Reloading for a worn 7.35 Carcano

[Nelsdou]

Several years ago I picked bought a 7.35 caliber Carcano M38 Short Rifle to compliment another 6.5 Carcano I had, also in that same M38 Short Rifle configuration. The 7.35 is of Terni manufacture 1939 and stamped SA, reportedly exported to Finland during the war. The metal finish is good and the beech wood stock is stained to a walnut finish.  It is a rather odd small rifle, but easy to handle, and the relatively small cartridge (7.35X51) looked interesting from ballistics standpoint.
   


  The 7.35 is a .300 inch bullet diameter to which I procured a number of 128 grain Hornady bullets, reloading dies, and a number of cases resized from 6.5mm Carcano and 257 Roberts brass.
   
  My initial attempt in reloading and shooting this rifle using H4896 and 4064 resulted in really poor scattergun results. At the time more pressing matters deserved my attention so I set the gun back into the safe for further investigation for a future time. I figured that it had some serious defect that would likely take some serious work to overcome.
   
  Fast forward to today to the point I essentially tore the rifle down and re-evaluated the brass and the re-loading information for 7.35. My basic resource for reloading and shooting the 7.35 was the Dave Emary Paper found here:  http://personal.stevens.edu/~gliberat/carcano/
   
  First I did some major cleaning of the barrel and got through all the layers of copper/carbon/copper.  From the teardown of the rifle I found the rifle lands in the bore were in good shape but showed some edge wear or "rounding out the grooves". The chamber was cut with some amount of freebore; I supposed to allow for seating out bullets, debris, or safely from over-pressure, but combined with what I suspect is additional throat wear exacerbates the amount of bullet jump into the lands. By my reckoning the 128 grain Hornady jumps a full caliber before engraving into the rifling. Since the remainder of the barrel looked good and a .291" pin gauge fit tightly at the muzzle, I decided to try some further work to see if the rifle would shoot.  Next was a check on the stock fit up and I found that the bayonet lug and wood were putting a high upward and lateral force on the barrel. Some minor wood work and shaping relieved this and I also polished the muzzle crown for a square clean edge.
   
  Using QL version 3.9 and taking into account the issue of dealing with bullet "jump", I biased the QL queries for faster powders to slam the bullet into engaging the rifling as quickly and squarely as possible but also fill the cartridge as much as possible for reliable and consistent ignition characteristics. The P-max for this cartridge in QL is about 48,000 psi. A promising candidate in Alliant AR-Comp showed 2,700 fps for the 21 inch barreled rifle, 40 grains filling the cartridge 93%, but alas, my local suppliers had none of the AR-Comp in stock. My 2nd choice was IMR 4198 that QL indicated would push the 128 bullets to 2,600+ fps, and I started with 33 grains and a COL of 2.800". Range results were fair but resulted in smoked cases that needed more pressure. Next I tried 34 grains IMR 4198 that filled the cases to 85% and they sealed acceptably staying within the realm of 48,000 psi. The 34 grain load of IMR 4198 worked well given the condition of this rifle and my limited ability to shoot open sights, these being 200m V-notched sights. At a 100yd target my results were averaging consistent groups of 5 inches. That's not bad considering I started at minute of barn accuracy.



Overall the 7.35Carcano is a gun that "works" but is quirky in regard to the .300" bullets, the 200 meter V-notched battle sights, and the 6 round clip loading. A fun rifle to take to a military shoot for show and history but will never be my "go to" weapon of choice.

[gitano]

Hello Nels! Glad to hear from you.

From experience, I respect your reloading skills and efforts, so any of my following comments should be taken with that qualifier into account.

