I have a 30 sherman magnum that I have had nothing but issues with as far as brass is concerned, it's 300 prc based , I get 2 firings on brass and those aren't really top end loads either , the bolt sticks bad after 2 firings , brass has no pressure signs . It is a carbon barrel so I don't think there is enough metal for a set back I think I'll need a straight rechamber , would a 30 nosler work ? 300 rum ? Other good options ? Thanks.
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30 sherman rechamber options
- Thread starter locotrician
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Is it a proof barrel by chance? Do you by chance have a carbon ring in the throat? What brass/powder/bullet are you running? Speed and barrel length? Just curious
It's a carbon six , tried adg and lapua brass , shot berger 215 and 199 hammer hunters , I can't recall velocity off the top of my head but I'll look , as far as a carbon ring , I suppose it's possible but I don't have a scope to know for sure . Thank you .
Copy I'm not real familiar with the Sherman but the prc has been know to have some problems getting brass sized down near base.. I only have 2 firings on my brass so far no issues, but have read guys having trouble with clickers as soon and 2 or 3 firings.
I think one solution for PRC was a new reamer, this is the alex wheeler print. Maybe compare this with the sherman and see if its the reamer that maybe causes the issues. Not any kind of expert, just an idea.
Before you find a solution you need to identify the problem.
You need to take some measurements at the base of the fired case and compare it to new brass and resized brass to see if the die
is the issue or the chamber is oversize.
Bolt sticks bad on opening I assume, but how does it close on a loaded round?
You need to take some measurements at the base of the fired case and compare it to new brass and resized brass to see if the die
is the issue or the chamber is oversize.
Bolt sticks bad on opening I assume, but how does it close on a loaded round?
Measurements are no problem for me to get I have a good mic, will it tell me what I need to know when I don't have a reamer print to go off of? Bolt closes like butter and is no issue on first firing and only an issue on about 40 percent second firing but after that it gets to about 80 percent . I'm not needing a hammer or anything I just have to pound on it with my hand to get it open. Thanks for the help all involved.
Are you resizing the Cases enough? Sherman designs his reamers so the clicker issue won't happen. Who did the chamber job? Maybe a bad chamber any markings on brass? I really don't know if anything will now out the 30 sherman because of the design and 40 degree shoulder. I would call sherman and see Maybe the died are bad. Also what are your speeds?
I talked to rich a while ago and he didn't seem to think the dies had issue and I stopped messing with if for several months , just coming back to it now , as far as if the brass is being sized enough I cant say for sure , they go right in the chamber when loading just fine and I am full length sizing with dies I got from rich directly. Chmabered by a well known smith i have used for all my builds , reamer used I got right from rich as well , speeds with 215 are right al 3000fps with 199 hammer 3076 , 27 inch barrel .
Yeah that is the obvious and smart move , I just tried here first because he is very busy and I hate bothering him just to ask something I should be able to find out on my own . I haven't measured the bump since I set the die up but was set to one and half thousandths .
You said some are 3 times fired some 2 times fired? I would really double check my die because when you blow the brass out on a ackley it actually sucks back in growth and then they truly don't form til 3rd firing so it could be possible that your not sizing it enough and causing stiff bolt opening. Yeah I see what your saying but unless some one that knows the measurements on your shank and have the prints handy and knows might be smart to ask him hopefully someone else smarter than me chimes in. If it wasn't a carbon it's doable
Color a fired case with a black sharpie chamber that,it will rub off where you’re having problems
Just to be clear when you say. Not sizing the brass enough do you mean the die is too large /has defect or that I should try setting the die for more bump ? Thanks for all the help .
shouldn't have to set it back at all. The 300 RUM body/shoulder junction is ahead of the neck/shoulder junction on a 300 PRC
I would be trying to find the issue you have instead of rechamber IMO
Do you have a way to measure shoulder bump? Yes you might need to screw the die down more to size the case but the sharpie trick would help to see where the case is binding in chamber.
I can measure setback but am currently away from home for a while and won't be able to get to my reloading tools fpr several days perhaps weeks .
Try turning the necks about 0.002" on the brass and soak the throat to get rid of any potential carbon buildup in the throat.
After that:
The RUM might clean up the chamber. I'm not sure how much body taper was removed from the PRC to make the improved version you have.
The RUM is 0.521 @ ~2.38" and the regular PRC is 0.516 @ ~2.12 so there's a decent chance it will clean out the existing chamber. You'll need to know the diameter at the shoulder of your chamber.
The throat may or may not clean out, depends how much FB you have in the current chamber but it's likely you'll be fine.
I'm sure it'll hold it, whether or not it should is an entirely different story.
also the Sherman is .521 at the shoulder and the RUM is .525 so no issue there. Had to check my notes but reason I know is I was trying to set back and re-chamber the opposite direction so I could mag feed. Ended up with a new tube.
Literally just picked it up from the smith so haven't played loads yet.
I believe that is the max for h1000 , everything I have seen for n570 and 300 prc is max 83.0 . A quick Google to double check the data have saved also shows 77 range as max for h1k and 83 for n570 .
