need 22-250 AI 75 gr. amax reloading data goodgrouper and others

[308 nate]

HI,
I need some reloading data for the 22-250 AI and the 75 gr. amax. I am going to be chambering a Savage .223 SS. BB. with a 1 in 9 twist to 22-250 AI in order to shoot in the modified firearm class at the jamboree. also do you feel the 1 in 9 twist will stabalize the 75gr.amax?

What do you think about fire lapping the barrel as a .223 and then rechambering it? or would I be better off lapping it with a lead core? or should I forget about lapping it?
TIA,
308nate

 

[REM 700]

I am using 42.5 grs. rl-22,winchester brass,rem 9 1/2 primer with the 75 gr. a-max. Velocity is 3420 fps with 30 inch hart barrel. Mine is a 8 twist and i think the 9 twist will work for that bullet. Fireforming with 39 grs. rl-22.

 

[goodgrouper]

My load is currently 44.5 grains of H4831sc and gives 3350 fps with my 25 1/2" barrel. I used the David Tubb's Final Finish in my barrel once it started blowing up the amax's. THis happened after about 2100 rounds. I ran 44 #5 grit bullets through the barrel. Before FF, it would take about 8 patches of Coppermelt to come clean and after FF it takes 3! However, my barrel is enough far gone that it doesn't like the secant style shape of the amax's anymore. It does still like the 80 grain Nosler J4 comps though.

Before FF, the load was 42.5 H4831sc and was max. Now, I have to bump up 2 full grains to get the same velocities back. I have seen the Tubb's break in kit work miracles on factory barrels time and time again, but I am still experimenting with it on custom barrels. So far so good.

If you want to firelapp, I would do it before you rechamber to the AI so you will have a fresh, smoothened throat to work with. Also, DO NOT USE the NECO kit. Only use David Tubb's FInal Finish Throat Maintenance kit and don't use all the bullets in it.

Oh, and yes the 75 amax will do fine in a 9" twist. THat is actually what it recommends on the box. /ubbthreads/images/graemlins/wink.gif

 

[Ronin]

My barrel is a 1 in 8 twist, 26 inch Border, chambered to a .252" AI neck, fave load at the moment is 39.5g RL22 under 75g A-Max moly, gives 3200fps and very good accuracy (.3's at 100). Same bullets with 38.5g of 4831SC and 38.5g Vit 160 give slightly less speed but if I put more powder in the case I run into pressure, accuracy not quite as good as with RL22. Lapua 69g Scenars are very good as well with 39g of Vit 140 if you wanted another option.

Iv'e shot the RL22 load predominatley for three years (1300) rounds of A-Max molys and it isn't showing any signs of losing accuracy. The Ackley cases do stretch more than I thought they would but it is nothing you cannot keep on top of. Otherwise no problems whatsoever, A-Max causes blow ups in Fox and rabbit sized targets at any range, I have shot them at so far. /ubbthreads/images/graemlins/wink.gif

 

[308 nate]

Thanks you all for the loading data!
it's great.

goodgrouper, I think I will try firelapping as a .223
as that was my feelings also on lapping before I chambered to 22-250. The lapping kit I have is made by wheeler engeneering, do you see any reason not to use this? I have had this kit probably for 5 years I would like to use it unless you see a reason not too.The reason being you mentioned to only use tubbs. The kit comes with 220 grit 320 grit and 600 grit.
308nate

 

[goodgrouper]

I have not heard of Wheeler engineering and I'm afraid I haven't experimented with enough kits to know exactly what to tell you.
I do know however that the Neco is way more aggressive and not quite as precise in it's application of grit as Tubb's. I think the grits can be coded the same numbers like sandpaper but the actual material used for the grits may be different. At least, that has been what I have seen. THe Tubb's TMS system uses 50 bullets that are all 500 (or was it 600?) grit and it is plenty.

If I was to use your kit, I would not even think about using the 220 or 320. I would just use maybe 25 of the 600 grit. On the other hand, $30 isn't that much money for TUbb's and it is really cheap compared to the cost of a new barrel. /ubbthreads/images/graemlins/wink.gif

THis firelapping thing is my current study of deep examination and I'm afraid that I just haven't had enough experience with all the different kits and different scenarios yet. With new factory barrels, FF is absolutely the cat's meow-no question in my mind.
With new custom barrels, it absolutely doesn't get used.
And with worn out custom barrels, the jury is still in deliberation! /ubbthreads/images/graemlins/wink.gif

 

[308 nate]

To all,
I thought I would share how the 22-250AI did at the Jamboree.

I arrived in Pierre Monday night and awoke early Tue. morning to head out to the range.
When I arrived at the range I drew my shooting relays and it turned out I was in the last relay in both the modified and the unlimited so I did not end up shooting until 3:00 in the afternoon just enough time to wear off some of the adenaline. It was a beautiful day 70 degrees and overcast with a 2:00 wind varying from 2-12 MPH we were allowed 20 shots at 18 balloons 4 balloons at 107 yds(worth 25 pts.),4 at 240yds(worth 40pts.), 5 at 365yds (worth 60pts.). and 5 at 492 yds,(worth 75pts.) all balloons were aprox 3-5" in diameter.

And so finally it's my time to shoot....
and I'm hoping I just fit in the norm as I make no claims to be a super shot. My spotter is a gentleman I met a few minutes before He spots for me....really great guy but He had never spotted for anybody before.So I decided to start with the 4 balloons at the 240yd. mark and managed 0 misses.
then I proceded to the 365 mark and again managed 0 misses.
from there I went to the 492 mark and to my disbelief I manage to take all 5 balloons with only 1 miss.
So I am left with 5 shots for four ballons at 107 yds.
And yes I ended up with 1 shot left over and a perfect score of 935 points and this was pretty amazing to me as know one else out of 200 shooter the first day shot a score over 800 points. /ubbthreads/images/graemlins/shocked.gif
but to my surprise all this score got me was into the finals
and in the finals all shooter start with a clean slate.I drew a bench to the other side of the range which had some deep gulleys out by the 3-500 yd. area.
There were 11 shooters in the finals and I ended up with another spotter who only had binocs and was giving me the wrong directions and managed to only shoot a score of 650 /ubbthreads/images/graemlins/frown.gif
which put me at about 6th place but needless to say I still had an AWESOME day with no regrets and am planning to go back next year.

I did not end up fire lapping the barrel, Here is what I ended up doing.
with a cheap coated cleaning rod I pushed a small jag through the chambered end of the barrel to within 6" of the barrel,then I pre-heated the barrel and jag and then poured in molted lead which encased around the jag and molded perfectly to the rifling. Once the lead cooled I pushed the lead core 3/4 of the way out of the muzzle and then applied 600 grit lapping compound and then started working the barrel. I did not feel hardly any tight spots so I only ended up lapping about 20 strokes. I then cut a half inch off the muzzle and recrowned and then chambered the barrel to 22-250AI.
Barrel break in was awesome, about 5-7 shots and the barrel was cleaning very easy.Maybe it was just a good barrel,maybe it was a combination of barrel and lapping.
FWIW.
here is the load I used
Winchester brass with the works.
75GR. AMAX
RELOADER 22 41.5grs.
Federal 210 primers witha muzzle velocity of 3380 out of my 25" barrel.

I also got to meet Richard schatz, a 1,000 yd world record holder with the 6mmbr dasher. He only lives about 30 miles from me and I'm hoping to get a chance to build a rifle for Him someday...maybe.

I also got to meet Gordy Gritters, one heck of a nice guy!

and a lot of other great guys.
All in all I had an awesome time and am still on cloud 9.
Thanks to all you who helped with loads and advice and such.

308nate