6.5x55mm Swedish and IMR 4831

[Fox]

Can I jump in and ask advice on my application? I'm kinda nervous about loading for an older action.

I have a Carl Gustov 1913 with the original barrel thats 18 1/2" . It shoots about a 1" group at 100 yrds after I bedded the action and using "Century Arms" 139gr SP shells. (I think they are Yugoslavian made.)

I have the Speers #14 reload book with the section for old military actions, I bought it because my other reloading books don't mention the military actions for the 6.5x55.
Hornady .264" 140gr SP interlock bullets,
IMR 4350 and Varget, (two of the powders listed in the Speers book)
Federal large rifle primers.

To establish the COL for my intance, could I take an empty case and a bullet and let the closing bolt seat the bullet up to the start of the lands, then remove and measure COL? Then compare that measurement to what is stated in the loading book and adjust accordingly?
Or, just measure the Century ammo that I know works and copy that measurement?
Or, just use the measurement from the Speers book of 3.000"?

Thanks.

If you want to use the magazine I bet you will find that you will have to seat the bullet a lot deeper than the lands to have it function in the magazine. I am loaded to a magazine maximum of 3.15", I have a friend who loads for target shooting, he loads out to 3.25" to best fit the throat but he has very little bullet in the neck, he can pull the bullet out with his fingers and he cannot put a round in the magazine.

I found that the throat of my M38 is shorter than a 96 and chambers just find at 3.15" but not wanting to push it out further as the ammo will be handled for hunting and put in the magazine.

 

[Ganderite]

Load the 4350. Use the book start data and work up in o,5 gr increments, to see what is accurate. Or, if you can access to a chrony, measure your factory and load to a similar velocity.

To approximate the effective distance to the lands that seems to work well with factory ammo, stick a loaded factory round in the muzzle and spin it. That will leave a mark on the ogive. Measure the distance from the bottom of the case to the spin mark.

Seat your Hornady round long and then spin it in the muzzle. Measure the distance from case head to the mark. Keep seating deeper until the mark is at the same place as the factory. That is close enough.

 

[cosmic]

When it comes to determination of maximum load, people are governed by their own convictions. And its obvious that some folks are quite comfortable loading hot, to no apparent ill effect. If I was developing a load for a single rifle of a particular caliber (ie did not intend to use this ammo in any other rifle), I would be tempted to push the load development to posted max(es), with the appropriate precautions.
However, I tend to shoot multiple rifles in the same caliber, so I will try to develop universal ammo that may be used in any or all rifles. In the end, this may be one or two loads that focus on different bullet weights, and powders to serve. I don't go through extensive load development with powder increments, I simply tend to go a few grains above minimum load. This makes life a lot easier for me as I rotate rifles through my inventory as I don't need to do extensive load development for each rifle, just try my basic universal loads.
OP - You seem to have answered your own questions. Please let us know how your efforts go - in particular if you achieve optimal accuracy near max load ...

 

[Ganderite]

BTW, many of the 1919 vintage Carl Gustafs were converted into 7.62/308 target rifle and shot at DCRA and other places for a long time. These shot a steady diet of ammo in the 55,000 to 60,000 psi for years, without a problem.

The action is not weak. As mentioned, the gas handling is not as good as a '98.

 

[jethunter]

The 6.5 bullet has a very long bearing surface. The small differences in barrels and chambers tends to result in a broad range of min and max, depending on what rile is tested.

I have a M36 that blows the primer on a START load.

Start low (say 41) and shoot 5 shot groups in 0.5 gr increments and see what groups well, where you reach the intended velocity and if you see any pressure signs.

This.^

Also throw into the equation that many milsurp 6.5x55 rifles are into their second century of use and have various degrees of normal wear and erosion/corrosion that contributes to the variance in bore and chamber dimensions.

 

[Fox]

OP - You seem to have answered your own questions. Please let us know how your efforts go - in particular if you achieve optimal accuracy near max load ...

