1-8t 55g bullets & aa2230 dirty necks/shoulder

[skany]

Hi guys

Ive recently picked up my 6br that iwanted to use for foxing & long range work!

i went with a .74 throate hopin that id have a chance with the lighte stuff

after plenty of reading i went for 55g nolers & a2230 & crossed my fingers!

I woked up to 34g of aa2230 wich made jsut over 3700fps with great acuracy consiering it was fairly blowy!
im going o keep going to see wht i max out at but that was the highest charge i loaded!


I did notice when i started to re prep the one fired brass that most of them were dirty around the neck /shoulder!

is this normal with aa2230?

i will add that the little 55s and jumpin & hanging out the case neck!

i also tried te 105amax wihshot great to but a bit slow as yet!2830 ish


cheers Andy

 

[JohnnyJohnson]

Skany

That sounds like way too much load for fox unless you just want to blow them up.

 

[skany]

Not realy

the higher the mv helps when shooting foxs by lamp light as it much harder to judge range!


ive been using a 243AI up untill now & dont want to give up much with the 6b(with a lighter bullet mind!)r

cheers andy

 

[BoydAllen]

I think that your load is too light, causing neck obduration issues. Run a pressure test, to seen how hot you can load, and watch the case necks as you go up. I think that this will solve your problem.

 

[jonbearman]

If the necks are sooted then it sounds like the load is not developing high enough pressure to seal the neck area. I would try diferent powders as well.AA2230 was developed for the .223-.308 cartridges.There are different powders to choose from like varget and h322 etc. Check your manuals again and see what might be a better choice.

 

[CPorter]

What is the loaded neck diameter and the fired neck diameter? If the difference is large, >.004", then it might be extremely difficult to seal at the neck without thicker brass.

Are these new cases or have they been fired several times? Work hardened brass doesn't expand as readily as freshly annealed brass. Especially important if your chamber neck is loose like above.

How deep are you seating? Seating deeper forces the pressure higher before the bullet leaves and helps seal at the neck shoulder junction.

If this is a single shot, try partially resizing the neck leaving the bottom 1/3 at the fired dimension.

 

[skany]

Thanks for your input guys

its all brand new lapua brass wich comes in .269 loaded & 270 fired with the 105 g pills!(i have a 272 neck)

ive just measured my 55g fired necks & they are 267.5 so presure is without doubt the problem!

i went with AA2230 as this is the powder that seems to give about the highest mv ive read about with 55s/6br


I shall seat them a little deeper next time & try again
thanks again

Andy

 

[BoydAllen]

If you do a pressure series with powder charge increases at about .3 grain, and stop when the bolt gets the least bit sticky, (FL sized cases), that should get you there. Take your time and pay attention to pressure signs.

 

[jo191145]

55 Noslers are nice but short. If you ever find some 58 V-Max hanging around pick up a box to try.
You just might be able to get near/into the lands with them. Helps increase start pressure. .012'' off the lands was my preferred setting last time I tried em.

Same with Ramshot X-Terminator. Ever see a lb on the shelf grab it for a try. Uncanny accuracy in 6BR with light pills. Fed205M preferred.

 

[AckleymanII]

Skany......

I'm running 33.5g and my necks are clean as a whistle, 55's running 3900 out of a 28" 12 twist.

Lot # of 2230 are all over the map, so you may have a slow lot#...34.0 is an absolute max load for my rifle, and I won't shoot it due to full lenght sizing needed after firing that load.

I''m running Lapua brass.

 

[Kenny474]

I think you would have had much better luck with a 1-12 twist throated for the 55's if that's what you plan to use.

It's difficult to make a barrel shoot both 105's and 55's well without issues, such as excessive bullet jump, pressure issues, over rotation on the lighter bullets, etc.

It's always best to go with a barrel machined and set-up for a specific purpose than try to make a "do-it-all" barrel. The all purpose (multiple bullet weight) rifle never does anything as well as a purpose built rifle, and will usually be much harder to make work as well.

Maybe ditch the 55's and go a bit heavier, (70gr Nosler) as you will be able to get closer to the lands without the bullet nearly falling from the case. Or have a 1-12 barrel machined for the 55's.

I have been watching a guy at the range the past few days try to get his .243 (which has a rather long throat) to shoot both 58gr V-Max's and 105gr A-Max's with little success. I almost thought I was going to end up with a new rifle, as he looked as though he was going to throw it in the bushes at one point.

 

[skany]

Hi guys


im more then happy how the 55s shot thru the 1-8 twist they were very good the same as the 105s again shot very well with all carges i tried!

im going to seat the 55s deeper & go again

forgot to say on my first post the 65vmax were also very good & i had them 10tho off!

the 55s had 250fps on them tho!



cheers Andy

 

[skany]

been to the range again today

the 55s needed to be seated a full 40tho deeper to seal the necks corectly!!

they dont mind the jump/twist mind as they were printing under half inch @ 200 yds @ 3720ish fps

i didint up the powder charge i just messed with seating deapths today!

im intrested to see how these noslers perform on foxs!

cheers Andy

 

[Ackman]

Don't know what you mean by .74 throat. If you're talking freebore, that's a lot for light bullets. I also shoot 55's with AA2230........at 34gr my gun is right about 3700 too, it's not a heavy load. Best in my gun is another 1.5gr and that same 55BT is at about 3920. Now that might damage a fox pretty badly.

 

[skany]

Hi Ackman

its your old post that made me intrested in trying AA2230

yes i ment freebore & i know its a lot but i needed this tube to shoot heavys as well!1-8


im going to carry on working up untill i get some presure signs & back of a little as long as the acuracy is still there!


I couldnt be more happy with the 55s considering that arent sposed to work in a 1-8 !

i can get 65vmax smack on teh lands but the way the 55s are shooting i may as well take teh extra speed as the BC is about the same for both bullets!

hope to have a go at the foxs some point this week!

cheers Andy

 

[skany]

worked upto 35.4g of aa 2230 & tried it out today
gave me 3793fps av mv no tight bolt or anything but i thought i could see some marking on the face of the brass so i went with 35.1g for a steady 3763fps!

here the results @ 200yds top 3 groups are 55 g noslers the other groups are 105g amax & seating deapth adjustemnts!(not helped by me aiming at a differnt dot mid group "twice")

im taking the rap for the center top group as ididnt wait long enough after wallking out to set up the target! :'(

anyway who says 1-8s wont shoot 55s

cheers Andy

 

[jonbearman]

I think you should try some 68 grain bullets with a load of h322.It works for me with a jump to the rifling.I use 29.6 grains and of course start low and work up.

 

[skany]

dont thin the 68s will give me wht im after!

im more then happy with the 55s as they should be a good fox killer!

cheers andy