6BR 70 gr Nosler Ballistic Tip loads w/ N133

[SS427]

I can't find any load data for the 70gr Nosler Ballistic Tips in 6BR using N133 powder. Pretty sure the load data is in a current Nosler reloading manual, but don't want to buy another manual just for that.

Can someone tell me the recommended min and max load for this bullet using this powder? If you give me data outside of the max range, be sure to tell me so I know to work up to it.

I would call Nosler tomorrow, but I figured they might be closed on Christmas Eve. I know those Bend Oregon people like to snow ski whenever they can.

 

[fdshuster]

Otter: My standard 6BR "light" bullet load has been 30 grains of N133 with the 68 gr. Berger #24411 & 70 gr. Sierra #1505, Federal 205 or 205M (doesn't seem to matter), seated to touch. Developed that load years ago for my first 1-14, then another in 1-14, a third with a 1-9.25 twist, and finally my fourth chambering with a 1-8. That load has been consistantly accurate in all four rifles. When developing the load I began at 28 grs., and increased in 1/2 gr increments to 31.5 before I started to get hard bolt lift (slight), and slightly flattened (not cratered) primers. Then backed off to 30 grs. So it may be far enough below the "red line" to be fine with your 70 gr. Nosler's. If you decide to try it, you may also want to try it with .020", then .010" of jump, before seating to touch, where it does prefer to be in my rifles.

 

[Laurie]

Otter,

The current Nosler manual does have a Viht load for the 70gn Ballistic Tip, but it's for N135 (28.5-32.5gn).

Vihtavuori lists N133 as 25.3-28.7gn for the 70gn Sierra MK to give 3,140 fps max in the 6mm BR Norma chamber. That MV seems very low compared to those a friend recently achieved with 68gn G&C flat-base 8-cal ogive benchrest bullets and N133.

He started on 29.0gn (3,189 fps) and worked up to 32.5gn (3,561 fps) on a cool day (48F) without any pressure problems. His rifle has a 1-8" twist barrel and is throated with an intermediate amount of freebore (to suit the 90gn Lapua Scenar). Bullets were seated just into the lands so if your rifle has a short throat, you'd be seating deeper and raise pressures. Accuracy was excellent especially at the higher charges - which were compressed loads incidentally. Brass was Lapua, primers Fed 205M.

Most people and reloading manuals regard N133 as being on the fast-burning side in the 6BR with 70/75s despite this being the standard powder in the not that much smaller capacity 6PPC, and advise N135 for the BR. It looks like N133 can perform very well though with this weight of bullet so I'd give it a try. Start just below Viht's maximum and go up from there in small steps.

Usual caveats / warnings with other people's data applies, and note the temperature issue - we can get away with a lot of loads in the UK that you wouldn't in the US summer as we're a great deal cooler here, even compared to northern states.

Best wishes, and a Good Christmas,
Laurie

 

[SS427]

Thanks guys. I just assumed Nosler would list N133. Very interesting they don't consider it a viable powder and include it in their list. I've gotten quite a bit of feedback that N133 can be a very accurate powder in slow twist 6BRs, just like the 6PPC.

I've always found bullets have more impact on accuracy over any other component, at least with the guns I've owned so far, so I'm trying three different readily available 70 grain bullets. I have N133 and understand from Frank he has excellent luck with it in his 14 twist 6BR, so I'm starting with that powder. Next up will be H322 and Varget. I would try N135, but I don't have any and can't find it available locally. To make matters worse, VV powders are costing $35 a pound locally.

Usually Nosler recommends less powder for the same bullet type and weight than Sierra, so I didn't want to use the Sierra load verbatim. In this case I will and just watch for pressure signs very closely. I think the reloading manuals are getting conservative with their loads, and suspect the lawyers do the writing now. Manuals ten and twenty years old almost always have a heavier max charge listed for the same bullet and powder combo.

 

[Laurie]

I've tried a few 70s or thereabouts in my own 6BR which is 28" barrel 1-8", no-turn neck, and Norma version -throated for 105s, so can use a bit higher loads than yours with five powders:

70gn Sierra MK
28.5-30.0gn H322 Max load 3,236 fps groups from 0.3 to the inch depending on charge
29.5-31.0gn H Benchmark 3,289 fps groups from 0.5 to 1"
28.5-30.0gn AA-2015 3,273 fps groups from 0.25" to the inch depending on charge
26.5-28.0gn Alliant Re10x No chrono readings 0.6-0.8"

66gn Berger HBC-FB (Flat-base, long secant ogive nose - no longer produced)
30.5-32.5gn Viht N135 No chrono readings 0.6-0.8" in poor range conditions

Of that bunch, H322 and AA-2015 were the best by a fair margin with most groups under the half-inch and showing promise if they were fine-tuned.

Viht N133 is very much in line with this pair, so with my friend's results in mind, I'd certainly give it a go, as well as H322. It'll ber interesting to see how Varget performs with this bullet weight.

Best wishes,
Laurie

 

[SS427]

Those charges are in the range of what I plan to test with the H322 and Benchmark powders I have. I will be sure to let you know how they perform.

In theory I'm thinking Varget won't perform all that well with these light bullets, but in reality I think they will do great. I've gotten some of my best groups in a varieity of factory guns with Varget, even though it wasn't even a recommended powder. I will post results on this powder too.

Really foggy and cold today, but no wind. I may have some results to post as early as tomorrow.