7.5 Swiss

[dak0ta]

Hi,

I was wondering if Redding makes the best dies for my K31. Also, should I get 284 Win brass and resize it or just get 7.5x55 Swiss brass? Does it really make a difference?

Also what kind of powder and bullets and primers do you recommend?

Cheers,

Dak0ta

 

[cougar1717]

I'm not sure about the dies, but I've got a friend that loads for his K31 with Prvi brass. Since the cartridge similar in projectile and capacity to .308 Win, some of powders and projectiles (H4895 and the like with your choice of .308" bullet) that work in .308 Win are good choices for 7.5 Swiss. Do not use .308 Win reloading data for the 7.5 Swiss (obviously), but the powder and projectile choices are similar.

 

[Slamfire]

Get 7.5 Swiss cases.

Back when the only 7.5 Swiss cases were Norma, at $2.00 each, I sized and trimmed 284 brass.

It worked, but the rim was smaller. So the occasional case would fall off the bolt face during extraction. Not a problem if you want a single shot rifle, but otherwise it will cause a jam, and you have to get your fingers in the action to get the case out.

I conducted some load development for the 7.5 Swiss. I have never purchased Swiss ball, but a bud gave me a chance to shoot some across my screens.

AA4350 gave excellent accuracy and just about duplicates Ball velocities with 51.0 grains and a 168 Nosler Match bullet. As you can see 52.0 grains produced velocities over Ball, so I do not recommend that load. It is here for reference. Incidentally AA4350 is Accurate Arms copy of IMR 4350, they told me grain for grain it gives the same pressure curve. Buy whatever cost less.

Instead of AA4350 I am shooting surplus WC852 in the 7.5 Swiss. This is a ball powder, and I purchased my lot from Jeff Barlett at GIBrass.com . It turns out Accurate Arms purchased a 90,000 pound lot of WC852, faster burning than Jeff’s lot, and now it is labeled as 2700. My lot of WC852 shoots extremely well, was dirt cheap, and I am using that up. But if I did not have the surplus powder, I would give IMR4350 or AA4350 a go as it shot very well.

I think this cartridge likes powders in the 4064/4350 burn rate range.

[SIZE="3"]7.5 x 55 Swiss  Model K-31 

AP11 Swiss Ball headstamp DA 78						
24 Mar 04 T = 70 ° F								
					
								
Ave Vel =	2565				 	 		
Std Dev =	11				 	 		
ES =	23				 	 		
Low =	2551				 	 		
High =	2574				 	 		
N= 4

168 gr Nosler Match  51.0 gr AA4350 INDEP brass and primer OAL 2.850		
22 Dec 01 T = 58 ° F								
Ave Vel =	2536					 		
Std Dev =	17					 		
ES =	45					 		
Low =	2510					 		
High =	2555					 		
N=	9							
								
								
168 gr Nosler Match  52.0 gr AA4350 INDEP brass and primer OAL 2.850		
22 Dec 01 T = 58 ° F								
Ave Vel =	2624							
Std Dev =	31							
ES =	72							
Low =	2588							
High =	2660							
N=5[/SIZE]

 

[schnarrgj]

With the RCBS dies I have had very good results. For powder, I find that I use imr 4064 the most.

 

[Afy]

Get the 7.5 Swiss cases, the Privi ones are decent. The K-31 does very well with the GP-11 Surplus ammo, which essentially is match ammo. Works like a charm in the STGW as well.

I have the redding dies and use privi brass.

 

[NuJudge]

I use an RCBS die set, because I load for several K31 and 1911 rifles, and I refuse to dedicate cases to one type of rifle, or to one rifle. If you ever get a 1911 or 96/11 rifle, the K31 die by Redding won't size the cases enough to use in them.

I am shooting up the last of my WC852, which I tried with a lot of bullets in Swiss GP11 brass with PMC Berdan primers. Initially, the best results were with Remington 165gr bulk softpoints. My lot of 852 was about 4831 speed. The barrel on the most accurate of my K31 rifles came to me nearly new, and until it had been shot enough to advance the throat a bit, Sierra and Hornady168s had to be deep seated and did not shoot well. If your barrel is newer, you need a bullet that has a rapidly decreasing diameter just ahead of where the cannelure would be. The rifling on a newer K31 barrel comes almost back to the case mouth.

I was reading a Sierra manual, and they suggest IMR4064 with the Sierra 168 MK bullet. I have been shooting this in Prvi brass with mild RWS primers, with excellent results. Groups of about an inch at 100 yards, and about 2.5" at 200. I tried Varget (burn rate very similar to 4064) with the same bullet, and could not get anything like the same results.

I have been shooting some cast bullets through one of my K31s that merely shoots OK with jacketed, with very good results. The bullet I am using is the RCBS 165gr GC Silhouette bullet, using H4198, GP11 brass and PMC Berdan primers.