338 RCM

[Silvertip93]

I have a 338 RCM built on a Montana Rifle Company 1999 Action with a 27" Krieger 1/10 twist barrel it shoots very nice and is a pretty impressive cartridge for a compact magnum.
I setup it with a 10 MOA rail and a Zeiss Conquest v4 6-24×50.
I've been shooting the hornady superformance 200 grain SST ammo and am getting a average 3059 fps from the 27" barrel.
unfortunately ammo is getting hard to find and getting very expensive and hornady even discontinued the 200 grain loads.
So I'm gonna have to start reloading for it and develop a few good loads for it and am looking forward to seeing what I can get from a 338 RCM out of a 27" barrel I have not found much information on the 338 RCM and am looking for anyone who has some experience with reloading for the 338 RCM I'm thinking I would like to see what I can get for Speed and accuracy from a 185 grain bullet my goal is to try and stay right at or over 3000 fps with at 185 to 200 grain bullet
I think its very possible with the 27" barrel.
Does anyone have any load data that they have tried and found works well for the 338 RCM shooting a longer barrel ?

 

[adk hunter]

Search bar.
Seabecon (sic) had some excellent input.
Hammer data thread has some load info on 175/200 class bullets.
I am running the 205 grain power hammer and think it is a good compromise and doesn't hog powder space.
Nosler 210 partitions may be even better choice depending on range.
I've never gotten near those Superformance speeds but have a 24'' barrel.

 

[AZShooter]

I own two, a sporter with a 22" barrel and a 14 lb long action with a 30"barrel. Neither is using the bullet you want to shoot. I will share with you what I use with the 30" barreled rifle anyway.

The rifle is a Mark X action in a Joel Russo stock. The barrel was a Lilja 7 mag rebored and rifled by Classic Barrel works to .338 with a 1 in 9 twist 6 groove. Trigger is stock but set at 1 lb. This mauser type action also has a Near Mfg picatinny rail. It is a long action so I had the throat lengthened to shoot 300 gr OTM Bergers. It shoots bugholes at 100 yd and with the .818 G1 BC works quite well at longer distances. It is going to sound strange until the numbers get crunched. 54 gr of RL-17 fed 210 standard primer 2454 fps. I can load it hotter but this node if very accurate.

I tried the 300 Berger set up in the sporter for single shot as the bullet was too long to fit magazine and got accurate results with a velocity of 2350 fps, also with 54 gr of RL-17.

A contributor to LRH, Broz, did some elk hunting the 300 gr Berger OTM from his 338 Lapua. He reported he had excellent results including a long shot of 880 yds with an impact velocity of 1966 fps. I am taking this rifle on a coues wt hunt Friday, Nov 10. The 30" RCM will yield the same impact velocity at 700 yds. Due to the slower velocity it will not tear up meat yet you can believe it will exit!

Link to Broz's post:

Berger 230 and 300 OTM Hybrid terminal results

We took two elk today with the Berger 300gr Hybrid OTM from my .338 Lapua mag. Bullet performance was pretty much identical with 1 1/4 to 1 1/2" exits. First was at 825 Yards and a rib cage shot. Impact velocity was 1966 fps. Exit was about 1 1/4" Second one was a bedded cow at...

www.longrangehunting.com

We will be hunting at 4850 ft here is the trajectory including wind drift in a 10 MPH crosswind:

4850 DROP COMEUP MIL DRIFT
100 1.4"
300 11" 1 3"
400 27.3" 1.9 5.4"
500 51.1" 2.9 8.6"
600 82.7" 3.9 12.6" 2037 fps 2766 ft/lb

Hope you get the results you are looking for with a 185 gr bullet.

 

[Silvertip93]

I own two, a sporter with a 22" barrel and a 14 lb long action with a 30"barrel. Neither is using the bullet you want to shoot. I will share with you what I use with the 30" barreled rifle anyway.

The rifle is a Mark X action in a Joel Russo stock. The barrel was a Lilja 7 mag rebored and rifled by Classic Barrel works to .338 with a 1 in 9 twist 6 groove. Trigger is stock but set at 1 lb. This mauser type action also has a Near Mfg picatinny rail. It is a long action so I had the throat lengthened to shoot 300 gr OTM Bergers. It shoots bugholes at 100 yd and with the .818 G1 BC works quite well at longer distances. It is going to sound strange until the numbers get crunched. 54 gr of RL-17 fed 210 standard primer 2454 fps. I can load it hotter but this node if very accurate.

I tried the 300 Berger set up in the sporter for single shot as the bullet was too long to fit magazine and got accurate results with a velocity of 2350 fps, also with 54 gr of RL-17.

