30 Nosler vs 30 Sherman Magnum

Sterlingb06

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  • Feb 11, 2020
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    So not trying to pick fights or start wars, but I am trying to objectively understand what the differences are. If I have my dimensions correct (if not correct me please), everything is so close, that you can almost fire one round in the other's chamber (I am not condoning this, its a bad idea, but you get the point).

    A little backstory, I was looking for my next big 30 magnum and came across the 30 Sherman magnum. Seeing at it was a AI version of a 300 PRC, for which factory 300 PRC ammo shoots great in its chamber, I started my journey of reading all the different forums on it. I saw that its H20 capacity was similar to 30 nosler as well as MV with similar brass/bullets/barrel lengths, so I started looking for the differences to see which one made more since for me. Note: I will have a barrel spun up and I reload, so no need to bring in the factory rifle crowd.

    I found the SAAMI specs drawing of the 30 Nosler on Quickload as well as the 30 Sherman Magnum's drawing on Gordon's Reloading Tool (neither program one had the other's cartridge so couldn't do a proper comparison of loads in the programs). Here are the images.

    30Nosler.png


    30ShermanMagnum.png


    First of all, does anyone with experience not agree with these dimensions? If so, no need to read the next paragraph...

    If not, what I found was they both have a magnum bases (.534"). 30 Nos is slightly rebated with a base diameter of .550" and 30 SM stays at 0.534". The Nos has a little more taper but due to the wider base and shorter case/shoulder junction, the Nos has about the same case diameter at the shoulder - 0.004" larger ( 0.528" vs 0.524"). The case/shoulder junction occurs at 2.115" for the Nos and 2.164" for the SM (so 0.050" difference) but with the 35 degrees (Nos) vs the 40 degrees (SM), the neck shoulder junction is closer to each other at at 2.246" vs 2.272" (Nos vs SM), a 0.026" difference. The SM also has a 0.024" longer neck so the SM has a case length that is ~ 0.050" longer. Throw all this into the regonculator and they have the same case capacity, and for the same bullet they are within 0.050" in COAL (for example, a properly seated 215 Hybrid is just above 3.600" for Nosler - just choose jump to get your needed freebore).

    I know the standard 30 SM reamers have a nominal freebore setup for the heavier bullets so a 215 Hybrid will be higher in the neck and COAL will be up around 3.700+", but you can get the Nosler freebore'ed to do the same. I am just now figuring out that all of these cartridges are the same if you get to choose your freebore? Am I overlooking something or not giving something enough credit/weight?

    So my question to all - does everybody agree that if I hand you two rifles (one chambered in each), that you could not load one better than the other, know which one you were firing if given to you blind, or even giving you one round of each could you tell me which is which (no peeking at the headstamp)?

    Last request - there has to be at least 1 hide member that has both of these. Can you please post a picture of the two side by side and do not label them? I have seen 300 PRC vs 30 SM and 300 PRC vs 30 Nos but not 30 SM vs 30 Nos. I would like to see if there is truly a discernable difference.

    PS: I have read most of the posts on 30 SM, not looking for quip remarks, but rather looking to have an objective conversation.
     

    Steel head

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  • Aug 3, 2014
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    Splitting hairs
    Easy way to make the decision is brass quality, brass availability and possibly freebore but a short freebore is easily remedied.
     
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    Supersubes

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  • Sep 6, 2006
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    Splitting hairs
    Easy way to make the decision is brass quality, brass availability and possibly freebore but a short freebore is easily remedied.
    Agree, lapua brass for the win. Hell, all three of them are splitting hairs from a case design perspective. I’ll stick with the PRC.
     

    Sterlingb06

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  • Feb 11, 2020
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    Thanks guys. I guess the rebated rim is a factor to some (mag feeding, might have to machine action rails, etc.). Anyone have real world experience with noslers out of stock actions - problematic or no?

    And I didn't add the mix the 30-28 nosler. It has the same .550" base diameter, taper and 35 degree shoulder as the regular 30 nosler but with the shoulder a little more forward like the 30 SM/300 PRC, it adds another few grains of H2O capacity.

    It seems like its the largest case that is designed for heavy bullets and with regular mag capacity limit of 3.715". But again, all this for 2-4ish grains of powder room.

    I would still like to see a pic if someone has these rounds.

    And to the point on brass - adg makes brass for PRC and nosler so whenever it is in stock, this should be moot.
     

    Schw15

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  • Jul 21, 2019
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    My buddy had a 30 sherman shot it just enough to fireform brass. I ended up with it and actually sold it on a whim without even putting the barrel on. The guy who bought it we talk and he seems to really like it 2930ish I think 250 a-tip rl33 28 inch bartlein barrel. I got the itch for a new cal and just pulled the trigger on a 30 nosler it will be throated to my dummy rounds. Looking at the two the biggest selling point for me was I didn't have to blow out any brass like the 30 sherman and the 30 nosler was cheaper overall to get everything. I can say I fell in love with the case design but it will be 3 months or more easily til I get my barrel. Now I had a 28 nosler a few years ago for hunting on a tenacity with cip mags and had no issues with feeding.
     

    Sterlingb06

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  • Feb 11, 2020
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    Yeah I just chalk up the fire forming of 100 rounds to watching the barrel speed up and find some good lower velocity nodes, finding a decent seating depth then stretching it's legs for indications on it's general accuracy.

    Hate to "waste" barrel life and components but should be able to hit the ground running on the higher nodes with a decent amount of info by then.

    Any guesses in barrel life of SM vs nosler? Also, who did he get to chamber the bartlein?
     

    Schw15

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  • Jul 21, 2019
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    It was straight jacket who did the barrel. Yes I agree I just had so many ackleys before I got tired of messing with that part. As far as barrel life I don't have any idea sherman has said 1800 in the past. I'm guessing 1300 to 1500 for my 30 nosler but basing it off of 300 win mag and the extra powder ect. But that is no science behind that guess haha
     

    Steel head

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  • Aug 3, 2014
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    Yeah I just chalk up the fire forming of 100 rounds to watching the barrel speed up and find some good lower velocity nodes, finding a decent seating depth then stretching it's legs for indications on it's general accuracy.

    Hate to "waste" barrel life and components but should be able to hit the ground running on the higher nodes with a decent amount of info by then.

    Any guesses in barrel life of SM vs nosler? Also, who did he get to chamber the bartlein?
    I always enjoy shooting the fire form loads and barrel speed up shots smacking steel at distance.

    They always shoot pretty good and you get a good idea of how it’s speeding up.