You know me... I like to think ANY rifle can be manipulated to a point where it can shoot "reasonably well". Of course one man's 'reasonably well' is another man's 'atrocious', so I'll clarify my "reasonably well": Better than 3 minutes of an angle. The reasoning behind that personal 'standard' is that it makes sense to me that even with a 'skanky' throat, bore, and muzzle, the skankiness is UNIFORM. In other words, it doesn't "move around" from shot to shot. Therefore, whatever the 'badness' is, it is consistently bad and should throw the bullets in roughly the same direction shot to shot. And we're back to another relative term "roughly". Again, my "roughly" is about 3 MoA. I simply can't conceive of the shot-to-shot variation that is a function of the "hardware", that could sling bullets RANDOMLY. Just doesn't make sense to me.

My thoughts are:
1) With some exceptions, many old firearms had highly variable bore diameters,
2) When bullet diameter doesn't WELL match bore diameters, precision goes to Hades,
3) Milsurp rifles are notorious for having inconsistent bores,
4) Italian (Carcano) rifles are notorious, (deservedly so OR NOT), for having poor manufacturing STANDARDS - like bore diameters.
Therefore, getting a Carcano to "shoot straight", (better than 3 MoA), can be a challenging endeavor.

My personal experience with Soviet rifles colors my attitude about Carcanos, as they share similar 'notoriety' for poor workmanship and quality control. Believing what the "experts" said, I loaded some 7.62x54R cases with .308 bullets. I could not consistently hit a 3-foot by 4-foot piece of sheetrock AT 40 PACES! That from what appeared to be an UNFIRED M-44! The bore was a "perfect" as it was gonna get. So that no one has to "do the math", the "precision" of that rifle with those bullets was WORSE THAN, (not all the bullets actually hit the 3'x4' target), ONE HUNDRED AND TWENTY minutes of an angle. I too, was using open, 'battle' sights. I don't think that was the 'problem'.

Turned out, that particular bore was .312". Measuring all of the 20-some-odd Soviet rifles I owned, the bore dimensions ranged from .307" to .315". THAT'S GROOVE DIAMETER ONLY. ALL were chambered for the 7.62x54R cartridge. More significantly, I think, was the "roller coaster" that was the dimension of the bore as one moved from breech to muzzle. By which I mean the bore diameter varied greatly, within one barrel, as one traversed from breech to muzzle. I couldn't measure the variation, but could 'sense' it using an aluminum 'slug'. If you take an wad of aluminum and push it through the barrel from breech to muzzle, as the bore diameter changes, you can really feel the change in resistance to the aluminum slug as the bore diameter changes. (It doesn't work as well with lead.) The "wow" in some barrels is nothing short of amazing. STILL... in the final analysis, that "wow and flutter" is "consistent" from shot to shot.

So, I suppose that most of the above appears as "the ramblings of Paul as he writes to hear himself speak", but that's not my intent. Rather, my intent was to suggest that there are reasons why I think MAYBE this thing COULD be made to shoot "straightER". The problem, as I see it, is getting the variety of jacketed bullet DIAMETERS that one needs to actually test the rifle's ultimate capabilities thoroughly. I've just never had the motivation to do that with krap Soviet rifles, and I don't have a Carcano. Even though I have NO first-hand experience with Carcanos but plenty with Soviet Mosin Nagants, I am skeptical of the Italian rifles because the Soviet rifles and the Italian rifles share similar reputations regarding quality of manufacturing. I could certainly be wrong in that 'lumping together' of the two.

Paul

[Nelsdou]

I appreciate the input Paul.


This rifle  has a "fair" bore but an oversized throat, and I'm limited to  short-in-length bullets for seating out of the cartridge. I could swage  down some .308 150 to 165 grain bullets to .301 or .300 and I am sure  that could improve the shooting results. But frankly at this point I'm  not interested in swaging bullets for one particular rifle. I got some  improvement in using a faster powder and some minor reworking of the  rifle components and I'm willing to let it go at that.


I  have other rifles begging for my attention that have more accuracy  potential and functionality. For example, I have a post-war Husqvarna  sporter, mauser action in 8mm that I have yet to fire. It appears to  have an excellent bore, a tight throat and Euro spec rifling  (.323/.311). When I push a cleaning swab down the bore I get smooth and  constant resistance but approaching the muzzle I get slightly more  resistance as if the muzzle is choked. My first thought that this is  combustion or jacket residue and it simply needs a deep cleaning. Is it  possible that some rifles barrels could have slight choking by design?

