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You have but one rifle....a 270 AM

 
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  #15  
Old 04-16-2007, 03:51 PM
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Re: You have but one rifle....a 270 AM

Resized a second batch or 7mm RUM to 270 AM. I've read to stop short of resizing the the full lenght of the neck. Which I've done, can anyone tell me the reason for this??
Also, anyone loading for this round I would be interested in knowing your COL with the 169.5 and 195 Wildcats and do you know what you have for a throat in your rifle??
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  #16  
Old 04-16-2007, 04:44 PM
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Re: You have but one rifle....a 270 AM

bearless:

You stop just short of doing the entire neck so that the small portion left gives you a slight crush fit of the case in the chamber. This makes sure the case is held in place initially during the fire forming process.

I do this with 270 AMs as well as 7mm AMs. I have a pic of the 7mm AM done this way but not the 270 AM, if you need to see it.

My buddy's 270 AM, with the 169.5 Wildcats just at the lands, measured to ogive with Stoney Point gage is 3.219" average. This is with what Kirby considers his standard length throat. This is approximately 3.8870" oal to tip. I measure and set all rounds to ogive and not the tip. Your methods and gages will probably give you a slightly different measurement, but this is close.
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  #17  
Old 04-16-2007, 06:48 PM
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Re: You have but one rifle....a 270 AM

Tim,

Sorry I'm so tardy.

I gave up on neck turning. It didn't do any good, one way or another.

Just for fun measure the diameter of the two different bullet weights.

Went out today to test my bipod. Temp was 60*. Had to pound the bolt open. The loads were pretty good at less then 30* but apparently too hot for 60*. Shot great though. [img]/ubbthreads/images/graemlins/cool.gif[/img]
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  #18  
Old 04-20-2007, 08:45 AM
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Re: You have but one rifle....a 270 AM

Dick
What method are you using to get your seating depth. I can't get a seating depth. The barrel has a tapered lead and I can't get consistant measurements. Tried a rod with two clamps, marking the bullet and just trial and error seating til it chambers.
With the clamps I've taken three reading with a 169.5 gr Wildcat and used five different bullets, total of fifteen readings. After each reading with each bullet I removed it, turned it and measured again. Got a spread of .143. Thats 3.692 to 3.549.
Plus I found out today that Richard is no londer going to offer his 195 gr bullets that I had ordered because of problems with his components. Availabiliy of other bullets I have no idea. His words "I have a new style bullet out with a aluminum tip that will replace these in a month.These will be built on a heavier jacket and will be superior in
every shape and form with a huge increase in bc.I was planning on dropping
the "old style" anyways,this just hurried it up a bit.The only downfall will
be a higher cost per bullet."
Phil
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  #19  
Old 04-20-2007, 09:01 AM
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Re: You have but one rifle....a 270 AM

[ QUOTE ]
These will be built on a heavier jacket and will be superior in every shape and form with a huge increase in bc.

[/ QUOTE ]

The email I got referred to them as "scary". I've seen a picture and they are exactly that.
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  #20  
Old 04-20-2007, 12:56 PM
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Re: You have but one rifle....a 270 AM

bearless:

I use the Stoney Point gage for testing for seating depth. I also use a wooden dowel down the muzzle. I seat the case in the chamber as consistently as possible each time. I use the dowel and the rod in the gage at the same time and use both hands with as delicate a touch as possible and have the bullet captured by the rod in the gage and the dowel as I touch the lands. I do this at least 5 times and take the average. With care and practice you can get pretty consistent with it. Also, the gun is held in a gun vise so the only thing I'm doing is manipulating the rod and dowel and I'm not having to hold the gun plus do the measurements.

You can't jam the bullet with any force into the lands and expect to get accurate measurements. It has be be done with feel and finesse and as close to the same each time as is humanly possible.

Also note that you can't tighten the set screw on the rod of the gage with too much force or you will create an indentation on the sliding rod. Then future measurements will possibly be affected when you try to tighten the set screw but the point is deflected into the dimple you left the last time when you tightened it too much.

I then keep the bullet that I used with the case and always use the same bullet for future checks to track throat wear etc. The bullet is marked and set aside and kept just for measurements.

[ QUOTE ]
With the clamps I've taken three reading with a 169.5 gr Wildcat and used five different bullets, total of fifteen readings. After each reading with each bullet I removed it, turned it and measured again. Got a spread of .143. Thats 3.692 to 3.549.

[/ QUOTE ]
I just did a new bullet/load measurement and for 5 different tries the variation was .002", which is +-.001", so you can get it down with care, patience and practice. I also mark the case neck and the bullet with a mark so that each time I put the bullet into the case to measure I have the same relation between the bullet, the case and the rod in the gage. I just want to be sure that everything I can control is the same each time I take a measurement.

If you are using the same brand and style bullet, but in different weights, mark the weight on each bullet with a marker. You should also weigh the bullet when testing to make sure the correct bullet is being used. It'd be easy to use the wrong bullet and get an incorrect measurement because the bullets of different weights look the same.
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  #21  
Old 04-20-2007, 04:55 PM
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Re: You have but one rifle....a 270 AM

Yes, a Stoney Point overall length gage is a wonderful tool. I have one and a wide assortment of modified cases, but not one in 270 AM. I will send a fire formed case out Monday to be modified
What I'm doing should give me the same info. I close the bolt and from the muzzle run a rod to the bolt face then tighten a clamp at the muzzle. Then with very light finger pressure push a bullet into the chamber touching the lands. I then run the rod to the bullet tip and tighten the second clamp at the muzzle. Measuring between the clamps should give COL.
This is fine, I got fairly consistant measurements from three tries with the same bullet. But is this the info I need??
What I did was take five bullets and fifteen measurements hoping to get an average reading that I could use as my seating depth. I don't understand why this isn't working for me.
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