7.5x55 swiss loads

[wayne h]

i am looking for loads for the 7.5x55 swiss that uses a 170 grn gas checked cb. the powders i would like to use is either h4831-h4895-imr 3031 or aa2520. does any one have any such loads you would share. thanks wayne h

[mag_01]

Wayne I use A 200gr boolit gas checked with 29grs. to 35grs. of IMR-3031 .

[wayne h]

thanks for your reply. i now have something to work with. wayne

[FAsmus]

Wayne;

For more loading information on the 7.5x55 I have used data associated with the 7.62x51.

The cases are close enough capasity for data to interchange reasonably well and CB loads shouldn't really press the pressure limitations of the K31 anyway.

Good morning,
Forrest

[FAsmus]

Gentelmen;

Just an update here, although I'm mystified about why lots of the posts on this thread no longer appear.

Just lately I have run the K31 through another of the "proving tests" done to see if the loads worked up last summer still print as well now ~ in the cold of winter ~ as they did during the heat of the year.

The answer is; Yes! The load of 29 grains Varget and the RCBS 30-165-SIL is still shooting very well.

Just a note here regarding the thread on 7.5x55 Swiss dies. I load only with the Lee collect neck-sizer dies and so far the cases have 7 cycles since new. No signs of excess sizing (why? when it may be held to the minimum necessary?) and dedly accuracy every time.

Good afternoon,
Forrest

[Buckshot]

Gentelmen;

Just an update here, although I'm mystified about why lots of the posts on this thread no longer appear.

Just lately I have run the K31 through another of the "proving tests" done to see if the loads worked up last summer still print as well now ~ in the cold of winter ~ as they did during the heat of the year.

The answer is; Yes! The load of 29 grains Varget and the RCBS 30-165-SIL is still shooting very well.

Just a note here regarding the thread on 7.5x55 Swiss dies. I load only with the Lee collect neck-sizer dies and so far the cases have 7 cycles since new. No signs of excess sizing (why? when it may be held to the minimum necessary?) and dedly accuracy every time.

Good afternoon,
Forrest

...........Forrest, possibly you're refering to this one ?: http://castboolits.gunloads.com/showthread.php?t=72704

If so it's still here and intact :-)

.............Buckshot

[Calamity Jake]

"Just an update here, although I'm mystified about why lots of the posts on this thread no longer appear."

Go to the bottom of the topics page(in this case CB Loads/military rifles) and change amount of subject lines from week to month or whatever you want then click apply.

[FAsmus]

Gentlemen;

Yes ~ I belatedly went looking more carefully and found that thread too.

Thanks for the reminder though.

Good afternoon,
Forrest

[inuhbad]

FASMUS,

What's your Overall Length of your 7.5 rounds loaded with the RCBS 30-165-SIL boolit?

[FAsmus]

Inuhbad;

The overall loaded length is 2.930, which compares well with 3.045 for the ball round I have on hand. Thus the cast load works through the magazine perfectly.

Good evening,
Forrest

[bkbville]

FAsmus et al:

Does the bolt completely close on the 2.930 with the 165 sihl, or do you have to slam it hard?

[jonk]

I find that 30 gr of 4895 and a 200 gr bullet works fine in my G.1911. The K31 is trickier with the short throat, but if you play around with it it will work. Personally I do best with the Lee 155 gr in the K31 as it is a bit more pointed and rides up into the bore better than most cast designs... that is the ogive is more favorable.

[FAsmus]

Bkbville;


Does the bolt completely close on the 2.930 with the 165 SIL, or do you have to slam it hard?

F- The bolt closes with gentle pressure, allowing the straight-pull cam to work easily. I'm sure the cartridge overall length has to be adjusted to fit the individual rifle in consideration of the wear in that particular rifle's barrel. Mine is 2.930, anyone else's will be determined by trial.

Good morning,
Forrest

[bkbville]

Jonk,
Yeah, the K31 is challanging.

