7.5x55 Swiss Questions

[Jlr2267]

Ended up at exactly the same OAL, 2.895", based on chambering a partially seated round, then backing off another .01 inches

Does anybody have a good start load with Reloder 17 and a 168gr bullet? I have read that R17 and 4350 are both very good and that R17 is thought to be the factory GP11 powder.

 

[captmoto]

Pretty long read here but this gives about all you could ask to make match ammo. You could definitely substitute (I use PPU brass and Hornady 168s) but Reloader 17 is definitely the powder. This is directly from the Guru of Swiss rifles, Pierre St. Marie.
Being nearly a dead match for the GP11 projectile, we use Berger 175 VLD's exclusively. Identical seat depths put the ogive right at the lands where it belongs.
RE17 also seems to be a dead match for the original powder, and not strange since it comes from the same factory in Switzerland making that powder since 1911. The main difference would most likely (maybe) be the coagulents. Under a scope it looks the same, weighs out the same by 100 logs and even smells the same.

This is ABSOLUTELY NOT a recommendation of any kind for your own reloads or your rifle. This is what we did and how we did it before hBN and using ICP's exclusively.

The brass is and for the past 10 years has been the beefy Swiss RUAG National Match brass. Norma brass will not act the same. The cases are FLS sized on a Forster with the primers being seated on a Forster. If you know the Forster press, you'll understand why this was important to us. TTL is critical and is always done on a Wilson. Projectile seating is done with a Redding Micrometer die and repeatable neck tension is also critical. (For us)

The RE17 data was worked up from 46 grains and ended at 50.1gr with an un-treated barrel. This ended as an accuracy load for us. It may or may not for you. This is a relatively hot load!

The switch to ICP's meant an immediate drop in velocity so we worked back up to 52.1gr of RE17 to achieve the same velocity as with the untreated bores and non-ICPs. The barrels are all hBN slurry sealed now.

There is an inherent danger here if you have rifles with untreated bores in the same rack as rifles with treated bores, and that's exactly why every bore in any and all calibers and rifles in our armoury here are hBN slurry sealed. There's no chance of inadvertently using an ICP with a 52.1gr charge in a rifle with an untreated (read higher velocity) barrel.

As you approach the RE17 47.5gr charges you must chronograph those shots.
Use GP11 cartridges as a MV control base and chronograph them. If you're using a 175gr projectile you'll want to emulate the MV of the GP11 with your own reloads. From there, follow the groups as they open or tighten. They can close, open and close again up the scale. Consider 5 round groups as your minimum. Once you're satisfied with that, go to 10 round groups to make it prove itself.
Record/chrono every shot until you find that golden recipe for your particular rifle. You may end up with a completely different and lower charge that works for you.

Just for fun, break a GP11 cartridge and weigh the charge and projectile weight, then run a complete spec check on the case. It's informative and educational.

Good shooting and reload safely and logically. Record everything.
If you don't have a Chronograph, this will all be a roll of the dice, and not a very safe one.

 

[Jlr2267]

Pretty long read here...

Fantastic info captmoto! Sounds like you have this load figured out. I have to admit that loading "off the books" makes my butt clinch a little bit. Your kindly shared info eases my concerns greatly. Thank you.

 

[35 Whelen]

Loading the 7.5x55 is one of those subjects that is way overthought. I've used FL Lee, FL RCBS and mostly the Lee collet die. They all work fine. I really believe the "this die is for that rifle and this one for another" is largely internet rumor, but I could be wrong.

I shot two or three years of local High Power with a K-31 so have loaded and fired thousands of rounds. I mostly use cast bullets, but did quite a lot of load development and testing with jacketed. You can buy expensive match bullets if you want, but the most consistently accurate bullet I tried was the homely, unassuming Hornady 150 gr. FMJBT. I even fired a couple of 600 yd. groups and it did quite well at that range. I even got very good 100 yd., accuracy from .30 caliber 150 gr. M2 pull down bullets. Re-15 is your friend.

THe Hornady:





Photobucket is acting up so I can't post anymore pics!
35W

 

[Jlr2267]

Loading the 7.5x55 is one of those subjects that is way overthought.

Thanks 35Whelen, I'm trying to keep it simple...Lee dies, PPU brass, Hornady 168gr BTHP, Reloder 17, Winchester Primers. I've got my ladder loads ready to go. Hope to shoot them next week. It's a tack driver with PPU 174gr SP and GP11 surplus, so I know it's capable. I just have to dial in my reloads.

 

[atblis]

Which Lee collet neck die are you using?

 

[35 Whelen]

Which Lee collet neck die are you using?

I'm using the Lee collet neck sizing die.

35W

 

[atblis]

Is there a 7.5x55 collet die?

Google says there is now. I swear there didn't used to be.

 

[Hikingman]

Yes, there's a Collet Die.

Here's my setup with part numbers:
Lee Collet Set #90186 (7.5x55);
Hornady #644360 Series III (7.5).

 

[Dioxin]

quote from 35 Whele
"Loading the 7.5x55 is one of those subjects that is way overthought. I've used FL Lee, FL RCBS and mostly the Lee collet die. They all work fine. I really believe the "this die is for that rifle and this one for another" is largely internet rumor, but I could be wrong."

I'm afraid you are wrong

I've recently had this proven to me that this isn't overthought.... I just bought 600 once fired RUAG Match Boxer cases... the first thing I do is run them through the Full length resizer I have from Redding marked "7.5x55 Swiss" I then attempt to chamber them in my match rifle...no bueno!!!! I use a candle to place soot on the neck area to find out where the contact is.... its in the shoulder...

I then implement some googlefu to find out that my Redding Die is actually for the K31 chamber and NOT the GP11/7.5x55 Swiss data.

So luckily for my current reloading efforts, by using rounds only shot in my rifle I've been fine, but as soon as I've tried to use a round chamber in a K31 I get MAJOR issues chambering the rounds. K31 shoulder diameter is 11.90mm the standard GP11 shoulder diameter is 11.63mm. So I've been neck sizing in a FL Die where I thought I was Full Length resizing!!! So now I have to order a new Die and play pot luck almost that its the right chamber....

I reload 7.5x55 Swiss Extensively let me know if you have further questions.

Regards

Dio

 

[tcoz]

Dioxin is absolutely correct. The Redding 7.5x55 Swiss die set is exclusively for the K31. I believe RCBS might make two separate sets.

 

[Edarnold]

7.55x55 Swiss reloading history:
Back in the day, when the widely sold Swiss surplus rifles were the long and short 1911 series, and K31s were only available from a few importers with contacts in Switzerland, things were different. This was before there was RUAG boxer, Prvi Partizan, Hornaday Custom, or any other boxer-primed brass except the expensive and scarce Norma stuff to feed your need,and the excessive sizing of brass fired in a K-31 by the GP-11 dies of the day was in fact a big deal. Losing cases to cracking, or having to anneal to extend case life, was a major drawback to reloading, and was probably the main cause for the heavy demand for surplus GP-11: reloading for most shooters was just too much hassle. So there was great rejoicing when Redding announced that they would be making dies especially for reloading for the K-31. Since then, the default Swiss rifle most shooters acquire is the K-31, not one of the venerable G- or K-11s, and the needs of reloaders have changed accordingly.
If you have a rifle from the 1896/11 or 1911 series, you can get a correct sizing die for the GP-11 chamber from RCBS, for one. Just make sure you specify that's what you need. And be so grateful you can get all this excellent boxer-primed brass so easily.


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