Sierra 107 TMK Load Data

[Brado16]

Do the 107s like or need a decent jump? Just got my hands on some, and a loaded Dummy round loaded to the lands is 2.9150” in my rifle, but my MDT mags are limited to 2.85”. If I load them to 2.80”, that’s 0.115” jump. Any input?

 

[Q_Sertorius]

Do the 107s like or need a decent jump? Just got my hands on some, and a loaded Dummy round loaded to the lands is 2.9150” in my rifle, but my MDT mags are limited to 2.85”. If I load them to 2.80”, that’s 0.115” jump. Any input?

My Tikka did not like them at 2.8”.

 

[ztc92]

Do the 107s like or need a decent jump? Just got my hands on some, and a loaded Dummy round loaded to the lands is 2.9150” in my rifle, but my MDT mags are limited to 2.85”. If I load them to 2.80”, that’s 0.115” jump. Any input?

My post a recently with a 1.1” group was shot from a 243 with a COAL of about 2.820 and an estimated jump of about 0.025”. Best group I’ve shot from this gun so far and I have no plans to mess with it.

 

[Ryan Avery]

6CM
18" 7.5 Twist
Alpha Brass LP
RL 16 41g 90 thou jump @ 2850
5 shot at 700 yards
Group size is good enough for hunting.

 

[ChrisAU]

Seeing these 6CM speeds has me wondering if I’m loading my Dasher too hot? I was gonna back off 0.2gr of Varget anyway but I was at 2816 with just 80 rounds on my 18” Dasher. It is the first load dev I’m done with Alpha brass so maybe I’m not looking hard enough for signs?

 

[Matt5266]

6CM
18" 7.5 Twist
Alpha Brass LP
RL 16 41g 90 thou jump @ 2850
5 shot at 700 yards
Group size is good enough for hunting.

Ryan what about was the group size out of curiosity?

 

[Sako300]

758 yards. Back to back shots I only had 2 rounds left of the H4350 40.5 gr , 2.932 COL, 107s. Just aiming dead center. Just under 4 inches apart.
Tikka factory .243 20’’
2835 fps

 

[Brucebarker024]

Has anyone tried the 107 in a 6 um?

 

[bielenbm]

Has anyone tried the 107 in a 6 um?

I have been thinking about it. I have a slow barrel so this would bring my speed back up.

 

[ChrisAU]

Seeing these 6CM speeds has me wondering if I’m loading my Dasher too hot? I was gonna back off 0.2gr of Varget anyway but I was at 2816 with just 80 rounds on my 18” Dasher. It is the first load dev I’m done with Alpha brass so maybe I’m not looking hard enough for signs?

This reminds me, @FrankieP1988 where did you wind up leaving yours? 33gr? 33.2 is where I had left off at 2816 out of my 18” Dasher with 107’s. Yours is a 22” correct?

 

[FrankieP1988]

This reminds me, @FrankieP1988 where did you wind up leaving yours? 33gr? 33.2 is where I had left off at 2816 out of my 18” Dasher with 107’s. Yours is a 22” correct?

sorry been super busy and haven't messed with it in a lil while. Yes 22" barrel

I did a second powder ladder on 1x fired brass on 3/20, hit pressure at 32.7 with heavy bolt lift and at 33.0 gr had heavy bolt lift and light swipe. On virgin brass I didn't hit pressure until 33.0 gr with heavy bolt lift... I'll probably end up backing off a grain and call it good ending up around 32 gr. I'll have a bit more time to tinker in a couple weeks and will post results.

here are the average fps for the ladder

32.1 2830;
32.4 2853;
32.7 2878;
33.0 2916

 

[ChrisAU]

sorry been super busy and haven't messed with it in a lil while. Yes 22" barrel

I did a second powder ladder on 1x fired brass on 3/20, hit pressure at 32.7 with heavy bolt lift and at 33.0 gr had heavy bolt lift and light swipe. On virgin brass I didn't hit pressure until 33.0 gr with heavy bolt lift... I'll probably end up backing off a grain and call it good ending up around 32 gr. I'll have a bit more time to tinker in a couple weeks and will post results.

here are the average fps for the ladder

32.1 2830;
32.4 2853;
32.7 2878;
33.0 2916

Mine so far is a mirror; pretty much 10 FPS per 0.1 gr of Varget even with the 18” barrel. I’ll have to push mine a little harder to get there than you with the shorter barrel but I think 2800 once broken in completely will be easy. Just makes me happy I didn’t do 6CM ha.

Edit to add, for a hunting rifle I have enough new brass to last me a while.