Just about anything I cast fits in my K 1911, but the 155gr Lee (I assume the 312-155-2R is what you mean) is too big for my K11's throat - I have to seat it back.

I'm aware of the bump die but I'm hoping the 165 Sil works out.

My test seating comes in at 2.850 though I haven't had a chance to shoot these.

[jh45gun]

Twenty grains of 2400 and any cast bullet from 150 to 180 grains with a gas check using the bump die works just FINE.

[roverboy]

Thanks everybody for the info. I've recently got interested in loading for the 7.5x55.

[Ray1946]

My Lee 180 gr. casts at 168grs. and produced some really nice groups sitting on top of 19.0 grs. of 4759 and a Rem 9 1/2 primer. This load was used in a 1911 and a 96/11. I have a K31, but haven't done any cast bullet shooting with it yet..................Ray

[PatMarlin]

I pulled everything out of the safe for an inspection and wipe down. Ran a patch down all the bores as well. Life has been a bit hectec the past few years, and this was way over due. Good thing to as there were a few little rust specks that got in there. Actually 4 specs to be exact on 2 rifles. Must be from handling and not wiping down before putting back in. just minor and dissapeared with 0000 and some oil.

Which brings me to my K31, that's sitting next to me right now. I never fired cast through it yet. What are the pressure limits of the K31?

They sure are neat rifles. I love the bolt and action on it, plus the overall feel. Swiss have always made good stuff.

[Bob S]

From the original Swiss manuals for the K31 and K11:

Maximum chamber pressure ........ 3200 Atm

(3200 Atmospheres = 47,027 psi)

Resp'y,
Bob S.

[madsenshooter]

From a CIP data sheet sent to me by Dave at CH4D: Pmax=3800bar = 55,114PSI The 3800bar is by transducer. I'm out of picture room or I'd post the data sheet. The same is on the Swiss rifle site, but someone removed the pressure data.

[Pirate69]

Think you are both right.

The original chamber pressure spec for the K31 cartridge is 3200 bar or 46,000 PSI. The current CIP spec for the 7.5x55mm GP11 Swiss cartridge is 3800 bar or 55,000 PSI. Spec velocity is approximately 2600 fps with a 174 grain bullet, performance easily surpassed with safe handloads.

[madsenshooter]

Could be the 46,000psi was set because of the older rifles the GP11 could be fired in, but since they've sent all those to us, it's been upped. Don't know, but I have shot a few fairly hot, 2700fps+, 168gr loads in my K31 with no problems, no sticky extraction etc. This is with a K31 die that doesn't size the case as much as some others. I think that Swiss rifle website removed the pressure data out of respect for the older rifles available. The massive receiver of a K31 has to able to handle loads on par with the 30/06 in my opinion.

[j20owner]

Some 1911's were converted to .308 Win after being imported here in the states about 50 years ago.

[Pirate69]

I actually bought one in the early 70's and sold it in the mid 80's. Had an offset scope and a poor mount. It was fun to shoot. I broke the bolt stop somehow and had it brazed.

[madsenshooter]

What was I thinking, the diff is probably the same we've seen here in crusher derived pressures vs transducer derived. Same pressure, different #'s

[PatMarlin]

Below 47k is goodn'uff for me. Thanks ...:Fire:

[Clark]

At least 6 years ago:
7.5mm Swiss, K-31, 284 brass sized with Lee die, CCI200

1) 168 gr Sierra .308 Match King

a) 42 gr IMR4895 ok, kinda wimpy
b) 45.5 gr IMR4895, ok, primer starting too flatten, 4" group open
sights

2) 189 gr cast w/gas check, .3095
a) 28 gr IMR4895, ok, 10" group open sights

I never shot those K31 rifles again.
I put them in storage and have not thought about them since.
I am not shooting again without a scope.
I can't see the target.

