Freebore/seating issues

[jmcgowe]

I recently rebarreled my Savage 12 F/TR in .223 with a Shilen 7 twist barrel. I wanted room to seat 90 gn SMK's in the new barrel so I provided Shilen with some dummy rounds so that they could ream the freebore. The dummy rounds were seated 2.069" BTO (2.565" OAL). I finally located my Hornady OAL gauge and measured the length to the lands...it averaged 1.835". This measurement was with a very light touch on the gauge. This makes no sense...it means I've been shooting the rifle with a .234" jam ???? I then took some measurements with some moderate/heavy pressure applied to the gauge, which resulted in measurements of 2.075" to 2.165". I did so with the bullets marked with a Sharpie so I could see the land etching. Here is a picture of the results.

You can see the ink removed on each of these bullets as they were pressed into the barrel. However, these are the only markings...there are not land etchings on any other spot on these bullets. Obviously, one would expect etchings from all the lands, not just one. Very strange.

At this point, I think I need to get the rifle to a good gunsmith to check out the freebore measurement and the cause of the strange etchings.

However, if anyone has any thoughts on this, I'd love to hear them. Thanks in advance.

John

 

[stacy]

CALL SHILEN AND GET THER REAMER SPEC'S BUT YOU'LL NEED .169 FOR THOSE 90 GRS THAT WORKS GREAT FOR ME IN TWO 223 ACKLEY'S

 

[robbor]

I recently rebarreled my Savage 12 F/TR in .223 with a Shilen 7 twist barrel. I wanted room to seat 90 gn SMK's in the new barrel so I provided Shilen with some dummy rounds so that they could ream the freebore. The dummy rounds were seated 2.069" BTO (2.565" OAL). I finally located my Hornady OAL gauge and measured the length to the lands...it averaged 1.835". This measurement was with a very light touch on the gauge. This makes no sense...it means I've been shooting the rifle with a .234" jam ???? I then took some measurements with some moderate/heavy pressure applied to the gauge, which resulted in measurements of 2.075" to 2.165". I did so with the bullets marked with a Sharpie so I could see the land etching. Here is a picture of the results.View attachment 997281

You can see the ink removed on each of these bullets as they were pressed into the barrel. However, these are the only markings...there are not land etchings on any other spot on these bullets. Obviously, one would expect etchings from all the lands, not just one. Very strange.

At this point, I think I need to get the rifle to a good gunsmith to check out the freebore measurement and the cause of the strange etchings.

However, if anyone has any thoughts on this, I'd love to hear them. Thanks in advance.

John

My uncle got a bad shillen prefit that had 6-7 ridges inside at the base of the chamber like they stopped the reamer in it while cutting, chamber was bananna shaped. I was a wildcat chamber and the first thing they asked was did you reload your own ammo, duh YES. He was told that voids his warranty.

 

[Ned Ludd]

PTGs Rem ISSF reamer for the Berger 90 VLDs has a 0.169 freebore that is only .0002" over bullet diameter. In fact, the freebore is so tight that it requires a significant amount of push on the Hornady OAL gauge plastic rod before the bullets will even slide in to touch the lands. The bullet appears to hit a "hard" stop, which is actually just the start of the tight freebore. Once you get the bullet moving with a solid push, it will slide further until it hits a true "hard" stop. It requires some practice and finesse to accurately measure the distance to just touching the lands because of this.

Sounds like you may be dealing with the same issue of a tight freebore. Shilen could probably give you the reamer specs. I can guarantee you that a .0002" over bullet diameter freebore is tight enough to remove some marker from the surface of a bullet, so those marks you showed above may well be from the tight freebore and not from the lands. In addition, the Hornady plastic pushrod is not strong enough to push a bullet more than .015"-.020" into the lands, so I strongly doubt that is what is happening. True land marks should match the number of lands and be spaced equidistant around the bullet.

