5 degree lead

skeetlee

Active member
After talking with JGS yesterday the fella recommended I buy his 22LR match reamer. Looking at the specs this reamer has a 5 degree lead. All the chambers I’ve ever cut and had success with were 1.5 and 2 degree. I haven’t even heard of a 5 degree lead. Can anyone here shed some light on why one might want the 5 degree lead on a 22 chamber??
 
After talking with JGS yesterday the fella recommended I buy his 22LR match reamer. Looking at the specs this reamer has a 5 degree lead. All the chambers I’ve ever cut and had success with were 1.5 and 2 degree. I haven’t even heard of a 5 degree lead. Can anyone here shed some light on why one might want the 5 degree lead on a 22 chamber??

Howdy skeetlee,

I've never heard of a 5 degree leade either. Calfee has obviously built a lot of record setting rifles with a 2 degree. You could always experiment.......but you may end up with a reamer you won't use again as you cut the tenon off and start over. Any chance it's a mistake on the specs? Everyone is human and can make a mistake.

Take care,

Greg
 
After talking with JGS yesterday the fella recommended I buy his 22LR match reamer. Looking at the specs this reamer has a 5 degree lead. All the chambers I’ve ever cut and had success with were 1.5 and 2 degree. I haven’t even heard of a 5 degree lead. Can anyone here shed some light on why one might want the 5 degree lead on a 22 chamber??

Hey Lee, I just saw your email as I was catching up and responded with my thoughts. Hopefully that helps and if need be, reach out anytime.

MB
 
Lee, I don't even think it's possible to get 5deg. Stick with 1.5-2 where the preponderance of good match rifles are.
 
I’m going to guess it is a matter of perspective.
The included angle of a 1.5 and 2 degree reamer is 3 & 4 degrees respectively.
Which makes me think 5 degree is the included angle of the reamer or a 2.5 degree lead.
 
After talking with JGS yesterday the fella recommended I buy his 22LR match reamer. Looking at the specs this reamer has a 5 degree lead. All the chambers I’ve ever cut and had success with were 1.5 and 2 degree. I haven’t even heard of a 5 degree lead. Can anyone here shed some light on why one might want the 5 degree lead on a 22 chamber??

For years the ".22LR Match" chamber" had a 5 degree lead. The steeper angle meant a shorter lead.

Back in the day they seemed to shoot well. I'm sure there are many rifles with the 5 degree lead chambers and the owners are perfectly happy with them.

Many reamer makers still offer these and may have them available on hand.

They haven't been popular with the bench rest crowd since the BR 50 days.

Changing the subject slightly. Have you ever tried to measure a chamber reamer to see if it is actually a 2 degree lead or something else?

Not easy to do. Whatever the maker marked it? It is! And I for one can't prove different.

TKH

PTG22lrreamerspecs.jpg
 
Last edited:
In my infinite wisdom (which means none), when I had JGS make my first reamer, I had them make it at 1' 45" thinking why not split the difference and see what happens since I planned to shoot Lapua and Eley. Most theories at the time had Lapua better at 1' 30" and Eley at 2'. As Tony says, other than making me feel good that it says 1' 45" on the print, I have no idea what it is. It seems to shoot just fine. I suspect the bigger factor using a reamer is concentricity to the bore when used and how the chamber is finished after using it than half a degree of lead.

The only way I would be confident I was getting a true 2 degree is with a CNC and a boring bar. I would think even with a manual lathe and boring bar the margin of error could have you well on both sides of it at that degree.
 
+/- 15 minutes

JGS’ stated tolerance for the angle is +/-15 minutes.
Which I’d be surprised isn’t checked on an optical comparator prior to shipping.
Or a CMM. (Probably a PitA)
Or a high end camera system. They are pretty sweet.
 

Attachments

  • BFB9AE6C-2578-4BB5-A4E3-0CFAD896C288.jpeg
    BFB9AE6C-2578-4BB5-A4E3-0CFAD896C288.jpeg
    203.2 KB · Views: 178
I have the reamer coming. it will be here on Monday just not sure if I should keep it or send it back change is hard on this old boy. LOL I have heard that this reamer design does in fact shoot well. extraction is supposed to be a plus with this design also I chamber more NRL type 22 rifles than I do benchrest but no matter I want everything that leaves my shop to be as accurate as possible. Thanks for sharing and I hope everyone is doing well. Lee
 
Lee, on a side note. I spent approx 20 years of my life on Lake Shelbyville about every weekend. My parents had a houseboat at Lithia. Those were the good ole' days. Was through Mattoon almost every weekend. Lots of good folks in that area.
 
In my infinite wisdom (which means none), when I had JGS make my first reamer, I had them make it at 1' 45" thinking why not split the difference and see what happens since I planned to shoot Lapua and Eley. Most theories at the time had Lapua better at 1' 30" and Eley at 2'. As Tony says, other than making me feel good that it says 1' 45" on the print, I have no idea what it is. It seems to shoot just fine. I suspect the bigger factor using a reamer is concentricity to the bore when used and how the chamber is finished after using it than half a degree of lead.

The only way I would be confident I was getting a true 2 degree is with a CNC and a boring bar. I would think even with a manual lathe and boring bar the margin of error could have you well on both sides of it at that degree.

Not for nothing but IMHO it's got nothing to do with angle, it's all about depth.
Guys that chamber for specific lots of ELEY, particularly short lots in MI barrels often have issues with long lots of ELEY as well as Lapua. Why do you think the self appointed "great one " used to carry on about demanding ELEY label over all length given bbl's he was/is chambering.
Guys that cut a mid- depth chamber seem to avoid the issue, shoot Lapua pretty well.
 
Not for nothing but IMHO it's got nothing to do with angle, it's all about depth.
Guys that chamber for specific lots of ELEY, particularly short lots in MI barrels often have issues with long lots of ELEY as well as Lapua. Why do you think the self appointed "great one " used to carry on about demanding ELEY label over all length given bbl's he was/is chambering.
Guys that cut a mid- depth chamber seem to avoid the issue, shoot Lapua pretty well.

I don't disagree Tim. I have been between .130 and .145 protrusion trying different things. I don't have a set depth. I check the engraving and see where it is. I had a very successful shooter show me what he thinks works best for engraving so that is what I try to get to. I suspect the chamber isn't what's holding me back in the grand scheme of things.
 
Back
Top