JGS 1045 Reamer

[turkeynut]

I’m looking to buy a new reamer 6ppc with .268nk, what other changes would you all make to this reamer? I’m planning on shooting 65-68gr Bt on .790 or .825 jacket. Thanks

 

[ELR LVR]

Give yourself .003-.004" over loaded neck dia.
looks like .070" leade - make sure that's what you want for your bullets
Give yourself .002" to .003" over head dia of your brass to prevent clickers
Make sure you want 1.5 deg leade angle, if not call it out.

 

[anschuter2013]

I used that 1045 print as the basis for my .269 neck 6PPC reamer. After letting my gunsmith look it over, he recommended changing the .2433 diameter freebore to .2438 because a lot of flatbase BR bullets are bigger than .2433 at the pressure ring. If you're only shooting boattails, you'll probably be ok with the. 2433. Also, the .060 freebore length might be a bit long if you ever intend to shoot lighter bullets on a .790 jacket. Just my 2 cents.

 

[butchlambert]

I have used it for many many years and wouldn't change anything. Spend your time shooting and learning to read your flags. A few thou on a reamer ain't going to make your barrel into a screamer.

 

[Clancy]

Bare minimum .2436 for freebore diameter. A full thousandths over bullet is even better.

Just my opinion.

 

[anschuter2013]

I wanted a .269 neck so I didn't have to turn my necks so small and remove a ton of brass. Now I skim to clean up and shoot. I don't think I'd like a standard .262 neck diameter. Spend my time shooting, not turning.

 

[Jud96]

Personally I would shorten the trim length to 1.500-1.510”, I ran the 1.525” length with .050FB for a year and never trimmed my brass, but it added .025 to the amount of bullet outside the neck. I now run an 1.500” and trim my brass to 1.485” and it doesn’t grow much. For BT bullets I’d run .050FB and make the FB diameter 0.2437-0.244. I run a 0.269 neck and my next one will be .270-.271 for just a skim turn on Lapua or Alpha brass. When I had the 1.525” length chamber with .050FB 0.244FB dia. I couldn’t run the popular 65-68BT 7-10.5 bullets without them falling out of the case to touch the lands. With my current reamer I can run any BT bullet with any ogive and still have 1/3 or more of the bearing surface in the neck.

 

[turkeynut]

What about .200 line? Would it help to be bigger in that area.

 

[Clancy]

Personally I would shorten the trim length to 1.500-1.510”, I ran the 1.525” length with .050FB for a year and never trimmed my brass, but it added .025 to the amount of bullet outside the neck. I now run an 1.500” and trim my brass to 1.485” and it doesn’t grow much. For BT bullets I’d run .050FB and make the FB diameter 0.2437-0.244. I run a 0.269 neck and my next one will be .270-.271 for just a skim turn on Lapua or Alpha brass. When I had the 1.525” length chamber with .050FB 0.244FB dia. I couldn’t run the popular 65-68BT 7-10.5 bullets without them falling out of the case to touch the lands. With my current reamer I can run any BT bullet with any ogive and still have 1/3 or more of the bearing surface in the neck.

Very important, especially with a .060 freebore.

 

[ShtrRdy]

What's the downside to having a 0.2433" diameter freebore?

 

[David Conder]

I got the same reamer but with .035 fb

 

[turkeynut]

I got the same reamer but with .035

How far down do the 68gr bt seat in the neck?

 

[David Conder]

1/8 to 3/16

 

[David Conder]

Jgs has this reamer on file

 

[DaveTooley]

What's the downside to having a 0.2433" diameter freebore?

Some barrels are larger than .2433". And that's not accounting for any concentricity issues. That means you have lands starting at the end of the neck. NOT GOOD
With the skill set of current day smiths .244" wouldn't be a problem.

 

[ShtrRdy]

Some barrels are larger than .2433". And that's not accounting for any concentricity issues. That means you have lands starting at the end of the neck. NOT GOOD
With the skill set of current day smiths .244" wouldn't be a problem.

Assuming the chamber is cut centered to the bore I was thinking a 0.2433" freebore diameter on a 6PPC chamber with a freebore length of, say, 0.050" would tend to align the bullet with the bore. For this case let's assume the bullet diameter is 0.2430".

 

[Clancy]

@ShtrRdy I’ve said this about 200 times on here, but cute little tolerances are not your friend.

Freebore is freebore. Not guide bore, not alignment bore…. Freebore.

.2436 minimum. No problems, nothin to lose.

 

[DaveTooley]

Everything I've done design wise the last 25 years has been to loosen up tolerances. That leads to consistent performance. Consistent performance leads to improved accuracy. I started with a .261" nk PPC. then it went to .263". Now it's .268". FB's used to be tight, not anymore. I wouldn't order a reamer under .2438". I think one ammunition maker has not done themselves any favors by sticking to the old ways. You can't force precision onto the target.

 

[turkeynut]

So .4402 @ 200 line would be fine if using a custom die or add little extra?

 

[J.J. Coe]

Everything I've done design wise the last 25 years has been to loosen up tolerances. That leads to consistent performance. Consistent performance leads to improved accuracy. I started with a .261" nk PPC. then it went to .263". Now it's .268". FB's used to be tight, not anymore. I wouldn't order a reamer under .2438". I think one ammunition maker has not done themselves any favors by sticking to the old ways. You can't force precision onto the target.

The only 2 changes i did on my 1045 was .269nk, and .2438 on the fb diameter. I think some people think JGS hits the numbers on the print. They're hitting the number within there tolerance, -0 +.0005.
My fbd is actually .244 and the nk is .2694........perfect as far as I'm concerned.