load variations

[Lefty7mmstw]

I'm using 80.6 gr of IMR 7828

been there, done that with 7828. You will get lower pressure and equal or better uniformity with rl25 with 140 grain pills in the 7stw...

http://www.longrangehunting.com/forums/f28/4000-fps-7mm-stw-w-140-bullet-109862/index7.html

I have a few pressure graphs on that thread using a pressure trace from my old sendero 7stw using rl25 and 7828 with 140 sierra bullets...

 

[Buck268]

been there, done that with 7828. You will get lower pressure and equal or better uniformity with rl25 with 140 grain pills in the 7stw...

http://www.longrangehunting.com/forums/f28/4000-fps-7mm-stw-w-140-bullet-109862/index7.html

I have a few pressure graphs on that thread using a pressure trace from my old sendero 7stw using rl25 and 7828 with 140 sierra bullets...

Thanks for the info, I'll have to pick up some RL25 and give it a try.

 

[WildRose]

I feel that I'm close to the top of my charge range and was just playing around to see if I could see any differences in accuracy. My goal was to try and hit 3,500 with the 145's and keep my clover leaf. I'm so close I can taste it, that why I'm working on small details.
In the factory set up we always kept the 0.50 jump as Barnes recommended, with my custom I just found that 0.10 jump is working great. I know I'm limiting myself a little because 1st and foremost, this is a hunting rifle and for all my adult life Barnes is my favorite pill. I shot Barnes in my Black powder, Slug gun and rifles and has performed flawlessly from Elk, Bear and Deer.

My next test within the next few weeks is to shoot at 300 yards to check my group there.

I would back down a bit. You're going to greatly shorten your barrel life pushing it that hard.

I have 3 stw's and my original is pushing 2000 rounds and still showing minimal throat erosion.

I'd have burned it up quick trying to reach for that kind of velocity.

I have two kills with it at over 1,000 yards with the second being a one shot kill on a bobcat. It was around 1,500 rounds then.

I almost hate to talk about the round count because people can't believe it's held up so well.

 

[Buck268]

At this point, I've put 50 rounds through it and continue to monitor with the bore scope. I've loaded 5 more rounds to test at 300 yards to see if my group holds up. If it does well, I'll shoot 5 more at 600 and call it good and practice long range with my smaller calibers. Then save up for the elk hunt........

 

[WildRose]

At this point, I've put 50 rounds through it and continue to monitor with the bore scope. I've loaded 5 more rounds to test at 300 yards to see if my group holds up. If it does well, I'll shoot 5 more at 600 and call it good and practice long range with my smaller calibers. Then save up for the elk hunt........

Well if you're being that conservative it'll last you a lifetime.

 

[Buck268]

Well if you're being that conservative it'll last you a lifetime.

I'll try to, wish I had a setup like Lefty7mmstw to see my pressures. So far brass seems to be coming out well with no pressure signs. To be completely honest; I really wanted to hit 3,500 and clover leaf at 100 yards. But, for now 3,454 is close enough and 0.20 MOA we'll see what it holds at 300 yards. I think I may also try some good brass currently using Remington brass.
Hopefully my CDS dial for my VX-6 will be in within a few weeks.

 

[WildRose]

I'll try to, wish I had a setup like Lefty7mmstw to see my pressures. So far brass seems to be coming out well with no pressure signs. To be completely honest; I really wanted to hit 3,500 and clover leaf at 100 yards. But, for now 3,454 is close enough and 0.20 MOA we'll see what it holds at 300 yards. I think I may also try some good brass currently using Remington brass.
Hopefully my CDS dial for my VX-6 will be in within a few weeks.

Honestly I wouldn't worry about it much.

Run your load through a ballistics program and look at the difference in drop at 600yds using a 3500MV and a 3200MV.

When you're dialing for drops it matters even less.

For the first 10-15 years I was loading my own I was just rabid about always trying to squeeze every FPS I could out of every load and finally figured out it just wasn't worth it.

 

[Lefty7mmstw]

Honestly I wouldn't worry about it much.

Run your load through a ballistics program and look at the difference in drop at 600yds using a 3500MV and a 3200MV.

When you're dialing for drops it matters even less.

