6MBR free bore?

[Fido]

First chamber job for me I have a few questions.
Reamer PTG .269 neck .080 free bore.
I bought a used heavy barrel 1-14 and I think new reamer for 150 Just to practice on. Rem 700 action.

I loaded some 100g and 87g bullets just to see if they would shoot. Was all I had at the moment.
I have read the 14 twist will not stabilize them true fact. I didn't even shoot the 100s.
I was trying to get the bullets to the lands but even the 100g seemed short.

I loaded up some 55g and 60g tonight and there is no way of even getting close to the lands.

What diameter on the reamer will dictate where the free bore stops? I am guessing .2425 ish. Bullets are very close to .243 maybe 1 or 2 Tenths of a thou over .243.

The way I measure the reamer I am getting about .220 of free bore?
I also dropped a bullet down the chamber, barrel off) and measured the distance from the end of barrel to the big end of the bullet. I calculated over .200 as well

Any advice how to measure? Maybe the reamer was marked wrong? anyone have reamer specs. for a .080 free bore?
I eventually plan on buying a 1-8 twist barrel to shoot the 100-105 grainers. I would like to get this reamer figured out first though.
Thanks for any help.
Stephen

 

[Fido]

They say a pick is worth a thousand words.

Measured hear I get .245 not too much of a concern or is it?

This is aprox. .080 from where the brass ends. My brass is 1.550.
measures .2445 no .243 bullet is going to touch hear, unless a reamer will cut a smaller dimension. Maybe a worn out one?

This is where I measure .243 on the reamer it gives aprox. .210" from the end of the brass to this point.

Ya think the reamer is marked wrong? I read on .080 free bore is about middle of the road as far as bullet length/weight. But the .210 measurement has me stumped.
Thanks for any help guys.
Stephen

 

[Forum Boss]

Can't comment on the photos. It's notoriously difficult to measure reamer dimensions with calipers and manual micrometers.

I would send the reamer back to Dave Kiff at Pacific tool and Gauge. First load a dummy round to just touch the rifling if you can. That will help Dave assess whether the reamer dimensions are correct.

FYI, for other readers, this is one reason why I strongly recommend you ALWAYS cut a dummy chamber with a barrel stub first when you receive a new reamer from any source. Don't assume the dimensions are spot on.

 

[sjk]

As noted before me it is difficult to measure reamers or any dimension therof without the use of a comparator especially if the dimension is to a theoretical vertex. The next best way is to turn up a ring with a CSF on the dia. and check the distance in a V block to the face of the ring. Note it. Then open it up to the seconf dia.,CSF again) and read the indicator. Subtract the two indicator readings. This will give you the exact length of what you're checking. A little time consuming but it will tell you all you want to know as far as length/dia. is concerned. Note. It is not effective on a drastic taper dia due to the slop involved but for that length it should work fine.

 

[Fido]

Thanks guys.
Like I said the barrel was used so I didn't really have much of a concern with the dimensions being off. This stuff was just to play with.
I have loaded a few 100g bullets and they are showing the .210 free bore as well so something is wrong hear.

I bought the reamer second hand it didn't look used.
Maybe someone reground it?

I'm not doubting my measurements when I measure the neck I get .269
I plan on buying a 1-8 twist but I would like to get this reamer figured out first.

Stephen