7.5x55 Powder help

[JG727]

Does anyone know of a good powder to use in 7.5x55 Swiss loads?
Last Friday I loaded 150 rounds. The Horandy Manual listed powders I did not have on hand. The only one listed I had access to in any real quantity was some old IMR 4350. This works, but because the powder dispenser doesn't like to release the extruded powder in nice consistent groups I ended up setting it to throw a charge in the 43 grain range and then add powder by hand till I got to 45 grains.
As you can imagine, this took quiet a while and it took me 2 hours just the load the cases with powder.
Does anyone have any recommendations for a powder that dispenses nicely but is suitable for use in a rifle cartridge this size?

I have access to lots of Accurate 2520 and Accurate 2700, but I can't find any loads for them.

I'm hoping for a middle of the road FPS, 2400-2500.

Thanks for your patience.

 

[cougar1717]

7.5 Swiss has a similar case volume and velocity to 308 Win. Powders that work well in 308 will also work for 7.5 Swiss (but only use data for the appropriate caliber). I would suggest H4895, but you seem to be looking for ball rifle powder, so I would suggest TAC, H335, H414. I'm sure there others. But please don't complain if your reloads aren't as accurate as GP-11.

 

[JG727]

Thanks!

Thanks! I'm not looking to replace GP-11, I have some GP-11 stashed away for true accuracy shooting, but the K-31 is just so much fun to shoot that I want some (relatively) affordable ammo. Stuff I use when I am taking friends to the range or going up to my uncle's woods and blowing up water jugs.

 

[8mmman]

4064 & 4831

4064 and 4831 worked best in my 3 K31's. Most shot very well with the M80 FMJ 308 bullets and all shoot great with 165 grain SP bullets.

 

[MachIVshooter]

7.5 Swiss has a similar case volume and velocity to 308 Win. Powders that work well in 308 will also work for 7.5 Swiss

My thoughts exactly. The 7.5 is an intermediate sized cartridge in the world of rifle rounds, so there is a huge array of powders that are suitable. Other than your metering problems, the 4350 you have on hand is a great powder for cartridges with 40-70 grain capacity. I've used it in 7.5x55, 49.0 grains over a 150 Hornady FMJ-BT. That gave me 2,600 FPS and produced pretty decent accuracy.

 

[jerkface11]

I always just used .308 data. The pressure rating on 7.5x55 is a little lower but it has a little more volume too.

 

[MachIVshooter]

I always just used .308 data. The pressure rating on 7.5x55 is a little lower but it has a little more volume too.

Why? Not like it's hard to find the correct data, especially with access to the good 'ol interweb

 

[soloban]

IMR 4064 works really well. I want to say Sierra recommends 44gr with a 168 gr bullet (double check my data!!)

 

[jerkface11]

When I was loading for it there wasn't much correct data. Plus what was out there was nearly identical to .308. Kind of like it is now.

 

[Afy]

N140 and N150 work well. I personally am just sticking with GP11. My K31 and STGW57 seem to prefer it.

 

[db_tanker]

I'd also look at some AA 2520 and AA2495 for this case...I know that the volume is close to the 308 and these powders work well with the 308. I have used both and was very pleased with my results.

 

[JG727]

Thanks everyone!

Thanks!
I have access to a good amount of 2520.
For economy reasons I am using cheap pulled 147 grain ball bullets.
I will use the middle range of the .308 load data in the Horandy book.

 

[soloban]

Be aware that the OAL listed in most manuals is WAY too long. The books use the 1911 rifle which has a longer freebore distance. I recommend making a dummy round and making sure it chambers before you load up a bunch.

 

[rogn]

You might want to consider some of the Reloader series also, the ball powders work best in a specific pressure range. If yo drop back too far; bigger case , lowwer pressure the bsall powders like AA2520, H414 MAY BECOME eratic. The extrudedpowders tend to be far more flexible. The H4895 would be a great choice. As would R-15; -19.

 

[jwr_747]

a plinking load I use for all my 30cal. bolt gun stuff with 150gr.bullet is 22.5gr of SR 4759.light and fun load...jwr

 

[Slamfire]

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.

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 sold it as AA2700. 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.

[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]

 

[Mac Attack]

I use 45 grains of Varget under a 168 gr SMK and COAL of 2.905 in PRVI brass. This load to be shoots great out of my 2 K31's and on par with GP11.

 

[IMtheNRA]

I agree with Soloban - the OAL in all manuals was surprisingly long for my K31 rifles. I did the old "marker and dummy cartridge" test to figure out my optimal OAL.