6.5 WSM testing results

[Brent]

We shot the Pacnor 30" barreled 6.5 wsm with a 8-32 NF scope yesterday while checking psi and velocity with the Oehler 43. We shot the 140 Berger and 123 Lapua Scenar at 200 yards, both loaded up with RL25. Temp was +35F, ALT 88ft ASL and wind 3-5 at our 6-8 o'clock.

We shot a 5 round group at each 1gn increment.

140's were 66-68gn.
123's were 67-69gn.

123gn Scenar, OAL 3.080", CCI-250, Win brass, seated to lands. average velocity and pressure below;

67gn = 3417 @ 61,6 psi (.5 moa, includes two foulers, otherwise .25 moa)

68gn = 3461 @ 63,7 psi (.4 moa - bolt lift stiff on one shot)

69gn = 3532 @ 68,0 psi (.5 moa - stiff bolt lift)


140gn Berger, OAL 3.1", CCI-250, Win brass, seated to lands, average MV and psi below;

66gn = 3134 @ 55,2 psi (.6 moa, includes two foulers, otherwise .3 moa)

67gn = 3210 @ 58,3 psi (.5 moa - bolt slightly stiff on two shots)

68gn = 3252 @ 63,4 psi (.6 moa - bolt stiff every shot, some real stiff)


Start low and work up to these loads looking for pressure signs, these are max loads in this gun.

At 3417 fps, the 123gn Scenar with a BC of .574 ballistically out performs the 140 Berger at 3175 fps with a BC of .63, anyone else use these at the faster speeds and found the same? 123's shot about 1 moa flatter at 200 yards than the 140.

 

[jcpython357]

Brent, Is there anyone that makes the 6.5WSM (prod) or is this a 7WSM necked down to 6.5 wildcat.Jay

 

[Brent]

Jay,
The 7mm case is longer than the 270 or the 300wsm, which are the same length, this is so you can't fit the 7mm in the 270 bore on accident.

His is based on the 270/300 case length, as Norma makes brass for the 300 and it is already overbore enough.

Shawnie Tools had the rented reamer, Pacific Tool made the reamer for her Dave Kiff said.

 

[*WyoWhisper*]

Pretty impressive stuff..

sounds like this would make a great Dall Sheep or Bighorn Sheep hunting rifle....

hmmm... McMillan HTG stock in a woodland camo ( browns and greys ) 24" barrel about a #4.. fluted, jewel trigger, Lupy 3.5-10 M3 ...
hhmmmmmm

now who wants to loan me the cash ????

 

[Brent]

I just may have to build one too, it would definatly get a McMillan too. I really like how well it does with the 123gn Scenar, sheep, caribou, perfect!!

Here's some more detailed data on the loads we tested too.

The top loads with the 123gn Scenar and RL25 were unruley as far as psi and velocity goes, ES was 61 fps, psi climbed after just three shots on the 68gn load with not letting it cool much.
After letting it cool "completely" psi on the last two shots went down. Bolt lift was not stiff on the second and third shot, but we let it cool to see if psi would indeed come down.

69gr RL25 123gn Scenar;

3503 @ 66,100 psi
3556 @ 69,4
3554 @ 69,7
3535 @ 68,1
3512 @ 66,8 We let it cool 3-4 minutes between shots to keep psi down on this load.


68gn load;

3451 @ 63,200 psi
3483 @ 64,0
3512 @ 67,1 (let cool after this)

3429 @ 61,9 (cold bbl)
3432 @ 61,9


The 67gn load below this was fairly stable though.

3401 @ 61,3
3401 @ 60.9
3398 @ 60,0
3423 @ 61,6
3441 @ 63,2
3435 @ 62,9

The 68gn 140 Berger load below was too hot,

3203 @ 59,6
3260 @ 63,9
3295 @ 66,8 We stopped here, bolt lift was consistantly stiff and getting
pretty heavy. Very tight group though.


The better load was 67gn below,

3228 @ 59,6
3194 @ 57,0
3194 @ 57,4
3199 @ 58,0
3234 @ 59,6 Slightly stiff bolt lift was felt on 2nd and 3rd shot but not
any others.

66gr were all fine too,

3114 @ 55,7
3158 @ 56,1
3137 @ 54,4
3141 @ 55,4
3121 @ 54,4

All these groups were shot using mixed brass though, some he had fireformed and mixed in with a bunch of virgin brass, so ES was not really representative, and neither were groups IMO. I think it has great potential
if he eliminated some variables. Mirage was pretty bad and wind wasn't helping any either. I think groups could have shrank by half maybe if everything was perfect, we'll see...

 

[4mesh063]

Brent wrote

"The 7mm case is longer than the 270 or the 300wsm, which are the same length,"

Brent, I keep hearing this from people and I don't see the difference. My brother built a 7wsm and uses 30wsm brass. I have the prints for chamber dimensions and it sure looks to me as if a 7mm round would go into a 30wsm.

The dimensions I will quote are going to be 7mm first then 30 Cal.

