Sierra 116 TMK Load Data

[MThuntr]

Doing basic load test and fireforming on 116s and 6mmPRC (NSI) 20" Preferred barrel on Tikka with OG6-S. .180" freebore loaded at 2.98" CCI BR2 primers, Lapua brass, .271 neck bushing, 241 mandrel (yes I'm probably moving more brass than necessary and will adjust things later because these seem to be too snug). Also I hate how Hornady dies smash these bullets so I'll probably get Frankford die set. Weights measured by A&D 120i.
Temp upper 70s and sunny with strong variable winds

RL26
54gr 3088fps
54.5 3088fps
55 3144fps (stiff bolt ejector)
55.5 3170fps (stiff bolt, ejector)
56 3213fps (very stiff bolt and heavy ejector)

H1000
52.5 2830fps
53 2945fps
53.5 2933fps
54 2967fps
54.5 3005fps
55 3013fps
55.5 3061fps
56 3057fps (faint ejector, primer flow)
56.5 3125fps (bolt, ejector, primer flow)
57 3140fps (heavy bolt, ejector, crater)
57.5 3149fps (heavy bolt, major ejector)

These are based off 1 shot so this is tread lightly. Looks like mid 50s is giving me a sign to follow.

54.5gr of RL26 is showing promise. I have 5 rounds loaded but the rain hit so hard I couldn't really see the target so 3 will have to suffice. Velocity hovered around 3100 which I expect will settle down once I get a 10rd session loaded up.

 

[bwill6]

I’m used to seeing rings from the seating die on my eldms, but nothing like this. Far right is my starting load and charge weight increases going left. None felt like they took significant seating force. I’m assuming that it’s related to the load being compressed. But my eldm load is compressed as well and it doesn’t get this mangled. Think a different seating die might fix this?

6mm ARC
Hornady brass
Staball Match from 26.5-31.5 grains
Lee seating die

 

[Marbles]

I’m used to seeing rings from the seating die on my eldms, but nothing like this. Far right is my starting load and charge weight increases going left. None felt like they took significant seating force. I’m assuming that it’s related to the load being compressed. But my eldm load is compressed as well and it doesn’t get this mangled. Think a different seating die might fix this?

6mm ARC
Hornady brass
Staball Match from 26.5-31.5 grains
Lee seating die
View attachment 1075388

I sanded and polished my Redding seating stem as it deformed the TMKs, though not that bad.

First just used sand paper around a bullet, the checked a bullet up in a drill with honing compound on it. Turned 3 bullets into close range target bullets, but no more marks.

 

[coya]

I’m used to seeing rings from the seating die on my eldms, but nothing like this. Far right is my starting load and charge weight increases going left. None felt like they took significant seating force. I’m assuming that it’s related to the load being compressed. But my eldm load is compressed as well and it doesn’t get this mangled. Think a different seating die might fix this?

6mm ARC
Hornady brass
Staball Match from 26.5-31.5 grains
Lee seating die
View attachment 1075388

Form's recommendation of the frankford arsenal universal seating die will make those rings disappear

 

[Bluefish]

I’m used to seeing rings from the seating die on my eldms, but nothing like this. Far right is my starting load and charge weight increases going left. None felt like they took significant seating force. I’m assuming that it’s related to the load being compressed. But my eldm load is compressed as well and it doesn’t get this mangled. Think a different seating die might fix this?

6mm ARC
Hornady brass
Staball Match from 26.5-31.5 grains
Lee seating die
View attachment 1075388

Had the same issues and tried massaging the seating stem with no luck. Finally filled it with hot melt glue then stuck a bullet in. Seemed to fix the issue.

 

[Schutzprecision]

I’m used to seeing rings from the seating die on my eldms, but nothing like this. Far right is my starting load and charge weight increases going left. None felt like they took significant seating force. I’m assuming that it’s related to the load being compressed. But my eldm load is compressed as well and it doesn’t get this mangled. Think a different seating die might fix this?

6mm ARC
Hornady brass
Staball Match from 26.5-31.5 grains
Lee seating die
View attachment 1075388

I’m using the Redding competition bullet seater for the 116tmk. No marks on bullet. Works great

 

[sveltri]

Loaded up 10 243ai 116 tmk and 46-50.5 N565. I did have to use a 3" drop tube for the 50.5 as it was up to the neck-shoulder junction without. Seated with the Frankford universal seater at 2.965 and test fit in the Tikka M+ mag. Will feed from the mag for this first test to ensure proper feeding at that length. Will report back with velocities and pressure findings.

