FINALLY Got to Shoot My 338 Ultra Mag.

[Coyboy]

Tarey, How have you been sizing the brass? and are these groups all on new brass or once fired?

The reason I ask, I was doing load development last week for a 300 wsm on a #5 contour, with 180gr. NAB. They were all loaded with new brass and h4350 and h4831sc were yielding 1-1.5" groups. I tried one load with 190 SMK with the same powder and they went into 3/4". So I figure the gun has to like somthing. I measured cases just behind the shoulder and the new ones were about .010" under sized from spec. So I thought I would FLS and just bump the shoulder on the once fired brass. I loaded up 5 rounds exactly the same as the loads that shot 1-1.5" with the h4831sc and those five on once fired brass went into .515" go figure.

Have you given H1000 a try yet?

 

[GNERGY]

I shot 2 fouling shots before shooting each group then cleaned barrel after and 2 fouling shots again for next group.

Jim, I used once fired brass that has been full length sized in the same die that the new brass was sized in I sent you. I have 100 new brass but haven't prepped them yet.

I am going to try some touching the lands and then changing the powder up and down a grain.
If that doesn't work what powder should I try next Retumbo or 7828 or H 1000 ?

Thanks for the help guys
Tarey

 

[Long Time Long Ranger]

Back the die off some and neck size only so you get a good headspace off the shoulder each shot. Your groups will shrink.

 

[GNERGY]

LTLR I sent Jim some new sized cases and he chambered my barrel to fit those cases, I think it is called ( match chamber ) they are a perfect fit. Am I explaining that right ?
OK, I see what you are saying. But I resized all my once fired cases already.

I will definately try that.

Tarey

 

[Coyboy]

Tarey, I would not use a powder slower than H1000, you might try Reloader 22, and even give H4831sc a shot. A 338 rum is not that overbore comparred to the other cartriges in that line up, and your not using the real heavy bullets. The Edges favorite powder is H1000 with 300 grain bullets so I would think on the burn rate of H1000 and faster.

 

[RMulhern]

Looks good but the friggin bolt is on the wrong side!!

 

[GNERGY]

I shot some more groups at 200 yds. ( if you can call them that ) on saturday and the 250's are still not grouping with RL 25 seated at the lands.
So I was researching and found out that the Barnes 225gr. TSX is a great bullet with real good accuracy potential.
I think it would be a better bullet than the NAB for holding together for hunting.
Should I change Bullets or change powder for the 250 NAB's
Thanks Tarey

 

[liltank]

I shot some more groups at 200 yds. ( if you can call them that ) on saturday and the 250's are still not grouping with RL 25 seated at the lands.
So I was researching and found out that the Barnes 225gr. TSX is a great bullet with real good accuracy potential.
I think it would be a better bullet than the NAB for holding together for hunting.
Should I change Bullets or change powder for the 250 NAB's
Thanks Tarey

Well, don't know if you chased my other thread or not, but I tried some really deeper seating depths due to some advice from guys shooting really well at 1000yrd benchrest competition. They suggested seating VLD type bullets to depths of .080" to .100" from the lands. I did that and my results are a dead g-hog at 648yrds and 1.550" at 300yrds on paper. Maybe try seating some at .050", .075", .100" and .125" from the lands. You might find a magical spot. My cousin got the same results with his 338 Lapua and 300grn SMK's. He had a hard time getting them to group and now they are shooting pretty tight.

One guy suggested touching the lands with virgin brass, full sizing every time, and seating deep after the first firing. So far so good for me. Just out of curiosity, the three shots touching in the first group.... were they the first three shots? I'm thinking you may have some heat stringing.

Tank

 

[GNERGY]

Liltank, the bottom hole on the first group is the fouler and next 3 were the group.
I did read your other thread and I might just have to give that idea a try.

I like Nosler bullets but am seriously considering the Barnes TSX 225 gr. they hold together better and the reviews say they are really accurate.

Tarey

 

[X-man]

Am I the only guy here that thinks a 250 Accubond at 3150fps is too hot for the 338Ultra?

Maybe I'm on crack, but mine bugholes at with H-1000 and RL-25 at 3000-3050fps.

Best of luck.

 

[liltank]

but mine bugholes at with H-1000 and RL-25 at 3000-3050fps.

Best of luck.

Maybe that is a good suggestion. Back it down to 91 or 92 grains and slow it down. Maybe it can't handle that type of speed out of your rifle. Always worth a try.

Tank

 

[GNERGY]

I have loaded to 95 grs. without the bolt handle getting hard to lift, like Kirby described in his thread load development. And I dropped down a grain to 93 without them grouping any better.
I'm using a 30 inch tube to wring all the velocity I can get out of this.

I'm going to load some seated deeper and see what happens. gun)
If that doesn't work I'm buying some Barnes bullets.
Tarey

 

[LjMann22]

Have any of you guys tried the sierra match kings in 300 gr? I have heard of it being used in the 338 edge but I haven't heard of anyone trying it in a 338 Rum. I am jsut getting started and needing some info. Sierra's website shows the ballistic coefficient on it at .760 at 2300 fps and above, so that sparked my interest.

thanks for the info guys, happy shooting

 

[sp6x6]

The bergers at .818 are shooting in my norma, at less case capacity than you have, I have shot 4 groups under 2'' at 400, best was 1''.Have had stuff like yours and had a 6'' group w/hornady 285, go figure, Im still trying them, my brass is as Coyboy said above , about 5-6 thousand short virgin.