 

[jmcgowe]

PTGs Rem ISSF reamer for the Berger 90 VLDs has a 0.169 freebore that is only .0002" over bullet diameter. In fact, the freebore is so tight that it requires a significant amount of push on the Hornady OAL gauge plastic rod before the bullets will even slide in to touch the lands. The bullet appears to hit a "hard" stop, which is actually just the start of the tight freebore. Once you get the bullet moving with a solid push, it will slide further until it hits a true "hard" stop. It requires some practice and finesse to accurately measure the distance to just touching the lands because of this.

Sounds like you may be dealing with the same issue of a tight freebore. Shilen could probably give you the reamer specs. I can guarantee you that a .0002" over bullet diameter freebore is tight enough to remove some marker from the surface of a bullet, so those marks you showed above may well be from the tight freebore and not from the lands. In addition, the Hornady plastic pushrod is not strong enough to push a bullet more than .015"-.020" into the lands, so I strongly doubt that is what is happening. True land marks should match the number of lands and be spaced equidistant around the bullet.

gstaylorg, that sounds exactly like what is happening, which is a relief. When I did push through the initial stop, I did get a reasonable reading of 2.075" (compared to the reaming depth of 2.069"), so it may just be my technique that needs work. And I couldn't agree more that using the Hornady OAL gauge requires practice and finesse. I don't know if the small diameter .223's exacerbate this situation; I do know that my friend doesn't seem to have any problems with his .308's. I just wish there was a better way to do this measurement. I tried the Wheeler Accuracy method of measuring with a loose bolt, but even after removing the firing pin and ejector, I couldn't get it to work. So, I guess I'll just have to work on my technique with the Hornady gauge. Thanks very much for your comprehensive comments.

John

 

[Ned Ludd]

First time I tried to measure distance to the lands in a .223 set up for 90 VLDs how far the bullet was sunk down in the case really threw me for a loop until I realized it was almost exactly the length the freebore should have been. At that point it wasn't too difficult to figure out. It still takes a bit of practice to push hard enough to get the bullet moving, but not so hard you jam it way past the lands once it does get moving. Don't seem to have this issue with any of my .308s.

 

[Richard Jones]

....... I just wish there was a better way to do this measurement. I tried the Wheeler Accuracy method of measuring with a loose bolt, but even after removing the firing pin and ejector, I couldn't get it to work.

John,

That loose bolt method doesn't work well, at least for me, on a Savage, due to the loosely-goosey extraction issues with the rear bolt cam/baffle. I've gone so far as to remove the front spring washer to help with the feel, but it still didn't work well. The best way for me remains the slit case/sliding bullet method.

That action Mr. Wheeler is demoing on is a small step up from my Savage.....

 

[squint-n-squeeze]

John,

That loose bolt method doesn't work well, at least for me, on a Savage, due to the loosely-goosey extraction issues with the rear bolt cam/baffle. I've gone so far as to remove the front spring washer to help with the feel, but it still didn't work well. The best way for me remains the slit case/sliding bullet method.

That action Mr. Wheeler is demoing on is a small step up from my Savage.....

I've found the loose bolt method works OK on my Model 10, as well as my friend's Savage F-Class. Finding the threshold for sticking vs not requires a sensitive touch, but it is possible to tell the difference between +/- one thou seating depth.

A custom action would be a lot easier, I'm sure!

 

[jmcgowe]

John,

That loose bolt method doesn't work well, at least for me, on a Savage, due to the loosely-goosey extraction issues with the rear bolt cam/baffle. I've gone so far as to remove the front spring washer to help with the feel, but it still didn't work well. The best way for me remains the slit case/sliding bullet method.

That action Mr. Wheeler is demoing on is a small step up from my Savage.....

Interesting that removal of the front spring washer didn't help. That was the one thing I didn't try, but I was starting to think that that may have been the problem. I guess not. Thanks for saving me that step.

John

 

[jmcgowe]

I've found the loose bolt method works OK on my Model 10, as well as my friend's Savage F-Class. Finding the threshold for sticking vs not requires a sensitive touch, but it is possible to tell the difference between +/- one thou seating depth.

