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7.5 Swiss load data

nemesisenforcernemesisenforcer Member Posts: 10,513 ✭✭✭
I'm looking for some good data to use when reloading my 7.5X55 K31. Most sights want me to pay for their info and reloadersnest.com (which I was referred to by a friend) has some good free info, but not on the bullets or powders I use (lots of norma bullet/powder combos, which I don't use.)

I use Speer, Hornady, and Sierra bullets, (currently the Speer 180 grain for all my 30 caliber needs) and Hodgon powders, mainly Varget and 414, though I have some others and access to lots more.

The Lee manual I have has data for the 7.5 but it seems pretty anemic. It's got a respectable case volume and the factory stuff I have put it in the 308/30-06 range. The reload data however urges loads that reduce factory performance by quite a margin.

any resources or loads that you know of that will help me scratch this itch?

Comments

  • jonkjonk Member Posts: 10,121
    edited November -1
    From www.swissrifles.com:

    The following loads have all been found to be quite accurate.

    Remington PSPCL 165gr:
    N203...................40.5gr
    BLC2..................39gr
    3031....................36gr
    414......................43gr
    4064....................37gr
    4831....................47gr
    2520....................39gr

    Military Ball 173gr "pulled":
    414.......................43gr
    4064.....................39gr
    3031.....................35gr
    4350.....................38.1gr
    4064.....................39gr
    BLC2...................40gr

    Sierra Match king 168gr:
    4064.....................43.9gr
    4350.....................46.8gr
    4064.....................37gr

    Sierra Match king 175gr:
    4064......................42gr
    4350......................45.8gr

    Sierra 165gr HP/BT:
    4320......................44gr
    4064......................43.5

    Berger VLD168gr:
    4895......................44gr

    Nominal seat depths for the 1911:
    3.060"

    Nominal seat depths for the k31:
    2.890"

    Addendum: Here are some recent additions to the list.

    1. Bullet: Norma 146gr. FJPBT
    Powder: Vit. N140 49grs.
    Primer: CCI 200
    Case: RWS

    2. Bullet: Sierra 165gr. SBT (2145)
    Powder: 4350 ACCU 51.6grs.
    Primer: CCI 200
    Case: Norma

    3. Bullet: Hornady 168gr. BTHP (3050)
    Powder: 47 grs. ROT R903
    Primer: CCI BR2
    Case: Norma

    4. Bullet: Berger 168gr. HPBT/Moly
    Powder: DuPont IMR-4320 47.4grs.
    Primer: CCI 200
    Case: RWS

    5. Bullet: Lapua D-46 185 gr. (.308)
    Powder: Vit. N160 50 grs.
    Primer: Norma LR
    Case: Norma

    6. Bullet: Hornady 190gr BTHP(3080)
    Powder: Vit. N160 51.5grs.
    Primer: CCI 200
    Case: Norma

    7. Bullet: Hornady 190gr BTHP (3080)
    Powder: ROT R907 46grs.
    Primer: RWS 5341
    Case: Norma
  • jonkjonk Member Posts: 10,121
    edited November -1
    165g
    N203......40.5g.........1.69"
    BLC2......39g...........1.75"
    3031......36g...........1.8"
    414.......43g...........1.56"
    4064......37g...........1.0"
    4831......47g...........1.13

    173g
    414.......43g...........1.10
    4064......39.............97"
    BLC2......40g............1.59
    4350......38.5g..........1.76
    3031......35.............1.97

    k31#2 mfg date 1946

    165g
    3031......36.2g...........1.85"
    4064......37g.............1.0"
    414.......43.1g...........1.65"
    4831......47g.............1.23"

    173g
    414.......43..............1.15"
    BLC2......40g.............1.83"
    4064......39..............0.91"
    4350......38.1g...........1.94"
    3031......35..............1.75

    k31#3 mfg date 1955

    165g
    N203......40g..............1.98"
    3031......36g..............1.87
    BLC2......39.1g............1.40"
    2520......39...............1.55"
    4831......47g..............1.30"
    414.......42...............1.57
    4064......37g..............1.0"

    173g
    4350......38...............1.99"
    3031......35g..............1.85
    4064......39g..............0.88"
    BLC2......40g..............1.65"
    414.......43g..............1.10"

    FURTHER testING

    All rounds fired from an Accurite Rest, all groups consist of two five rd groups.
    Brass, Norma, Projectile- 165g Remington SPLSC & 173g fmjbt, "pulled". Primers, CCI-LR. Brass TTL & champfered inside/outside.