The big thing was trying to figure out what others have been doing, by the looks of it most people load under minimum in most cases for a target round. I loaded 41-46.5gr now and will start at the bottom. I also contacted Hogdon to verify their load data for their powder with the rifle in question. I know there are a pile of rifles made in a lot higher pressure cartridges on the 96 action as sporters, they are not weak actions inherently and used within safe limits will be fine. I also know how steel works, unless it corrodes it does not just fall apart over time, you need a seam like damascus or pitting and other corrosion to cause any issues. I wonder how many people believe that 98 Mauser actions will be garbage in 2050 because they will now be 150 years old, even though they are very strong actions.

 

[Rick65Cat]

Just inspected my case stamps as well. I have 111 cases of "nny" which is Yugoslavian manufactured for Privi Partizan and 63 cases of "CA" which is Century Arms made by Norma(?) What I think I'll do is take one of each case exactly the same length and fill them to the brim, then measure each amount on my digital scale to see if theres any weight difference due to case wall thickness differences.

 

[cosmic]

The big thing was trying to figure out what others have been doing, by the looks of it most people load under minimum in most cases for a target round. I loaded 41-46.5gr now and will start at the bottom. I also contacted Hogdon to verify their load data for their powder with the rifle in question. I know there are a pile of rifles made in a lot higher pressure cartridges on the 96 action as sporters, they are not weak actions inherently and used within safe limits will be fine. I also know how steel works, unless it corrodes it does not just fall apart over time, you need a seam like damascus or pitting and other corrosion to cause any issues. I wonder how many people believe that 98 Mauser actions will be garbage in 2050 because they will now be 150 years old, even though they are very strong actions.

Well - The life of steel is a bit more complex than you describe. A flaw in the steel will propagate to failure at some critical stress level, depending upon the size and location of the flaw. Back at the turn of the 20th century people learned a lot about the properties of steel, and how to design with an appropriate margin of safety. For rifles, the protection against metallurgical weakness such as flaws, lack of ductility caused by improper heat treating, alloy impurities etc was the proof loads done after production.
By the middle of the 1900's methods such as radiography, liquid penetrant examination, and other non destructive methods became available for the designer to work to a better defined, and perhaps lesser factor of safety.
Case in point, No 4 Lee Enfields that were destined for 308 usage were radiographed to insure receiver integrity. Receivers were rejected if flaws of a certain size were detected. Proof loads were still applied, based upon the higher load pressures anticipated with 308.
Does that mean that any given Lee Enfield is unsafe to shoot 308 in? Not necessarily, It just means that the original margin of safety has been compromised, and without further survey has an increased risk of failure. As they say in engineering school, welcome to the "perversity of inanimate objects".

 

[Ganderite]

Just inspected my case stamps as well. I have 111 cases of "nny" which is Yugoslavian manufactured for Privi Partizan and 63 cases of "CA" which is Century Arms made by Norma(?) What I think I'll do is take one of each case exactly the same length and fill them to the brim, then measure each amount on my digital scale to see if theres any weight difference due to case wall thickness differences.

No need to fill them before weighting. just weigh them. The outside dimension of the cases is the same. If the case has more brass in it (heavier) the inside dimension will be less (less capacity).

There can be a 40 gr difference in brands of cases. A heavy case takes less powder. About 2 gr less.

Sort your cases by brand and then weigh a few samples of each brand so you know if they are "heavy" or "light". If someone share loading data with you, be mindful that their cases might be the light Winchester whereas your cases might be much heavier.

 

[Fox]

Well - The life of steel is a bit more complex than you describe. A flaw in the steel will propagate to failure at some critical stress level, depending upon the size and location of the flaw. Back at the turn of the 20th century people learned a lot about the properties of steel, and how to design with an appropriate margin of safety. For rifles, the protection against metallurgical weakness such as flaws, lack of ductility caused by improper heat treating, alloy impurities etc was the proof loads done after production.
By the middle of the 1900's methods such as radiography, liquid penetrant examination, and other non destructive methods became available for the designer to work to a better defined, and perhaps lesser factor of safety.
Case in point, No 4 Lee Enfields that were destined for 308 usage were radiographed to insure receiver integrity. Receivers were rejected if flaws of a certain size were detected. Proof loads were still applied, based upon the higher load pressures anticipated with 308.
Does that mean that any given Lee Enfield is unsafe to shoot 308 in? Not necessarily, It just means that the original margin of safety has been compromised, and without further survey has an increased risk of failure. As they say in engineering school, welcome to the "perversity of inanimate objects".

