#1
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20 Grendel reamer specs?
So I'm trying to spec out a reamer for a 20 Grendel (bolt action) and wondering about neck clearances, length and free bore. I picked up a 20 ppc bushing FL die and sized down several Lapua and Starline brass. Lapua ends up at .234" and Starline .232" loaded diameter with a 39 gr Blitzking. I'm building a light carry gun on a Howa mini 7.62 rifle, 11tw Mullerworks barrel. Probably a 23-24" barrel, .560's muzzle diameter. BIB's 40gr are on the menu for this one and I'm told they prefer a short freebore and to spec the reamer zero freebore. OK, so that's settled, except what neck diameter and do I shorten the OAL on the case since the brass seems to shorten up considerably with sizing down operations. I was thinking of 10-20 thou shorter neck on the reamer and if it's too short I can trim to proper length. Still plenty of neck to seat a bullet and keep the throat back closer to the bullet.
I guess it might be relative, but has anyone noted OAL changes when sizing 6 PPC down to 20 PPC? Do you keep the same trim to length of the parent cartridge or will the necked down version end up shorter to some extent? As for neck diameter I was thinking .2375 or just a .238 neck, really don't want to turn necks on these little buggers but maybe its a good idea??. What say you? |
#2
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It's been done---.20 Titan by Todd Kindler. Contact him, or PT&G might have a reamer print.
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#3
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Also, Greg Tannel has a .20 Titan reamer.
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#4
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why not just do a .20 PPC or .20 Beggs Dies will be cheaper
ML
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When I die I hope my wife doesn't sell my gear for what I told her I paid for it. |
#5
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Dies
Grendel bushing dies work very well for the 20 Titan.
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Good shooting! Gary NRA Endowment Life Member |
#6
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My experience with a 20 Swift is the neck will get longer when you neck down, The length will probably still be shorter than the maximum length if you are starting with new brass. As far as freebore and throat, what I did was go with none. I am sure that you will hear terror stories and how you will blow it up, but mine works perfect with not a single problem. You just have to seat the bullet deeper. I made a bullet seating die by running the reamer into a die blank, that will seat the bullet exactly at the lands. Don't knock it unless you have tried it, my swift will make better than 5,000fps. You can always add throat and lead later.
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A gun is just like a parachute, if you really need one, nothing else will do. |
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