Model93 Mauser and 2400?

[tacofrank]

I just picked up a pretty decent 93 carbine in 7X57. I've cleaned it and think I am ready to shoot it. I shoot 16 grains of 2400 under an RCBS 168 grain SP in my 1908 Brazilian and shoots great. I have a 100 plus loaded but no boolits to load a different charge or powder and don't want to cast today and shoot tomorrow.
Is that load to much for a 93? Any of you shoot a 93 with 2400 and if so any thoughts?
Thanks,
TacoFrank

[racepres]

I have an M93 or two.. the 7X57's do Not get a very heavy Boolit...as I began casting 7mm for my TCU.. Anything that the M95 Chilean gets...the M93 gets also.. But... I cannot find your particular load.. I would certainly start at least 10% lower...just to See!!!
Hopefully someone has BTDT... And will Chime in..

Note: I do Not take it as Gospel... But...it has been said, that the M93 from German MFG (mine is) may be stouter, than the Oviedo ...sp?
Spanish Made...or??? Reworked???? Someone Knows.. But aint Talkin... Be nice to Know, as I have one of those... currently being fed 135gr Lee Boolit over Red Dot or Unique..

[tacofrank]

I heard and red the the Spanish metalurgy was lacking. I just like getting old military guns to shoot well with cast bullets. If it shoots will I stretch try to ring gongs a 2,3,and 400 yards. Pretty optomistic. Lol!
We shoot military bolt rifles in compitition out to 500 yards. No real trick for the 03s or Krags.
I have a Lovern mold I think is a 130-40 grain. Might be the way I need to go.
Got 8lbs. of Red Dot and 2 lbs. of Unique.
My Brazilian rifle and goes to 300 yards pretty well concidering stock sights and old eyes.
Thanks for your reply raceprez.
TacoFrank

[atr]

I once had an Oviedo 93 in 7x57 and shot both cast and jacketed without a problem. The problem was that the barrel was junk and accuracy was non-existent. Since I had several other 7x57's I sold off the Oviedo. Personally I don't think your 16gr/2400 with 168 cast should be a problem.
best
atr

[pworley1]

The Lyman 44th gives 18g of 2400 as the best accuracy load for the 168g cast. I think you should be just fine with 16g.

[tacofrank]

ATR & pworley1,
thank you both for your replies. The gun was filthy and cleaned up way better than expected and has a great bore no pits and bright. Good to decent trigger. Should be a fun project. May be shoot as well as my Brazialian 1908? Can't expect much for $50.
Fingers crossed. Lol!~
Thanks Again for your rplies,
TacoFrank

[uscra112]

16 grains is pretty mild - QL calculates peak pressure at only 20,000 psi.

[tacofrank]

Thanks uscra112,
I really appreciate your reply. I've used 14-16 grains in several military bolts but none with questionable metalurgy sp?. I picked the 93 up Saturday and started the clean up as soon as I got home. Planned on loading some 14 grain ammo and realized I had loaded all my 7mm bullets. Now I feel comfortable shooting this carbine.
Should be shooting in a couple of hours.
Thanks again for your reply.
TacoFrank

[racepres]

I heard and red the the Spanish metalurgy was lacking. I just like getting old military guns to shoot well with cast bullets. If it shoots will I stretch try to ring gongs a 2,3,and 400 yards. Pretty optomistic. Lol!
We shoot military bolt rifles in compitition out to 500 yards. No real trick for the 03s or Krags.
I have a Lovern mold I think is a 130-40 grain. Might be the way I need to go.
Got 8lbs. of Red Dot and 2 lbs. of Unique.
My Brazilian rifle and goes to 300 yards pretty well concidering stock sights and old eyes.
Thanks for your reply raceprez.
TacoFrank

I too heard about the "soft" Spanish Mauser.. things I have Personally Found. Yes..Mostly accuracy is Poor... in 7X57, probably due to Reworked Arms with Worn out Barrels.. yet I have one with German Markings, obviously converted to 1916 specs, which performs right next to the Chilean, which is Serviceable indeed..
the notion that the Steel is Soft??? Not on the One I D&T'd... harder than any I have ever D&T'd, and that is a Few, not a Couple. Also, once there was a plethora of 1916's in 7.62X51 NATO, around me.. Cheap, (yes I have one too) many around here have been fed a Steady Diet of factory 308's... I have the go-no goes for that and I am usually the one who checks them... all still just fine...
Bottom Line.. Check the bore (dimensions) carefully...and Maybe give her Fatter Boolits...

