Loading 308 HBC's - seat depth

[bobeager]

Looking for feedback re best loads for the new HBC's in Lapua Cases, particularly interested if anyone has tested / verified the data given in Spencer Dunstall's ATR article regarding the 50 thou jump.

I have a new 12 twist kreiger and will be using Lapua Cases, 2208 and CCI BR2 primers.

And. yes, I am dabbling in the "Dark Side" (Fstd)

[johnk]

Both Dyer projectiles have been set-and-forget for me. They've never been critical of seating depth, though I started out on one barrel with the .005" jump that was the good guts at the time. That barrel lasted 5000 odd rounds without a change of seating depth. As a matter of fact, when I went over to the HBCs I fired 50 of them in that barrel, setting at the same jump as the stubbies were at that time (sorry, I can't remember what it was). My next & current barrel was set to that jump too & I'm too damned lazy to run the OAL gauge in it to see what it is now.

Suffice to say that after I fitted a new rail recently, I benched it at 100 yards & it shot ½ MOA, about what it was doing the last time I shot it in anger at a proize meeting.

I think that sometimes we can get too precious about what's good & what's not. I know 40 odd years ago, I wore out a couple of good .222 magnum barrels trying to get the last gnat's gnut of accuracy out of it for benchrest competition - all for bugger all improvement.

John

[williada]

Suggest .015" jump. If you are getting too much vertical, try .025". Maintain the jump as the barrel erodes. The first 300 rounds tend to wear a new barrel at a faster rate until some work hardening is established.

David

[bobeager]

Tried 50 thou out ... no good at all with any load from 45.5 to 46.5. Worked well so far with 10 thou in lands, 46 grns 2208 giving 2925 fps avge with OK ES. Will try 10, 15 &20 out. Thanks for replies.

[RDavies]

As I am contemplating dabling in the dark side ( F std, but dont tell my mother), I have asked around to see where to start. It seems about 75% say they jump them, while the other 25% say they have to jam them, sometimes 20 thou. Some people I spoke to with 2 or more different 308 barrels say that one barrel shoots best jumping, with the other barrel shooting them equaly well jammed in. Not sure if it was the same reamers as well.
It seems barrels are like nice women, we all want a nice new good one, but none of us has them totaly figured out yjust yet.
Once I get my 308 going, I will get the powder load to about 2950 fps, then experiment with seating depth to see what it likes before experimenting any further.

[bruce moulds]

bobeager & rdavies,
how could you do it to yourselves?
bruce moulds.

[bobeager]

Bruce, basically on a Saturday afternoon our Goulburn Club is almost totally F Standard. In fact it would be 80% F Class shooters with a couple of full bore. The new members that are joining are F Std. The OPM's within 250 Kms of Goulburn offer F Std. I will shoot F Open at Queens and still very keen of the SSAA 500 metre Fly Shoot.

Regards

[RDavies]

Bruce, it was a momentary lapse of reason. Dont tell,anyone, it was just a phase I was going through. 3 hail Marys and some self flagelation coming up.
One alalogy though is this, even if we are used to eating, grain fed eye fillet, it is good to try hamburgers once in a while.

[jerryatric]

hi, quick note - mine are only 5 thou off , been the same for the last two 308 rifles . no drama,s & good enough acuracy to get 1st place the first time i shot them the other day at local . my load testing stops right there .

[Seddo]

I did my first lot of testing with some BHC's on monday. I dont have a bullet length guage so i seated them to just touch the lands, very slight graze on the projie when closing the bolt. Started at 46.8 and went to 47.4gr 2208, the best group was with 47.4 and they were all touching at 100m. I havent run them over a chrono but will get it done this week sometime.

[John E]

What brand of cases are you using Seddo?

John

[Seddo]

They were new lapua cases. I opened the box, ran then through the neck die and loaded away.

[stu_bear2002]

FWIW in my 26" barrel omark im now loading 45gr of 2208 with the proj just off the lands and the result was a 0.119" centre to centre (less than 5 cent coin)for 5 shot groups @ 100m now thats a vast improvement from 0.341" groups that i was getting with the 46.3
cheers stuey

[Barry Davies]

G'day Stuart,
That's good grouping, however 45 gn 2208 in your 26" barrel and 14 twist probably won't make it to 1000yds and probably 900 also ( accurately ) You need to look at speed, depending upon which projectile you are using.
Most 2208 is relatively mild ( slow burning ) and simply does not generate sufficient speed at low loads in your combination for long range.--2206H would be better.
Barry

[Barry Davies]

Deleted after Debug warning.
Barry