30 sherman magnum

[codyadams]

Word on the street is when they tested the cartridge they used to fast of a powder and had a low case fill. Causing issues with the steeply inclined shots. Then that news hit the internet and now all of the sudden many think the 300 Norma is no good for heavily inclined shots but all the other 30 cals with almost identical capacity are . Ive shot the 300 Norma Mag with full cases of retumbo at 1200 yards, inclined shots and it does just fine.

Figured it would be something like that.

 

[snox801]

Have fired it at up to 30 degree angle with no issues. Have not heard of that one.

That was one of the issues brought up when military was testing. I've also never heard anyone have issues but I'm almost positive that was one issue they complained about.
I went back and forth between that and a lapua improved. My problem was once you go to the bigger bolt face why not a lapua improved?

 

[CA48]

It's not the inclined but declined (downhill) shots that cause issues with low fill - the powder stacks against the bullet in the case and far away from the primer. With longer and fatter case it presents more of a problem especially if running a non-mag primer in colder weather.

Cheers,
-mox

I should of said inclined and declined as they can both cause inconsistency's with low case fill.

 

[snox801]

That case fill should not be a problem seems all my hammer bullets like a full case and they are happy.

 

[tashabay715]

Ok, ordered reamer, brass and dies from Rich for the 30 Sherman Mag. Used a Terminus Kratos action and Bartlein 1-9 twist 31 inch blank. Told gunsmith to make longest barrel possible. Barrel is 29+ inches. Put in McMillian A5 with TT diamond trigger. Topped with Nightfore NX8 4-32. Load development was a breeze. Ended up with 230 grain Atip, 83.5 grains N570 at 3.800 OAL doing right at 3100 fps. At 100 yards shoots one ragged hole. My first two shots today at 625 yards were touching. Hit steel every shot at 875 and 1080 with no sighters. Love this gun/cartridge combo. At 1000 yards still doing 2059 fps with 2164 ft/lbs of energy with only 19.5 MOA drop- Less than one turret turn on my NX8. Thanks Rich for all your work on this caliber. Ordered some more brass tonight.

 

[JBarton]

When I was building my 300PRC I was conflicted and had a hard time making up my mind between the 300PRC and 30SM. I went with the 300PRC and recently had the opportunity to purchase a 30SM barrel.
I picked up a 28" M24 8 twist Bartlein chambered in 30 Sherman Magnum by Straight Jacket Armory last week. It had 110 rounds down it when I received it. It also came with a go gage, 100 pieces of 30 Sherman Magnum head stamped ADG brass and a set of Hornady dies.
I pulled my 300PRC barrel off of my Archimedes action and spun the 30 Sherman Magnum barrel on. Head spaced perfect.

Sized all of the brass and loaded up some rounds in 0.3gr increase between each with Rl26 and 225gr ELDM's. 0.025" jump for starters.
I am very happy with the results to say the least. I have a decent 1 grain wide node at 3025fps I'm going to mess with.
I was not worried about accuracy while collecting velocity data and I think this barrel with the right load will shoot 1/2 moa or less. I also am liking the ADG brass and am going to have to get some more.
I will definitely post my load development results.

 

[snox801]

I need to get some 570 to see how it compares to rl26 with the 214 hammers.

 

[Broncoguy]

26 is garbage…great velocity but trash when it come to temp swings. Hard to use in the NW

 

[tashabay715]

26 is garbage…great velocity but trash when it come to temp swings. Hard to use in the NW

I need to get some 570 to see how it compares to rl26 with the 214 hammers.

570 is great for max velocity and accuracy, but it shoots super DIRTY in my 30 SM. Carbon ring in barrel throat a big problem with 570. My favorite powder with the 230 gr A-tips, but I am starting new load development with H1000 or Retumbo tomorrow after spending over an hour cleaning this barrel after 570.

 

[snox801]

I thought 26 was only bad after 80 degrees? Is this wrong I'm getting very good es and ok speed. Not worried about carbon it's a hunting rig and Cleaned after season and boretech makes it pretty easy. But very curious hope I can get my hands on some 570.

 

[Elk Hunter 338]

I thought 26 was only bad after 80 degrees? Is this wrong I'm getting very good es and ok speed. Not worried about carbon it's a hunting rig and Cleaned after season and boretech makes it pretty easy. But very curious hope I can get my hands on some 570.

I've had RL 26 in a great validated load...go from good too bad in the same range session at 70 deg in 30 nos.. I wont use it in any of my hunting rigs. I see way too much variance in conditions too trust it from place too place

 

[tashabay715]

I thought 26 was only bad after 80 degrees? Is this wrong I'm getting very good es and ok speed. Not worried about carbon it's a hunting rig and Cleaned after season and boretech makes it pretty easy. But very curious hope I can get my hands on some 570.

I may have an unopened 8 pound jug being delivered later next week. PM me and let me know where you are located, I may can help you out on the 570

 

[snox801]

Man I was pretty sure Cody did a bunch of testing and it looks not got tricky past 80 degrees and I rarely hit in that.
I appreciate the offer. I have a place near me that really has a good supply of powder. I will see what they have when I'm back in town and let you know.
Thanks.

 

[codyadams]

Man I was pretty sure Cody did a bunch of testing and it looks not got tricky past 80 degrees and I rarely hit in that.
I appreciate the offer. I have a place near me that really has a good supply of powder. I will see what they have when I'm back in town and let you know.
Thanks.

I think it varies some by cartridge too. My testing was in a .260 AI, I had rounds in ice and rounds at ambient temp. However, where my test was lacking was the rifle was not the same temp as the rounds. I had them in a freezer over night, then on ice in a zip lock bag on the way to shoot. My rifle was left in my truck under the back seat, it got down to about 45 that night. Pulled the rifle out of the truck, and shot the ammo that was 17 degrees and documented velocity. Waited for the sun to warm up, left my rifle and other rounds in the sun. I think it was like 67 and mid morning when I shot? only had like .15 fps/degree change, however it wasn't very high temp, and again, the rifle was not at 17 degrees like the ammo was. One day I may throw my rifle in the chest freezer and test it, then leave it in the sun to warm up, I can shoot off my front porch now and it would be more practical to do so. But ya, my testing wasn't perfect, and as stated, I think it may be different depending on case capacity, case fill, and other aspects. Just my thoughts, I know it can get spikey on the higher end of pressures.

Also, sorry for getting off topic......