    165g
    4831SC........45g........1.65"
    IMR3031.......35g........1.30"
    IMR3031.......36g......... .70"

    173g fmjbt
    4831SC........48g......... .88"
    IMR3031.......34g......... .90" in a perfect vertical string.
    IMR3031.......35g......... .44" & 1 flyer .82" out
    (second group 3031)....... .71 & 1 flyer .75" out
    All BLC2 loads exceeded 2"
  • nemesisenforcernemesisenforcer Member Posts: 10,513 ✭✭✭
    edited November -1
    those are all from swisslrifles.com if I'm not mistaken. Once again, no load data for the bullets I currently use for my 30 caliber stuff and I really don't want to run out and buy more bullets when I've got a box of perfectly good Sierra 180s to use. Where's the load data for those bullets that actually pushes the 7.5 to its true potential rather than barely 2000fps. I think the 7.5 is capable of at least 308 ballistics if not a hair better, but there's no info on my bullets and within the true power range of the 7.5
  • sandwarriorsandwarrior Member Posts: 5,453 ✭✭✭
    edited November -1
    nemesisenforcer,

    What powder do you want to use? The best for that cartridge would be H4350, H4831 or VV N160 and VV N165.

    Something the K-31 doesn't like is max loads. If you're shooting anything but a K-31 I would think twice about going to max. The older rifles may have good steel but they don't fully support the case head, I understand.

    Behind a 150 gr. Bullet:
    51 gr. of H4350(max)... I recommend 48-9 gr. for good accuracy
    55 gr. of H4831(max)... I recommend 51 gr. I found this to be very accurate and pushed the bullet out at 2760.
    50 gr. of VV N160(near max)...48 gr. was best accuracy load.
    53 gr. VV N165(Max) ...50.5 gr was best load.

    For the 168's(Nosler Custom Competition):
    48 gr. H4350(near max) ...best load was 44.5 gr. -2580
    50 gr. H4831(near max) ...best load was 46 gr. -2670
    46 gr. of VV N160(near max) best load was 44 gr. -2645
    48 gr. of VV N165(max) ...best load was 46.2 gr. This was the most accurate load I shot. 2620

    As a reminder, you should get hold of some reloading manuals and compare. My base data came from Sierra. Hope this helps.

    You could also try www.reloadersnest.com

    Edit:

    A little more thought on this. When I shoot the GP-11, standard 174 gr. Spitzers I get about 2600 fps even. These bullets have an incredibly high BC for a .30 cal of it's weight. Take a look at that long ogive. That is just above .308 performance. The same weight(175 gr.) bullet gets loaded to 2550 for M118LR out of an M24 w/ 24" barrel. With the 20" barrel that load goes to 2450 fps. In truth you should be able to squeeze 30-06 performance from this case in a same length barrel. I would only do that in a same style and quality action. The Swiss K-31 actions are good for strength. But as noted above everytime I get too hot with a load the groups spread out.

    Again, the reason you are seeing anemic loads is because of the older rifles. If you are shooting one of these maintain using a moderate load.
  • Rule.303Rule.303 Member Posts: 11 ✭✭
    edited November -1
    Get yourself a Hogdon manual (a great manual anyways). They list some data for 180 grain bullets. But be cautious about high end loads. If you get '.308' performance from your loads be thankfull. Trying to go beyond that is foolish. Even the late model rifles and carbines were not made that strong.
  • dclocodcloco Member Posts: 2,967
    edited November -1
    As others have stated, don't push the K31 locking lugs. Visit swissrifles.com and read up and take a look at the pictures of results prolonged use of hot loads.

    The case is fully supported. The locking lugs and the way the bolt closes is the reason to stay away from max loads.
  • PA ShootistPA Shootist Member Posts: 686 ✭✭✭
    edited November -1
    I load for my Swiss K-31, and have found (as you might also) that bullet selection is limited to those that have a significant ogive starting well aft. Those bullets that are parallel for a long distance from the base, and any amount forward of the case mouth, may give problems in chambering. The original Swiss bullet tapers from the case mouth forward. The previously-mentioned Remington 150 gr PSPCL works well for me, and is very accurate and readily obtainable.
  • nemesisenforcernemesisenforcer Member Posts: 10,513 ✭✭✭
    edited November -1
    Are the K31s really that weak? Really? I just looked at my chronograph data for the 174 gr. match bullets from switzerland that I've been running through mine and the average velocity for that 174 gr. bullet is 2571 fps. That's about .308 ballistics from a factory load in a cartridge made for the K31. Where would be the harm in reloading up to the same velocity with similar bullets?
  • sandwarriorsandwarrior Member Posts: 5,453 ✭✭✭
    edited November -1
    quote:Originally posted by nemesisenforcer
    Are the K31s really that weak? Really? I just looked at my chronograph data for the 174 gr. match bullets from switzerland that I've been running through mine and the average velocity for that 174 gr. bullet is 2571 fps. That's about .308 ballistics from a factory load in a cartridge made for the K31. Where would be the harm in reloading up to the same velocity with similar bullets?


