My Dad's 30/375 S.I. by Straight Shot Gunsmithing

[barnesuser28]

Sure do, BTW 80 grains showed NO signs of the slightest bit of over pressure, i could likely go to 81-81.5 and be safe.

 

[elkaholic]

Sure do, BTW 80 grains showed NO signs of the slightest bit of over pressure, i could likely go to 81-81.5 and be safe.

Very nice Riley! I figure 81 grains is around max in mine. You can get more velocity with Retumbo, and may get as good of accuracy too. You will just have to try it. You can load about 83 grains of Retumbo for 3100'....Rich

 

[elkaholic]

Sure do, BTW 80 grains showed NO signs of the slightest bit of over pressure, i could likely go to 81-81.5 and be safe.

79 grains is around 2970' in my rifle......Rich

 

[Broz]

I will guess from a Magneto speed 79 gr and .042" OL from a 26" tube to be right at or either side of 3K.

From there I would definitely load for accuracy not velocity if sticking with the 215's. I draw that conclusions from what I have seen from my 300 win with them at 3035 fps average. Although I have never seen any entrance over .308" in the hide, they were fragmenting pretty violently at 300 < and we didn't start getting exits on elk until 500 +. The closest bull was at 200 yards and we got 26" of penetration entering in the crease and passing through the far shoulder but it was in the last inch or so of meat just under the hide. 1 1/4" wound channel with a pile of fragmented lead and a largely expanded jacket. Think of them as a swarm and killer bee's traveling in a swarm of death. LOL

Jeff

 

[barnesuser28]

I just ran three of the 79 grain over the magnetospeed from a clean cold bore. 2895, 2896, 2908, avg 2900, es 13. I think i can explain the higher one, when i was seating the bullets, one of them seated with almost no resistance, i had to do a double check to make sure i put a bullet in the case. 2895 should make one heck of a deer/elk rifle.

 

[Broz]

Hmmm much lower than I expected from what I have seen with them in a few 26" 300 wins. But by no means a slouch. It might be just the ticket to 1000.

Jeff

 

[barnesuser28]

I think the 30/375 S.I. Has more capacity than the 300 win so a little less pressure with the same amount of powder. I am perfectly happy with 2895 fps, anything past the capabilities of this round it will be time to pull out the 338.

 

[elkaholic]

I just ran three of the 79 grain over the magnetospeed from a clean cold bore. 2895, 2896, 2908, avg 2900, es 13. I think i can explain the higher one, when i was seating the bullets, one of them seated with almost no resistance, i had to do a double check to make sure i put a bullet in the case. 2895 should make one heck of a deer/elk rifle.

Riley....that makes perfect sense. I forgot that you had a 26" tube; mine is 28". You will definitely get considerably less velocity than with the same load in a 300 WM because you have about 6 grains more capacity. Of course this also means you are doing it with a lot less pressure and it also means if loaded to equal pressure, you will probably exceed the WM by 75-100'....Rich

 

[barnesuser28]

I had to send my dies back to whidden as they were oversizing the brass, causing a few to get stuck in the die, but I got my rifle back from my uncle after getting bedded, and I had 8 rounds of loaded ammo left, so I pulled the bullets and decided to try some RL33 in the gun.

I loaded up from 82.5 (almost max retumbo load in Rich's gun) -89.5 grains. 85.5 was 100% fill and 89.5 was highly compressed, I left the loaded rounds to sit for about 30 min and none of them were pushed out from the compression. Bullets were seated .040 off lands, so they can fit in the mag.

Here are the results, based off the magnetospeed:
82.5 2807 fps
83.5 2818 fps
84.5 2890 fps
85.5 2929 fps
86.5 2994 fps
87.5 2995 fps
88.5 3067 fps
89.5 3092 fps

83.5-85.5 went into a sub .5 MOA group

86.5-87.5 were 2 inches higher and just over .5 MOA apart

88.5-89.5 were another 1.5 inches higher than the last and were about .75 MOA apart.

I think I have nodes at 83.5-85.5, 86.5-87.5, and 88.5-89.5

I will try these four loads and see which one shoots the best.

79 grains of H1000 for around 2900 fps

85 grains of RL33 for around 2910 fps

87 grains of RL33 for around 3000 fps

89 grains of RL33 for around 3075 fps


I don't want to try retumbo as I don't have very much and it is almost impossible to find any.

 

[bigngreen]

Reloader 33 might be a better match under a Berger 230

 

[barnesuser28]

Reloader 33 might be a better match under a Berger 230

Good idea! I will see if i can find some. Plus i would feel better about using the 230 on elk.

 

[elkaholic]

Looks pretty good Riley, and pretty impressive velocity for a 26" tube as well. I've been going to try some RL33 in mine, but haven't made up the heavier bullets yet. I figured it was probably too slow for my 208's, but it might turn some pretty good velocity even with a milder charge?.....Rich

 

[barnesuser28]

I just tested the 85 and 87 grain rl33 loads, 87 grains was .510 CTC and 85 gr was .207" CTC! I think i found my load.

 

[barnesuser28]

85 grains. Es of 12 and 2936 average in neck sized brass.