50,600 it will be listed as 51,000 ,etc.
There's been a lot of attempts to find a direct correlation between PSI and CUP, but the document I use has the readings in each taken by the factories using each method. No by guess and by golly there.
The reason the document was commisioned was to clear up misconceptions and unreliable information that had been passed on in the manuals.

Maximum deviation figures are used in lot testing of ammunition. If test samples from any lot exceed the maximum deviation figures the lot is condemned, which would usually result in being sold off as surplus.

The most modern long Range match loadings can be found on the Hodgdon site.

PS
Winchester matchgrade cases use a "Semi- Balloon Head" case that allows more effective powder space when 175 gr or heavier bullets are to be used. Winchester now uses the same semi-balloonhead casehead design for a number of other cartridges.
The extra space can allow lower pressures than with the conventional 7.62 or .308 case.

Also

Does the Model 43 measure true pressure?

Yes. It actually measures the strain (or stretch) on the outside of the barrel over the chamber. The strain is directly related to the chamber pressure by the inside and outside diameters of the barrel at the point of gage attachment. This provides an accurate indication of pressure in your gun; the same ammo can give a different pressure if fired in a different gun.

The only way to get a better measurement of the chamber pressure requires drilling a hole through the chamber wall into the case.


The readings from an Oehler M43 appear to be specific to the rifle used.
I suspect these strain gauge methods are subject to many variables, and useful only for comparasion purposes rather than definitive measurements.


Does the Model 43 measure SAAMI pressures?

The Model 43 is not intended to measure pressures in accordance with SAAMI standards. SAAMI standards require the use of qualified test barrels, reference ammunition, proper calibration, and adherence to exacting procedures. Oehler Systems 82 and 83 are made for SAAMI applications. Comparing the Model 43 to our industrial systems is like comparing an accurate varmint rifle to a rugged African double. They each perform their expected functions very well, but they are not interchangeable.

[Bret4207]

Here we go again....

[Jim]

Here we go again....

Yeah, really. H311, if every post I put up turns into a dogfight between OTHER people, I'm gonna stop posting. Sheeesh!

[fishhawk]

well this thread is on my watch list............

[Multigunner]

A simple exchange of information is hardly a dogfight.

Some rather simplistic comparasions have been made and published that gave some shooters the notion that PSI readings for the .308 would run at 10,000 PSI higher than the CUP readings for the same cartridge.
Also the intention for converting WW2 and earlier bolt action rifles to 7.62 , and the proof pressure requirements were often misconstrued.
Due to this , along with increased pressure ranges of modern long range target ammunition in .308, and rather high acceptable maximum deviation figures for milspec long range ball, the British NRA UK has had to call for reproofing of many No.4 rifles converted to .308. Those rifles were safe enough when the lower pressure NATO spec ball was the available and often only ammunition available for match use, but the ammunition now used in competition there pushes the maximum pressure standards for .308 Winchester.

I don't see the 1916 Mauser being better suited to these higher pressures than the No.4.

Rifles of this sort are best used with ammunition of known pressure ranges within the pressure range of M-80 Ball. Lower pressures would be better, since many if not all these rifles have seen some hard use in the past.


Also I'd have to add that if pressure readings from an example of the Oeheler M43 vary greatly from published figures I'd suspect the accuracy of the M43. Its not intended to take the place of the much more sophisticated systems used by manufacturers and regulatory agencies.

PS
I may seem to belabor the point, but having lost a friend, to injuries received after he ignored safety warnings, firearms safety is very important to me.

[oldhickory]

Just keep em light and watch for headspace issues, Jim and you should be o.k.

[Jim]

Just keep em light and watch for headspace issues, Jim and you should be o.k.

Exactly. I picked up this rifle 'cause it was in bad need of a good home, that's all. Although, i know I CAN run full house loads through it, I got it 'cause it's .30 caliber. Another Cast Boolits rifle!

[Larry Gibson]

Quite frankly I don't see the "dogfight" here either. Multigunner has answered my question is all and I've no disagreement with it. I just wanted to know where the information came from for my own use as I, for the most, part concur with it. I appreciate Multigunners detailed response, it was exactly what I was looking for.

As to Jim's rifle I would suggest he try the 311299 over 28 gr H4895 with a 1/2 gr dacron filler. Accuracy has been excellent in numerous FR7/FR8s I have shot it in. If the bore is worn the 314299 might be the better choice.

Larry Gibson

[Multigunner]

Larry
the document I mentioned, MIL-P-3984J AMENDMENT 3, was directed towards establishing specifications for ammunition that would meet the balistic and gas port pressure requirements while remaining within acceptable chamber pressure limitations. Ammunition from some contractors might well deliver the proper velocities and gas port pressures while generating significantly lower pressures, but that would be an unsought and unexpected benefit.

They are basically concerned with the qualities of propellents used by the manufacturers since this is the biggest wildcard in mass production of ammunition.