[Larry Gibson]

FYI

Some will say the M1916s and other Spanish M93s were intended for the special "CETME" cartridge developed for the first non-fluted chambered CETMEs to function. It is erroneously believed the 308 CETME cartridge has a lower pressure than 7.62 NATO cartridges. The M93/M1916s were made to use 7.62 NATO cartridges and could also use the CETME cartridge. Here is the Spanish manual for the rifles;



Additionally, I have a bit of Spanish CETMA Ammunition and have pressure and velocity tested it. Surprise...surprise the psi was 60,000!





I've also done a comparison of numerous different 308W, 7.62 NATO and 7x57 ammunition.

Here’s the pressure data I’ve taken so far with the Chilean M95 7x57 Mauser using an Oehler M43 PBL. The M95 is in excellent condition, has been “sporterized” with the original milsurp barrel now 22” long. All measurements are in “psi’s”as to conform to SAAMI and C.I.P. psi MAP and PTc max measured with conformal peizo transducers. All the psi’s listed are not “absolute” as they were measured using the commercial and military grade ammunition made for such arms. As with measuring velocities, measuring the pressure on one day may not be the same as what is measured on another day can vary when tested even the very next day under the same conditions. All testing was done using SAAMI testing procedures including the use of “reference” ammunition to obtain a “standard” psi measurement comparable to the standards set by SAAMI and C.I.P. All pressures shown are with the correction factor obtained through reference ammunition used. All velocities are muzzle velocities not screen velocities and are shown in fps. The psi figures are shown in thousands and hundreds, I. E.; 54,9 would be 54,900 psi.

All the following loads were tested yesterday. Ambient temperature ran from 70 to 80 degrees but all equipment including ammunition was shaded. Test consisted of 10 shots with the rifles switched after each test to keep the barrels cool. Two “foulers” were fired prior to each test string (as per SAAMI procedure). Yes it was a long 8+ hour day.

For the 7x57:
The SAAMI MAP is 51,0
The C.I.P. PTc maxis 57,0
Both are with transducer measurement.

Commercial Factory and hand loads:
Federal 175 RNSP; 49,9 2400
Rem-UMC 175 RNFMJ; 57,2 2311
Remington 175 RNSP; 48,2 2393
Winchester 175RNSP; 50,2 2376
My standard load 175 RNSP; 49,2 2334
Hornady Light Magnum 139 SPBT; 44,5 2624
My standard “light” hunting load 154 SP; 55,7 2579

Military Surplus:
CAVIM (Venezuela) 139 FMJBT; 46,0 2590
PS 1950 (Spanish) 154 FMJBT; 59,8 2442
PS 1951 (Spanish) 154 FMJBT; 60,5 2543
FAMME (Chile) 133 FMJBT; 55,3 2718
DWM 1918 (German) 172 Cupro RNFMJ; 54,8 2295

As we see the psi of both commercial and military ammunition made in 7x57 runs from 44,5 psi to 60.5 psi. Note the Chilean made military ammunition made for their own M95 Mauser gave a MAP of 55,3 psi, just under the C.I.P. PTc max of 57,000 psi.

Now, the original question of this thread was basically if 7.62 NATO ammunition would be safe in the M95s Chilean Mausers converted to “7.62. My response was if the M95s had new barrels most 7.62 NATO would be safe as most or the psi's of the ammunition over lapped. However, if the M9 5had a sleeved chamber and a rebored barrel then I would not feel it was safe. So now having some actual measured pressures of varied 7x57 ammunition let’s take a look at some actual pressures of varied .308W and 7.62 NATO ammunition actually measured with the same equipment.

The .308W/7.62 NATO test rifle was a M1909 Argentine M98 Mauser with a 24”heavy sporter contour barrel. The chamber was cut with a match reamer and headspace set to the minimum SAAMI spec for the .308W cartridge. Testing was done with the same Oehler M43 PBL using the same SAAMI testing technique as used testing the 7x57 ammunition. Reference ammunition was used to obtain the correction factor to give the psi as listed in thousands and hundred. The velocity is corrected to the muzzle and given in fps.


.308W/7.62 NATO:

SAAMI and C.I.P. MAP and PTc max; 62,000 psi as measured with transducers.

Commercial ammunition:
Winchester 150 PP; 61,7 2903
Remington 150 CL; 54,5 2924
Federal 150 PS; 57,3 2891
Winchester 180 PP; 57,7 2574

Military Ammunition:
M80 Ball WRA 68; 5 2,8 2790
M80 Ball LC 87; 61,2 2924
M80 Ball LC 90; 57,3 2852
CETME (Spanish) P 7.6 62; 58,7 2694
M118 SB LC 88; 62,9 2694
M118 LR (175 MK over 42.2 IMR 4064) LC 07; 59,9 2633
M852 MATCH LC 89; 59,0 2627
M852 duplication load (168 MK over 41.5 H4895, WLR, LC Match case); 57,4 2670
M852 duplication load #2 (168 MK over 42.5 IMR4895, WLR,LC Match case): 61,3 2730

Thus we see here the psi of commercial .308W and military (U.S.) 7.62 NATO runs from 52,8 psi to 62,9 psi. Comparing the commercial ammunition psi’s to the M80 Ball psi’s we see there’s not a lot of difference between .308W and 7.62 NATO. We also see that with the exception of 2 loads (one each commercial and M80 Ball) the rest fall within the psi’s the tested 7x57 ammunition psi range.

