Chamber Honing Questions

Horvik

Member
Joined
Jul 7, 2017
Messages
65
Reaction score
5
Points
8
Hello;

On my 338 Lapua Magnum reloads, it takes a bit of effort to eject cases after firing. it is no problem to eject the same round prior to firing. i carefully resize my cases and check of O.A.L. of the case.
My question is would it do any good (Or harm) to use a chamber hone to try to "polish up" the chamber walls? Your thought are appreciated.
All the best

 

Horvik

Member
Joined
Jul 7, 2017
Messages
65
Reaction score
5
Points
8
Broz;
By shank, do you mean the threaded portion that goes into the receiver? If so I would have to check.
 

Diverjeff

Well-known member
Joined
Mar 20, 2019
Messages
1,165
Reaction score
988
Points
113
Location
Corona,CA
Hello;

On my 338 Lapua Magnum reloads, it takes a bit of effort to eject cases after firing. it is no problem to eject the same round prior to firing. i carefully resize my cases and check of O.A.L. of the case.
My question is would it do any good (Or harm) to use a chamber hone to try to "polish up" the chamber walls? Your thought are appreciated.
All the best
I have the same issue with my 338LM and due to(I believe)my shank being 1.200" had to back off a bit on my powder charge.I have almost 500 rounds through it(100 factory Bergers and 400 reloads)and as long as I keep using my current charge of 88.5 grs. of H1000 behind a Berger 300 gr. OTM extraction isn't a problem(very slight pressure at the top of the bolt lift but not really a bother),any higher charge weight than that and bolt lift becomes difficult.As for the shank question,I believe the threaded portion of the barrel is referred to as the "tenon" and the actual shank is the area in front of the tenon as both Gordo and Broz stated. (y)
 

Horvik

Member
Joined
Jul 7, 2017
Messages
65
Reaction score
5
Points
8
The measurement I got is 1.230. Here is a pic of the rig.
 

Attachments

  • AR_30.jpg
    AR_30.jpg
    398.6 KB · Views: 44

Horvik

Member
Joined
Jul 7, 2017
Messages
65
Reaction score
5
Points
8
So guys, any further ideas as how to correct this problem?
 

Willys

Well-known member
Joined
Nov 27, 2022
Messages
1,033
Reaction score
780
Points
113
Your load may be too hot. What makes you think it isnt?

Usually chamber hone is needed when you can’t get a die to size your brass small enough and you get clickers at the top of bolt extraction.
 

Horvik

Member
Joined
Jul 7, 2017
Messages
65
Reaction score
5
Points
8
I am shooting in the middle of the recommended grain range according to lyman , hornady too.
 

Willys

Well-known member
Joined
Nov 27, 2022
Messages
1,033
Reaction score
780
Points
113
I’d measure sized case size vs fired case size at different spots like .400 up from base. You hope to see the sized case .002 smaller. If not get smaller die or make chamber bigger. Also make sure brass is trimmed enough ( can look from muzzle with borescope)

I have one that was .000-.0005 difference between sized and fired and clickers were bad. I tried a few different dies and got one to work but still some clickers - honed chamber a bit and got better. Need to hone a bit more. Honing = 320 grit sandpaper in slotted wood dowel and cordless.
 
Last edited:

Broz

LRO Owner~Editor~Long Range Hunting Specilist
Joined
Apr 17, 2013
Messages
15,438
Reaction score
11,728
Points
113
Location
Foot of the Big Belt Mountains near Townsend MT.
Sounds like it has a 1.250" shank. That's good. If there is no visible signs of the chamber being "ringed" when it was chambered and producing rings on the fired cases causing them to stick. Then try bumping the shoulder back to at least .004" maybe .005" of head space. If that doesn't work then polish the chamber. Concentrate on the area above the web (.200" line) in hopes of opening up the chamber so the dies will "size more".
 

Diverjeff

Well-known member
Joined
Mar 20, 2019
Messages
1,165
Reaction score
988
Points
113
Location
Corona,CA
Broz and Willys,

I may need to do this also(I have the CA MPR in 338LM and believe I have a 1.200" shank).
Measuring a fired case above the web(.200"-.400")I get .585",and after full length sizing(Redding Comp. die and Redding shellholder)with a .002"-.003" shoulder bump and firm camover I still end up with .585"(according to SAAMI the chamber dimension should be .587" but I have no way of measuring this).This is also with 1-3 times fired virgin Lapua brass and trimmed to SAAMI spec length using a fairly mild load of 88.5 grs. of H1000 so I wouldn't think I'm having springback or elasticity issues with the brass.As it is I'm having very light clicker issues and using a firm bolt lift will pop it right open but it would be nice to totally do away with the clicker issue.When polishing the area above the web with a split dowel and 320 grit is it pretty much a trial and error process going back and forth from the range until the problem is fixed(so I don't chance removing too much chamber metal if I'm shooting for only .001" or so)?

