chambering issues

[Bitteroot]

Myself, I start with the bullet I intend on using and select the appropriate finish reamer with the appropriate freebore for my application.
If the smith doesn't have that, I move on to another smith or better yet buy my own reamer for a couple hundred dollars and send that along with the barrel to my smith. Assuming he has the go and no go gauges I might need to purchase those as well but from that point on my brass and dies are all matching.

7 PRC AW

7 PRC AW Live Pilot High Speed Tool Steel Finish Chamber Reamer Print #7 PRC AW .318-.319 Neck, Freebore length .2333, freebore diameter .2852, Base diameter .535 Uses headspace gauge #3440 7mm PRC SAAMI

www.jgsprecision.com

 

[jseandsje]

Sounds like he throated it for the bullet that he thought you wanted it to be for when you should have and him chamber for the longer bullets and take what you get for the others.

I'd say build the round you want and send it back to him so he can throat it to the new specs.

I'm with bigngreen on building a round.

Make sure it feeds reliably from the magazine then take to gunsmith

Bigngreen kinda simplifies the confusion.

 

[voodoo21]

Update. Bought a box of factory eldx. The coal was 3.291 they chambered flawlessly. Since then my modified case came in. Nosler partition to lands is 3.200 coal, 2.669 cbto

 

[bigngreen]

What is the factory eldx cbto?

 

[82nd Bill]

Lots of good input on this post and it does seem to be either a HS issue with the case, shoulder which does not sound like the issue as the GS fired test rounds from the GS chambered. I assume you tried to chamber those cases to be sure, If not you should. You really should purchase the Hornady seating depth gage for all of your COAL and CBTO measurements. You will use it a lot..

So with that out of the discussion it seems to come back to seating depth and the bullet being jammed into the lands. and that is an easy fix for him. As has been mentioned several times above you need to send a dummy round for the hunting load and the target load and let him know what jump you want. Then have a real conversation with him to determine where you want it seated, as each bullet has its own spec and each seats to a different datum point.

 

[pavementends]

I hate to be repetitious but a guy with a sharpie and good light can troubleshoot many feeding issues. I also noticed in one post you had to force the extractor to snap over the case. It is easier to get accurate data if you remove the extractor and ejector and removing the firing pin can help with "feel"

 

[Kmccord]

My method for testing to the lands is to remove the spring loaded extractor and firing pin assembly. This is to allow the bolt to free fall when inserted all the way. Load one long and see if the bolt will drop, if not, seat a little further and try again, keep repeating until the bolt will begin to drop, but if it doesn't drop completely, then start seating the bullet less than before, once the bolt drops with no pressure, then you are at the lands. I do this for each new rifle with the bullet I plan to use.

 

[Bitteroot]

Finding a touch point has never been easier than ordering this simple little tool from PMA.
No more bolt stripping, no more barrel off or L&L tool fiddling to get the same number.
This works perfect each time in just seconds.

Touchpoint Seating Depth Tool - BR/308 Caseheads

The highest quality, most innovative reloading tools and shooting supplies for precision riflemen. Unparalleled customer service. Shop Now - PMA Tool

www.pmatool.com

 

[FEENIX]

Update. Bought a box of factory eldx. The coal was 3.291 they chambered flawlessly. Since then my modified case came in. Nosler partition to lands is 3.200 coal, 2.669 cbto

As I noted in #2, I use CBTO instead of COAL.

(SOURCE: https://bergerbullets.com/wp-content/uploads/2013/03/COAL.pdf)

Good luck!

 

[FEENIX]

Finding a touch point has never been easier than ordering this simple little tool from PMA.
No more bolt stripping, no more barrel off or L&L tool fiddling to get the same number.
This works perfect each time in just seconds.

Touchpoint Seating Depth Tool - BR/308 Caseheads

The highest quality, most innovative reloading tools and shooting supplies for precision riflemen. Unparalleled customer service. Shop Now - PMA Tool

www.pmatool.com

Agreed, there are plenty of new tools out there these days to make life easier for us. On my last custom build, because I have all reamers, my GS made me this handy tool.

 

[Bitteroot]

Agreed, there are plenty of new tools out there these days to make life easier for us. On my last custom build, because I have all reamers, my GS made me this handy tool.
View attachment 748690
View attachment 748691
View attachment 748692

I have both and the Gizzy works great, especially for setting up a shoulder set back and initial touch point but the threaded case for the L&L tool can be subject to interpretation as the throat wears. Both do the job of course but Pats little invention eliminates that bit of uncertainty or subjectivity as you can feel the slightest bit of bullet touch to the thousandth for those that record wear or adjust seating depth accordingly .

 

[FEENIX]

I have both and the Gizzy works great, especially for setting up a shoulder set back and initial touch point but the threaded case for the L&L tool can be subject to interpretation as the throat wears. Both do the job of course but Pats little invention eliminates that bit of uncertainty or subjectivity as you can feel the slightest bit of bullet touch to the thousandth for those that record wear or adjust seating depth accordingly .

Agreed! The key is understanding the task at hand and using the applicable tools. With the tool my GS made, I do not need the LNL tool because it is the same as my rifle's chamber. It is perfect, no. But yes, as the throat wears, one must adjust accordingly. I have an Excel tracking log for this type of pertinent information. Cheers!

 

[dballsmithda3rd]

You need more freebore than that. I think that chamber/throat was cut too short. I'd send it back in to get it properly reamed. You will not lose any precesion potential by allowing proper freebore. This will also help with pressure issues.

 

[voodoo21]

As I noted in #2, I use CBTO instead of COAL.
View attachment 748688
View attachment 748687
(SOURCE: https://bergerbullets.com/wp-content/uploads/2013/03/COAL.pdf)

Good luck!

Normally I do use cbto measurements instead of coal. In this case in particular I haven't shot the rifle yet. I'll shoot the factory eldx this weekend. Also I have some ablr and eldx bullets on the brown truck waiting to arrive. Playing with the couple bullets I have the specs are as followed

185 gn Nosler rdf distance to lands is 2.527 cbto. Loaded 0.020 off the lands would be 2.507 cbto, 3.185 coal

175 Nosler partition 2.669 cbto to lands
3.200 coal to lands

And as stated bought a box of factory eldx coal was 3.291 and chambered flawlessly.