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  #21  
Old 07-28-2021, 08:12 PM
nvtoy nvtoy is offline
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Default No throat

One other thing I haven’t seen mentioned. If the total cylindrical section of bullet is bearing against the case neck it would in my mind reduce runout. The factories only chamber long throats to reduce liability. Lawyers design the chambers to reduce pressure at the cost of accuracy.
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  #22  
Old 07-29-2021, 11:33 PM
moorepower moorepower is offline
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I have rifles with over 1/8" freebore that shoot well under 1/2". For those who don't reload, you don't want a 60kpsi round designed for .040 jump to be jammed in the lands with different kinds of ammo.
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  #23  
Old 07-29-2021, 11:40 PM
moorepower moorepower is offline
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Quote:
Originally Posted by montdoug View Post
As Kenny mentioned I change a lotta stuff that don't need changing and I need a gun smith as well. 10 thumbs .
My 527 Varmint Kevlar in .204 was about a half inch-ish rifle from the factory using RL10X and 39 grain Blitz Kings. What bothered me was that it's best accuracy happened with the bullet seated way out with hardy any neck purchase on the bullet and to long to fit in the magazine. Because the accuracy was there in factory form and the barrel had been carefully broken in so it cleaned real well, I decided to shake the dice and re-chamber the factory barrel (not always a good plan).
I sent it to Greg Tannel at Gre'Tan and he set the barrel back and re-chambered with a minimum spec, zero free-bore reamer and put a snug but no turn neck on it.
After that I could pick any bullet I wanted and seat it to both fit in the magazine and touch the lands with beau-coups bullet purchase in the neck.
Unlike GL's experience mine was a complete success which sure "does not always happen" with a factory barrel. Mine went from shooting 1/2 inch-ish groups with ammo to long to fit the magazine to shooting groups in which this isn't an uncommon group if I do my part.



Still using 39 BlitzKings with RL10X only it fits in the magazine and I use a lighter than book charge for faster than book velocities (just a titch under 3,900FPS).

Now the "WARNING"!!! "WARNING"!!! .
The 204 was designed with lots of free-bore to avoid excessive pressure with some hot loaded factory ammo designed to get max velocities, kinda like they did later on the .17 Fireball. With my chambering that factory ammo is into the lands "WAY to Hot" in my guesstimate . So I now have a rifle with a factory barrel that says it's a CZ .204 Ruger but factory ammo might well blow up in your face!! Not Good!!
What I have is a .204Ruger wildcat disguised as a factory rifle. Reloading data out of the manuals is useless or worse, dangerous!
I'm real happy with what I did, in fact I couldn't be more pleased but there are no free lunches in the shooting sports!
The reason I mention this so strongly is that I have a friend at Hornady who near passes out every time he hears guys talking about doing what I did. So for him and general safety of all I promised him that every time this topic came up I'd put up the warning flag.
Sure not talking down to anyone cause a lot of you know a lot more about this stuff than I do but a promise is a promise.

P.S.
I did the exact same thing with my VSF Remington in .17 Fireball for the exact same reason, OAL and relationship of ogive to lands. That time however I had Greg single point the action, double sleeve and bush the bolt etc etc, all in anticipation of a later barrel change that in all probability will never happen due to how it shoots now, "GREAT". I also put a Jewel trigger on it, and now have another wildcat designed as a factory offering and all the above warnings for the .204 still apply here as well.
As Kenny said again, I change a lotta stuff that don't need changing. I gets bored real easy.
At least with the Fireball, it was designed at around 52000 psi with a parent case designed for 62000 psi, "5.56", so you have a quite a bit of margin for eror. With the .204 being a 58000 psi round, not so much. Now looking at the bright side, about 1000 rounds down the pipe, with the .204, you will have freebore again with the throat erosion!
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  #24  
Old 07-30-2021, 12:38 AM
coyotespotter coyotespotter is offline
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The overlooked reason for shorter than SAAMI freebore is the flexibility to seat the bullet out further as wear occurs. With some chambers you have to change bullet brands/types to maintain the "jump" the barrel performs best at.
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  #25  
Old 07-30-2021, 01:37 AM
Nor Cal Mikie Nor Cal Mikie is offline
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"The overlooked reason for shorter than SAAMI freebore is the flexibility to seat the bullet out further as wear occurs"

That's my reasoning exactly.
Got an off the shelf 6BR barrel with a long throat. Didn't take long before the "perfect load" couldn't be done cause I couldn't get close to the lands and I didn't want to go with heavier bullets.
Sold that long throat barrel and had a custom zero freebore chamber cut to my specs.
I think I'am loading 55s now? .010 into the lands. BUGHOLES!!
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  #26  
Old 07-30-2021, 10:29 PM
moorepower moorepower is offline
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Quote:
Originally Posted by Nor Cal Mikie View Post
"The overlooked reason for shorter than SAAMI freebore is the flexibility to seat the bullet out further as wear occurs"

That's my reasoning exactly.
Got an off the shelf 6BR barrel with a long throat. Didn't take long before the "perfect load" couldn't be done cause I couldn't get close to the lands and I didn't want to go with heavier bullets.
Sold that long throat barrel and had a custom zero freebore chamber cut to my specs.
I think I'am loading 55s now? .010 into the lands. BUGHOLES!!
Can't you use a zero freebore with a 55 as long as the neck is? The reason i am asking, is I have an early Savage LRPV with a 1-12 that they must have ordered a reamer for 108's. It is one of the 1/8" plus, sub 1/2" guns. It's a 1-12 twist, and I want to set it up for 55-58 grain bullets. I want to send the barrel out to Kevin Rayhill, over the winter to set it back
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  #27  
Old 07-30-2021, 10:54 PM
Nor Cal Mikie Nor Cal Mikie is offline
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Find someone with a reamer with the specs "you want" and ship the barrel out for a set back. I've had a few Savage barrels "set back" so no problems.
If you can, find a ZERO free bore reamer. And I like as much bullet/neck contact as I can get. Flat base or Boat Tail. No worries about the bullets falling out of the neck because of not enough contact.
May depend on the contour of your barrel. Straight pipes will re chamber with no issues. Skinny barrel?? Might need a real close look.
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  #28  
Old 07-31-2021, 01:31 PM
moorepower moorepower is offline
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Rayhill has many 6br reamers. He wanted me to send a couple of dummy rounds, what I wanted for neck clearance and what freebore if any I want. I have been very happy with the work he has done in the past for me.I just need to figure what I want for freebore.
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  #29  
Old 07-31-2021, 09:13 PM
L.Sherm L.Sherm is offline
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Zero freebore will be fine with 55's in a 20 cal on a BR case
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