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View Full Version : Solid pilot VS removable pilot



skeetlee
05-21-2011, 12:03 PM
If a solid pilot reamer isnt desirable why do they even make them? Im just not sure i understand what a guy needs yet to chamber a barrel. i am doing as much homework as i can on this topic so please bare with me. Also can you cut a complete chamber with a finish reamer or is that a no no? I know some folks use drill bits before they insert the finish reamer but isnt that taking a chance that the chamber could have run out? Unless the drill bit is custom ground i guess. Lee

jackie schmidt
05-21-2011, 12:35 PM
Solid pilot reamers are designed to fit, for lack of a better word, the smallest "generic barrel" you might encounter. For instance, the solid pilot on a typical 30-06 spec reamer might have a solid pilot that measures around .2990, (just an example) which will go in just about any 30 caliber barrel made. It will guide the reamer suffenciently for the task at hand.

You have to remember that much of the shooting public does not demand the "nth degree" of accuracy, (or analitity), that we in the extreme accuracy game demand. The guy that buys the Adams and Bennet Barrel off the shelf to go on his deer Rifle is probably is not that concerned about "tenths".

I suspect that there are Gunsmiths scattered all over who don't even own a live pilot reamer.

Live pilot reamers fit a certain market. The added cost is considered a waste on something that simply does not require it........jackie

mike in co
05-21-2011, 01:51 PM
i used a solid pilot on an 03a3 bbl as it was short chambered by the military when i got it. mil issued bbl not a br nor target bbl.

br guys that drill...then single point bore so there is no(hopefully) runout....its taper bored to guide the reamer.
the drill is used to open the bore so a dial indicator can reach the throat...the bbl is then dialed in based on the throat, taper bored to match the reamer and finally reamed.

do a search on jackie's method
there are pics
mike in co

Boyd Allen
05-21-2011, 02:31 PM
I have been told that even if it is bored parallel, that it will work. Comments? Another thing, a friend who has chambered a number of barrels for his favorite hunting cartridge the .280 AE, but who lacks an indicator that can reach the throat, indicates those barrels (through the headstock) at both ends. cuts his chambers with a floating reamer holder and good pilot fit, and then reindicates off of the chamber, and cuts and threads the tenon.

skeetlee
05-22-2011, 12:23 PM
Thanks Jackie that makes since. I just didnt know. Lee

alinwa
05-23-2011, 11:12 PM
Another thought, from a very limited perspective.

I learned to chamber nearly 30yrs ago in gunsmithing school. The "Brownell's Method." If there were piloted reamers I never knew of them. I learned to fear "chatter," for us students the bane of our existence was the squealing reamer cuz' once't it started you were in for a long grind.

I took 25yrs off......

Now I've got a lathe again, it's like riding a bike. Only I'm better than I once't was..... much better. And I've learned some new thangs. HOWEVER, about 3mo ago I got a squeaker, a squealer, a HOWLER in my fevered imagination. My heart sunk, my guts churned and my eyeballs started to hurt... I sat down and went thru my setup and the only thing "different" was that I hadn't the correct sized pilot so I was chambering with a slightly loose-fitting bushing. I backed off and ordered some more bushings.

When the bushings came in I tried again WITHOUT the new bushings just to see was I twitching somehows ......still hadda flat tire.....so I installed a proper bushing, fed slowly and VOILAHHHHH!!!!! Problem solved. Did the same thing recently with a 325 (who wants a hunner'dollars worth of 8MM bushes???) and had to buy the proper bushing. A'gain, problem solved.


Now maybe I got lucky but IMO a nice tight bush really helps when that reamer starts humping up like a monkey.

FOR THIS ALONE I'll buy bushing reamers.

al

mike in co
05-24-2011, 01:44 AM
of dis'd al,
what do you do prior to reaming ??
mike in co

alinwa
05-24-2011, 02:16 AM
of dis'd al,
what do you do prior to reaming ??
mike in co

I locate and center the leade, drill and step-bore the chamber to within about ten thou. "Step-boring" means I step it in parallel sections, three steps in a short and four in a long chamber. I strive to have the steps engage nearly simultaneously. I haven't messed with taper boring and probably won't because I've got hangups with the process. (I believe reamers sometimes tend to hump and twist if left to their own devices :p )

weird eh?

al

mike in co
05-24-2011, 09:59 AM
naw, if it works, it works.
the 3 or 4 contact points point the reamer where you want it.
heck i may even try it....i taper bore currently.
mike in co

frwillia
06-01-2011, 06:26 AM
Most recent chamber I did was a .22 Hornet replacement, inexpensive ER Shaw CrMo barrel blank, to go on a Daley rimfire based rifle. Used a solid pilot PTG reamer. Barrel blank, once cut off, had a bore that was dead straight for 3" from the breech in which was as far as I bothered to measure (Grizzly Rod). Muzzle was orbiting in about a .003" circle. Muzzle end, when I cut the crown was really good too. That is the best ER Shaw barrel blank I've seen (of 5).

