Sierra Heavy TMK 6MM Testing

[Bluumoon]

Well stuffed 62g of n570 in the 6prc and didn’t reach any type of pressure but yield a velocity of 3260 about 30 fps faster the 109 eldm load I had. Grouped better than the 109’s. N565 at 60.5g yielded the same velocity but started getting into pressure and wouldn’t want to run it there.

What barrel length?

 

[NW_backcountry90]

What barrel length?

21”

 

[mtnbound]

Spun on a new 6CM barrel on my Tikka, so I did some load development today. H4350 and N555 are my tried and trued but gave some Superformance, Hunter, and 4831SC a go along with a few of the new 107TMKs. Only tried the TMKs with Hunter and 4831SC.

 

[huntsd]

Spun on a new 6CM barrel on my Tikka, so I did some load development today. H4350 and N555 are my tried and trued but gave some Superformance, Hunter, and 4831SC a go along with a few of the new 107TMKs. Only tried the TMKs with Hunter and 4831SC.

Good shootin! Hate to see the the 107s grouped the worst!

 

[brockel]

10rounds of 107tmk at 3100fps from 6prc

 

[nphunter]

5 rounds of 107’s from my .243, decent ES and SD, loaded up several more with this load and will shoot some bigger groups. Didn’t measure but it’s not much over 1/2”, if I could put 10 in a similar group I’d be pretty happy.

 

[Pistolpete28]

5 rounds of 107’s from my .243, decent ES and SD, loaded up several more with this load and will shoot some bigger groups. Didn’t measure but it’s not much over 1/2”, if I could put 10 in a similar group I’d be pretty happy.

View attachment 1034929

Nice shooting! Do you mind sharing your load? Are you using m+ mag?

 

[nphunter]

Nice shooting! Do you mind sharing your load? Are you using m+ mag?

Yes M+ Mags

H4350, 41.5gr
CCI BR2
Peterson Brass
COAL 2.918”, .020ish off lands
2760fps


16” barrel with a OG6.5 can

The load is a little hot, I had some light marks on a couple pieces of the brass but primers are fine. I’m going to stick with it if it shoots just as well next trip to the range.

 

[B_Reynolds_AK]

Yes M+ Mags

H4350, 41.5gr
CCI BR2
Peterson Brass
COAL 2.918”, .020ish off lands.

16” barrel with a OG6.5 can

The load is a little hot, I had some light marks on a couple pieces of the brass but primers are fine. I’m going to stick with it if it shoots just as well next trip to the range.

Velocity?

 

[nphunter]

Velocity?

2760fps

ES is right at 30 and SD is 10 for 3 different 10 shoot groups .015-.045 off

 

[elkfuler]

Yes, or close. The wounds I saw from the 107gr were excellent too. The 95gr is violent as well. TMK’s just create big wounds if you hit big bones.
But that is also a thing- put them in just lungs and ribs and they are fine, they won’t damage meat that way.

Only shooting ribs sounds great in theory. In practice other angles than straight broadside are likely. If in a target rich environment where I could pass on meat destroying shots I might consider the TMK.

 

[omicron1792]

Only shooting ribs sounds great in theory. In practice other angles than straight broadside are likely. If in a target rich environment where I could pass on meat destroying shots I might consider the TMK.

What’s funny about this is argument goes from tmk not being enough bullet to it’s too destructive. Makes me laugh.

 

[Lawnboi]

I think I’ll try the 116s too. Thinking a 24” 7 twist dasher with OG65 at 2800ish fps sounds good.

 

[Hurley88]

For anyone interested, I had my bolt apart last night and just decided to measure jump distance for a few different bullets.

Each seated where the bearing surface to boat tail junction was just at or a hair below the neck-shoulder junction of the case. I know, not super scientific but hey I guess I’m worth what I’m paid.

Bullet Jump
107 TMK: 0.1815
112 MB: 0.113
109 ELDM: 0.102
108 ELDM: 0.064
103 ELD-X: 0.0605

Looked at past data, the average 10-shot group size for the 112/109 is 0.8-0.9”. The barrel shoots almost 2” groups with the 103/108. The 107 TMK has only shot two groups, 1.02” and 0.97”

Not conclusive, just a stand alone data point with one barrel. But I’ve personally never seen a reason to care too much about jump distance with bullets like the ones I use. Personally I wouldn’t (and don’t) worry about the 107 jumping. Still going to scoop up some 116 though.

 

[shotoutofacannon]

107 tmks landed just before a trip to texas this weekend. 107 tmk 6 arc at 2510 fps. 204 lb boar at 130 yds. I aimed for the shield to give the bullet a bit of a challenge. Boar ran 30 yds and piled up. 1.5” hole through the shield and ribs on the entrance, about the same exiting the chest then caught inside the opposite shoulder. No exit.

I processed this boar last night and wanted to follow up on the post as penetration was better than I originally thought. I found the jacket nearly through the far side shoulder and the remaining core barely made it through the shoulder and was caught under the skin. So more like 13-15” penetration through a dense animal with a very wide wound channel. First pic is the jacket, second is the wound channel through offside shoulder after cleaning coagulation away. I’m impressed w the performance of the 107s.

 

[philcox]

41.5 in the 6CM seems to be nowhere near a full case. What are others seeing for case fill on H4350 in the 6CM?

 

[Hurley88]

Does it come up to the base of the shoulder? IIRC (probably don’t), that’s where it usually is for me

 

[eoperator]

41.5 in the 6CM seems to be nowhere near a full case. What are others seeing for case fill on H4350 in the 6CM?

Nosler gives aproximate fill %

 

[Pistolpete28]

7 shots -243 tikka (20”)
48.3 grains h1000
107 tmk
Starline virgin brass
COAL: 2.916”
Gm210m primers

 

[WyoWild]

41.5 in the 6CM seems to be nowhere near a full case. What are others seeing for case fill on H4350 in the 6CM?

41.5 gr should be around 93-95% case fill depending on seating depth. I tend to find great accuracy and nice velocity in the 41 to 41.5 gr range with 4350.

6 Creed is already a bit overbore so I like a moderate load. RE-16 and 6.5 Staball are great performers too.