1st time reloading 6mm norma br question

[fella5]

Thanks RonAKA!

 

[fella5]

If I do calculations using the OCW method and using loading data from Hodgdon (Varget) this is what I get.

Minimum load is 30.5 and maximum is 32.5 (Hodgdon) with 80gr bullet

Using the calculation for OCW, my starting load after the 3 sighter loads is 31.0 to 32.6 (/w 2% increments)

But what I've been reading is the "pet load" is around 30.0gr. So should I modify the OCW and start around 29.5 and work up to 32.5 with .3gr or 2% increments. Just wanted to get some suggestions before I start charging the cases.

Thanks again

 

[RonAKA]

I would not go below the Hodgdon minimum load. I don't think there is anything special about a particular load. What is important is the velocity out of your barrel. Within the minimum and maximum load you should find a sweet spot. 31 to 33 is a reasonable range to use based on my experience. My barrel likes 3100 fps, and I would like to try it a bit higher to see what happens around 3150, but I seem to have issues with predicting how much powder that takes.

Varget seems good, and I would not worry about your powder choice.

 

[fella5]

RonAKA,

Thanks again! I will start at 31.0 and work up .3gr until I start seeing pressure signs.

 

[RonAKA]

How much of the bullet needs to be seated in the neck?

I shot some 69 grain Bergers on Thursday that were seated 0.070" into the neck to give 0.010" jam. The three shot groups averaged 0.254". So you can get away with very little, at least in some cases.

 

[fella5]

Okay... I just thought there was a rule I read that the bullet should be seated at least the diameter of the bullet. Guess not. I will load them 80grs 0.010 from the lands and see.

 

[fella5]

Just measured the seating depth of the bullet into the neck and it is 0.1045. This is measured from the base of the case to the ogive 1.938. So I guess this seating depth will work for me since yours was seated 0.070.

 

[shipbuilder]

For what its worth, I found that the chamber length on my Savage 12F in 6BR was cut very long; COAL measurements to start .015" off the lands (Lapua brass, 105 gr. Scenars) were so long as to prompt me to call Savage tech support. They advised that, yes, they do cut their chambers long; final loaded rounds (that shoot quite well, with no signs of pressure at 30.3 grs. Varget) are some 0.126" longer than factory-loaded Lapua 105s. I concur with the need to work up with any powder; every rifle, especially factory units, have variations due to machine wear, tolerance stacking, etc. that can impact chamber pressures.

 

[fella5]

I actually measured again using a LNL OAL and base of case to ogive was 1.948. So I seated the Berger 80gr to 1.938. When I chambered a round and removed it, I measured it again and it was at 1.822. I guess the LNL wasn't chambering in all the way. So I loaded a couple more and got the same results... Base of case to ogive was 1.822. I'm wondering now how far the Berger 105grs will be seated in the case neck. Seems like the boat tail will be below the shoulder. Is this okay?

 

[fella5]

For what its worth, I found that the chamber length on my Savage 12F in 6BR was cut very long; COAL measurements to start .015" off the lands (Lapua brass, 105 gr. Scenars) were so long as to prompt me to call Savage tech support. They advised that, yes, they do cut their chambers long; final loaded rounds (that shoot quite well, with no signs of pressure at 30.3 grs. Varget) are some 0.126" longer than factory-loaded Lapua 105s. I concur with the need to work up with any powder; every rifle, especially factory units, have variations due to machine wear, tolerance stacking, etc. that can impact chamber pressures.

What was your measurement from base of the case to the ogive? My Savage 12F 6BR using 80gr Bergers and jammed to the lands is 1.822. Using the 80gr Bergers and bullet jammed to the lands, the bullet is seated 0.2285.

Here is what I have measured.

Case OAL: 1.556
Berger 80gr base to ogive: 0.4945
Base or case to bullet ogive: 1.822