300 PRC SHERMAN IMPROVED

BoatTail

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elkaholic,

Have have you thought about ordering a hydro die from Hornady to form your cases instead of fire forming? I have one for the 7 mm WSM that seems to work pretty good. I use mine to convert 300 WSM to 7mm WSM. The water in the die does a pretty good job of blowing out the shoulder. However you do need to make sure you hold the handle down on your press otherwise you get a strange elongated case.

The reason I ask is still considering the 300 PRC Sherman improved for my next build.
 

elkaholic

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elkaholic,

Have have you thought about ordering a hydro die from Hornady to form your cases instead of fire forming? I have one for the 7 mm WSM that seems to work pretty good. I use mine to convert 300 WSM to 7mm WSM. The water in the die does a pretty good job of blowing out the shoulder. However you do need to make sure you hold the handle down on your press otherwise you get a strange elongated case.

The reason I ask is still considering the 300 PRC Sherman improved for my next build.
I use a hydro die occasionally for my other stuff but the beauty of the PRC S.I. is that the factory ammo shoots well in my chamber so you don't need to do anything special.
 

elkaholic

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I got out briefly yesterday afternoon and tried a couple loads with different seating depths. None of the results were spectacular but a couple showed some promise. I need to do some brass prep (skim the necks and anneal) which helped the Hornady brass in my old barrel. I noticed that I would get 2 shots in the same hole and the third a little off.
IMG_20190202_162153906.jpg
IMG_20190202_161707941.jpg

The coal turned out to be much less than what I was told after I actually did some measuring. Good news actually.
225 ELDM/3.725"
215 Berger/3.732"
230 Berger otm/3.675"
 
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BoatTail

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Where did you get N570? I've been watching for it and haven't found it.
 

BoatTail

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Are you finding it better than the other powders you've tried for your 300 PRC SI? Which powder and grn amount do you feel like is working out the best for you? It looks like they're getting tight groups no matter what powder you use.
 

elkaholic

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Are you finding it better than the other powders you've tried for your 300 PRC SI? Which powder and grn amount do you feel like is working out the best for you? It looks like they're getting tight groups no matter what powder you use.
Ya, it's shooting pretty well. I think mostly I need to do some brass prep and maybe do some ladder tests when I get time. RL33, N570 are great for top velocity and good accuracy but Retumbo and H1000 also worked well in my old rifle. I think H1000 wold give me a good load in the 2950-3000' foot range as well as Retumbo. If you want to get into the 3000'+ territory, the slower powders are best. I really want to try some N565 as soon as I can get some.
 

curtiscd

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elkaholic,

Can this case be run through a standard Remington magazine (currently 7 RM), or will I need to open up the feed lips to accommodate a little fatter case. I understand I will need to install a Wyatt's extended mag box with the necessary mods to accommodate the length issue.
 

H59

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I wasn't sure if you had run any of your new fire formed factory 300prc cases through a 26"" bbl or were making an educated guess on velocity as opposed to your 28" bbl...but would you suspect that your getting 30-35 fps ...'ish ...per inch of barrel?
 

elkaholic

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hauser, id.
I wasn't sure if you had run any of your new fire formed factory 300prc cases through a 26"" bbl or were making an educated guess on velocity as opposed to your 28" bbl...but would you suspect that your getting 30-35 fps ...'ish ...per inch of barrel?
Haven't heard anything with a 26" yet but I'm thinking max around 3000' with a 225
 

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