    Nemesisenforcer,

    The K-31's are very 're-engineered' from all previous Schmidt-Rubin rifles. They have the strength to load up to 30-06 loads. I wouldn't do this with any other Swiss rifle though. The K-31's are the first actions to use locking lugs directly behind the chamber like the Mauser. Previously the locking lugs were at the rear of the bolt. If there were any concerns about any K-31's it would be about the first ones up to the year 1935. In that year they strengthened the action. read here: http://www.swissrifles.com/sr/index.html

    I will tell you I have loaded up the action to high 30-06 loads and found no issues. What I did find is that the action itself doesn't shoot as accurately as it can. It still shoots pretty good but not as good as it did before. I have some Mausers that won't shoot as good as it does with these loads. All I'm saying is if you want a standard military rifle that will shoot holes touching @100 yds./m then load the rifle with 174/175 match loads to around 2550-2600. which, again by the way, is slightly above .308 and not all that far behind 30-06 match loads.
  • nemesisenforcernemesisenforcer Member Posts: 10,513 ✭✭✭
    edited November -1
    quote:Originally posted by sandwarrior
    quote:Originally posted by nemesisenforcer
    Are the K31s really that weak? Really? I just looked at my chronograph data for the 174 gr. match bullets from switzerland that I've been running through mine and the average velocity for that 174 gr. bullet is 2571 fps. That's about .308 ballistics from a factory load in a cartridge made for the K31. Where would be the harm in reloading up to the same velocity with similar bullets?


    Nemesisenforcer,

    The K-31's are very 're-engineered' from all previous Schmidt-Rubin rifles. They have the strength to load up to 30-06 loads. I wouldn't do this with any other Swiss rifle though. The K-31's are the first actions to use locking lugs directly behind the chamber like the Mauser. Previously the locking lugs were at the rear of the bolt. If there were any concerns about any K-31's it would be about the first ones up to the year 1935. In that year they strengthened the action. read here: http://www.swissrifles.com/sr/index.html

    I will tell you I have loaded up the action to high 30-06 loads and found no issues. What I did find is that the action itself doesn't shoot as accurately as it can. It still shoots pretty good but not as good as it did before. I have some Mausers that won't shoot as good as it does with these loads. All I'm saying is if you want a standard military rifle that will shoot holes touching @100 yds./m then load the rifle with 174/175 match loads to around 2550-2600. which, again by the way, is slightly above .308 and not all that far behind 30-06 match loads.


    Good to know.

    When you talk about the action not shooting as accurately as it can, does that only apply to the hot loads themselves, or does it mean that the action was weakened by the high power loadings and won't shoot as accurately with anything because it's been permanently weakened?
  • sandwarriorsandwarrior Member Posts: 5,453 ✭✭✭
    edited November -1
    nemesisenforcer,

    The accuracy diminishes with high loads then comes back when loads are brought back down. 2-3" with hot loads and 1-1.5" with cooler loads. I've gotten groups under an inch with the cooler loads and as small as .445". I've never gotten close to an inch with the hot loads.

    The place you will see the biggest performance factor is the high BC of the GP11 round. Take a look at it and you will see how long and pointed it is compared to the shorter, more abrupt ogive of standard .308/7.62(M80) bullets. There is around a .200 difference in favor of the GP-11 for BC.
  • nemesisenforcernemesisenforcer Member Posts: 10,513 ✭✭✭
    edited November -1
    quote:Originally posted by sandwarrior
    nemesisenforcer,

    The accuracy diminishes with high loads then comes back when loads are brought back down. 2-3" with hot loads and 1-1.5" with cooler loads. I've gotten groups under an inch with the cooler loads and as small as .445". I've never gotten close to an inch with the hot loads.

    The place you will see the biggest performance factor is the high BC of the GP11 round. Take a look at it and you will see how long and pointed it is compared to the shorter, more abrupt ogive of standard .308/7.62(M80) bullets. There is around a .200 difference in favor of the GP-11 for BC.


    I've noticed that it's a very prominently pointed projectile, that's for sure. It and any reasonable reloads can probably shoot better than me anyway, so I'm not too worried. As long as the action isn't damaged or weakened in any way with the heavy stuff, I'll just make some hots and some not-so-hots.
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