Engraving lenght to Shilen Ratchet

Hi Bill!

You have plenty of experiences chambering Shilen Ratchet barrels.We have now few on the table and coming more and if you can give rule of thumb it is nice one.

About engraving lenght and big caliber.

Reamers are .2250 and .2255 Calfee style with 2 degrees leade angle.


I dont know yet what are the big calibers of those barrels,but if they are .2218/2219/2220 or so what kind of rule of thumb you can give to engraving lenghts to different big caliber measurements.

Like thisway 0,2220-->0,135 or so...0,2219-->0,130 or so...

We have time to make different engraving lenghts/shoot/change it/shoot and go on,but maybe we find right ones faster with your instructions.

Ps.I have noticed that sometimes people are talking different things like apples & oranges or other one is talking about fences and other one is talking fenceposts.

I mean when someone is talking about engraving lenght they talk how short or long rifling marks he/she has on bullets.And other one is talking about engraving lenght measured when bullet touch to leade and stop there.Big difference depending leade angle,barrel measurements,etc.

BR,

Timo,22 LR hand loading ammo fool friend

Sorry bout that....

Bill Calfee said:

Friend 22 LR hand loading ammo fool Timo


Friend 22 LR hand loading ammo fool Timo:


First some housekeeping:


As soon as you Finish folks show me pictures of a good, ball bearing, T handle lapping handle, and a lapping rod guide that's half again longer than the one in the picture you posted a while back, I'll continue with some more taper lapping instructions, OK.....



Here's a quote from your thread starter:


"I mean when someone is talking about engraving lenght they talk how short or long rifling marks he/she has on bullets.And other one is talking about engraving lenght measured when bullet touch to leade and stop there.Big difference depending leade angle,barrel measurements,etc."



Friend Timo, actually they are the same thing......with respect to the actual length of the engraving....


Long and short rifling marks on the bullet is also an indicator of how well the chamber is centered.....


On a perfectly centered chamber, all the rifling marks will be the same length, provided the bore/grooves are perfectly round in the part of the bore the chamber is cut in......


I'll finish this later as I just received a phone call I have to take.....



Your pistol fool friend, Bill Calfee

Click to expand...

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Sorry bout that....


It was a very important phone call......about a 22 rifle, of all things...


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Friend Timo, always keep something in mind that I learned years ago:


The absolute best accuracy comes when the chamber leade fully engraves the bullet, leaving just enough room for the CL ring to grow.

I'll let what I just said soak in for a while......


Meanwhile, here's something for you Finish folks to ponder........



We need about .025"-.030" of room for the CL ring to grow...................


From the front shoulder of the bullet to the crimp of the case mouth averages about .180" for most of the ammo we use.


You can do the math...............



More later....


Your pistol fool friend, BC

Hi Bill!

*Our "main gunsmith" is on fishing trip on northern Finland,but read this pages from phone. He just called me that write to Bill that next week he is making more equipments to lapping and we hope that we get to second class....

*Those rifling marks on lead bullets are often not so visible that sometimes people gives smaller engraving numbers what are real ones if they dont look with loop or younger eyes.

BR, Timo

Friend 22 LR ammo hand loading fool Timo

Timo said:

Hi Bill!

*Our "main gunsmith" is on fishing trip on northern Finland,but read this pages from phone. He just called me that write to Bill that next week he is making more equipments to lapping and we hope that we get to second class....

*Those rifling marks on lead bullets are often not so visible that sometimes people gives smaller engraving numbers what are real ones if they dont look with loop or younger eyes.

BR, Timo

Click to expand...

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Friend 22 LR ammo hand loading fool Timo:



You're quite right.......



I don't know how many times I've seen "Internet chambering experts" make that same mistake.....


Which is one reason I feel sorry for newbies trying to glean "good" information from the Internet.



Your pistol fool friend, BC


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PS:


Timo, you asked about engraving length for some Shilen ratchets you Finish folks have acquired...


And..................


You have Calfee spec reamers in .2250" and .2255" diameter with 2 degree leade angles...


The .2255" is worthless today with the pretty much standardized bore/groove specs RFBR barrel makers use.


The Calfee .2255", and larger, reamers were for things like Anschutz barrels, and barrels we used before the custom barrel makers here in the US standardized their bore/groove specs....


So the .2250" is the reamer to used for the ratchets....



So..........................


How much leade engraving?


Because of the big difference in the working length of the ammo today, and I mean a big difference, the leade engraving length has to be a compromise, so as to hopefully be able to handle different lots as well as possible..


So there's really no specific "one size fits all" engraving length...



To boot........


How well you can finish a chamber, without degrading the integrity of the leade, has a bearing on the engraving length.


Whether or not you do a post chamber lap also has a bearing on how much leade length you can deal with.



And then the biggie of all biggies:


What does one use to gauge the leade engraving length, as your chamber progresses?



That's enough for the time being.......


I'll comment more before long.......bc




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The chamber in Black Death, which uses a Shilen ratchet, and shooting Lapua, has a leade engraving length of slightly over .150".....


Even though I chambered Death back in 2008, I used a black Eley lot 6034, from about 8 years ago, to gauge it about five years ago when I had the barrel off to cast a lap and de-glazed the bore...


If everyone throughout the world had access to black Eley lot 6034, we could all be on the same page as far as setting leade engraving length accurately...