WSSM

[Bob3700]

Due to the fact that I live in a cave and rarely see what is going on in the world, I stumbled across a cartridge that looks very interesting.

It is a 6mm WSSM necked to 6.5. The owner claims that it will achieve 6.5x284 velocities with 4-5 grains less powder.

To look at it, you would think that you had put a 6mm BR Remington under a 5X power magnifing glass.

Short and fat is where this WSSM is at.

Anybody shooting this and what have been your results?

BB

 

[BoydHeaton]

I am running a 30 inch barrel 6.5wssm.I am getting 2920 to 2950fps with around 42gr of h4350

 

[mikecr]

I run 3050fps with 47.4gr IMR4350, 28" barrel, WS2 coated 139 Lapuas. I think my powder lot is slow, but my ES is very, very low.
From what I've seen, Winchester brass in 25WSSM is as good as any Lapua or Norma that I use in others. It's very thick though,.019" atleast)

 

[2644ever]

I had Dave Manson craft me a reamer for this one as soon as the 25 WSSM was released, I figured there would be less stress on the neck than with the 6mm... I was not really disappointed but I failed to see any worthwile difference with a 26O in the same 28" barrel and brass is more expensive. It's a good alternative when a magnum action is all you got.

 

[larrykramer]

,Chasing multiple "sweet spots" in South Texas) Loading for a shortened 6.5/270 WSM,Norma case @ 1.92", 1.37" base to shoulder, approx. 4.13cc capacity.) W/SMK 140,Fed 210,Shilen 27", 1 in 8 twist.,Data on the initial powder-type/ velocity: RE-19 @ 48-51gr.= 2947-3189 fps. / RE-22 @ 46-51.5gr.=2927-3267fps. / RE-25 @ 52-56gr = 2905-3240 fps. w/H4350 @ 43-48gr.= 2850-3023 fps./ H-4831 @ 48-54gr. 2908-3204fps./ IMR 7828 @ 52-55gr.= 2970-3130fps.) The Reloader's FILL THE CASE. My questions are: For best accuracy,1st Priority) with high velocity, should I focus on the accuracy nodes,all the powders yielded at least 1 "sweet-spot") that have the fullest cases and lowest ES?,,I understand this is positive) or what procedure/priorities will help me isolate the best load.? Comments or Suggestions, please. Thanks: Larry,Victoria, Texas)

 

[mysticplayer]

After developing my 6.5 Mystic, I can offer this advice. Go with the highest load density and lowest ES. But the real proof is holes in paper as far as you are going to compete.

I had three loads that worked equally well at 200yds. Two varied by powder amounts,2 sweet spots) and one by primer,fastest load).

I shoot F class and BR from 300m to 1000m. Testing at 300m, the load with the primer change was a dog,more tweaking might get it shooting though) and was dropped quickly.

The other two loads shot similarly with the slower load doing the best. This I used at a recent 300m F class shoot and did very well.

Now shooting out to 1000m, the faster load has proven more consistent. This is likely due to just going faster thus bouncing in the winds that much less. In fact, I am going to test the fastest load,different primer load) and see if speed that far out trumps raw accuracy,I don't dope wind all that well).

Numbers from a Chrony are interesting and will certainly eliminate obvious dogs but until you start putting holes in paper at the distances you wish to compete, really hard to say what a load will do.

Jerry

 

[larrykramer]

Appreciate the experienced feedback,,small town-nearest competetion is 100-150 mi.,so I am trying to learn here/wherever I can find any experienced info- saves me lots of time, money,and going up blind alleys) I will try some different primers. Started 200yd. yesterday, and most of the "100 yd loads" do not hold-up at this range..Thanks: Larry

 

[mysticplayer]

Larry, I have given up testing at 100yds because more often then not, it doesn't hold up at longer distances. My range has a 200yd backstop and where I do my preliminary testing. I quickly move to 300m and further to confirm.

Match primers really help with stringing. This I find to be the biggest problem to long range accuracy. Look for groups that are not round, or with one or two shots scattered outside an otherwise small group,just make sure it wasn't you or wind).

These are sure fire signs that the load will fall apart the further you go. With how well people shoot today, you do not have the luxury of only having 98% good ammo. Unexplained flyers destroy your concentration but more importantly, make you change your doping incorrectly.

Now you are chasing yourself and good scores rarely happen this way.

The group I want is round and clustered. At 200yds, many of the shots should overlap the other bullet holes in a proper match rifle. With enough rds fired, it should be one great big hole about 1/2" to 3/4" round. That is competitive in most any LR shooting sport.

Shoot with flags under the calmest condition you can. This is not about your shooting skills but about the mechanical limitations of your rifle. If you know your rifle can blow out the X ring, YOU WILL SHOOT IT - once you figure the wind/conditions.

I have tested loads that had significant vertical stringing yet yielded very good numbers over the Chrony. No one scores Chrony data.

So go out as far as you can and put holes in paper. Things will become clear very quickly. When testing, I limit my test loads to 2 or 3rds,reduce cost, time and wear). I want loads that can drive them into one hole. If the first two or three spray all over the map, odds are not good the next 50 will snuggle up tight.

I will retest promising loads in strings of up to 20rds,what an F class relay will shoot). Sometimes a load no longer works once the barrel gets hot.

Ultimately, test like you are going to compete. You need to know how the package works....

Jerry

 

[larrykramer]

Thanks: Larry