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acceptable runout range?

BigSwede

Well-Known Member
Joined
Aug 2, 2014
Messages
463
Location
Canadian border /northern ny
What should I be expecting with bullet runout in my loaded rounds when fire-forming 7mm-300wm? And another naive question .. Will it dissipate once the rounds are fired in my chamber and annealed for the second firing?
Thankyou Obiwan(s)
 
Are you measuring on the bullet or the neck? With what tool? Run out should be measured with a spinner type tool like the Sinclair. Measure right where the ogive begins. I will accept .002- .003" run out with that method.
 
Are you measuring on the bullet or the neck? With what tool? Run out should be measured with a spinner type tool like the Sinclair. Measure right where the ogive begins. I will accept .002- .003" run out with that method.

+1! That's the exact same tolerance my Hornady concentricity gauge says on the ideal/acceptable run out. I did some just a few days ago on my .300 WSM witt 215 Bergers and the result is as follows ...

Cartridge%20run%20off_zpslag5uiae.jpg


and the range result >>> http://www.longrangehunting.com/forums/f19/just-playing-different-primers-159193/
 
Well I've not used one before now but ... I'm using the rcbs case master and measuring on the bullet about half way up the ogive from the meplat. I'm getting disgusting numbers like .017 in runout on some of these virgin Winchester cases loaded with 180 vld's. Rare to get the .002-.003 acceptable range.. I did not measure unloaded brass. They are shooting groups of about 1 moa at 500. I sure hope they will settle down after fire forming. I have not measured yet but can I assume they will behave after firing in my chamber? These are sized in bushing dies to 7mm trimmed and chamfered/deburred.
 
Yes, lots of this will go away after first firing. Necking down induces RO. I get less when I neck down in 3 steps with 3 bushings. You can straighten them pretty easily drill a neck dia hole in your bench, a block of wood or 1/4 piece of aluminum. Drop it in and lightly push where needed. But you want the case supported at the neck, not on the bullet so you don't loosen the neck tension.

I pay less attention to this these days since I started running min spec reamers in the throat area. When the bolt is closed it will be centered.

If your custom rifle is shooting 1 moa at 500 I would relook at load work up.

Just my opinion

Jeff
 
Im in the midst of working up with h1000 but wonder if the brass condition will limit my success. I did manage to shoot a few 3 shot groups into 1/2 minute at 500 with 73.5 grains with the 180's jammed. I've since backed them out to magazine length and continued up to 75.5 grains. I admit I've been a bit sloppy in my initial go. I just wonder if the brass issues are most important. Should I go through the brass and remedy that so I have less neck runout prior to shooting them and then shoot a ladder to get in the ballpark? And.. Then shoot groups and tweak depth and +/-.2 grains etc? I'm only shooting new win brass and hoping it will make a large difference in second firing once I get a few formed and sorted to my liking.
 
Don't expect large accuracy gains with fired brass. More so in seating depth. Load work up can be 9 shots to 100. It takes time and you need to find what your rifle likes. I would NEVER leave accuracy for any mag box. I would single feed first or fix the mag box.

Jeff
 
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