[gitano]

But frankly at this point I'm  not interested in swaging bullets for one  particular rifle...

I  have other rifles begging for my attention that have more accuracy  potential and functionality.

Pretty much exactly my attitude with regard to my Soviet rifles!

As for the 'choking': My honest answer is "I don't know". I DO think the Swedes believed in 'choking' their rifle barrels as I have several 8mm Swede barrels that have never been mounted and are "choked". Not by making the diameter of the bore at the muzzle smaller, but by increasing the size of the OD of the muzzle for about 3 inches. As you know, this effectively 'chokes' the muzzle by not allowing the barrel to enlarge as much as it does as the bullet passes through it farther back in the barrel. Of those 'choked' barrels I have mounted on actions and shot, ALL shoot VERY straight. I have profiled at least one barrel I "made" with the muzzle swell, and it shoots "very straight" as well. I suppose the good news is that a thorough cleaning might answer that question for you regarding your barrel.

Paul

[gitano]

I was looking at the picture in the original post, and was struck, (again), by the 'straightness' of the Carcano. I have never shot one and wonder at the relative recoil. I USED to think that all of the 'angles and dangles' of some of the "modern" rifles helped mitigate perceived recoil, but now, through experience, have come to appreciate and prefer most straight-stocked rifles for how well they handle recoil. So... my question is:

"How would you rate the recoil of the 7.35 Carcano rifle as compared to other rifles of similar caliber and case capacity?"

Paul

[Nelsdou]

Paul, the recoil of the 7.35 is more mild than other military bolt actions that I have fired such as the k98, K31, or 7.62 NATO. Maybe most similar to the 6.5 Swede. The IMR4198 load I used in the 7.35 was relatively fast burning so the muzzle blast was also less than most milsurps.  The stock on the M38, both in 7.35 and 6.5 from the trigger guard back is really short. The Italian military man back then must have been short limbed or assumed to be fighting in heavy coats. From the writer of the paper that I referenced indicated the power of the 7.35 as being comparable to the 30-30 and I'd say that sounds reasonable. The rifle is heavier than it might look as the rear v-notch sight is a metal block that is slightly swaged and pinned onto the barrel.  The bayonet lug is another hunk of metal slipped onto the barrel and bolted into the forend of the stock.


The 6.5 version of the M38 short rifle is also infamous as the Oswald rifle and hence my interest in collecting it prior to the 7.35. Both the 6.5 and 7.35 have constant barrel twist, not the "gain" twist as some Carcano models do. Felt recoil is the same for both.


My experience with the 6.5 was once I got accustomed to shooting it using .266 bullets and found a good load, that I could routinely hit a softball at 100 yards. However my eyes were much better back then when I was doing that shooting. The 6.5 Carcano bullets are long round noses for the caliber and need a fast twist. That transfer of technology over to manufacturing the 7.35 may explain why it has so much freebore in the barrel leade.

[gitano]

Thanks for that thorough 'report', Nels.

Paul

[Nelsdou]

I may give this gun one more shot, no pun intended.


I had been looking for some ARComp powder from AA that appeared in my version 3.9 of Quickload that to be ideal for small cartridge - short barrel configurations, but none appeared to be in stock in my area. Finally, I scored a pound recently on a shipment made to Scheels.


For the 7.35 Carcano 21 inch barrel and 128g bullet, Quickload estimates 2,800 fps with ARComp is possible at 47KSI. My previous exercise had been loading IMR4198, estimated to be more than 100fps slower.


I am not sure if the Quickload estimate is over-optimistic on the ARComp or not, but I am intrigued to try it out. Now if I can get my eyesight to cooperate with the fuzzy v-notch open sights, I can hopefuily get some flat shooting results recorded.


If this shows good results, this ARComp might scratch some other itches I have in the space between fast and slow powders.

