30-338 reloading help

[jehan12413]

First off I apologize I couldn't find the thread I originally referenced on this topic.
I had a gun built last year using rem 700 receiver and 26" shilen contour 7 barrel. On recommendation of gunsmith I went to 30-338 over 300 why mag which I have been reloading for over 20 years. I have spent the last 6 months trying to figure out the loads with no luck so any help would be appreciated. I'm using 190 gr SMK and h4831 powder. The many sources I checked recommend starting at 70-72 grains. Some posts here reference 70 gr vel 3023, hunting 72gr, and even Sierra reccomend 73.3 with 180 gr bullet. Also I see bench rest guys like 65 or 66 gr IMR 4350 with 190 gr bullet. I can't get close to those loads and my vel is real low. I started 67 gr H4831 vel was about 2650 and flattening primers, worked up to 73 but started getting hard extractions and some head separation vel about 2880. Backed down to 70. Don't want to try IMR 4350 until I figure this out. I tried fed 215 primers first then win and cci. Have shoulder just snug against throat and bullet on lands, then off 045", then .125" then .180". Using .125" now. Seemed to have no effect, even tried 168gr SMK with virtually no vel increase. What I'm looking for is vel of about 3000 with 190 gr SMK.
Thanks for any help

 

[Trnelson]

30/338 win is good stuff. I have one myself with a 26" Schillen . IMO it begs for a slower powder than H4831. I ran into pressure as well before I found respectable velocity with H4831SC. IMR4350 isn't going to give you a great case fill ratio, but it has been used in the past. It didn't do well for me in my rifle. Out of frustration I tried the slowest powder I could lay my hands on as a lark and it quickly showed I was on to something! I use WC867 in mine with a 230g Berger OTM. I get 100% case fill and good velocity (2840fps). I started at 72g seated at magazine length and worked up .5g to my rifles maximum. I then dropped three grains and shot groups, going up .5g per grouping. Then I played with seating depths, the second I tried was 1/2 MOA so I haven't messed with it any further. The WC867 isn't temperature stabile, so it requires a "summer" and "winter" load. My load that is perfectly wonderful at <40• heavily craters the federal 215m primers and has a heavy bolt lift at 80• from a cold bore. No joke.
If I were in your shoes starting over with a new rifle I'd take a long look at RETUMBO, US869, and H1000. 308 Norma starting data is a good safe place to start if your not sure where to start.

 

[Trnelson]

Also, if it's a new barrel run a good break-in procedure with mild loads until the velocity stabilizes. There are plenty of good procedures in the search engine so I won't delve into that. Then start working on establishing a safe pressure. IMO you won't see anything worth much until at least about 35 to 50 rounds.

 

[J E Custom]

Something else to check.
Measure the neck diameter on a fired case and compare it against a loaded one. (There should be .003 to .004 thousandths difference) If the difference is less, you will have to turn the necks.

The fact that the 30/338 is considered a match round (No commercial ammo has ever been
loaded for it that I know of) the chambers are normally very tight.

Also take a fired case and try to insert one of the bullets you are using into it, If it doesn't slip
right in, the necks need to be trimmed because the neck chamber is a little short.

What leads me to this , is when you backed of the lands up to .180 thousandths and still have pressure.

My load of 71 grains of H 4831 and the 190 SMK would exceed 3000 ft/sec with no real signs of pressure.

For another source of loading data use the Old 308 Norma mag. the two cases are almost
identical and could share loading data. (It is not recommended that they be fired in each others
chamber but the loads will work).

Good luck, and let us know what you find.

J E CUSTOM

 

[jehan12413]

Thanks everyone for the help.
Your statement about 71 grains of H4831 and 190 gr SMK shooting over 3000 ft/sec is one thing that concerns me. I have read many similar statements and my velocities aren't even close to 3000. Also I said I'm using 4831, I meant 4831 SC but may switch to 4831 to see what happens. After reading all the posts barrel break in may have accounted for some of my earlier problems but I should be past that now. Also I was initially turning the necks before necking down but stopped after looking at the difference between fired cases and resized ones. The gunsmith told me that a little tight is ok and helps accuracy. Case length is also ok so I'm running out of ideas. Just picked up some Norma unprimed brass to try ( have been using rem) but I noticed the shoulders are set back quite a bit so I guess I'll have to fire once first.
Last of all I read several posts stating that many top bench rest competitors use IMR 4350 with standard primers for the best results and about 3000 fps so I would like to try that once I get this figured out. FYI the rifle is shooting 1/8 MOA so the accuracy is there.

