McGuire Ballistics, 338's!

[KH_Outdoors]

I'm running the 250 grain on my 33 nosler and haven't had much time to do much for bc testing between getting ready for bear hunting and shooting a NRL Hunter match.

First outing shooting paper was 671 yards and came up about half moa low. From my second outing shooting paper with only 2 rounds at 1071 yards I'm running a .350 g7. This bc seemed to be slightly high for me so far but I need more rounds to out on paper at distance under those perfect dawn conditions. Both outings I seemed to be the half moa low. Also running a 9.5 twist And at 3000' where I'm at I'm still technically stable with a 1.5 sg.

Next week I may get time to shoot again unless I run out of bullets first bear hunting and busting rocks.

Thanks for the Intel as always!

Looks like those 250's sit real nice in that custom throated 33 Nosler too.

Good luck on the bear hunt, look forward to seeing how they perform for you.

 

[KH_Outdoors]

Update on the 338 Norma + 250 gr CR. I went out and got baseline info with potential powder options.

As expected, they show comparable speed/accuracy as other 250 gr projectiles that I've used in this rifle.

It showed really good accuracy potential with all three powders tested. The McGuires I've tested in the past usually shoot well in that .020-.030" off the lands jump range. They also seem to like being pushed hard, often grouping best at the top end within 2-3 gr of pressure. These 338 cal bullets seem to be doing the same.

Next batch of 250's is on pre-order with @McGuireBallistics , so I'll get back on this one to true up BC's in a few weeks hopefully!

Hope you 338 Norma guys out there enjoy this one!

 

[KH_Outdoors]

I decided to see what the 338 Norma can do with the 225's while the 250 gr pre-order is coming in. Like with the 250's, I'm just looking to get a general feel for where safe pressures are, speeds, and if it likes one powder more so than another. Then I'll pick the combination to go forward with for load development & BC testing. These 225's are dang near perfectly suited to my 338 Norma's standard chamber freebore come to find. Hoping to still pressure out with these powders on hand, I swaped out the N565 for N560 on this test.

338 Norma/225 CR

Brass: Lapua 3x fired & meticulously prepped
Primer: Fed 215's
Powders: H1000, N560, RL26
Bullet: 225 CR seated .025" off the lands, 3.700" COAL

 

[Marine sniper]

Hopefully they shoot well, but that 250 gr. bullet is not a .830 G1 BC bullet.

 

[KH_Outdoors]

Hopefully they shoot well, but that 250 gr. bullet is not a .830 G1 BC bullet.

I'll be posting here how they true up for me

 

[Idaho Trecker]

Hopefully they shoot well, but that 250 gr. bullet is not a .830 G1 BC bullet.

I'm testing them also and with all transparency I am running a 9.5 twist. This is a 1.5sg at my elevation with the normal calculator. Right at the minimum fully stable according to that calculator but construction could make it slightly better depending how the tip is made and how much cavity is at the tip. As of now I'm running a .350 g7 and is fairly close so far. Once I work out a scope issue I'll be back to testing them in the 1000-1800 yard range.

 

[KH_Outdoors]

Little update on the 338 testing. I had to pull the 225's for some field testing and backup ammo for a hunt. Spoiler... the 225's crushed this spring bear season!

But, getting back to the 338 Norma & 250's. Got the first rounds loaded up. Decided to go with H1000 as we are well into summer temps now. I'd really like to try RL26 & N560 with the 250's in this cartridge once the temps mellow out a bit.

338 Norma
250 CR
H1000 87-88-89 gr
(5 rds each charge weight, 2 fouler/sighters)

 

[KH_Outdoors]

Update on the 338 Norma + 250 CR testing. Need to get caught up here!

Landed on a good load with H1000.

250 Copper Rose @ .025" off
89 gr H1000
Lapua 3x fired Brass
Fed 215 primer

2915 fps in my 24" barrel

This load has stayed close to .5 moa three shot group, and 1 moa five shot average so far. Off to zero at 100 and get some distance!

Going to use a .800 G1 to start with

 

[dgr416]

I wonder what those 225 grain will do in a 338 win mag and a 338-378 weatherby ? I have wanted a good long range bullet for both of those rifles in a 225 grain long range bullet .

 

[KH_Outdoors]

I wonder what those 225 grain will do in a 338 win mag and a 338-378 weatherby ? I have wanted a good long range bullet for both of those rifles in a 225 grain long range bullet .

They would work well I'm sure. Especially if you had one custom chambered with optimal freebore. The terminal performance with the 225 has been great!

 

[KH_Outdoors]

Update on BC testing with 250 gr CR's

First trip out, everything trued for me to 785 yards. If anything they were trending slightly higher BC than initial estimates. I'll put in a few more range trips to get a solid average, and go a little further out when conditions allow .

250 CR
2915 fps
.800 G1
100 yd Zero

Here's my drop chart used after truing. For reference, I'm 800 ft above sea level.

 

[KH_Outdoors]

Decided to try another powder before heading back out to the long range. H1000 has shot good in this rifle with the 250 class bullets, but I wanted to see what some N565 could do. Sure glad I did! Quite possibly the smallest 6 shot group the rifle has ever shot (also personally), and super low ES/SD.

Also, I do not deliberately do 6 shot groups for some reason. I had loaded up 6 to go shoot two 3 shot groups to simply get a feel for group size, point of impact consistency, velocities etc... after it one holed the first 3 I decided to see what a 6 shot group looked like. Literally no other reason fyi.

These 250's shoot!!

 

[Korhil78]

That's awesome!

 

[Phil Rizzo]

What cartridge again?

338NM I just looked up above. Fantastic