Thanks guys,
Jeff
 

Willys

Well-known member
Joined
Nov 27, 2022
Messages
1,033
Reaction score
780
Points
113
I’d measure sized case size vs fired case size at different spots like .400 up from base. You hope to see the sized case .002 smaller. If not get smaller die or make chamber bigger. Also make sure brass is trimmed enough ( can look from muzzle with borescope)

I have one that was .000-.0005 difference between sized and fired and clickers were bad. I tried a few different dies and got one to work but still some clickers - honed chamber a bit and got better. Need to hone a bit more. Honing = 320 grit sandpaper in slotted wood dowel and cordless.
Broz and Willys,

I may need to do this also(I have the CA MPR in 338LM and believe I have a 1.200" shank).
Measuring a fired case above the web(.200"-.400")I get .585",and after full length sizing(Redding Comp. die and Redding shellholder)with a .002"-.003" shoulder bump and firm camover I still end up with .585"(according to SAAMI the chamber dimension should be .587" but I have no way of measuring this).This is also with 1-3 times fired virgin Lapua brass and trimmed to SAAMI spec length using a fairly mild load of 88.5 grs. of H1000 so I wouldn't think I'm having springback or elasticity issues with the brass.As it is I'm having very light clicker issues and using a firm bolt lift will pop it right open but it would be nice to totally do away with the clicker issue.When polishing the area above the web with a split dowel and 320 grit is it pretty much a trial and error process going back and forth from the range until the problem is fixed(so I don't chance removing too much chamber metal if I'm shooting for only .001" or so)?

Thanks guys,
Jeff
I just polished a bit, took a couple shots, polished a bit more. Maybe with pin gages you could measure progress…..
 

Diverjeff

Well-known member
Joined
Mar 20, 2019
Messages
1,165
Reaction score
988
Points
113
Location
Corona,CA
Thanks Willys,

I think that's what I'll do then.Do you use wet/dry emery and lubricate it when honing or?Would it hurt to run it back and forth a bit(staying well away from the shoulder area)or just concentrate on the first .500" above the web area?It may take me a few tries,range is 100 miles round trip. :D
 

Willys

Well-known member
Joined
Nov 27, 2022
Messages
1,033
Reaction score
780
Points
113
I put some kroil ( cuz it was handy) on it . Id concentrate on bottom inch - you don’t want to balloon the middle.
I would do it at your range site. Just take a cleaning tools and can or 2 of brake cleaner - and calipers and box of ammo.
 

Diverjeff

Well-known member
Joined
Mar 20, 2019
Messages
1,165
Reaction score
988
Points
113
Location
Corona,CA
I do have some Kroil here and will just work on the first inch a little,shouldn't take much and should be easy enough to clean up at the range like you said. (y)

Thanks Willys
 

Horvik

Member
Joined
Jul 7, 2017
Messages
65
Reaction score
5
Points
8
I also checked the spent rounds discussed here and they are S & B brass , three times fired.
 

Horvik

Member
Joined
Jul 7, 2017
Messages
65
Reaction score
5
Points
8
Sounds like it has a 1.250" shank. That's good. If there is no visible signs of the chamber being "ringed" when it was chambered and producing rings on the fired cases causing them to stick. Then try bumping the shoulder back to at least .004" maybe .005" of head space. If that doesn't work then polish the chamber. Concentrate on the area above the web (.200" line) in hopes of opening up the chamber so the dies will "size more".
Broz;

Can you explain what you mean by visible signs of the chamber being "Ringed"? Will also carefull check the fired cases.
Thanks
 

Gord0

Well-known member
Joined
Feb 11, 2017
Messages
1,464
Reaction score
1,569
Points
113
Location
Michigan
Broz;

Can you explain what you mean by visible signs of the chamber being "Ringed"? Will also carefull check the fired cases.
Thanks
You'll see a ring around the brass that is slightly raised. There will be a corresponding indent in the chamber. Usually from a chip stuck on the reamer.
 

Broz

LRO Owner~Editor~Long Range Hunting Specilist
Joined
Apr 17, 2013
Messages
15,438
Reaction score
11,728
Points
113
Location
Foot of the Big Belt Mountains near Townsend MT.
Broz;

Can you explain what you mean by visible signs of the chamber being "Ringed"? Will also carefull check the fired cases.
Thanks
This is a severe example of a chamber that was "ringed" during the chambering process. It usually happens just below the shoulder. But if Defensive Edge did the chamber, and knowing what I do about the quality of work from Defensive Edge does. I would be very surprised if this was the issue.

