Berger 80.5s 223

[jlorenzo]

I have Varget, N140, N150, 8208 xbr, Tac, RL15, and some other powders.
Looking to find a F class load with Lapua brass, some form of CCI primer either 41s or 450s since I assume 400s are too soft.
I'm getting right around 3000fps with the 80gr ELD out of my 26" bartlein using N140/CCI 41s/LC. I know the Bergers will be more consistent.
My problem is Ive never loaded Lapua before so the reduced case capacity versus LC requires me essentially starting over. Hoping some more experience guys could chime in with suggestions. Thanks.

 

[mgdietrich]

24.5 or varget or N140 is a huge node. Start there with 80.5’s.
Use the 450’s

 

[dstoenner]

My node for 80.5 is 24.4 varget in lapua brass with BR5’s but my 26 inch barrel is 1:7

David

 

[LVLAaron]

How do these shoot from a Wylde chamber? I'm shooting sierra 80's now, but would like to switch to bergers in a new gun I built.

 

[mgdietrich]

No problem in a Wylde, I wouldn’t even change the load from the sierras.

 

[dstoenner]

How do these shoot from a Wylde chamber? I'm shooting sierra 80's now, but would like to switch to bergers in a new gun I built.

In my last match gun that was 1:8 Wylde the 80.5 shot better than the 80 smk. Used the same load of 24 varget with a COAL starting at 2.38 or so and chased the lands. stopped at 2.525.

David

 

[LVLAaron]

Thanks! I found a couple thousand at whidden and have them on the way!

 

[Jeff Porter]

Thanks! I found a couple thousand at whidden and have them on the way!

Dont be afraid to jump the 80.5's. Two barrels I as using now at 0.090" and 0.130" jump. Run the Berger Jump tests to be sure. Use the same loads as the SMK 80's.

 

[jlorenzo]

Can anyone comment on the changes you will see with the first firing of Lapua fire forming to post firing with just the shoulder bumped .002" with a FL sizing die? I assume there would be slightly less pressure with the brass having been formed.
Heres my rough data, 94 degrees out smoking hot,
80.5s
N140
Lapua
CCI 41s
I'll have to look at the CBTO again it was right around 1.99 something if I remember correctly.

26" Bartlein barreled Tikka.

 

[Ned Ludd]

~2840-2850 fps is not unreasonable velocity for a 26" barrel length with N140 and the 80.5s. That corresponds to a nice plateau in your velocity data.

With regard to charge weight in virgin versus fire-formed brass, I have always found that loads in fire-formed brass need to have the charge weight decreased by anywhere from about 0.1 to 0.3 gr to maintain the velocity achieved in virgin brass. I have always assumed that some of the energy that went into expanding the brass/moving the shoulder with virgin brass will cause the velocity to go up slightly once the brass is fire-formed and doesn't need to be expanded nearly as much on subsequent firings. In my hands, reproducing the velocity originally obtained from a tuned load in virgin brass is usually a good place to start when re-tuning the load using fire-formed brass.

 

[jlorenzo]

~2840-2850 fps is not unreasonable velocity for a 26" barrel length with N140 and the 80.5s. That corresponds to a nice plateau in your velocity data.

With regard to charge weight in virgin versus fire-formed brass, I have always found that loads in fire-formed brass need to have the charge weight decreased by anywhere from about 0.1 to 0.3 gr to maintain the velocity achieved in virgin brass. I have always assumed that some of the energy that went into expanding the brass/moving the shoulder with virgin brass will cause the velocity to go up slightly once the brass is fire-formed and doesn't need to be expanded nearly as much on subsequent firings. In my hands, reproducing the velocity originally obtained from a tuned load in virgin brass is usually a good place to start when re-tuning the load using fire-formed brass.

In an attempt to save components and figure out a load quickly, I shot 2 shots of each of those charges while chronoing them. None of the charges in the velocity plateau grouped very well but 24.4 was nearly one hole as was 25. I'm going with 24.4 for now just to go shoot but I will explore seating depth within that plateau. I am wondering what I should do if I can't get groups in the plateau? (this rifle tends to shoot almost anything pretty well, surprisingly the 80.5s seems to be much more picky in regards to charge and possibly seating depth), for example I loaded 10 rounds of N140/80gr ELD, shot them all at the same POI while chronoing and the total group was a cloverleaf.
With the 80.5s most of the two shots per charge where about an inch apart until 24.4 then they were nearly one hole as was 25gr. CBTO 1.998, even though not being in the plateau the spread between the two shots at 24.4gr was 6 fps which was pretty good compared to some of the other charges.

 

[LVLAaron]

Here's where I'd be testing seating depths:

 

[Jeff Porter]

If you are only shooting out to 600 no need to push too hard. Run them in the 2850 plateau abs do a jump test. Follow Berger’s plan and don’t be afraid to go long in the jump.

 

[fkimble@charter.net]

I'd be looking at the 2850 fps area, 3 loads almost same velocity, wider node.

Frank

 

[CharlieNC]

Regarding the brass comparison, I have not found a loading difference is required between LC and Lapua after evaluating a small charge weight range comparison around an optimized load. Same charge gives same POI and scores for me. The 80.5 is a great bullet, but I moved on to 90's for longer range.