[the other DWS]

I recently acquired a nice old Martini-actioned Swiss Schuetzen in the 7.5 Swiss cartridge. I'm hoping to get it tuned up so that I can use it in the Centerfire, 200 yd ASSRA offhand matches next season. Loads on this thread seem pretty much relative to the bolt action rifles. Anyone have data/experience with cast bullet loads?
IS there any significant difference in the earlier versions of the case?

(FWIW I have not yet checked the other thread---might be all my questions are answered there)


toDWS

[madsenshooter]

I'd do a chamber cast so you know just what you have. I'd mentioned Dave at CH4D sent me some CIP data sheets, one was titled 7.5x55 GP11 and from the drawing appears to be a tapered case. It doesn't have a shoulder! He had no idea what it was, nor do I. It isn't the GP11 7.5x55 Swiss military round!

[FAsmus]

The other DWS;

Sure there are!

My Swiss has not and will not shoot jacketed until it passes from my hands.

My current #1 load is RCBS 30-165-SIL over 29 gr Varget. This is not a one-hole group load, especially with the military sights but is reasonably fast and shoots consistently for week after week.

Also used in the process of load-working was RCBS 30-180-SP and various loads of powder. Things like (again) 29 gr Varget, or 22 gr IMR 4198 or 20 gr SR 4759 ~ this is really easy stuff to come up with since the 7.5x55 is very similar to the 7.62x51 and cast bullet loads may be transposed with good success.

Good afternoon,
Forrest

[STP22]

Forrest,

I`m with you in regard to never using j-word bullets in my K31;)

The additional loads offered up in this post has prompted me to take additional notes as to some other powder choices I`ve yet to see referenced. Now that the weather has cooled off a bit I can plan on making a real effort to keep plugging away with what has shown promise a year ago, Unique and either of the RCBS Silhouette boolits....and now some other recipes too.

My store of Varget is reserved for local F-Class matches for my Savage 6BRX.

Scott

[excess650]

My favorite cast loads for the K31 are:

22gr AA5744 F210 primers reformed WW284 cases, Saeco #315 175gr sized .311" and seated out so the bolt requires pressure the last 1/16" to close.

The same as above with Saeco #301 200gr in PP cases.

29gr H322 F210 primers in PP cases, 311644 sized .311" and seated to need pressure to close the last 1/16".

The first (2) loads remain accurate to at least 500m. I've shot the latter load to 900 yards and was pleased with the perceived grouping at that distance.

I DO have an RPA Paramount rear sight( much like the current RPA Trakker), so gives me 1/4moa clicks.

[Mr_yeti]

I have super good 100 yd results with 12.5gr unique, hard cast 22 bhn flat nose GC .3095 170gr bullets. Can touch all 5 with my brother's scoped k31 and 2" iron sights on mine. both are mirror bore rifles and set bullets back to the first band in the case. (I dont have my calipers or journal handy). no leadinf either. clean as a whistle when i swab it.

[airone46]

Maybe I'm O.T. and I do not know English, and the translator of my computer knows less than me !!!

I have read that using bulletts .308 can have problems: people should use a 7.5x55mm Swiss Type S Bushing Neck Die, made by Redding, but in Italy it costs 4 TIMES the real price given by Redding !!! $ 550 !!!!!! + the busches !

I think I calibrated the jacketed bullets with a bush .307: is that something you can do?
For lead bulletts, I could use the .308 or .309 diameter instead. the BULLET SIZING KIT .308 or .309 of Lee precision costs almost as much as a bush !!!

I have a Lee 312 MOLD DC CTL312-160-2R mold, but I still have not had the time to try it: did someone try this mold in K31? which diameter has calibrated the bulletts, and which powder?

Thank you

[hpbear101]

226822
This is my best cast bullet 50 yd group so far in my 1911. It is a Lasercast 170fngc, 18grs of 2400, and a Winchester large magnum primer. I recently bought a NOE 312299 mold and working with that bullet now.

