Reloading for 7.5mm Swiss?

[JHF]

I'm looking for some info for the best approach to casting for my swiss K31... are there any moulds for the 7.5mm swiss bullet? I know that you can use 308 bullets but i figured if there was a 7.5mm swiss mould, it would make more sense. Thanks for any tips

[462]

Neither Lee, Lyman, not RCBS make a 7.5 specific mould, however one of the custom mould makers may have something.

I've been using an RCBS 30-180-SP.

[JHF]

Neither Lee, Lyman, not RCBS make a 7.5 specific mould, however one of the custom mould makers may have something.

I've been using an RCBS 30-180-SP.

do you have any tips in terms of what casings to use and the actual reloading procedure for 7.5mm swiss?

[kirb]

NOE has a mould for the K31 I think is is about 180 gr boolit I am using the brass case from gaff and sons with good luck.

kirb

[Bret4207]

I'm looking for some info for the best approach to casting for my swiss K31... are there any moulds for the 7.5mm swiss bullet? I know that you can use 308 bullets but i figured if there was a 7.5mm swiss mould, it would make more sense. Thanks for any tips

Take a look in the "CB Loads/Military Rifles" and "Military Rifles" section down the main page. Lots of into there. In general terms the Swiss have tight bores and many people are finding new uses for those slightly undersized 30 cal moulds that don't do so well in the slightly fatter American bores.

[sav300]

Try Old West Molds for a mold.Have one for my K31 and it works great,if I do my job.
Measure your bore first tho.

[462]

JHF,
When I first started reloading the K-31s, the only brass I could find was Norma. No special tips or tricks involved, just slug the barrel, like sav300 said, and when you are ready to reload, make a dummy round and chamber it to determine correct seating depth.

[Charley]

If you can't find dedicated 7.5x55 brass, and don't want to pay thru the nose for Norma, .284 Winchester brass works fine. Simple sizing opens the case neck to .308, and forms the shoulder.

[NuJudge]

When it is in stock, this is the cheapest Boxer brass you will find:
http://www.grafs.com/retail/catalog/product/productId/12649

There have been several group buys of molds specific to the 7.5x55 in the K31. The first was a slightly modified clone of the RCBS 165gr Silhouette, made by Lee in 6 cavity (it came out slightly smaller in the nose than intended, which has worked out great-see post #128):
http://castboolits.gunloads.com/showthread.php?t=30157&page=7

The second was a slightly modified clone of the RCBS 180gr Silhouette, made by NOE. I believe NOE then made a clone of the RCBS 165gr Silhouette.

The Swiss K31 barrels when new have groove diameters of a bit under .308", but not enough to make a difference. Distance across the lands is about .297", which is a bit small for the usual .30 caliber mold's nose. The rifling also comes right back to the case mouth on a new(er) barrel, which just about requires a small nose, bore riding design.

If you have a worn K31 barrel, or one of the earlier Swiss designs, you can probably get away with more standard designs.

[JHF]

Thanks for the suggestions so far. Are the custom molds close to the GP11 surplus ammo? When it comes to using Norma casings for example, it's cheaper to buy GP11. I was looking for something economical but effective of course, if such a thing exists. What type of lead would be ideal if I was using wheel weights, the soft stick on weights or the clip ons?

I'm still new to reloading but I figured the first step would be to figure out the bullet casting aspect first. I won't be jumping into anything quickly, just researching slowly bit by bit.

[NuJudge]

Regarding cast bullets being close to the shape of GP11 bullets, such a bullet is unlikely to shoot well, as cast bullets have to have some changes to shoot as well as jacketed: long pointed lead noses are likely to slump to one side, and long boat tails are likely to get mis-shapen also on firing.

The designs you are likely to see discussed as giving good results are "Borerider" designs in the 165 to 180gr range, with a nose section about .298" in diameter, and a body diameter of .310" or so. The nose is likely to be a blunt point or rounded nose to help with feeding and maximize the support given by the tops of the rifling to the nose. For higher velocity uses, the higher pressures in the case will necessitate a gas check design to support the base.

[mpmarty]

Also please note that the only full length sizing die that conforms to the K31 chamber is made by Redding. None of the other dies are correct for the K31 chamber which is just a bit larger than the earlier Schmidt Rubin rifles. Using an RCBS or LEE sizer will work the brass too much. I concur that the Graf brass is a good buy and I too use .284 Winchester to reform to 7.5X55 it is basically a 30/284 wildcat with a different shoulder angle. I try to just neck size after they've been fired in my K31s. I find that I can generally use 308 Winchester loads with no trouble as the case is larger in volume, almost the same capacity as a 30:06 but short and fatter.

[spqrzilla]

Its true that Redding makes dies that more closely match the K31 chambers' unique dimensions. However, I've found that the standard 7.5x55mm dies work adequately and have not had any difficulties from the supposed overworking of brass.

[leadman]

I have been using Lee dies also with no problem at all. I use a RCBS 150-SP mold and it fits the K31 real well.

The GP11 brass is Berdan primed and therefore more difficult to load than boxer brass.

[Dutchman]

311332 with .300" nose and .309" body works perfectly in the K31. You have to seat the bullet deep enough to allow the bolt lugs to close easily since there is little camming leverage like a turn-bolt rifle.

314299 with .304" nose and .312" body works perfectly in the 96/11 but will not chamber in the K31.

I use Lee dies and Norma & Graf brass.

Dutch

[madsenshooter]

Also please note that the only full length sizing die that conforms to the K31 chamber is made by Redding. None of the other dies are correct for the K31 chamber which is just a bit larger than the earlier Schmidt Rubin rifles. Using an RCBS or LEE sizer will work the brass too much. I concur that the Graf brass is a good buy and I too use .284 Winchester to reform to 7.5X55 it is basically a 30/284 wildcat with a different shoulder angle. I try to just neck size after they've been fired in my K31s. I find that I can generally use 308 Winchester loads with no trouble as the case is larger in volume, almost the same capacity as a 30:06 but short and fatter.

CH4D makes a K31 specific die set too.

[excess650]

I believe that Hornady and Redding both make 7.5x55 and K31 specific dies. There IS a distinct difference in that the K31 chamber is larger in diameter at the shoulder by some .012" or so.

My first batch of 100 cases were simply reformed 284 Win cases, and haven't shown evidence of stretching despite the incorrect dies. I suspect that the low pressure cast bullet loads were the key.

My favorite "off the shelf" mold for the K31 is Lyman's 311644. Its 200gr with my alloy, GC and lube. They drop from the mould just shy of .311" and the ogive is .298". There is a bit of taper ahead of the first groove, and this bullet has proven to be a good fit in even new or nearly new barrel. I've shot this bullet to 900 yards over 29gr H322 in one rifle.

The Saeco #315 tapered bullet is also a good bullet with a tapered design. Its a better fit in my rifle with worn throat, but shoots well and feeds from the magazine in other rifle as well.

The Lyman 311041 shoots very accurately in the K31 that I tried it in, but won't feed from the magazine.

[FAsmus]

JHF;

Back there in 2008 I bought a K31 and started a thread about working it up in cast bullet shooting. Many members contributed to the subject and you might find it quite down your ally as a resource for loads/bullets, tuning the rifle to shoot better and for various ideas about sights. Go check it out, it runs to five pages by now;

"The 7.5x55 Swiss"

Good evening,
Forrest