Anyway, I just reamed the chamber. No drilling, no pre boring, no special dance, no eyes of Newt, just reamed it, carefully of course, but just reamed it none the less. Wonder of wonders, it came out to be maybe the best looking chamber I've ever done. Under bore scope examination it looks perfectly symmetrical in the throat, nice crisp leades, no smearing, no scarring from the solid pilot, nice finish on the chamber walls, throat indicates still centered, directly indicating the breech end of the chamber it was still dead nuts.

Sometimes I get lucky. A broken clock is right twice a day. I don't know. But now and then KISS works remarkably well.

I have a bit more to do before we can shoot it, but so far it looks promising.

So, at least for little chambers like the Hornet, a removable pilot does't seem to be required. If I'd bought the reamer I'd probably have bought it with a removable pilot, but my buddy bought it and wanted to keep cost down.

Fitch

Jay Cutright
06-01-2011, 07:15 AM
I'm not saying this is the right thing to do, but, I recently reamed a chamber by starting with a tight fitting bushing and reamed about .250 deep. I then removed the bushing and finished reaming the chamber with out any problems what so ever. In doing it this way I was able to push more oil through the barrel while reaming and in my opinion it allowed the reamer to self align enough to allow for any difference between the lands & grooves.
I did predrill and bore but, I did not taper bore it, I suppose had I taper bored correctly I wouldn't have needed to use the bushing at all.

skeetlee
06-01-2011, 06:01 PM
So what is the general though about pre drilling a chamber before using the reamer? I was under the impression that this was a no no? I think i would rather go slow and cut the hole chamber with the reamer. Might take a bit longer, but if you would only go .030 to .040 at a time then clean and remove chips, wouldnt that make for a straighter chamber? Lee

frwillia
06-01-2011, 07:06 PM
So what is the general though about pre drilling a chamber before using the reamer? I was under the impression that this was a no no? I think i would rather go slow and cut the hole chamber with the reamer. Might take a bit longer, but if you would only go .030 to .040 at a time then clean and remove chips, wouldnt that make for a straighter chamber? Lee

Pre drilling is a bad idea unless it is followed by pre boring out to within .010" or .020" of the smallest diameter before the chamber shoulder. Drilling can go anywhere, wander all over, and does. The single point boring bar will by definition cut a cylinder that is perfectly centered on the lathe axis. The purpose of drilling is to make a big enough hole to use a boring bar in. The boring bar is to true up the hole and eliminate the wandering around of the drill.

So the boring bar makes a cylinder that is perfectly centered on the lathe axis, that's the good news or the bad news depending on how the barrel blank is aligned with the lathe axis. It is the alignment of the barrel blank with the lathe axis that is the critical issue and the subject that has caused more discussion in this forum than about any other topic I'm aware of. Pre drilling and then boring makes the alignment more critical than just reaming the chamber in my opinion. But, trust me on this, opinions will vary!

Fitch

mike in co
06-01-2011, 10:17 PM
or tapered with the boring bar....
open the hole with the drill...reach in and rezero on the throat...now bore....to match the reamer finish with the reamer....


Pre drilling is a bad idea unless it is followed by pre boring out to within .010" or .020" of the smallest diameter before the chamber shoulder. Drilling can go anywhere, wander all over, and does. The single point boring bar will by definition cut a cylinder that is perfectly centered on the lathe axis. The purpose of drilling is to make a big enough hole to use a boring bar in. The boring bar is to true up the hole and eliminate the wandering around of the drill.

So the boring bar makes a cylinder that is perfectly centered on the lathe axis, that's the good news or the bad news depending on how the barrel blank is aligned with the lathe axis. It is the alignment of the barrel blank with the lathe axis that is the critical issue and the subject that has caused more discussion in this forum than about any other topic I'm aware of. Pre drilling and then boring makes the alignment more critical than just reaming the chamber in my opinion. But, trust me on this, opinions will vary!

Fitch

jackie schmidt
06-02-2011, 08:21 AM
Fitch, I taper bore within .003-004 of finish, leaving the reamer's job to do nothing more than produce the final shape and finish in the chamber. That allows the reamer to be inserted a tad past 1/2 way.

Also, it is very criticle to get the barrels ID running truly straight with the lathe's axis regardless of which method you use. If you use a floater, and the barrel is not running dead true, the reamer will start to wobble as it encounters spots in the ID that are not true. So, what does this hurt? The subsequent machining operations will not be true with the chamber.

Of course, if you do not use a floater, the chamber will in all likely hood be oversize, as the reamer will bind, and cut oversize, depending on how much clearance the pilot has in the bore.