Bolt face to shoulder, 1.6585, 1.6588
Angle, both 35deg.
Body-Shoulder radius .050
Shoulder to neck Radius .120
Base to Neck beginning 1.8131, 1.7970 **
Overall Chamber Length, Both 2.1100

The face to shoulder is only .0003 and that's certainly not enough to keep a case out.

** The base to neck change is only a continuation of the 35Deg shoulder down to 7mm at .3230 as opposed to stopping at the 30 cal diameter of .3460.

Want a real laugh, back from the neck .25918 you should have a diameter of .32287

I wonder who's gonna hold 5 decimals! The entire neck and shoulder area is shown to _5_ places.

I'd bet if you took a 7mm case it'll go in a 30WSM.

These prints also show a freebore of 0.0000

Why such a slow powder, just for testing??

It won't take long before the Berger is flatter I would presume. The velocity's are proportional to the weights and the 140's gonna keep right on truckin.

 

[Brent]

4mesh,

your brothers is a wildcat based on the original 300wsm dimensions, the 7wsm is .038" longer at the body-shoulder junction than the 270wsm or the 300wsm... the 7wsm won't fit, trust me. My dad had to send his 7mm brass back to Sinclair and get the 270wsm brass because it was too long, I measured the stuff when it got here so I'm positive. You could easily see the .040" difference with your eye.

The powder he chose was the powder some BR guys were using with it, H1000 was the other one.

The Berger won't keep up even at 1000 yards, check out the ballistics yourself, I wouldn't BS ya.

That was my first thought too though. There is a summery chart on the Oehler 43 as well as a trajectory chart, just click the button after you shoot the group and it displays the bullet path, wind deflection, velocity, energy, power factor and recoil energy, the other chart gives AVE, SD, High, Low, ES for all data collected such as Vel13, Prf, BC, TOF2T, Horz, Vert, peak, Area and Rise... Burst rate if you shoot full autos too.

The 123 Lapua is pretty **** long too, the BC and velocity tells the story.

 

[Brent]

Sam,

what OAL are you using for the 140's? Dads is built on a 700 LA and is using a 3.1" OAL on them, the 123's are 3.080" long.

They scream!!

 

[4mesh063]

Brent,

That's nice to know. The prints I have are from JGS 06/12/2001. Interesting that the dimensions either changed or perhaps this was before the advent of the "Winchester" 7mmSM. In any case, this is the chamber He put in the gun, so, I guess it's now a wildcat.

Now that I think about it, he bought a box of 7mm WSM cartridges to measure so we could make a drawing for the chamber and I don't remember them being visibly longer than the 300 Brass that came later. I had him get 300 brass because of the extra neck thickness from the resize process. In retrospect, the necks never got thicker so it never helped.

I'll have to investigate this more. I do know that with a turned neck, the factory rounds He bought will chamber in his gun.

If you have a fax, get me the number and I'll send ya the prints I have. See if they compare to your guns (which I guess You're saying they won't). Interesting.

 

[Brent]

4mesh,

check this page, this is what you're looking for... http://www.shortmags.org/shortmags/ref_data/case_dimensions.htm

Don't have a fax, but the 300 is the same as your brothers and my fathers to the shoulder. They are all the same OAL, but the 7wsm has a .50" shorter neck than the 300, so that's where they robbed the extra shoulder length from.

He should be able to chamber the factory 7wsm stuff if he needs a new throat yet by just running the reamer in another .038" though, shouldn't even have to set the barrel back on this one.

My dads going to get the Norma 300wsm brass next time, maybe they'll grow in thickness a little, we'll see. He's got about .004" total clearance by comparing formed ones with loaded ones that had a couple thou turned off them, should get back a thou or so anyway and be closer to .002" total.

 

[4mesh063]

No rechamber comming here, the gun shoots consistant 10s at 1000. This gun is not reamed anyhow so a rechamber operation is a little more in depth than that. I'll go now and check the SMags.org to see the differences. Obvoiusly, there are some.

Thanks.

 

[4mesh063]

Brent,

I picked up 50 Norma brass for my brothers gun last fall. They were real nice as fas as consistancy. There was NO noticible increase in thickness in the neck after going down to 7mm. Not even .001. It did help having to resize down for concentricity though. More forming = More chance to straighten up. We're a bit on the lazy side as cases go. Everything is automated. The Norma brass cleaned up inside and out on 48 out of 50 peices. The Winchester brass was good for about 15 out of 50.

Look for the brass to grow nore longer than thicker.

However, The Winchester brass is still in use except the ones that the primer ockets went loose on, and his Norma brass has almost all failed at the head. He's probably got 6 or 700 rounds through the gun on those brass. The norma brass lives about 3-5 firings. I got 416 brass that did the same thing last year so be sure get new stuff. My new 416's are gonna live forever.

 

[Guest]

I have two different 6.5 WSM reamers, one for short actions and one for long actions and ultra long bullets. Both have 35 degree shoulders and slightly improved tapers. This cartridge ROCKS! I will post some data late this week on the longer of the two set-ups.

 

[Brent]

Is there something new with the new Norma brass or something? If not, sounds like he'd be better off stickin with the Winchester if it's that bad?

Thanks for the tip on the Leica Rangefinder's LED blinding affect at dusk.

I'll have to check them out and see how it does compared to my YP1000.