I'm sure the pressure is up there. My 26" 300 norma improved will go 3050 but it's pretty warm. Accurate node at 2990 w/ N570. Case capacity is 10gr more Than prc/30sm.
30 sherman magnum
- Thread starter elkaholic
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Copper Basin
Well-Known Member
My load work last summer. This is what worked in my rifle only. Not what you may experience in your rifle. Rich runs in the low 3000's I believe with a 28" tube. I use labradar as my chronograph.
Copper Basin
Well-Known Member
It is getting close to max pressure. I need to get a strain gauge and attach it to a test barrel to know exactly. No primer kisses from the ejector and an easy bolt lift. Still that does not mean I am not close to max pressure.
5RWill
Well-Known Member
So N570 is the go to for these big magnums? Seems another powder that's impossible to procure
Oh i'm not doubting you just thought it would be unobtainable. My results for magnums have always been a little less than what i'd built the wildcat on the basis of. 6.5 SAUM and my 7SS i simply don't achieve what most have velocity wise. I suspect it's just the DA and where I live. But the results are still outstanding. Also i tend to have wishful thinking. I wanted 3000fps out of the 7 SS with the 180gr ELD M with a 24" proof. I got 2900. I'm not disappointed though in the slightest. If i could do 2850 reasonably with a 30 sherman and that bullet i'd probably run with it, i'm hoping i have a fast barrel.
For whatever reason with whatever cartridge i build upon (with the exception of my 6.5x47) i gravitate towards the highest BC and weight i can muster at moderate velocity lol.
N570 is king of overbore in 6.5-338 cal cartridges. Once you get silly overbore and need more case fill, H50BMG and US869 become more appropriate. N570 does great in 338 and 300 rum, prc, norma, 30 and 28 Nosler. It's even top performer in 6.5 saum/prc. It's kinda like rl26, does great in a lot of applications. It's hard on throats and burns HOT though.
5RWill
Well-Known Member
Can you +p the 30 SM?
stahl4life
New Member
nice
Yessir, it recontours the lead, only adds like 0.003 to freebore. Makes bullets generally like being at lands to 15k off. Somewhere in there will shoot well.
5RWill
Well-Known Member
Reading about it for $200 seems the gains are worth it if all it requires is sending the barreled action to defensive edge. Would probably relieve my woes with sticky cases every now and then with my 7SS. Today had a hard stick. Figured it was after a cleaning maybe i had some oil or lug grease in the chamber it was uncharacteristic. Or RL26 does indeed jump but i've never had that issue.
5RWill
Well-Known Member
Understood, that is the nature of increasing powder charge, velocity, and coincidentally pressure. But truthfully idk that i'd care. It would be a hunting rifle and once in a blue moon to shoot a little ELR for fun. Wouldn't see near the use my 6.5x47 does or any of the comp based rifles.
codyadams
Well-Known Member
For a hunting rifle, even if it took the barrel life from 1200 rounds to 750 rounds, it would be well worth it for the velocity increase. With a hunting rifle, you develope a load, confirm drops, then hunt with it. Use your 6.5x47 (in my case my .260AI) for keeping your skills sharp. Shoot maybe 50 rounds a year from the hunting rifle? So say 100 rounds developement and 50 rounds a year for confirmation and hunting, that gives you 13 years of use......even at 100 rounds a year, likely more than many people would shoot if they had another rifle that was easier on barrels to shoot, that still gives you 6-7 years of use.
Wouldn't do it in a competition gun, or your high volume gun, but a hunting rifle? I can't see why not to. I'm tempted to send my .338 Norma in for it.
bigngreen
Well-Known Member
I've seen dual land throats take a LOT of life out of a chambering, when your talking a long range chambering and the accuracy and stability needed you spend WAY more shooting trying to stay on spot you can have reliable shooting. It's the same reasons dual land throats were abandoned 40 years ago. One test gun I had barrel life go from 1200 round to 300 rounds with dual throating, added 150 fps on a high BC bullet, wouldn't ever do it again, got rid of the reamers even cause it's just money down the toilet IMO!
I know Kirby Allen is no longer a fan of +P style throats. He started out somewhat supportive, but ended up going thumbs down.
If I needed another 100fps, I'd just opt for a larger capacity cartridge, but use a standard throat.
If I needed another 100fps, I'd just opt for a larger capacity cartridge, but use a standard throat.