[Nelsdou]

My ARComp loads proved to be a bit hotter than I expected. I shot about a dozen at the range with fairly accurate results but the brass showed flatten primers. Double check of the QL the loads should have been well under maximum. Notes to myself on ARComp is to back off 95% on loads approaching the upper end of the pressure spectrum. For this rifle the stated maximum pressure is 47 Ksi. If I do any more loading on this rifle it will be with new brass as well.


On the other hand I got a good result with ARComp on a cast bullet load (lower pressure regime). I have a rifle in Swedish mauser 6.5x55, a small ring turk M98 mated to a 21 inch sporter barrel. I can't remember if it is a Midway or ER Shaw barrel, but it prints tiny groups using Beartooth .265 135g cast bullets w/gaschecks over 19 grains of AA5744. They have not been chronographed but estimated velocity is about 1,800 fps.


ARComp is a slower powder than AA5744, but configuring the ARComp load to provide the same approximate peak pressure as the AA5744, I should get about 100 fps more than the AA5744 load. Range results today achieved similar accuracy and slightly higher impacts on target over the AA5744 load. Yea!


The other thing I find great about this cast bullet/Swede cartridge is that I don't need to resize the case necks between loads; just replace the primers and reload. Hopefully the brass should last many, many loads. BTW this is Lapua brass, I can not guarantee that this would work with other brands of brass.

[Nelsdou]

Another update on the 7.35: I tried several rounds of loading the  128g bullet over 38 grains of ARComp and got excellent (for me) results,  four rounds printing into a group a little over two inches at 100  yards.  However, I'm still having fiddley dimensional issues with the  brass re-manufactured from 257 Robert cases.  Powder Valley Inc. just  happens to have both 7.35 and 6.5 Carcano brass in stock made by Prvi  Partizan, which is very cool as Powder Valley Inc. is less than 200 miles away:jumpingsmiley:.  So  the existing 7.35 brass is going to scrap and I'll start over with load  development with new brass, including case capacity measurement and QL  forecasting.


I am quite pleased with the ARComp  powder. QL predicts 100% combustion in this short rifle barrel with  light bullets and nearly 100% cartridge fill. Muzzle blast is also  noticeably less.

[gitano]

Cool!

We await the next installment. I am particularly interested in seeing what uniformity in case dimensions means at the target butts.

Paul

[Nelsdou]

Upon receiving my Prvi Partizan (PPU) brass I resized a number of cases and did a capacity check between them and the cases made from the Win 257 Roberts brass. The PPU came in just slightly over the 7.35 Carcano standard of 51.5 grains of water and the 257 Roberts cases came in 4% under the standard. Visually between the two, the 257 Roberts cases has thicker rims and case necks than the PPU.


Loads were made up with 38 and 39 grains of ARComp, PPU brass and 128g Hornady SPs. Range results at 100 yds with the 38g load were low and off the paper. Making the misstep that I was left of center rather just low on target I wasted a number of rounds fiddling with the front blade sight before getting it back into proper alignment.  The 39g load worked much better, shooting flatter trajectory and to point of aim. The PPU brass worked flawlessly in chambering and ejection. Both loads were relatively mild in both recoil and muzzle blast. Cartridge primers remained rounded and no expansion was noticed about the case web areas.


Another lesson in measuring cases before relying on QL computations.:o



With the PPU combo with ARComp and the 128g bullets, I am very close to an OCW load at node 5. Calculated velocity for the 39g load is 2,700+ fps. Node 4 is within reach but would require pressure of 58KSI, far beyond what I would want to attempt with this rifle. I believe I can dial it in to be quite accurate with ladder testing around the 39g charge weight which is about 93% fill and 45 to 46 KSI for the 7.35 cartridge.

[j0e_bl0ggs (deceased)]

What is 'KSI'?

[sakorick]

KSI   Thousands of pounds per Square Inch???

[j0e_bl0ggs (deceased)]

The si unit is ksi (lower case) but for everyone out there quickload does not use ksi, was just being pedantic for the general viewer.