80.5gn Berger FB seating depth???

[Aussie Denis]

G’day All,
I’m about to do initial load tests on a new .223rem using 80.5gn FB bullets. 30” straight profile, 1:7T throated looooong. I expect to find a load around 25gn varget or ar2208 here in Aus.
I’d love to get a general idea of what seating depth everyone is running these bullets at. I have a lot of experience with 155.5 FB in .308 which love to be run at .010” jump in many and varied combinations. Therefore I plan to run my powder charge tests on this .223 at .010” jump unless the general concensus suggests something else. I’d really appreciate your help. Thanks, Denis.

 

[Danley]

In my 223 I loaded them .015" off and had no reason to try further seating depth test.

 

[watercam]

They are pretty forgiving. I jump mine .035"-.040" simply to negate any ogive variation. Have had good groups over a wide range of depths.

 

[swadiver]

i jam 'em 10 thou. just a bit more consistent performance for me compared to a jump. not night and day. i am using N140, getting great accuracy and averaging just over 2900 fps with no pressure signs from a 28" Bartlein barrel. i am preferring the N140 over Varget or H4895 these days.

 

[dstoenner]

I jump mine .020 and in my Wylde chamber at 1800 rounds i am at 2.440

David

 

[loud_noise]

I jump them 15 thou. As has been said already, quite forgiving as a bullet.

 

[Clancy]

Interesting comments above. I’ve used them in a lot of barrels and it was .005 off or bust.

They shot decent farther off or hard jammed, but all the bugholes came at -.005.

 

[Larry70]

I think a 223 will shoot at just about any jump, my best with the 80.5 is .010
23.7 H4895 just over 2900 FPS sub moa @300

 

[loud_noise]

Interesting comments above. I’ve used them in a lot of barrels and it was .005 off or bust.

They shot decent farther off or hard jammed, but all the bugholes came at -.005.

Thanks for the suggestion. I might give that a go. What powder and charge are you using with that jump length?

 

[Ned Ludd]

OP - if you have noticed, the replies you have gotten are all over the map. Some of that can likely be explained by the different methods (and results therefrom) used to determine distance to touching the lands. I would suggest that you start by testing the 80.5s jumped from .003" off to about .024" or .027" off in .003" increments. If the 80.5s out of your setup tune in within that range, it should be very obvious. If you don't find a satisfactory seating depth initially with jumped bullets, then I would go back and test at "touching", and .003", .006", .009" into the lands.

 

[Aussie Denis]

Thank you everyone for your experience. I agree that from the info provided it seems that these bullets are definitely not fussy with seating depth. Absolutely agree that all barrels are different and the homework needs to be done as always to achieve best results. In terms a seating depth for the initial powder tests, I feel like a light .005” jump will be a better place to start than my original .010 jump idea. Thanks again for your help. When I get to seating depth tests, I’ll post some pics..

 

[Ned Ludd]

Thank you everyone for your experience. I agree that from the info provided it seems that these bullets are definitely not fussy with seating depth. Absolutely agree that all barrels are different and the homework needs to be done as always to achieve best results. In terms a seating depth for the initial powder tests, I feel like a light .005” jump will be a better place to start than my original .010 jump idea. Thanks again for your help. When I get to seating depth tests, I’ll post some pics..

My suggestion would be to start them at .015" off the lands. The reason for this is as follows: The 80.5 is a tangent ogive bullet, which typically indicates jump tolerance. If you carry out the initial charge weight testing at .015" off the lands, you can then do a seating depth test from .003" off to .027" off in .003" increments (i.e. -.003", -.006", -.009", etc.). The chances are very good you will find a seating depth optimum somewhere within this range. Because .015" off is in the center of this seating depth test window, you will not be changing the seating depth of the bullet by more than .012" in either direction during the course of seating depth testing. In my hands, this is not normally enough to change the effective case volume such that you can reliably measure a difference in velocity. Thus, it is not typically necessary to re-optimize charge weight following seating depth optimization.

Alternatively, you can start with a slightly reduced charge weight (for safety reasons) and carry out a coarse seating depth test (i.e. ~.005" increments) first to get a rough idea of where they might like to be seated in your setup. Then carry out charge weight testing and a fine increment seating depth test. I use both approaches regularly and typically end up at the same point, regardless of the method used. Sometimes the coarse seating depth first approach is a little easier with a new bullet for which I have no good idea where it might want to tune in. Good luck with it. I think you'll find the 80.5 Fullbore to be an outstanding bullet.