A custom action would be a lot easier, I'm sure!

Squint, that is really good seating depth accuracy. Funny how a few guys are able to get the loose bolt method to work with Savage bolts, but a lot of us struggle. Maybe I just have to put in more time with it. Thanks for your comments.

John

 

[Richard Jones]

Interesting that removal of the front spring washer didn't help. That was the one thing I didn't try, but I was starting to think that that may have been the problem. I guess not. Thanks for saving me that step.

John

I went down this morning and tried again. The only way I can get the bolt to fall on its own is to remove the firing pin assembly, the front spring washer, the front AND the rear baffle. With just the rear baffle installed, I still get that 'click', even with NO brass. I've got 3 more, but I doubt any of them is going to pass this test. Unclear to me how anyone can accomplish this with a Savage, but I'm willing to learn. I still think your best bet is with the slit case method.

 

[savagedasher]

Best thing is to use is a rod with two sliding locks go from the end of the bore to the bolt face with one slide on the rod and set it push a bullet in the lands to where it stops add the other slide And stop it on the tip of the bullet . With two stops and some math using a caliper you got the exact distance . Larry

 

[savagedasher]

I have had great luck with a fire fourm case from that gun and makeing my own chamber Case Larry

 

[squint-n-squeeze]

Squint, that is really good seating depth accuracy. Funny how a few guys are able to get the loose bolt method to work with Savage bolts, but a lot of us struggle. Maybe I just have to put in more time with it. Thanks for your comments.

John

I find it helps to put a very thin coat of grease on your locking lugs and extraction ramp before starting. There is a lot of slop in the Savage bolt, so it helps to open and shut the bolt each time before putting the seated dummy into the chamber, to get a feel for how much wiggle to expect. The "click" when you are at the seating threshold is very subtle. When in doubt, use an inertial puller to knock the bullet out a little bit, then re-seat it a thou longer.

 

[CharlieNC]

Best thing is to use is a rod with two sliding locks go from the end of the bore to the bolt face with one slide on the rod and set it push a bullet in the lands to where it stops add the other slide And stop it on the tip of the bullet . With two stops and some math using a caliper you got the exact distance . Larry

To get a "rough" measure to be sure you are in the ballpark, you can quickly mark the rod with a fine tip pencil. Works good as a sanity check in a pinch.

 

['Freak]

Try Sinclair’s Bullet Seating Depth Tool #749-004-650. You work its much more substantial stainless steel rod through a Delrin action guide, with no “special case” involved, shoving directly against either the base of a bullet or, in a separate step, against the head of any case of your choosing, but ideally a case already fire formed to the full extents of the chamber.

Two stop collars get positioned on the rod, the first indicating distance to the base of the bullet, and the second indicating distance to the head of a case whose shoulder is pushed full against the chamber’s shoulder.

A measurement betwixt the two stop collars is length from the case head to the base of the bullet. Add to that measurement the bullet’s base to ogive length obtained via a bullet comparator and the result is case head to ogive length for the loaded round.

 

[jepp2]

Best thing is to use is a rod with two sliding locks go from the end of the bore to the bolt face with one slide on the rod and set it push a bullet in the lands to where it stops add the other slide And stop it on the tip of the bullet . With two stops and some math using a caliper you got the exact distance . Larry

Bingo! That is exactly the setup I use and I can establish bullet touch distance within 1-2 thousandths. I got mine from a guy, and the stops are exactly .500" so I just measure the distance between (or outside measurement - 1.000"). Took a little while to develop the "feel" for the light pressure to use to seat the bullet to touch the lands. I use a wood dowel for this step. Very repeatable. I also can measure how much my throat erodes based on my records.

Yes I am measuring from the bullet tip, not the ogive. But I can easily convert using the standard bullets I have selected for my seating depth records.

[URL=http://s860.photobucket.com/user/jepp2/media/COL5_zps0c16fc31.jpg.html][/URL]