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Post by elkman1310 on Mar 28, 2020 17:22:04 GMT -5
Well I have wanted to build a 7mm for 1k benchrest. I went back and forth with using the 7mm Whby. then the 7x61 S&H and also 7mm SAUM. Saw a 7/300wsm rear on Ebay with the right neck and freebore I could live without with ordering a reamer.
So I took the old Hart barrel and hacked off the chamber and went from the 7mmWhby to a 7/300wsm the barrel finished off a 26 inches plenty long enough for initial testing to see If I like this combo or not. I have a new Krieger 1-8 twist that I can chamber for this cartridge if I like want I see.
7/300wsm has more capacity than the 7 SAUM but a hair less than the standard 7wsm . The 7wsm has a really short neck and gets a lot of negative feed back from F-Class shooters. I can also use my 300sm dies to do all the resizing once the cases have been fired. Instead of necking my 300wsm brass down I will be necking up 270wsm brass. The 270wsm brass has the shoulder moved ahead a few thousands more than a 300wsm but that can be sized away with no problem.
I am waiting on the 270 wsm brass. But there is no big hurry are local range is closed because of the Virus no telling when we will open back up. From info I have be able to find either RL 25 and H1000 powder will be the powders that work best for accuracy at 1k using 180gr bullets I am hoping to shoot the new 190gr hybrid in the new 1-8 twist barrel.
Barrel life is not going to be good for absolute best accuracy 500&600 rounds before it will need set back and chambered again the 300wsm is much better usually around 1,000 some go longer and some go a lot shorter time will tell. |
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Post by jims on Mar 28, 2020 18:38:21 GMT -5
Should prove interesting
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Post by elkman1310 on Mar 28, 2020 19:06:37 GMT -5
We only have two shooter at our club that shoot a 7mm. Both use a Saum but they both say it is marginal with bullets above 180gr. I really want to shoot 190 or up to 197gr bullets the 7/300 should be able to get me into the 2850 to 2950 zone. I really don't want to go above that if it was just a speed thing I could go with any case bigger than this but its all about hitting just the right balance so I'll see if the 7/300 wsm works or not.
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Post by elkman1310 on Mar 30, 2020 17:16:04 GMT -5
Well the 270wsm brass came a day early so I took the time to prep 30 cases for this gun. I am surprised at the quality of this batch of Winchester brass the 270wsm checks out better weight wise than the 300wsm. out of a bag of 50 (41) weighed between 225.65grs to 226.70 that is better than my Norma brass there were (7) than weighed 228.10 to 229.00 then (3) light ones at 224.30
The necks do have some dents no big deal since I simply ran my 7mm expander through them to open them up to neck turn which straightens any dents right out. So (1) Sort by weight (2) size the case (3) expand necks (4) trim all to length (5) Chamfer outside of neck and bevel inside (6) Neck turn brass down to 13.000 in two steps (7) machine primer pockets with KM tool (8) deburr flash hole with KM tool
(9) Anneal brass in my AMP induction annealer.
All these steps are necessary for small groups at 1k along with weighing primers and powder charges to 1/100th of a grain. and the list goes on and on.
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tedb
Full Member
Posts: 190
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Post by tedb on Mar 30, 2020 19:18:09 GMT -5
What Winchester brass you shooting I believe have 20 supreme 20 brass 270 wsm if you want it there once fired. I’ll never get back reloading them. There yours if you want them
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Post by jims on Mar 30, 2020 19:52:56 GMT -5
Good to hear that Winchester has good brass.
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Post by elkman1310 on Mar 30, 2020 20:55:50 GMT -5
Thanks for the brass offer I don't need anymore. Just wanted to try the Winchester 270wsm to see how that compared to the 300wsm brass. Both are good lots but sometimes Winchesters quality sucks.
Norma brass is usually always good but their weights can vary a lot too.
Hey at $28.00 for a bag of 50 that's a real savings over the Norma. The Winchester 300wsm has shot really well in testing at 1k as long as you do all the prep work.
I loaded up some 180gr VLD's with a couple different charges of RL25 to see what kind of velocity I get and where my max pressure might be. There are two nodes for this bullet 2950fps and 3050fps don't really care to hit the 3050fps node. When you hammer 10 shots out of a barrel as quick as you can Berger bullets has a nasty habit of coming apart much above 3000 fps. That's why they tell you not to use the 195gr EOL for competition maybe you will loose a bullet once in a while.
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Post by elkman1310 on Apr 10, 2020 21:48:20 GMT -5
Well I decided to but the new Krieger 1-8 twist barrel on. Everything looks good the only change I made was to throat the chamber out this reamer has a .188FB which is ok but not really what I need so I throated it out another .070
Our local ranges or shut down till the first of May I hope they reopen then until then I really can do much testing.
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7/300wsm
Dec 14, 2023 10:51:34 GMT -5
via mobile
Post by savagenut on Dec 14, 2023 10:51:34 GMT -5
Well I decided to but the new Krieger 1-8 twist barrel on. Everything looks good the only change I made was to throat the chamber out this reamer has a .188FB which is ok but not really what I need so I throated it out another .070 Our local ranges or shut down till the first of May I hope they reopen then until then I really can do much testing. Do you still have this reamer? |
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7/300wsm
Dec 14, 2023 11:57:28 GMT -5
via mobile
Post by dennis on Dec 14, 2023 11:57:28 GMT -5
Elkman passed away
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