338 Lapua & 300gr Sierra Match King

[kyhuntclub]

I just started reloading for this caliber. I have been working with the 285 gr Hornady's. I finally found some 300 gr MatchKings in stock and picked a few boxes up. I am curious as to what you guys have been loading these with?

I have following powders on hand:

IMR 7828SSC
Retumbo
H1000
RL25

 

[vh20]

Retumbo and H1000 are very popular choices. There are those who say that Retumbo is the "perfect" match for 338LM (including some of Hodgdon's techs). I've had my best luck with Retumbo and the 300gr. SMK with loads that gave me just a hair over 2700 (like around 2725). That has been the sweet spot for me. Depending on Lot Number, that equates to somewhere between 89.5 - 90.0 gr. in my gun with CCI 250 primers. A lot of guys prefer the WLRM or Fed. 215 Match primers over the CCIs, but I had 2000 of the CCIs on hand when I did my load development. I wanted to try the others later, but then the craziness hit and they weren't available.

I've been told and observed posts on here that indicate H1000 can give similar accuracy to Retumbo, but at a typical cost of about 100 fps. lower velocity.

Also I should add the 300 SMK really wants a 1:10 twist or better.

 

[Enough Said]

92.0 H1000
2,760
Trim to 2.714
B2O 2.980

TRG-42

 

[Dan Newberry]

Our accuracy load is 89.3 grains of Retumbo in Lapua brass with the 300 SMK's. 2700 fps from the Savage 26" barrels... And that's plenty of velocity for 1 mile shots (proven on 1 mile targets) and long case life.

 

[kyhuntclub]

Thx for the replies. I have a Armalite AR30A1 with a 26" barrel 1:10 twist. It really liked the 285gr Hornady(.30-.40 MOA) with 90 grains of Retumbo. It also liked 89 of H1000 but showed signs of high pressure in 90 degree weather. I will be looking hard at the 89-90 range of Retumbo with the 300gr MK.

 

[lead ƒarmer]

I will have to try these loads if I can ever find retumbo again.

Sent from my POS phone using Tapatalk 2

 

[P7id10t]

Good Post!
I just found Retumbo on the shelf, and since I've heard so much good about it, I thought I'd give it a try.
Since I've never shot it before, I figure I'll use it on the Scenar 300gr pills I have. 26" Savage 110BA, 1:10

 

[Heman]

92.5gr H1000 with a 300gr SMK, it was good enough to get me waterline 9oclock 10 on the NRA LR target at 1800yds this past Sunday at Atterbury for the longest shot match, just got lost in the wind and couldn't get the second shot in the black. Shooting it in a TRG-42.

 

[shooter1054]

I guess I'm swimming against the stream. I'm loading 250 Hornady's over 84.5 R-19. When I do my part, I can get 5-7" at 1000. Most people tell me that R-19 doesn't work well in a 338LM and I should bump up to R22. When I lose accuracy and it can't be traced to anything else, then I'll consider changing.

 

[P7id10t]

I guess I'm swimming against the stream. I'm loading 250 Hornady's over 84.5 R-19. When I do my part, I can get 5-7" at 1000. Most people tell me that R-19 doesn't work well in a 338LM and I should bump up to R22. When I lose accuracy and it can't be traced to anything else, then I'll consider changing.

Interesting. I use R22 for the 225 and 250 grainers. I like the accuracy the combo offers.

 

[P7id10t]

92.0 H1000
2,760
Trim to 2.714
B2O 2.980

TRG-42

What's your B2O translate into distance from lands? Curious.

 

[shooter1054]

Interesting. I use R22 for the 225 and 250 grainers. I like the accuracy the combo offers.

I'm not knocking the R22. I've never tried it. I tried the R19 and Retumbo and the R19 was better and I was happy with what I got from it. The best I've gotten was a 5 shot group at 1k that could be covered by a playing card. Four of the 5 could be covered by a pop can. The 5th was a called flyer.

 

[vh20]

Good Post!
I just found Retumbo on the shelf, and since I've heard so much good about it, I thought I'd give it a try.
Since I've never shot it before, I figure I'll use it on the Scenar 300gr pills I have. 26" Savage 110BA, 1:10

Savage 110BA in 338 should have a 1:9 twist (as does my 110FCP). The 110BAs in .300 Win. Mag. have a 1:10 twist.

 

[P7id10t]

Savage 110BA in 338 should have a 1:9 twist (as does my 110FCP). The 110BAs in .300 Win. Mag. have a 1:10 twist.

Yup, my bad. Dunno why I had 10 twist stuck in my head.

 

[Enough Said]

What's your B2O translate into distance from lands? Curious.

.015 off the lands.

 

[jkonzal]

I have had very good luck with 90gr's of RL-25! I didn't try Retumbo, but didn't have any luck with H1000 or RL-19.

 

[Creature]

300gr SMK
92gr H1000
CCI primer
3.700 COAL(IIRC)
Lapua brass
26" bbl
2700fps