IMG_20171026_122559956.jpg
 

Horvik

Member
Joined
Jul 7, 2017
Messages
65
Reaction score
5
Points
8
Took chamber and brass pictures for examination.
 

Attachments

  • 338LapuaMag2023-07-06_13-36-14-37.jpg
    338LapuaMag2023-07-06_13-36-14-37.jpg
    19.4 KB · Views: 44
  • LapuaMag2023-07-06_13-36-05-87.jpg
    LapuaMag2023-07-06_13-36-05-87.jpg
    20.3 KB · Views: 43
  • IMG_20230706_132900_2.jpg
    IMG_20230706_132900_2.jpg
    143.3 KB · Views: 44

Horvik

Member
Joined
Jul 7, 2017
Messages
65
Reaction score
5
Points
8
Did you try bumping the shoulder back .004" to .005" as I earlier suggested?
I believed I initially bumped the shoulder back to that amount using the 8 Redding Competition Shellholder along with mild camover on the Big Boss I am using. I am going to have to revisit the procedure in its entirety. I watched and followed your video, but this Armalite bolt when you remove the spring the handle comes with it, so have to make a workaround.
I could not download the original pictures, had to resize them to get it to download here.
 

Alex Wheeler

Well-known member
Joined
Jul 11, 2017
Messages
777
Reaction score
2,650
Points
93
Location
Dillon, Mt.
You say bit of effort to eject, need more detail. Is the bolt lift heavy? If so is it heavy from the bottom up or just at the top of lift? If its not heavy and the bolt lifts all the way to the top is the bolt hard to pull back?
 

Horvik

Member
Joined
Jul 7, 2017
Messages
65
Reaction score
5
Points
8
You say bit of effort to eject, need more detail. Is the bolt lift heavy? If so is it heavy from the bottom up or just at the top of lift? If its not heavy and the bolt lifts all the way to the top is the bolt hard to pull back?
Bolt is heavy from the bottom up.
 

parshal

Active member
Joined
Dec 20, 2017
Messages
257
Reaction score
214
Points
43
I wouldn't hone anything. Use 0000 steel wool wrapped around a wooden dowel on a drill. It won't take more than 4-5 seconds. You can do it dry. If any imperfections are not resolved by that you're not going to be able to fix it yourself. You run the risk of changing chamber dimensions too much.

If it's really bad they'd need to set the chamber back a thread or two and clean it up.

Alex can certainly weigh on the above but I'd do no more than that.
 

Alex Wheeler

Well-known member
Joined
Jul 11, 2017
Messages
777
Reaction score
2,650
Points
93
Location
Dillon, Mt.
Bolt is heavy from the bottom up.
A 400 grit finish is a very common finish but unless your chamber is very rough I dont think its the problem. You want to make sure your cases are clean, no lube on them and the chamber is dry and clean. No oil or solvent. Also make sure your bumping the shoulders at least .003" If your seeing ejector marks then you do have real pressure. Poor lug contact or bolt faces that are not flat can give heavy lift as well. But extraction timing and bad sizing dies can be ruled out for this problem.
 

Horvik

Member
Joined
Jul 7, 2017
Messages
65
Reaction score
5
Points
8
A 400 grit finish is a very common finish but unless your chamber is very rough I dont think its the problem. You want to make sure your cases are clean, no lube on them and the chamber is dry and clean. No oil or solvent. Also make sure your bumping the shoulders at least .003" If your seeing ejector marks then you do have real pressure. Poor lug contact or bolt faces that are not flat can give heavy lift as well. But extraction timing and bad sizing dies can be ruled out for this problem.
Alex;

Can you elaborate a little bit on what you mean by "seeing ejector marks" ?

All the best
 

RustyInOR

Member
Joined
Nov 25, 2021
Messages
60
Reaction score
58
Points
18
I have a chamber honing brush from Brush Research for each of my long range chambers (6.5CM, 300WM, 300PRC, 300NM and 338LM), and a jug of their honing oil. I hone per the directions on every new chamber, or if things "tighten up" like the OP describes, and I do a brief proactive hone after 500-ish rounds down range when I do a deep-cleaning of the bore. That's always gotten me good results, so as long as it works ... I'll keep doing it. Note ... I never hone without lots of oil, and I don't exceed about 30 seconds with the drill set at the correct RPM.
 

Horvik

Member
Joined
Jul 7, 2017
Messages
65
Reaction score
5
Points
8
After reading all the comments relative, i am at the ready to do the honing I believe.

 

Forum Sponsors

Top