Sierra 107 TMK Load Data

[Ryan Avery]

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[YaakRiver]

Picked up some 107s at UM last month. Load dev starts today and I'll post data and outcomes.

 

[Matt5266]

Getting a box friday will post results soon as i get a chance to test them as well. really want these to shoot in my 18" Tikka 243 1:8 twist.

 

[mtnbound]

REPOSTING TO NEW THREAD.

107 TMKs, 2.90coal, 6CM, 16.5” PBB 7.5” twist, Hornady brass, Fed210. I will have to redo 4831SC as I forgot to turn on my chronograph. My old barrel liked H4350 but this one doesn’t seem to like it as much.

 

[Jmedin]

6 Dasher
20” barrel
107 TMK
30.5 Varget
1.745 CBTO
2710 FPS SD 6.7

 

[NoDakhunter]

View attachment 1052259
6 Dasher
107 TMK
30.5 Varget
1.745 CBTO
2710 FPS SD 6.7

Barrel length?

 

[Jmedin]

Barrel length?

Whoops 20”

 

[Plague]

Repost for this thread. Average muzzle velocity over 100 rounds with this load ended up being 2960 fps. 21” barrel 1:8 twist.

 

[sierracharlie338]

I can play. Loading these in my 20” GT.
Will add data as soon as I get some loaded and shot.

 

[JoeB]

6 Creed on the way planning to try TMK

 

[Lawnboi]

21” dasher, 120 fb, 7.5 twist
40k off jam as pictured below
31 grains of varget
Alpha brass
REM 7 1/2
2725 average

That’s a 10 shot group. I need the better cover for my OG 65, the light one just isn’t cutting it.

 

[sierracharlie338]

21” dasher, 120 fb, 7.5 twist
40k off jam as pictured below
31 grains of varget
Alpha brass
REM 7 1/2
2725 average

That’s a 10 shot group. I need the better cover for my OG 65, the light one just isn’t cutting it.


View attachment 1052651View attachment 1052652

Damn thing shoots. There’s no denying that!

 

[Q_Sertorius]

Looking far more promising now. Thank you to [mention]pods8 (Rugged Stitching) [/mention] [mention]cq0302 [/mention] [mention]blacktailcentral [/mention] and everyone else who gave advice in the other thread.

Tikka T3X
.243 Winchester
20”
1:8” twist
OG-P 6mm suppressor

2800 feet ASL
80 degrees F

H4350 - 40.5 grains
107-grain TMK
COAL - 2.941”
Once fired Hornady brass
Winchester Large Rifle Primers

2834 FPS

The first five were all touching. The next five opened it up a bit. The marked group on the right was the group of factory I used to sight in the new scope I stuck on it (SWFA 5-20x).

I noticed that number 10 was scraped up. I assume due to insufficient lube inside the neck or something. Shot it anyway.

No pressure signs. I think the velocity is right around what I want it to be at 2834 fps.

 

[huntsd]

Looking far more promising now. Thank you to [mention]pods8 (Rugged Stitching) [/mention] [mention]cq0302 [/mention] [mention]blacktailcentral [/mention] and everyone else who gave advice in the other thread.

Tikka T3X
.243 Winchester
20”
1:8” twist
OG-P 6mm suppressor

2800 feet ASL
80 degrees F

H4350 - 40.5 grains
107-grain TMK
COAL - 2.941”
2834 FPS

The first five were all touching. The next five opened it up a bit. The marked group on the right was the group of factory I used to sight in the new scope I stuck on it (SWFA 5-20x).

I noticed that number 10 was scraped up. I assume due to insufficient lube inside the neck or something. Shot it anyway.

No pressure signs. I think the velocity is right around what I want it to be at 2834 fps.

cool to see you said no pressure signs. I know box max isnt necessary "max" I just get nervous going so far over. I dont know my ass from my elbow when it comes to how they find this data. But its still weird to me that box max is 37.5 for the 107 then jumps all the way to 41.1 for the 108

 

[Q_Sertorius]

cool to see you said no pressure signs. I know box max isnt necessary "max" I just get nervous going so far over. I dont know my ass from my elbow when it comes to how they find this data. But its still weird to me that box max is 37.5 for the 107 then jumps all the way to 41.1 for the 108

Small sample size, but I just tried out 40 grains of H4350 in the .243. The 10-shot group was still acceptable (1.39”), but the ES and SD were 51 and 14.4. So, I am going to stick with 40.5 of H4350 and call it a day for the 107s. Time to try again with the 116s.

Edit - different bullet, but FWIW, my Lyman manual lists 42.2 as the max for H4350 with the 107-grain SMK.

Edit #2 - Hornady lists 42.1 as the max for their 108-110 grain bullets.

 

[huntsd]

What velo did you hit with 40 grains?

 

[Q_Sertorius]

What velo did you hit with 40 grains?

2794

 

[Matt5266]

Looking far more promising now. Thank you to [mention]pods8 (Rugged Stitching) [/mention] [mention]cq0302 [/mention] [mention]blacktailcentral [/mention] and everyone else who gave advice in the other thread.

Tikka T3X
.243 Winchester
20”
1:8” twist
OG-P 6mm suppressor

2800 feet ASL
80 degrees F

H4350 - 40.5 grains
107-grain TMK
COAL - 2.941”
2834 FPS

The first five were all touching. The next five opened it up a bit. The marked group on the right was the group of factory I used to sight in the new scope I stuck on it (SWFA 5-20x).

I noticed that number 10 was scraped up. I assume due to insufficient lube inside the neck or something. Shot it anyway.

No pressure signs. I think the velocity is right around what I want it to be at 2834 fps.

Glad to see you got it squared away Q.

2 questions, what did you determine was the culprit of thw problems you were having & what primer are you using?

 

[Q_Sertorius]

Glad to see you got it squared away Q.

2 questions, what did you determine was the culprit of thw problems you were having & what primer are you using?

I am using Winchester Large Rifle primers. I bought 500 at a gun show back in 2022, so I am using them up before I dip into my “better” ones.

Edit - I just added the brass and primer information to the other post.

I think I had the COAL screwed up. I tore everything down, checked it all, cleaned it, tightened it, and put on a different scope, but the rifle still shoots the factory ammo the same.

The 107s I shot last Saturday were 1.55” and 1.62” with the same powder charge. So, the only variable that changed is the COAL.

 

[mtnbound]

Looking far more promising now. Thank you to [mention]pods8 (Rugged Stitching) [/mention] [mention]cq0302 [/mention] [mention]blacktailcentral [/mention] and everyone else who gave advice in the other thread.

Tikka T3X
.243 Winchester
20”
1:8” twist
OG-P 6mm suppressor

2800 feet ASL
80 degrees F

H4350 - 40.5 grains
107-grain TMK
COAL - 2.941”
Once fired Hornady brass
Winchester Large Rifle Primers

2834 FPS

The first five were all touching. The next five opened it up a bit. The marked group on the right was the group of factory I used to sight in the new scope I stuck on it (SWFA 5-20x).

I noticed that number 10 was scraped up. I assume due to insufficient lube inside the neck or something. Shot it anyway.

No pressure signs. I think the velocity is right around what I want it to be at 2834 fps.

What resize die are you using? Number 10 sure looks like you have a lot of neck tension.