7mm 197gn Matchking

Reloading equipment, methods, load data, powder and projectile information.

7mm 197gn Matchking

Post by bladeracer » 20 Jun 2018, 11:19 pm

I bought some of these to try out (actually, I just bought them because they look so cool - six-calibers long).
Anybody already tried them?
I really don't expect them to stabilise in my 9.5"-twist 7mm-08.
Been crook but I need to do some shooting to free up some brass.
I also powdercoated some 112gn cast bullets I want to test in it.
Attachments
20180618_100817b.jpg
20180618_100817b.jpg (584.13 KiB) Viewed 2563 times
Last edited by bladeracer on 22 Jun 2018, 12:51 am, edited 1 time in total.
Practice Strict Gun Control - Precision Counts!
User avatar
bladeracer
Field Marshal
Field Marshal
 
Posts: 12654
Victoria

Re: 7mm 197gn Matchking

Post by Stix » 20 Jun 2018, 11:39 pm

How will you get them down & out the barrel with no room for powder...?
The man who knows everything, doesnt really know everything...he's just stopped learning...
Stix
Colonel
Colonel
 
Posts: 3675
South Australia

Re: 7mm 197gn Matchking

Post by bladeracer » 20 Jun 2018, 11:54 pm

Stix wrote:How will you get them down & out the barrel with no room for powder...?


Plenty of room for powder :-)
They seat only .100" longer than the 175gn ELDX.
The ELDX sits on 37.4gn of AR2206H but I'm only looking at 35.5gn under the SMK to start with - that's only 5.5gn more than I run in the .204.
Practice Strict Gun Control - Precision Counts!
User avatar
bladeracer
Field Marshal
Field Marshal
 
Posts: 12654
Victoria

Re: 7mm 197gn Matchking

Post by SCJ429 » 21 Jun 2018, 8:16 am

You are giving up a bit of velocity using 2206, short cut would be a better option but that is where you start running out of room. I have not used those particular SMKs but other SMKs need batching to shoot well. What are you going to use them for?
SCJ429
Lieutenant Colonel
Lieutenant Colonel
 
Posts: 3206
New South Wales

Re: 7mm 197gn Matchking

Post by bladeracer » 21 Jun 2018, 10:49 pm

SCJ429 wrote:You are giving up a bit of velocity using 2206, short cut would be a better option but that is where you start running out of room. I have not used those particular SMKs but other SMKs need batching to shoot well. What are you going to use them for?


I never load anything for maximum velocity.
I know AR2213SC gives more velocity for less pressure with very heavy bullets, but I don't have any to try as I haven't generally been shooting the very heaviest bullets in any caliber. I also bought some 240gn .308 bullets though so I will be getting some AR2213SC very soon, and I'd like to try it behind the 147gn ELDM's in 6.5x55mm.
I don't plan to use them for anything more than ornaments, but I'm going to shoot some just to see if they might stabilise. If they miraculously do stabilise, then I might get some more and see what sort of accuracy I can get out of them.

I've already noticed minimal variance in bullet length, but far less than I'd expected with a bullet of this design. More than 50% fall right on 1.7230", with two longer than that, the longest is 1.7245", and the shortest is 1.7135". But all of them are .9170" to the ogive in the Hornady .30-cal comparator. I was thinking it might be worth filing the points down so they're all the same length, but weight variance is excellent, from 196.94gn up to 197.04gn, with about 40% right on 197.00gn. I think they're extremely consistent. If they don't stabilise, it might be worth experimenting by shortening the point by .010" at a time to see how short they need to be to stabilise in my barrel.
Practice Strict Gun Control - Precision Counts!
User avatar
bladeracer
Field Marshal
Field Marshal
 
Posts: 12654
Victoria

Re: 7mm 197gn Matchking

Post by sungazer » 22 Jun 2018, 5:49 pm

I think 2209 would be slow enough for the 308 but getting a 240gn to stabilize and then to shoot well is going to be a challenge.
sungazer
Sergeant Major
Sergeant Major
 
Posts: 1525
Other

Re: 7mm 197gn Matchking

Post by Stix » 22 Jun 2018, 7:23 pm

bladeracer wrote: If they don't stabilise, it might be worth experimenting by shortening the point by .010" at a time to see how short they need to be to stabilise in my barrel.


Gees man...you've got too much time on your hands....
If i had enough time to be doing that id buy a lathe & learn some tool making skills...
The man who knows everything, doesnt really know everything...he's just stopped learning...
Stix
Colonel
Colonel
 
Posts: 3675
South Australia

Re: 7mm 197gn Matchking

Post by No1Mk3 » 22 Jun 2018, 7:58 pm

G'day bladeracer,
I can't see how shortening the point would affect stabilization as it is a function of riding surface as much as mass. Overall projectile length has no bearing on the matter. Looking forward to seeing your results with 2213SC if you go down that path as I intend to buy a 7mm Rem Mag this year and want to load some heavier than factory projectiles. All my other 7mm are military and I stick to milspec 173g 2300fps for them, Cheers.
No1Mk3
Second Lieutenant
Second Lieutenant
 
Posts: 2090
Victoria

Re: 7mm 197gn Matchking

Post by SCJ429 » 23 Jun 2018, 9:28 am

The length of a projectile plays a part in stability. A projectile with a boat tail design may not achieve stability where a flat base of the same weight may shoot perfectly well. Lead free bullets are long for their weight and often do not stabilise in slow twist barrels.
SCJ429
Lieutenant Colonel
Lieutenant Colonel
 
Posts: 3206
New South Wales

Re: 7mm 197gn Matchking

Post by bladeracer » 23 Jun 2018, 12:24 pm

Stix wrote:
bladeracer wrote: If they don't stabilise, it might be worth experimenting by shortening the point by .010" at a time to see how short they need to be to stabilise in my barrel.


Gees man...you've got too much time on your hands....
If i had enough time to be doing that id buy a lathe & learn some tool making skills...


I already make my own brass bullets on the lathe :-)
Practice Strict Gun Control - Precision Counts!
User avatar
bladeracer
Field Marshal
Field Marshal
 
Posts: 12654
Victoria

Re: 7mm 197gn Matchking

Post by bladeracer » 23 Jun 2018, 12:25 pm

No1Mk3 wrote:G'day bladeracer,
I can't see how shortening the point would affect stabilization as it is a function of riding surface as much as mass. Overall projectile length has no bearing on the matter. Looking forward to seeing your results with 2213SC if you go down that path as I intend to buy a 7mm Rem Mag this year and want to load some heavier than factory projectiles. All my other 7mm are military and I stick to milspec 173g 2300fps for them, Cheers.


Bullet length is what determines stability, not weight or bearing surface.
Practice Strict Gun Control - Precision Counts!
User avatar
bladeracer
Field Marshal
Field Marshal
 
Posts: 12654
Victoria


Back to top
 
Return to Reloading ammunition