Ammunition manufacturers run test batches of ammo loaded using propellents delivered by lots. Sometimes variations in propellents require that the actual charge weight be stepped either up or down to deliver the specified velocity using the specified projectile.
Pressures can vary so long as they do not exceed the average working pressures and maximum deviation pressure specifications.
The document goes into extreme conditions as well, such as when ammo becomes heated by storage in amorered vehicles in very hot climates.

A poster on another forum once mentioned that during his service unused ammunition carried on long dessert patrols was sometimes dumped , possibly condemned or held as an emergency reserve. Fresh ammo was loaded aboard before each new patrol. I don't remember when and where this was done.

A book on WW1 munnitions production, told of millions of rounds of ball ammunition being dumped after exposure to harsh conditions. Apparently far more ammo was dumped unfired than was ever fired in combat.
Ammo salvaged from damaged vehicles and scattered by exploding ammo dumps littered the battlegrounds. A British official told of examining a battle site and practically walking on a carpet of unfired SAA that littered the ground.

From the looks of some milsurp ammo I've run across ammo like this scavenged from the battlefields has at times ended up being sold to civilian buyers.

For this reason I'm very leery of most milsurp ammunition. Milspec ammunition freshly maufactured should be fine, though the long range 7.62 may be a bit hot for some older actions, but stuff thats been condemned by lot testing is not something I'd want to put through a new rifle much less an old one.

These days I only buy milsurp ammo in order to salvage bullets and reloadable cases, I reload these with fresh primers and powders and loads taylored to the individual rifle.


PS
I'd like to add that the 7.62 NATO was designed with double base Ball Powder in mind. Ball powders can deliver specified velocities at lower average pressures than the single base powders used for the WW2 era .30-06 cartridge.
Some NATO countries found that double base powders were not so well suited to the gas operation systems in use by their military, Australia used only single base powder for its 7.62 Ball.
Ordinarily single base powders generate higher pressures for the same velocities, but there have been great improvements in manufacturing which have reduced pressures of some single base powders.
The 4007 SSC super short cut powder sounds promising.
Listed loads using 4007SSC (found on the Hodgdon site) that mimic the .303 MkVII generate far lower pressure than any other propellent listed and a good 5,000 CUP lower than the Cordite load which was considered a fairly low pressure load.

I figure the 4007SSC should be a good choice for full velocity loads in 7.62 Conversion rifles.
Haven't found this powder locally yet, very few shops here carry reloading supplies.

Also British target shooters have reported that the most accurate loads for their 7.62 conversions, and modern rifles in that chambering, basically mimic the MkVII .303.
Use of hotter long range target loads is directed at maintaining super sonic velocities at 1200 yards, their longest range match.
My persoanl opinion is that pushing the limits of 90+ year old actions is not very wise, even if the rifle is in excellent condition. In fact a rifle in very good condition should be babied a bit to be sure it stays in that condition as long as possible.

I'd hate to use a hot load in a nice tight mauser then find the lugs had suffered set back after a few hundred or a few thousand rounds.
A friend who built up a number of fine custom target rifles and sporting rifles on various Mauser actions used to bring by mauser actions hat had suffered varying degrees of damage from hot loads. He blueprinted actions for long range match use, so he was very much up on what to look for.

[Larry Gibson]

Multigunner

Lots of good reasoning you’ve posted there. The more I pressure test milsurp ammo (of various different milsurp cartridges), both old and "fresh", the more I also just salvage components, especially from the foreign stuff. I sometimes "adjust" the load to a more favorable pressure level. Done a lot of that with the Turk 8x57 and some combloc 7.62x54R. It's not to difficult to pull the bullets, dump the powder and then reload with a lesser charge, especially with a progressive press like the 550B. Many time I load the powder and bullets in boxer primed commercial cases and use the berdan primed cases with cast bullet loads. Works for me anyways.

I'm fortunate in that I can measure the psi via the Oehler M43. As you mention the M43 gives the psi in the test rifle but I've found psi's to be fairly consistent rifle to rifle given fairly equal bores. I am also fortunate in that the technicians at Federal and Winchester gave me the actual psi of several lots of their different factory cartridges they tested in their "production" test rifles. They Oehler M82 is the industry standard for that. I had bought those lots of ammo in those cartridges so I was able to use that ammo as "reference" ammunition. I was pleasantly surprised as to how accurate the M43 was with those lots of ammunition. I am in receipt of an article by Dr. Oehler where in he had several different methods of pressure measuring (2 strain gauges for a M43 and a M82, two PCB Model 117B31 conformal transducers, and a PCB M165A01 case mouth transducer which is the NATO standard measuring system) to a Universal Receiver that uses the C.U.P. pressure measuring method. That gave 5 transducer psi reading and a copper crusher measurement for each shot fired.

The results of his extensive test measuring the psi of each shot tested via 6 different methods was interesting to say the least. Let me give you a couple quotes from the article; “If all accuracy claims (referring to claimed psi’s) were true, the readings should be practically identical; they are not.”……..”The test reinforces our old contention that a simple description of pressure as “56,000 psi” is incomplete. For a pressure number to be meaningful, the method of measurement must be included.” Perhaps now you see why I asked for your sources, only to make them meaningful in my own research.

Thanks again for the insightful information, most enlightening.

Larry Gibson