6br 107SMK's jammed or jumped?

[Heavies]

Hello all,

I am getting ready to start load devolpment for my new 6br. Got 107 SMK's, Lapua brass, Varget, and Wolf SRM primers.

Gonna start off at 29.4, 29.7, 30, 30.4. My question, should I start off jammed or jumpped at the lands?

I was thinking of 'at the lands', but differences in bullets will make an accuate mesure difficult, unless I sort bullets. Don't want to do that. So I was thinking either .010 into or .010 out of.

If I go .010 into, will I be able to unload without pulling the bullet out of the case, and what is the most that can be 'jammed' and still be able to unload an unfired round?

Any thoughts or advice? Thanks a bunch!

B

 

[Heavies]

Thanks for the advice. I'll start .005 in and mess with depth after I find a good load.

Do you have any problems unloading an unfired round at .010

Oops. Sorry I'm up too late. Didn't see the part about soft seat.

 

[Tozguy]

Just a suggestion, but with a new barrel why not see for yourself and seat a bullet using the action (using an unprimed but sized case, with a bullet seated very long). Unchamber the round and you will see what happens. A stuck bullet is easy to remove from the throat with a cleaning rod through the muzzle. Chances are you will be able to see marks from the neck on the bullet to indicate how far it was seated by the action. Repeat with progressively deeper bullet seating until you find the length that allows maximum contact with the lands but still allows unchambering the bullet. In my experience with a 6BR there is a range of .015 to .020'' for bullet seating that shows full contact with the lands but not enough to pull the bullet out.

 

[RonAKA]

I've had a bullet stay in the barrel when seated with a 0.010" jam. However, it was with a much lighter bullet that was only seated 0.070" into the neck. Suspect you will have much more in the neck with a 107 grain. I use a 0.267" bushing, and get about 0.001" fit on the bullet.

 

[Heavies]

Thanks guy's, for all your input! Got some more to think about now.
hehe ;D

What is the consensus on the starting loads I came up with? Should try .1 grains at a time or is that too fine?
I think .3 would be good, then tweek the best next session.

 

[bward]

My 6br likes the 107 mk jumped. Every barrel is different though.

 

[Heavies]

Gonna try some Rl-15 as well. Any loads anyone would like to share.
I am going to use this rifle for mid-range F-Class, 300,500,600

 

[jlmurphy]

+1 on the forgiving nature of the SMK with regards to seating depth. I would stick with the Varget, it is from the Hodgden Extreme line of powders, made to be temp. insensitive, whereas the Re 15 is a double based powder, and while capable of higher velocity, is much more temp. sensitive.

 

[bward]

If you try varget, start with around 29.5 and work your way up until you find a good load. For me it was 30.2 grains.

 

[hardrock6]

I had the exact same results as bward. 30.2 107 smk RL15 .180 5 shot group @ 100

 

[Heavies]

Thanks guys, for all your help!
This is the very beginning of load development. I needed to find a load for a match I have this Sunday.
Here is the best so far. I haven't had time to chrono, or anything. I'm gonna run with it and see what happens! ;D

Tried some RL15 too, looks promising, but it still needs work. ;D

 

[Heavies]

This group was with New Unfired brass.

Should I bump the charge up say .1 grains with the fireformed brass?
Any body experienced with that?

Funny I got one group in the one's, but with a flier that opened it up to about .5"ctc Darn. =p