A contributor to LRH, Broz, did some elk hunting the 300 gr Berger OTM from his 338 Lapua. He reported he had excellent results including a long shot of 880 yds with an impact velocity of 1966 fps. I am taking this rifle on a coues wt hunt Friday, Nov 10. The 30" RCM will yield the same impact velocity at 700 yds. Due to the slower velocity it will not tear up meat yet you can believe it will exit!

Link to Broz's post:

Berger 230 and 300 OTM Hybrid terminal results

We took two elk today with the Berger 300gr Hybrid OTM from my .338 Lapua mag. Bullet performance was pretty much identical with 1 1/4 to 1 1/2" exits. First was at 825 Yards and a rib cage shot. Impact velocity was 1966 fps. Exit was about 1 1/4" Second one was a bedded cow at...

www.longrangehunting.com

We will be hunting at 4850 ft here is the trajectory including wind drift in a 10 MPH crosswind:

4850 DROP COMEUP MIL DRIFT
100 1.4"
300 11" 1 3"
400 27.3" 1.9 5.4"
500 51.1" 2.9 8.6"
600 82.7" 3.9 12.6" 2037 fps 2766 ft/lb

Hope you get the results you are looking for with a 185 gr bullet.

thanks.
I'm looking forward to seeing what this cartridge is capable of producing out of my gun.
I think it has really good potential

 

[Silvertip93]

I own two, a sporter with a 22" barrel and a 14 lb long action with a 30"barrel. Neither is using the bullet you want to shoot. I will share with you what I use with the 30" barreled rifle anyway.

The rifle is a Mark X action in a Joel Russo stock. The barrel was a Lilja 7 mag rebored and rifled by Classic Barrel works to .338 with a 1 in 9 twist 6 groove. Trigger is stock but set at 1 lb. This mauser type action also has a Near Mfg picatinny rail. It is a long action so I had the throat lengthened to shoot 300 gr OTM Bergers. It shoots bugholes at 100 yd and with the .818 G1 BC works quite well at longer distances. It is going to sound strange until the numbers get crunched. 54 gr of RL-17 fed 210 standard primer 2454 fps. I can load it hotter but this node if very accurate.

I tried the 300 Berger set up in the sporter for single shot as the bullet was too long to fit magazine and got accurate results with a velocity of 2350 fps, also with 54 gr of RL-17.

A contributor to LRH, Broz, did some elk hunting the 300 gr Berger OTM from his 338 Lapua. He reported he had excellent results including a long shot of 880 yds with an impact velocity of 1966 fps. I am taking this rifle on a coues wt hunt Friday, Nov 10. The 30" RCM will yield the same impact velocity at 700 yds. Due to the slower velocity it will not tear up meat yet you can believe it will exit!

Link to Broz's post:

Berger 230 and 300 OTM Hybrid terminal results

We took two elk today with the Berger 300gr Hybrid OTM from my .338 Lapua mag. Bullet performance was pretty much identical with 1 1/4 to 1 1/2" exits. First was at 825 Yards and a rib cage shot. Impact velocity was 1966 fps. Exit was about 1 1/4" Second one was a bedded cow at...

www.longrangehunting.com

We will be hunting at 4850 ft here is the trajectory including wind drift in a 10 MPH crosswind:

4850 DROP COMEUP MIL DRIFT
100 1.4"
300 11" 1 3"
400 27.3" 1.9 5.4"
500 51.1" 2.9 8.6"
600 82.7" 3.9 12.6" 2037 fps 2766 ft/lb

Hope you get the results you are looking for with a 185 gr bullet.

loading for a longer barrel length what have you found as far as burn rate is it better to use a faster burning powder or slower burning powder to achieve velocity without over pressuring ?

 

[AZShooter]

Can't answer that question on powder choice for barrel length.

I read an article on RL-17 when it first came out. I immediately used it in a 284 Win and was pleased with the higher velocities with both 120 gr and 168 gr bullets.

When I built the 338 RCMs I used it as first choice and never tried another powder. I found it a perfect match with the 300 gr bullet. Chrono graphing I had very similar velocities shot to shot including quite a few registering the same velocity.

Original article on RL-17

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[sable tireur]

Lots of load data:

https://shootersreference.com/reloadingdata/338-rcm-ruger-compact-magnum/

I have owned and shot the .338 RCM in several rifles built for others. A friend of mine (a gunsmith) built one for his African hunts. First hunt yielded 8 - one shot kills and one took a safety second shot. We reload although every rifle was checked with factory ammunition.

Looks like most factory Hornady loads run from about $2.00/each up to the outrageous amount $4.50/each.

Best of luck!

ADDED:

I have switched my last short action .338 RCM over to the .338 WSM cartridge. Better, easier reloading and testing. I have dropped the 185 gr. in favor of the Badlands Super BD2 200 gr. bullets. Far better ballistics:

yds/vel/ToF/drop/drift