Sierra 107 TMK Load Data

[pods8 (Rugged Stitching)]

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

Did you chamfer the inside of the neck?

 

[Q_Sertorius]

Did you chamfer the inside of the neck?

No, that is something I used to do. But the last couple of batches I’ve done (about 200 rounds), I didn’t bother. I guess I should have bothered.

 

[Q_Sertorius]

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

The RCBS full length resizing die. Out of this batch, that one was noticeably harder to seat. I should have investigated more closely as soon as I encountered resistance.

 

[ztc92]

For anyone chasing quick drop, I’ve been playing with ballistics calculator and the 107’s to figure out if I need to chase any more speed with my 16” barrel.

I’m finding that the 107 at 2700 FPS seems to be the sweet spot. It’s near perfect quick drop to 700 yards at 5000 DA and still within 0.2 mil of quick drop at 0 DA and 10,000 DA.

I think this short barreled 243 should be about perfect as long as I can find a load that shoots.

 

[shayes11]

Im at 2730 through a 20" 6 ARC and it lines up quite well with quick drop too, FWIW.

 

[Ag509]

Im at 2730 through a 20" 6 ARC and it lines up quite well with quick drop too, FWIW.

What are the load details on that if you get a chance please?

 

[shayes11]

30gr Lever, Hornady once fired brass, 107 TMK, COAL 2.275 (basically mag length in my Howa Mini) CCI 450. 70 degree day @ 2300.

I went up to 31gr of Lever at 2820 but had some heavy bolt. Accuracy wasnt great either and then 30.5 at 2770 didnt impress me a ton. 30.0 ended up working out with quick drop and didnt feel like I was anywhere near pressure. Definitely still need to play with it more though.

What are the load details on that if you get a chance please?

 

[HairyScandinavian]

No, that is something I used to do. But the last couple of batches I’ve done (about 200 rounds), I didn’t bother. I guess I should have bothered.

I loaded up some test 223 rounds and forgot to chamfer the necks, loaded about 10 and kept finding these tiny little copper rings laying around the press. I finally figured out when I seated the bullets the case would shave a slim ring off of it. I pulled all the bullets and you can just barely see a tiny mark where it was shaved, probably shoot fine but I thought it was interesting.

 

[Q_Sertorius]

I loaded up some test 223 rounds and forgot to chamfer the necks, loaded about 10 and kept finding these tiny little copper rings laying around the press. I finally figured out when I seated the bullets the case would shave a slim ring off of it. I pulled all the bullets and you can just barely see a tiny mark where it was shaved, probably shoot fine but I thought it was interesting.

Yeah, I went back to chamfering.

 

[BAKPAKR]

View attachment 1052351View attachment 1052353
Repost for this thread. Average muzzle velocity over 100 rounds with this load ended up being 2960 fps. 21” barrel 1:8 twist.

Is the 2960 fps a typo? Seems kind of high for a 21” 6mm ARC with 107s.

 

[Plague]

Is the 2960 fps a typo? Seems kind of high for a 21” 6mm ARC with 107s.

It is not a typo. I initially doubted the readings on the garmin. But using that speed had my data close enough for a first round impact at 850 yards on steel.

 

[Willie IV]

I can probably go back thru the original TMK thread but who's running 107 TMKs in 6CM with H4350? I just finally got my reloading bench complete and all the toys purchased. This will be my first batch off the bench. I have a 20" 1:7.5 twist saami cut barrel on a tikka semi custom. What powder charge ranges and COAL's has everybody started with?

 

[Matt5266]

Well the wind was pretty bad and target was slightly moving about. Add in my suck factor as a shooter and groups are not great right now. Plan on loading 10 more of those and maybe drop a half grain and load 10 of those. And see when its no so windy. Last shots started trending right but wind was blowing to the left. So kinda wierd. Maybe it was me? Don't have my Garmin with me at the moment but was about 2850 fps

 

[ztc92]

Amazing how much better these 107’s shoot when you load them short enough to avoid touching the lands and don’t have pressure spikes and blown primers.

Really happy with the 107’s with H4350. I’ll load up a handful of these and see how we’re doing for velocity with a goal of hitting 2700 to make a quick drop friendly load.

107’s beat the 116’s by a good margin so I’ll probably just stick with them.

Edit to add: Tikka 243, cut down to 16.5”. Using factory norma brass and CCI 200 LR primers.

 

[Pistolpete28]

Based on my shooting today, 40-40.5 grains of h4350 is the sweet spot with the tikka 243. 41 grains had ejector marks on the brass. I’ve tried lots of different loads of h1000 with the 107s, but accuracy is not great.

 

[brucemt]

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.

2.900 coal or 2.800?
Did you ever get a chance to get a chrono on the 4831sc?