22 creedmoor

CaptArab

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You're reading a lot into my statement. Nowhere did I advocate running over-pressure loads.

It's a simple reality that there are presently only TWO brass manufacturers that will actually allow you to run most cartridges at their advertised capabilities. Alpha, and Lapua.

Just because the brass doesn't instantly crack in half, doesn't mean the brass can actually take the pressure... though I think it would be better if that would be the case since most people are using inferior brass and suffering the consequences, but they don't notice. Most people aren't trying to get very many firings out of their brass, so they don't even realize what is happening.


Good stuff here Greg- thanks!
 
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Disturbingiraq

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So I figured I would chime in. Take this advise for what it’s worth. I was shooting 77 gr Berger OTM’s with 4350. I can’t remember the exact charge as I am not sitting at my bench. Long story short was fighting carbon ring and pressure issues with a very mild load. Went and looked at some retumbo data and came up with these numbers. I’m still working on seating depths and fine tuning it. But again at 45.0 grains it’s very mild and shoots really well. Did make a bullet switch to 77 gr otm scenars. Single digit SD’s so far and will go to a ten shot string shortly. Maybe Sunday as I have a date with some prairie dogs tomorrow. Barrel is a carbonsix and zermatt origin short action.
 

Cynical

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    View attachment 7913100So I figured I would chime in. Take this advise for what it’s worth. I was shooting 77 gr Berger OTM’s with 4350. I can’t remember the exact charge as I am not sitting at my bench. Long story short was fighting carbon ring and pressure issues with a very mild load. Went and looked at some retumbo data and came up with these numbers. I’m still working on seating depths and fine tuning it. But again at 45.0 grains it’s very mild and shoots really well. Did make a bullet switch to 77 gr otm scenars. Single digit SD’s so far and will go to a ten shot string shortly. Maybe Sunday as I have a date with some prairie dogs tomorrow. Barrel is a carbonsix and zermatt origin short action.
    I shot the Berger 77gr OTM’s with 42.2 of H4350, average of 3390fps from a 22” 7 twist. It was on the edge, some swipe and minimal cratering but bolt lift wasn’t noticeable. So you like Retumbo over H4350 With this bullet? Its hard to turn away from a load that shoots excellent to chase improvement with a different powder, for me. CCI450 and Alpha ocd brass, for anyone wondering.
     
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    Disturbingiraq

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    I shot the Berger 77gr OTM’s with 42.2 of H4350, average of 3390fps from a 22” 7 twist. It was on the edge, some swipe and minimal cratering but bolt lift wasn’t noticeable. So you like Retumbo over H4350 With this bullet? Its hard to turn away from a load that shoots excellent to chase improvement with a different powder, for me. CCI450 and Alpha ocd brass, for anyone wondering.
    If you’re not having carbon problems I would stay where you are. I would be staying if it wouldn’t carbon buildup and cause pressure. I am hoping slowing the burn rate down I can prevent most of the carbon at the start of the bore.
     

    4O6shootist

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    I shot the Berger 77gr OTM’s with 42.2 of H4350, average of 3390fps from a 22” 7 twist.
    What barrel maker? Do you know the bore size? I'm wanting a 7 twist for my 16 or 18" build but can only find 218 bore vs desired 219. Lots of people have had jacket failures once the barrel gets a lil fire cracking. I just don't want to be one of they guys with a problem.
     

    Cynical

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    What barrel maker? Do you know the bore size? I'm wanting a 7 twist for my 16 or 18" build but can only find 218 bore vs desired 219. Lots of people have had jacket failures once the barrel gets a lil fire cracking. I just don't want to be one of they guys with a problem.
    Bartlein barrel, Joe Walls/Exodus Rifles chambered it I may have the freebore # somewhere but I don’t know it as I sit here on the recliner. I haven’t seen any of the otm’s explode (yet), but I have read about the vld’s having that at high rpm. I am trying 73gr Hammer Hunters with StaBall soon though, partially out of concern for bullet integrity and partially because I want a ‘hunting’ bullet.
     

    4O6shootist

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    Bartlein barrel, Joe Walls/Exodus Rifles chambered it I may have the freebore # somewhere but I don’t know it as I sit here on the recliner. I haven’t seen any of the otm’s explode (yet), but I have read about the vld’s having that at high rpm. I am trying 73gr Hammer Hunters with StaBall soon though, partially out of concern for bullet integrity and partially because I want a ‘hunting’ bullet.
    I shot a few antelope with my 22" 7.7tw 22 creed last year using the 70gr absolute hammer. Stiff load of rl26 pushing them at 3700fps. Load shot sub 2" groups at 400y consistently. The hammer had a decent wound channel, and killed well. The bc is dogshit but at lighting speed, drops are pretty good out to 500y. I'm building another currently with a magnesium element 4.0 folding chassis and a short barrel for strictly supressed. Trying to find a 219 bore 7tw barrel currently.
     
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    CaptArab

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    I shot a few antelope with my 22" 7.7tw 22 creed last year using the 70gr absolute hammer. Stiff load of rl26 pushing them at 3700fps. Load shot sub 2" groups at 400y consistently. The hammer had a decent wound channel, and killed well. The bc is dogshit but at lighting speed, drops are pretty good out to 500y. I'm building another currently with a magnesium element 4.0 folding chassis and a short barrel for strictly supressed. Trying to find a 219 bore 7tw barrel currently.
    Patriot valleys 22 cals are 7 twist 219
     
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    Ridge86

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    Has anyone tried h1000 or retumbo with an 80gr Berger or hornady bullet with a 1:8 twist?
     

    4O6shootist

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    Has anyone tried h1000 or retumbo with an 80gr Berger or hornady bullet with a 1:8 twist?
    I tried it with 77tmk, full case with a drop tube, believe around 46.5-47gr was only getting 3320 from a 22" barrel. It'd work better with heavier bullets I feel. H4350 pressured out arpund the same velocity, rl16 was near 3400. N555 shoots very well at 3400 and 3500. 3500 is too warm to run on hot days, but anything below 75 its good to go. Rl26 will flat out scream near 3600, rl23 does well around 3400 as well.
     
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