Those are the actual measured pressures of cartridges used in 7x57 and .308W/7.62 NATO rifles. Obviously the measured psi’s are different, as they should be, than the pressures listed on “data sheets”. All the measured pressures were within the SAAMI MPLM (Maximum Probable Lot Mean), EVPAT 7.62 criteria and the C.I.P. PK (Maximum Individual Statistical Pressure).

[yeahbub]

In the 7x57, 30 cal., 8x57 class of cartridges, 16gr of 2400 is a classic start load for cast boolts of conventional weight and design. Your stated experience in your Brazilian speaks for itself as a place to start. Thats where I started in 7.62x54R with bore riders and Loverins. YMMV with experimentation with various weights/lubes/sizing diameters, etc , but I'd say you're in the zone, so to speak.

I was hoping a '93/'95/'96 donor action would fall in my lap to build a front-locker .30-30 someday specifically for cast, but if it was in 7x57, whats not to like?

Good luck and keep us informed how your efforts turn out.

[atr]

tacofrank
check the barrel crown....it that is bunged-up your accuracy most likely will be nil.
atr

[tacofrank]

Thanks all for the heilp and replies. Especially Larry Gibson. Wow! great replie Larry. I've copied and saved your info and with your OK will share it if and when the need arrises.
Took the rifle to the range and while I had fun it grouped 6-8 inchs at 100 yards and 7-8 inches to the left. Barrel is in very nice shape with great rifling and a bright bore and crown. My bore riding bullet easy enters the bore. I need to slug the barrel and get a bullet to fit. Might try powder coating the ones I have to increase size a little.
I thought I replied to this thread a little while ago and it has disappeared. Sorry to be redundant if this reply has appeared earlier.
Again many thanks for your help and replies.
TacoFrank

[yeahbub]

It sounds like your bore-rider's nose is a bit small which may well explain the large groups. Your bore-rider's nose may also not quite reach the rifling in a long or worn military throat. This is a problem I've run into in mil-surps with some regularity. One trick I use to arrange a proper fit in a generous throat is to paper patch whatever mold I'm already using. The bore-ride noses are alrady the correct diameter to patch to groove diameter+ anyway, which increases diameter up front where it can make contact and center properly. Some folks size their boolits to bore diameter and then patch up, but I've had good results patching conventional designs as cast and sizing them afterwards, usually the day I cast them, while they're still soft and size easily with a smear of lube on the paper.

[uscra112]

A bore rider's nose should not enter the rifling easily. And if it fits at the muzzle it may not fit back close to the breech.

Slugging the bore isn't an easy way to measure the lands - better to use gage pins, but that risks damage to the rifling if not done very carefully. Some time ago I made some aluminum pins to do this for a rather rough old Krag. Not accurate to tenths, but it told me enough.

That said, it'll be a lot easier just to powder-coat or patch some of your bullets to tighten up the fit, and run another trial. Let us know how it works out.

I've been building up a couple of .28-30-120 single shots over the last year or so, which means I've cast a supply of 7mm bullets. This thread reminded me that I have a 7mm Mauser myself, which I've never even tried out. Got brass, too, so there's yet another candidate for a range date. *sigh* I think that makes 15.

[tacofrank]

Yeahub,
I think I'll try powder coating first. I pretty new to it but so sfar pretty successful. I've never paper patch any bullents and will most likely give it a shot.
Thank you for your replie.

[tacofrank]

uscra112,
I will powder coat, measure and if needed put another coat on. I have a 1908 Brazilian that shoots great (To me) with my bore rider. I have a Lovern mold that that I don't remember the size and weight it casts. I'll play with it in both rifles.
Thank you for your repliy.
TacoFrank

[blastit37]

I hope you guys know that a brand new military 7x57 barrel is .286 in. not .284 in. as U.S. 7x57 bullets are. That is why long 175g bullets work so well in the old Milsurps, they don't pitch and yaw down the barrel as much as a liter one does.

[tacofrank]

Hi blastit37,
After I size and lube I am at .285-.2855. Hoping powder coating will bump me up enough to reduce groups to a considerly smaller size. I cast outdoors and its been to cold for me to cast.
I'll also try some as cast without gas checks.
Thanks for your reply.
TacoFrank