This is true but time itself does not cause a flaw to become a problem, something has to happen, in the case of steel it is generally corrosion that causes the issue. Not all Lee Enfields are safe for 308 but as long as the receiver is not corroded or otherwise damaged they are safe for the originally intended 303 British load. This is the same case with a 1940s Husky action, if there is no corrosion and no damage to the receiver or chamber then you should have no issues loading at the pressures designed for. The fact that the military ammunition was down loaded to 46,000 PSI was not necessarily due to a flaw in the gun but could simply be because they wanted a higher rate of accurate firing and a reduced recoil helped significantly with that.

Again, not talking about doing anything they were not designed to do and all guns need to be checked, even modern ones, but if they are well cared for there is no reason to not shoot something just because it is old, and 80 years is not an old gun anymore, I shoot a few over 100 years old, it is a lot of fun.

 

[Rick65Cat]

Sort your cases by brand and then weigh a few samples of each brand so you know if they are "heavy" or "light".

Weighed the empties of two cases that were identical in length....the "nny" was 186.4 gr. and the "CA" was 188 gr. A 1.6 gr difference.

 

[Ganderite]

Weighed the empties of two cases that were identical in length....the "nny" was 186.4 gr. and the "CA" was 188 gr. A 1.6 gr difference.

That is, statistically, the same weight. If you weight a batch of both types, you will find overlap. This means you can use the same load in each brand.

BUT, it does not mean you can mix the brass. Things like neck tension will be different, so for best accuracy, keep the brands separate.

 

[Fox]

I received an email back from Hodgdon, their data is to SAAMI specifications, 51,000 PSI, so if building up to that maximum load looking for any signs of pressure should not hurt any rifle in good condition with no corrosion or damage. If you have concerns about your rifle have it inspected by a gunsmith.

Here is an article on the small ring vs large ring mauser.

http://www.chuckhawks.com/small_ring_mausers.htm

 

[madtrapper143]

My favourite load is from the Hodgson manual #26 using H4350. It states 2450fps from a 28" model 96 with a 160 grain round nose. My barrel is 24" I have not run this load over a chrony. But recoil is very low and there is absolutely no pressure signs. This load also eliminates black necks so chamber seal is good. My gun is a sported 96 Carl made in 1906 and it kills deer like a lightening bolt. Accuracy is excellent. There is no need to run any 6.5x55 chambered rifle hot. The safety factor aside the Swede kills well and shoots straight with safe moderate loads that's why I like it so much. The same manual lists 140 grain bullet at max with 2708 fps. with a charge of H4350. Again a nice well mannered load that has to shoot flat and far. It is fun to note guys with "old" Winchesters and Savages a round the deer camp that were made in the 1910's and 1920's. When I note my rifle is older they don't seem to believe me.

Darryl

 

[Fox]

My favourite load is from the Hodgson manual #26 using H4350. It states 2450fps from a 28" model 96 with a 160 grain round nose. My barrel is 24" I have not run this load over a chrony. But recoil is very low and there is absolutely no pressure signs. This load also eliminates black necks so chamber seal is good. My gun is a sported 96 Carl made in 1906 and it kills deer like a lightening bolt. Accuracy is excellent. There is no need to run any 6.5x55 chambered rifle hot. The safety factor aside the Swede kills well and shoots straight with safe moderate loads that's why I like it so much. The same manual lists 140 grain bullet at max with 2708 fps. with a charge of H4350. Again a nice well mannered load that has to shoot flat and far. It is fun to note guys with "old" Winchesters and Savages a round the deer camp that were made in the 1910's and 1920's. When I note my rifle is older they don't seem to believe me.

Darryl

I took a few 1915 rifles out to deer camp before too, I do not like anything new but a 1915 military rifle does not look as old as a 1950s Win 94 that they let rust all summer in the cellar.

I went with IMR 4831 mainly because of the low pressure numbers vs velocity, the H4350 has a higher pressure and lower velocity at max listed load with IMR powder. I am hoping to get out on Sunday if it is not too cold to see what groups I can get, I hope for a 2600-2650fps load below max to group under 1 MOA, if I can get that I am golden.

