7mm stw short barrel loads

[Lefty7mmstw]

My friend, you have a balancing act to do. To anywhere near the potential velocity, your going to have to go to a faster powder. Using the usual slow burners, your going to have a muzzle flash, akin to that of a bazooka. The long and short of it is that something in the range of Imr4350 or so is about your best option.
Ultimately, the rifle you have can very easily be re barrelled, something in the 26+ length. That cartridge, thrives on a long barrel, and a propellant that stops burning just short of the end of the muzzle. You will learn to fall in love with that cartridge, I certainly did, for more then 30 years,I was obsessed with it. Still am. Good luck to you, enjoy.

something on the order of rl22 would prolly be one of the best balances in a shorter bbl 7stw. 4350 is a bit fast...

 

[7stw]

something on the order of rl22 would prolly be one of the best balances in a shorter bbl 7stw. 4350 is a bit fast...

Lefty, first of all, it's been awhile since we chatted. Hope all is well. Yeah, I guess good old rl22 would work. I was just trying to figure what would work , and all burning barrel. Maybe IMR 4831. I thought 22, but thought you still might get quite a blast, but not much velocity. I used to love that stuff, then came RL25, game over. The 22 inch barrel really has me thinking.

 

[JMW67]

hybrid 100v should be about right in this application

 

[Lefty7mmstw]

Lefty, first of all, it's been awhile since we chatted. Hope all is well. Yeah, I guess good old rl22 would work. I was just trying to figure what would work , and all burning barrel. Maybe IMR 4831. I thought 22, but thought you still might get quite a blast, but not much velocity. I used to love that stuff, then came RL25, game over. The 22 inch barrel really has me thinking.

I am well, and you?
As far as the powder burn speed, I'm playing with rl16 (doubly base 4350) in a 14" 516 barrel in 7-08 on my Striker pistol lately. 140 AB's and rl16 are very promising but hotter ignition may be in order, as it's tossing 2 groups at times separated by an inch or two.

 

[ButterBean]

Lefty, first of all, it's been awhile since we chatted. Hope all is well. Yeah, I guess good old rl22 would work. I was just trying to figure what would work , and all burning barrel. Maybe IMR 4831. I thought 22, but thought you still might get quite a blast, but not much velocity. I used to love that stuff, then came RL25, game over. The 22 inch barrel really has me thinking.

You guys are all over it, I was gonna say RL23 and the 140 should work, but with the 22" tube you may be right IMR4831,RL16, 17 or Hybrid 100V may be in line

 

[1894C]

I'm calling BS on the "slow powders will yield higher velocity in shorter barrels just like long barrels. I have a 30" 300 wby that sends 215s over 3300 with rl33. Rl26 over 3200. I burned a barrel off that rifle years ago (at that time 28") and had a spare action laying around so I took 6" off the chamber end and spun it back to a 300 wby making it just short of 22". Back then I was shooting imr7828 and 200 accubonds Getting around 3100 FPS from the 28". When I cut it down to 22" I was getting between 2750 and 2800 FPS with the same can of imr7828 that was a speed demon in the 28". I changed over to rl19 with 200 grain accubonds seated .030 jump and I was getting 2,900 FPS.


Shorter barrels get the most out of heavy bullets and FASTER burning powder

 

[7stw]

I'm calling BS on the "slow powders will yield higher velocity in shorter barrels just like long barrels. I have a 30" 300 wby that sends 215s over 3300 with rl33. Rl26 over 3200. I burned a barrel off that rifle years ago (at that time 28") and had a spare action laying around so I took 6" off the chamber end and spun it back to a 300 wby making it just short of 22". Back then I was shooting imr7828 and 200 accubonds Getting around 3100 FPS from the 28". When I cut it down to 22" I was getting between 2750 and 2800 FPS with the same can of imr7828 that was a speed demon in the 28". I changed over to rl19 with 200 grain accubonds seated .030 jump and I was getting 2,900 FPS.


Shorter barrels get the most out of heavy bullets and FASTER burning powder

I absolutely concur. The shorter barrel, definitely makes you think outside our "normal" slow burner box. That being said, I do t think you'll see true potential speeds, without pressures, or low load densities. This round simply needs more real estate..
It's kinda like tie up one leg on a thoroughbred race horse, and expect it to compete. . Peace out, everyone be safe, and Vote!

 

[Lefty7mmstw]

I'm calling BS on the "slow powders will yield higher velocity in shorter barrels just like long barrels. I have a 30" 300 wby that sends 215s over 3300 with rl33. Rl26 over 3200. I burned a barrel off that rifle years ago (at that time 28") and had a spare action laying around so I took 6" off the chamber end and spun it back to a 300 wby making it just short of 22". Back then I was shooting imr7828 and 200 accubonds Getting around 3100 FPS from the 28". When I cut it down to 22" I was getting between 2750 and 2800 FPS with the same can of imr7828 that was a speed demon in the 28". I changed over to rl19 with 200 grain accubonds seated .030 jump and I was getting 2,900 FPS.


Shorter barrels get the most out of heavy bullets and FASTER burning powder

rl19 should go faster than 7828 with a given bullet; it's a double base powder and about the same burn rate as 7828... I've lost velocity many times trying single based powders out 300win's etc.. Now, if you go to a slightly slower single base powder you may actually gain velocity if you have enough room to get to pressure.

 

[Lefty7mmstw]

I absolutely concur. The shorter barrel, definitely makes you think outside our "normal" slow burner box. That being said, I do t think you'll see true potential speeds, without pressures, or low load densities. This round simply needs more real estate..
It's kinda like tie up one leg on a thoroughbred race horse, and expect it to compete. . Peace out, everyone be safe, and Vote!

The biggest problem with a slow burner in a short barrel is concussion. You may also have more trouble with accuracy in a non perfect barrel because the gas pressure is still higher. That said, I've run 22-250, 243, 7-08, 308, 30-30, 35 rem, and (my Pop's pistol) 300wsm in 10" to 14" barrels in Contenders and Strikers and every chambering used a powder that was in the normal burn range for the cartridge.

 

[Dean2]

Short barrel, try Hybrid 100V or 4350. Also load up some rounds with Retumbo. Check velocity and Shoot it near dark and check the muzzle flash. I guarantee you won't gain much speed with the Retumbo if any and you will have a whole heck of a lot more flame and noise.