Berger 180 Hybrids

[bartman007]

Dave,

Thanks for the feedback. I'll back off 1 grain and see how that goes. I did notice with 2217 that there was about 80 fps difference in the muzzle velocity between my two loads that were 1 grain apart.

You're right about .5 to 1 thou neck tension, it may be a tad light when having to extract a round. I normally run 1 to 2 thou by default, and found that has been great for elevation consistency. Never had a Chrony before, so didn't have the opportunity to check SD, but now do!

Interesting what Rod has noticed about elevation with a heated up round. That there is little difference. I'll keep that one in mind, as I too did think about having to aim lower to compensate. Rod, it must have given you a little fright when you saw the shot go low!

Alan, did I give Dave enough of a clue when I mentioned the other powder that I'm using

[DaveMc]

No worries Bartman - I would guess you will find the same velocity between 1 and 0.5 gr down.
It was actually my comment that I nearly dropped out bottom of 6 but I aimed there, guessing it might go a little higher with temp. Looking at Rods shot too I think there was no real change in elevation for his either. My powder was 2213 - think rod was using 2209.
Don't worry - I won't be changing powder or primer or anything in a hurry.

Will just try with these hybrids....???? Jump and Jam

I am actually all for sharing info - I think this world championship coming up will be great for the sport here. We could/should all focus on helping each other and "the greater good of the nation" (Geez that sounds a bit Pommie like!). We will all be better off for it.

[DaveMc]

Thought I would post some links to some info on Hybrids.
First this one.

http://appliedballisticsllc.com/index_f ... 80Hyb.html

Note: Alan bottom of page the 1 in 9 twist is supposedly even reasonably stable in his "worst case conditions (-18 degrees C, 0 % humidity, sea level) - I haven't seen too many days like that. At normal conditions it should be very stable.

However rumours of 190-200 grainers are on the cards so 8.5 might be worth trialling???

Dave

[Cameron Mc]

I had a good yarn with Bryan Litz at the Nationals about twist rates.

Basically what he said was the bullet factories factor in a fair "safety" margain regarding twist rates to cover all possible scenarios.

I use 1-9.5" with 175 smk's. Never had stability problems. Sierra says use 1-8.5" or faster.

Cameron

[DaveMc]

I think Marty likes the 1 in 9.5 too Cameron.
Dave

[AlanF]

Thanks Dave and Cameron - you've converted me. I know that 8.5s are common in SA, so that's what made me think about it.

If you're reading this Raven, maybe the instability was caused by the turbulent wind at Lower Light . I remember during the leadup in 2007 getting the wildest vertical wind shot I've ever had. It was only 600m and I think it was at 2 o'clock in the 4 ring (on the Open target that was) . So what you need to do Richard is apologise to your 9 twist barrels, and move to Victoria where the wind is more respectful.

Alan

[RAVEN]

Alan the 1:8.5 seem to work better here in SA
Stew and I work up loads together with our first 1:8.5 in 2005 the results were very similar 57Gr 2213 gave approx 3000fps stew was slightly faster X 20fps
Had a 1:9 never liked it
That was a slow barrel most accurate load was 2700fps couldn’t get much past 2760 with 2213sc and 2880fps with R17
Bruce has had a few 1:9's and nothing to shout from the roof tops there
168 Berger worked best for me in the 1:8.5
180gr worked better in my 1:9 but slow go figure
I have 2 new 1:8.5 one a 5R and one straight rifling I will be testing these in parallel
Whatch out for the Jolly Roger

I remember during the leadup in 2007 getting the wildest vertical wind shot I've ever had

We allow for that Alan


RB

[AlanF]

Richard,

Canberra is a fortnight away. Would be a great occasion for "Jolly Roger"'s debut. I will have the latest addition to the fleet there, "HMAS Ugly", resplendent in battleship grey (with a few small scratches inflicted by enemy action).

Alan

[RAVEN]

Alan would be nice but I have an appointment with some brown trout in Tassie at the end of this month.
You can be sure I will be watching with interest
Did you buy 4 ltrs of that grey Alan I see you lent it to Rod

[RDavies]

Did you buy 4 ltrs of that grey Alan I see you lent it to Rod

Blasphemy. Mine Isnt battleship grey, it is something French sounding which means "Glorious Platinum" or something fancy like that.

These 190-200gn Hybrids sound interesting. I have a tack driving 8" twist barrel waiting for some long bullets to suit it.
As for twist rates, I bought what was supposed to be a 9" twist, but it ended up being closer to 10", and wouldnt shoot 180s, another 6mm barrel which is supposed to be 8", but is about 8.5-8.6"
My next 284 barrel will be an 8.5" just to be sure in cool dense air with longer Hybrids and any future bullets.
My next 9" twist barrel will be for a short mag of some kind to use in warm, less dense air at 2000 m altitude.

[DaveMc]

Oils ain't oils, Barrels ain't Barrels and obviously now Grey ain't Grey I must say though it is a very modern grey Rod - those French sure know how to market to the meterosexual!

2000m and hot - Are you moving up to Ravenshoe???

Good point though. Any barrel should stabilise in those conditions....

A couple of guys around the traps have the 180 Sierras now too. Reporting good results so far.

[AlanF]

...I have an appointment with some brown trout in Tassie at the end of this month...

My brother had an appointment with this one last week (Waikaremoana, NZ).



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[AlanF]

My next 9" twist barrel will be for a short mag of some kind to use in warm, less dense air at 2000 m altitude.

Good to hear you have Raton, NM on your mind Rod . All other participants in this thread take note - nominations close Dec 31 (see ATR 94, page 4).

[RAVEN]

Humm nice fush

[AlanF]

Humm nice fush

You wouldn't eat that one with cheeps.