Ok , thanks for all your input , I have several things to try when I get back home . Hoping this isn't the issue as the velocity doesn't really seem to match up , I have an improved case, Burning more powder than the parent , and I'm getting less velocity and I even have a longer barrel . Your right about viht site , I don't know why they are so much lower than everyone else .
I think Sherman is a bit spicy with his loads and Vhit seems to be a bit conservative.
bullet might be a bit light for N570, not getting a good burn to produce velocity. I bet you'd benefit from a quicker powder and lighter charge
bullet might be a bit light for N570, not getting a good burn to produce velocity. I bet you'd benefit from a quicker powder and lighter charge
I tried 4 bullets and 4 powders , n570 produced the best accuracy with both the 215 and the 199 , I agree with you that it's probably too slow but I don't argue with the target or the chronograph, well not often anyway , I did have better velocity on the 199 with another powder but without my notes I don't remember which it was . The database received when. I asked was for the 215 and n570 and told to start at 83 and work up slowly, which is what I did . If you google load data you will find others shooting more 570 than I am. I get that that doesn't mean much but it is of some evidentiary value when trying to sleuth some load data.
I have a C6 in 30 SM, with a 20" barrel. C6 did a prefit for me. Also run n570, but mainly with 225 eldms and 245 eols.
You have to FF the brass correctly to blow out the shoulder with a lighter load. After that, you can start cranking it up a bit. I did start to have slight clickers on a batch of brass when I was running it too hot, on about the 4th firing, and also when the barrel became dirty. Swapped over to another batch of brass, lowered my charges a bit, and no clickers on 6th firing. I
Max loads in my rifle where pressure signs started to show with n570 (workup with yours):
225 eldm: 83.0 gr 2850 fps
212 eldx: 83.5 gr 2920 fps
214 HH: 82.5 gr 2942 fps
245 EOL: 81.0 gr 2743 fps
Just because Rich or someone on their facebook page says that you can run 1,000 grains of powder and its supper duper fast, doesn't necessarily mean that it is a sustainable load that will be safe or easy on brass.
You have to FF the brass correctly to blow out the shoulder with a lighter load. After that, you can start cranking it up a bit. I did start to have slight clickers on a batch of brass when I was running it too hot, on about the 4th firing, and also when the barrel became dirty. Swapped over to another batch of brass, lowered my charges a bit, and no clickers on 6th firing. I
Max loads in my rifle where pressure signs started to show with n570 (workup with yours):
225 eldm: 83.0 gr 2850 fps
212 eldx: 83.5 gr 2920 fps
214 HH: 82.5 gr 2942 fps
245 EOL: 81.0 gr 2743 fps
Just because Rich or someone on their facebook page says that you can run 1,000 grains of powder and its supper duper fast, doesn't necessarily mean that it is a sustainable load that will be safe or easy on brass.
I tried 4 bullets and 4 powders , n570 produced the best accuracy with both the 215 and the 199 , I agree with you that it's probably too slow but I don't argue with the target or the chronograph, well not often anyway , I did have better velocity on the 199 with another powder but without my notes I don't remember which it was . The database received when. I asked was for the 215 and n570 and told to start at 83 and work up slowly, which is what I did . If you google load data you will find others shooting more 570 than I am. I get that that doesn't mean much but it is of some evidentiary value when trying to sleuth some load data. Thanks .
Great information, I agree with what your saying about internet load data , this is a hunting rifle for me , brass life is of little concern if it goes 3 or 4 that's fine by me , I don't usually plush for velocity so maybe that why I am having so much trouble with figuring this out, but being this is fpr hunting Is the reason I went with the sherman to get some extra velocity, and the reason I'm thinking of having punched out to a rum, if I have to download it to 2900 fps range then it's of no more use than a straight prc or even a win mag . As far as the brass being fire formed right , maybe that's an issue , it definitely looks formed to me when comparing to unfired . Thanks for the data and speeds .
Bushing is .335 or .336 , I have both , can't remember which one I settled on .
The speed with that barrel length shouldn't be bad at all I believe you could get there almost in straight 300 prc. But I'm in the camp that thinks all this new tough brass hides pressure and a lot of people over load and get crazy results but actually in pressure and usually doesn't come out til the 3rd to 4th firing. I know guys shooting the 215 2950 to 3000 in 300 win mags so idk that is a head scratcher for sure. But I got very unlucky with the sherman 7 max only could get 2880 with 183 in 28 inch barrel other guys were getting 3000 in 26 inch. I had stiff bolt opening at 2950 to 3000 but resized and kept going and brass held up fine with 5 firings but once I backed down to the 2880 node all problems went away. That was the first time I had that issue and it is very annoying
What action? Wondering if you have a titanium action….
If you’re bumping your shoulder back .002” you might need to rework your load. Go from 81gn of n570 and go up till you find the sticky bolt.
Well there is only 1 way to find out I suppose, I'll just take a new piece and drop down to the 2900 fps load and shoot/size/reload 3 or 4 of them at that node and see if it still happens . I know that there will be no more Sherman's in my future. (Nothing against rich, he seem like a good guy )