 

[Trnelson]

Excellent point on the potential need to trim!

 

[jehan12413]

I have been trimming to the recommended trim to length ( 2.490" ) but I'll check bullet fit when I get back in town tomorrow.

 

[Buttermilk]

My 30-338WM has been excellent using IMR4350 and H4831sc.

Mine is in a T/C Encore, setup as a handgun.


I've used the Berger 175 VLD, the Nosler 180 BT and 180 AB. All have been 1/2 to 2/3 MOA with good loads.

The Sierra load manual has some good data.

 

[TOM H]

Thanks everyone for the help.
Your statement about 71 grains of H4831 and 190 gr SMK shooting over 3000 ft/sec is one thing that concerns me. I have read many similar statements and my velocities aren't even close to 3000. Also I said I'm using 4831, I meant 4831 SC but may switch to 4831 to see what happens. After reading all the posts barrel break in may have accounted for some of my earlier problems but I should be past that now. Also I was initially turning the necks before necking down but stopped after looking at the difference between fired cases and resized ones. The gunsmith told me that a little tight is ok and helps accuracy. Case length is also ok so I'm running out of ideas. Just picked up some Norma unprimed brass to try ( have been using rem) but I noticed the shoulders are set back quite a bit so I guess I'll have to fire once first.
Last of all I read several posts stating that many top bench rest competitors use IMR 4350 with standard primers for the best results and about 3000 fps so I would like to try that once I get this figured out. FYI the rifle is shooting 1/8 MOA so the accuracy is there.

I'm shooting a 1/12 twist barrel @26" chambered for the 30-338mag and 1/11 twist barrel @ 25" also chamber for the 30-338mag. My latest build is 270Wby and that rifle started life with 1/10 twist barrel @ 26" chambered for the 30-338mag and all three rifles build by different gunsmiths.

1/11 twist barrel, 73gr/H-4831sc with 180gr bullet @ 3034fps and 75gr/H-4831sc with 165gr AB @ 3188fps.

1/12 twist barrel, 70gr H-4831 with 200gr @ 2835fps,73gr/H-4831 with 180gr bullet @ 3017fps.

the 1/10 twist barrel not going to put up any loading data but was on par with other 30-338mag.

I also use Fed 215 primer 1/11 twist barrel and Rem 9.5M with 1/12 twist barrel.

Mine are hunting rifle.

Fred Huntington RCBS chamber first rifles for the 30-338mag and my loading data came from Fred Huntington JR and my first one was chambered just like he was. My other two chambered same way.

I never kept up with 30-338mag that Rem chamber 40x in or it as a match rd. I'm sure someone would have reamer print on 30-338mag Huntington did and if that's what you wanted get a copy compare to your chamber.

 

[J E Custom]

I'm shooting a 1/12 twist barrel @26"

I never kept up with 30-338mag that Rem chamber 40x in or it as a match rd. I'm sure someone would have reamer print on 30-338mag Huntington did and if that's what you wanted get a copy compare to your chamber.

Good point !

Mine was a Single shot 40x by Remington with a 27&3/8'' hart barrel. it was for 1000 yard matches
and sometimes I hunted with it.

But I don't think it was anything special, because all I did was size 338 Winchester brass to 30 cal and load it.

I never shot 4831 SC in it because it was not available at the time. My loads were not excessive,
just near max.

J E CUSTOM

 

[J E Custom]

I have been trimming to the recommended trim to length ( 2.490" ) but I'll check bullet fit when I get back in town tomorrow.

I have seen many chambers (Custom and factory) that had short necks, and trimming to listed case length was not enough and had to be throated longer to shoot factory ammo.

Some of these factory rifles were of the high end variety and I not sure how/why they were done this way. Some of the custom rifles were done on purpose but the change was not noted on the barrel ID.

I have also seen chambers with NO free bore that caused High pressure. and after using a SAMME spec reamer the problem of pressure went away and velocity increased.

J E CUSTOM

 

[jehan12413]

Thanks for the good info. I just got home and checked some fired cases and unfortunately the bullets will slide right in so I guess that's not my problem. Just out of curiosity I competed them to my 300 WBY ( also a rem 700) and got similar measurements.
Neck ID after sizing-.303"
Neck ID after firing -.312-.313"

300 WBY after firing - .309"