For the first 10-15 years I was loading my own I was just rabid about always trying to squeeze every FPS I could out of every load and finally figured out it just wasn't worth it.

Yup, my current 7stw (27") is running 3340 fps with a 140 ab using rl25 for the fuel. The load was doing about 3250 fps is my last rifle- a 24" bbl... the same ammo would do 3400 fps in my Sendero (26")... It kills the same no matter what and my longest kill with that load was actually with the slowest barrel at 480 yards or so.

Save the money for the pressure testing equipment and use the shoe test. If the bolt takes any more effort to open that a tap with your shoe would produce, you are over pressure. I got lucky and was using my brother in law's pressure trace; I only had to buy a transducer and put it on my rifle.

 

[Buck268]

Yup, my current 7stw (27") is running 3340 fps with a 140 ab using rl25 for the fuel. The load was doing about 3250 fps is my last rifle- a 24" bbl... the same ammo would do 3400 fps in my Sendero (26")... It kills the same no matter what and my longest kill with that load was actually with the slowest barrel at 480 yards or so.

Save the money for the pressure testing equipment and use the shoe test. If the bolt takes any more effort to open that a tap with your shoe would produce, you are over pressure. I got lucky and was using my brother in law's pressure trace; I only had to buy a transducer and put it on my rifle.

So far so good on the bolt, opens very easy. This stuff will drive you crazy and broke...
I'd really like to get my ES down in the single digit, right now I'm running an ES of 12.

 

[Lefty7mmstw]

So far so good on the bolt, opens very easy. This stuff will drive you crazy and broke...
I'd really like to get my ES down in the single digit, right now I'm running an ES of 12.

I went out this afternoon with the 7stw using the 140ab/rl25 load and some 196 chinchaga pills loaded with rl22... The chinchaga's were not quite holding moa... more l.d. needed there... The 140ab/ rl25 load tossed a .74" 3 shot group and a .97" 3 shot group at 200 yards... 23 degrees and breezy here with a bit of mirage...

as far as es, don't sweat it so much... you need decent e.s., but I've seen es that would make you cringe do well accuracy wise... It falls apart a bit more at longer range with poor es, but even close to single digit is plenty good...

 

[Buck268]

I went out this afternoon with the 7stw using the 140ab/rl25 load and some 196 chinchaga pills loaded with rl22... The chinchaga's were not quite holding moa... more l.d. needed there... The 140ab/ rl25 load tossed a .74" 3 shot group and a .97" 3 shot group at 200 yards... 23 degrees and breezy here with a bit of mirage...

as far as es, don't sweat it so much... you need decent e.s., but I've seen es that would make you cringe do well accuracy wise... It falls apart a bit more at longer range with poor es, but even close to single digit is plenty good...

Do you prefer rl22 or 25 or is it just a recipe thing for each pill?

 

[eshorebwhntr]

So far so good on the bolt, opens very easy. This stuff will drive you crazy and broke...
I'd really like to get my ES down in the single digit, right now I'm running an ES of 12.

SD of 12 might warrant more work if you really wanted to. ES of 12 is pretty **** good in my opinion.

12 fps won't show up until wayyy out there.

 

[Buck268]

The more I hear you guys talking, the more I think I'm getting to picky. I guess there's a point when one asks, how much better can I get. But, there's the common sense law, does it make a difference and is it woth it.
I believe most of us get to a point that we just want to tinker around and I think that's where I'm at.

 

[Lefty7mmstw]

Do you prefer rl22 or 25 or is it just a recipe thing for each pill?

With the 140AB/rl25 load I was trying to get decent speed/accuracy with the pressure slightly reduced (from 7827, etc.) for rifle and brass longevity.
The 195-196 grain bullets have been very flaky in this rifle accuracy wise (I thought I had a load with rl33 and the 195 Berger but it fell apart when the weather cooled off). I was simply trying to get enough speed but get the pressure off a bit earlier to control any bullet yaw enhanced by exit pressure. I wasn't really caring about barrel/ brass lifespan in a load I only planned to shoot a few times a year, but I may have to just forget the heavy bullet ballgame in this rifle; I have a few other rifles doing well with heavy bullets and this rifle seems to loath them.