 

[mtnbound]

I’m used to seeing rings from the seating die on my eldms, but nothing like this. Far right is my starting load and charge weight increases going left. None felt like they took significant seating force. I’m assuming that it’s related to the load being compressed. But my eldm load is compressed as well and it doesn’t get this mangled. Think a different seating die might fix this?

6mm ARC
Hornady brass
Staball Match from 26.5-31.5 grains
Lee seating die
View attachment 1075388

Using a VLD stem in your seating die will help solve the problem, and so will reducing your powder charge or adjusting your neck tension.

 

[sveltri]

Loaded up 10 243ai 116 tmk and 46-50.5 N565. I did have to use a 3" drop tube for the 50.5 as it was up to the neck-shoulder junction without. Seated with the Frankford universal seater at 2.965 and test fit in the Tikka M+ mag. Will feed from the mag for this first test to ensure proper feeding at that length. Will report back with velocities and pressure findings.

 

[mxgsfmdpx]

Took the gun/load from my post number 88 out this morning here in Wyoming. I have a local competition starting in a couple hours and wanted to make sure everything was dialed in with the gun, load, and Revic Bino profile. It’s also stormy and a bit windy so I went to a spot I’ve never shot before to see how it went.

Two cold bore shots at 643 yards, followed by 867 yards on a 12” gong. Two really good wind calls and elevation was spot on using factory G1 BC.

Revic profile set at 2,720 FPS. First shot was 2709 and second shot was 2723.

 

[eoperator]

Barrel length?

 

[sveltri]

Barrel length?

Started as a 22.7" .243 WIN, so just slightly shorter now.

 

[TradLife406]

6 UM 40
First 10 out of a new pipe with the 116's.
Standard 66 of n570. About .110 off the lands.

 

[JBahr]

UM cut 6 PRC in a 22" 1:7.5 Twist

H1000 57.5gr... Shot from the lands at 2.347" CBTO all the way to .100" OTL in ten thou increments, 5 shot groups all right around MOA. Speed dropped off to about 3130 from 3170 closer to the lands. ES is about 28 avg, SD 9ish.

I'm still fireforming brass while doing this so I expect a little improvement to accuracy, ES and SD.

 

[Grizzle]

UM cut 6 PRC in a 22" 1:7.5 Twist

H1000 57.5gr... Shot from the lands at 2.347" CBTO all the way to .100" OTL in ten thou increments, 5 shot groups all right around MOA. Speed dropped off to about 3130 from 3170 closer to the lands. ES is about 28 avg, SD 9ish.

I'm still fireforming brass while doing this so I expect a little improvement to accuracy, ES and SD.

Isn't that a little hot for first firing? Where did your barrel show pressure?

 

[Duxnbux]

Any info for the 6UM with the 116s and h1000? My gun doesn’t seem to like N570 with any bullet combo so far.

 

[JBahr]

Isn't that a little hot for first firing? Where did your barrel show pressure?

I'm not really blowing out the shoulder, 6.5 PRC to 6 PRC is near identical enough I might as well load close to what I want and get data. The neck geometry is the only variable, which is why I went this route. Already had all the 6.5 PRC stuff.

Still plan to validate the data with fireformed loads. Happy to see MOA accuracy and the speed with a mild load. Started to see pressure at 59 gr of H1000, speed went to 3280 FPS close to the lands.

 

[Grizzle]

I'm not really blowing out the shoulder, 6.5 PRC to 6 PRC is near identical enough I might as well load close to what I want and get data. The neck geometry is the only variable, which is why I went this route. Already had all the 6.5 PRC stuff.

Still plan to validate the data with fireformed loads. Happy to see MOA accuracy and the speed with a mild load. Started to see pressure at 59 gr of H1000, speed went to 3280 FPS close to the lands.

I understand 6 prc I just asked because mine is hitting pressure at 57 with virgen Lapua brass. I'd need a hammer at 59 to open it

 

[PathFinder]

Any info for the 6UM with the 116s and h1000? My gun doesn’t seem to like N570 with any bullet combo so far.

Try down around 62 for a really mild load. Up around 64-65 should be max, and a little slower than top end N570 velocities.