When truing the barrel, you either have to get two predetermined spots at the chamber end running dead true, (Gordy Method), and ream, or true the muzzle and a predetermined spot, (the throat), running dead true, and then single point bore a third spot dead true with these two spots.

All of this while avoiding any stacked tolerances that can crop up in any set-up when attempting to machine a certain fit truly staright with an imperfect section.

As you said, opinions will vary.:D......jackie

Wayne Shaw
06-02-2011, 11:32 AM
Just to add a twist to this topic, I had a solid 22BR reamer a long time ago. Got a new barrel blank from one of the top makers, and the bore was smaller than the solid pilot. Had I not checked before starting, I could have made a real mess of the inside of that barrel. I took the reamer to a friends place, and used his lathe to spin the reamer and I carefully stoned down the pilot to fit.

It happens.

frwillia
06-02-2011, 02:39 PM
Fitch, I taper bore within .003-004 of finish, leaving the reamer's job to do nothing more than produce the final shape and finish in the chamber. That allows the reamer to be inserted a tad past 1/2 way.

That's doubtless the best way, but I don't do it that way.


Also, it is very criticle to get the barrels ID running truly straight with the lathe's axis regardless of which method you use. If you use a floater, and the barrel is not running dead true, the reamer will start to wobble as it encounters spots in the ID that are not true. So, what does this hurt? The subsequent machining operations will not be true with the chamber.

Of course, if you do not use a floater, the chamber will in all likely hood be oversize, as the reamer will bind, and cut oversize, depending on how much clearance the pilot has in the bore.

When truing the barrel, you either have to get two predetermined spots at the chamber end running dead true, (Gordy Method), and ream, or true the muzzle and a predetermined spot, (the throat), running dead true, and then single point bore a third spot dead true with these two spots.

Gordy uses his alignment method, then drills and bores (I don't think he taper bores, but I could be mistaken about that) before reaming. I use his alignment method, then ream using my floating pusher (which you've seen pictures of). I seldom make more than one or two chambers with a reamer, so I don't worry about the reamer wear. So far, I've not had an oversize chamber or eccentric throat doing it this way. But that could be luck too.

I would think that having drilled and bored, absent a muzzle flush, there is an increased chance of catching swarf in the cavern ahead of the reamer and rubbing it (galling), but nobody has mentioned this happening, so maybe it's not an issue.


All of this while avoiding any stacked tolerances that can crop up in any set-up when attempting to machine a certain fit truly staright with an imperfect section.

As you said, opinions will vary.:D......jackie

We agree on that!

Fitch

skeetlee
06-02-2011, 06:01 PM
thanks guys. Very interesting. Kinda off topic but here goes anyway. My FL sizer is sizing my brass on this new barrel we just did .002 at the shoulders. Do you think .002 is to much resizing at this point? I have always had the understanding that .001 resizing at this point was about right? Lee

frwillia
06-02-2011, 07:50 PM
thanks guys. Very interesting. Kinda off topic but here goes anyway. My FL sizer is sizing my brass on this new barrel we just did .002 at the shoulders. Do you think .002 is to much resizing at this point? I have always had the understanding that .001 resizing at this point was about right? Lee

Working with Brass cases is more like trying to do precision cheese slicing. IMO, if you can hit .002" +/- .001" bumping shoulders on fired cases, you are doing great with brass.

Fitch

alinwa
06-03-2011, 01:39 AM
thanks guys. Very interesting. Kinda off topic but here goes anyway. My FL sizer is sizing my brass on this new barrel we just did .002 at the shoulders. Do you think .002 is to much resizing at this point? I have always had the understanding that .001 resizing at this point was about right? Lee

I think it's too much.

I currently run my dies .002 under at the shoulder which produces a sizing effect of around .001 (springback)

But then I'm one of those weirdo's who'll shoot a case 50 times without doing ANYthing to it......

al

alinwa
06-03-2011, 01:40 AM
Fitch, I taper bore within .003-004 of finish, leaving the reamer's job to do nothing more than produce the final shape and finish in the chamber. That allows the reamer to be inserted a tad past 1/2 way.

Also, it is very criticle to get the barrels ID running truly straight with the lathe's axis regardless of which method you use. If you use a floater, and the barrel is not running dead true, the reamer will start to wobble as it encounters spots in the ID that are not true. So, what does this hurt? The subsequent machining operations will not be true with the chamber.

Of course, if you do not use a floater, the chamber will in all likely hood be oversize, as the reamer will bind, and cut oversize, depending on how much clearance the pilot has in the bore.

When truing the barrel, you either have to get two predetermined spots at the chamber end running dead true, (Gordy Method), and ream, or true the muzzle and a predetermined spot, (the throat), running dead true, and then single point bore a third spot dead true with these two spots.

All of this while avoiding any stacked tolerances that can crop up in any set-up when attempting to machine a certain fit truly staright with an imperfect section.

As you said, opinions will vary.:D......jackie

friggin' awesome post

al