[uscra112]

A few years ago I came into a small quantity of 160 grain Eagan MX-3 bullets, cast very hard, gas checked. On the supplier's recommendation I used 21 grains of Blue Dot, for something over 2000 fps, in Norma brass, CCI LR primer. Rifle is dead stock K-31. I still can't believe how accurate it was. Original sights had me shooting half inch down to bug-holes at 50 yards off ordinary bags. Never followed this up, had other fish to fry, but in the last year I managed to scarf two very similar Eagan moulds off Gunbroker, and need to try it again.

[Oily]

Lyman 311413 spitzer with 25 gr 5744 does well in my K31 if a little dirty. The spitzer design lets you seat the boolit out far enough to keep the gas check in the neck. Only accurate to 200 yds or so but fun with the open sights. If I can hit the 6" gong at 100 yds with open sights without fail I am a happy camper.

[webfoot10]

The Lyman mold 311414 for the 300 Savage works well in the K31.
20 grs of 2400 and bullet GCed and sized .309 works through the
magazine and chambers with no hangup. 1 in groups at 100 yds.
The 311414 by lyman is discontinued, but NOE makes a copy or
you could use the NOE .313-150 Ranchdog mold as well sized to
.309.

[webfoot10]

Maybe I'm O.T. and I do not know English, and the translator of my computer knows less than me !!!

I have read that using bulletts .308 can have problems: people should use a 7.5x55mm Swiss Type S Bushing Neck Die, made by Redding, but in Italy it costs 4 TIMES the real price given by Redding !!! $ 550 !!!!!! + the busches !

I think I calibrated the jacketed bullets with a bush .307: is that something you can do?
For lead bulletts, I could use the .308 or .309 diameter instead. the BULLET SIZING KIT .308 or .309 of Lee precision costs almost as much as a bush !!!

I have a Lee 312 MOLD DC CTL312-160-2R mold, but I still have not had the time to try it: did someone try this mold in K31? which diameter has calibrated the bulletts, and which powder?

Thank you

airone46, The Lee 312 mold 160-R2 might work, but the nose might be too big to
chamber. My K31 measures .307 bore dia. I size the 311414 bullet to .309 and
have no problems, The 311414 tappers down similar to the swiss bullet so slides
in nicely. All you can do is try the Lee bullet. I don't know what powders you have
over there. I use 2400 and AA2520 powder and start at 20 grs. and work up till
you find the load that works best.
webfoot10

[uscra112]

You remind me that mint K-31s are said to have a short throat and leade. If not worn, bullets with a fat ogive won't chamber. Which leads back to the 311414 as being a good choice. Mine IS worn, else that Eagan I mentioned wouldn't fit.

[airone46]

I have the old NORMA 203 (NO the NORMA B203!).
It is similar to the IMR 4320 and the W N135.
Unfortunately for the Italian law we can not hold more than 5 kg of powder and this quantity also includes that contained inside the cartridges loaded!
Once the packs were very small: they were 100 or 250 grams at most. Now the packs are 500 or 1000 grams, and it is easy to exceed the legal quantity!
I also load cartridges for shotguns, so I also have powders for these cartridges!

For this reason I can not buy so many types of powder! Also if a type of powder is not good I spent my money unnecessarily! With the 100 gram packs it was easy to consume them quickly!

The Lee MOLD DC CTL312-160-2R seems to me suitable for the K-31 because the Shmidt-Rubin has a very short trhoat, and this bullet is the one that has the most tapered shape.
Or maybe I'm wrong?

[uscra112]

If that mould actually drops at .312 inches it'll take a lot of sizing to work at all, IMHO. The lands diameter of the K-31 is only .299" in most rifles.

The old 203 looks in Quickload to be too slow for cast bullets. But if that's what you have, try it. 35 grains to start. Cast 'em very hard.

Here's another CB thread that you should read. http://castboolits.gunloads.com/showthread.php?56631-The-7-5x55-Swiss

[Lance Boyle]

The rcbs sil molds work ok too.

[skeet1]

I have just started using the NOE 311-195 K31 mold and it fits my chamber very well because of the tapered nose. Looking forward to testing for accuracy. At this time I'm using 2400.