 

[Fox]

I finally went out to the range to see what my gun could do. I shot the 139gr PPU over the chronograph to see what it ran compared to the box, the box claims 2550fps, ran 2450fps average out of my gun. I wanted to check this to make sure my targets were not that crazy, seeing that my gun shot slower than box I wanted to reduce my target a little and go for 2550fps instead of the 2650 I wanted originally.

I shot 41gr, 2450fps, not enough for me.
42gr, 2500fps, not bad.
43gr, under 1 MOA, 2550fps, no pressure signs.
44gr, group opened up a bit 2575fps, no pressure signs.
45gr, heavier recoil, 2675fps, bolt was stiff, not comfortable with the veclocity jump as a sign of pressure and the stiff bolt, no primer issues, no other pressure signs but not feeling it.

My target was an accurate round slightly over factory, 43gr it is, 2550fps, 1 MOA, I have my 400 yard deer gun load.

Giving myself some room with the vertical zone of the vitals I can sight this gun in at 225 yards and have a center hold on the chest of a deer out to 275 yards, at 400 yards my drop will be about 22in, I need to verify these on the range of course.

 

[Fox]

So, it was recommended to me to shoot these loads in the summer, just to check out how they did in hot weather.

The velocity was not much different but I ended up with case head swipe on the factory ammo and the 43.0gr reload. I talked to a few people and did a ton of reading, decided to make sure the bore was good and clean and the chamber was dry and try it again. I was able to get rid of the case head swipe on the factory ammo but the swipe on the reloaded ammo got larger. I no longer feel comfortable with this so going back to the drawing board.

I was told that loading out closer to the grooves may actually increase the pressure so I am going to do this load build up again with the Nosler data that takes into account the Accubond LR bullet, which is the closest I can find to the Hornady ELD-X that I am going to use and set the COAL to that which was recommended, maybe 2550fps in this mauser is asking for too much.

 

[Chilly807]

Velocity and pressure change due to temperature rise and fall is one of the reasons I switched to H4350. I still use some IMR 4831 but I suspect once it's gone I won't buy more. I was using H414/W760 but not in a 6.5 Swede.
Having to adjust loads for temperature is a pia few people need.
The appeal of a temperature- stable powder and load is pretty much universal.
IME, you're right about pressure/velocity increasing with proximity to the lands.
I recently did a seating depth test with a chronograph using a Tikka 243. The shorter rounds were definitely slower than the longer ones. The distances from the lands that I tested ranged from 0.010" to 0.130" in 0.040" increments using 5 round batches with identical powder charge weight.
Your results will vary from mine most likely, but the longer=faster trend should be the same. As I recall, the differences weren't extreme but certainly noticeable.

 

[Fox]

The weird part is that the factory ammo and the reloads changed about the same for velocity, actually both slowing a bit, I would suspect due to the extreme humidity of the day, but not more than the variation of the ammo itself, essentially the factory dropped about 150fps and the reloads dropped about 50fps.

I have the bullets loaded out as far as I could to fit in the magazine, I like this idea, should be accurate but a friend of mine said that the lack of enough jump could cause a pressure increase over standard cartridge length, I thought that if they were not jammed into the rifling I was ok but I may play with it.

I am going to move down to the Nosler load data minimum, 40.5gr and go for accuracy there, I was looking to push this as fast as possible for the action but with the high BC bullet and my goal of a 400 yard deer gun that difference is not all that substantial.

@2550fps I am looking at a 265 yard point blank range when using a 6in kill zone, 1300 ft lbs of energy at 400 yards and 22.3in drop at 400 yards when sighted in at 225 yards

@2500fps I am looking at a 260 yard point blank range when using a 6in kill zone, 1244 ft lbs of energy at 400 yards and 23.9in drop at 400 yards when sighted in at 220 yards

@2450fps I am looking at a 255 yard point blank range when using a 6in kill zone, 1190 ft lbs of energy at 400 yards and 25.6in drop at 400 yards when sighted in at 215 yards

Not really enough to stress an action for.

I will keep this thread going when I get more data, 50 loaded cartridges to break down now but I know the powder so I will be able to save all the components for the build, just annoying as I thought I had it nailed.