Sticky/stuck Bolt Troubleshooting

[tahoe1305]

I reviewed a few of the past threads on this and am not sure I've found my exact solution yet.

Curious to the groups thoughts on my issue. Facts below:

-built a new CF 7 WSM off a savage SA. Have roughly 100 rounds down it. Half factory loads. Half virgin brass (non sized before loading) hand loads. And about a dozen sized second firing loads (where problem is).

-factory loads shot great a little bit of a sticky bolt on some but nothing that worried me.

-the virgin brass (Hornady) pressure work ups to alliants max pressure for RL26 (71.2 published) I got to 69.2gr before I saw a light ejector swipe and slightly heavier bolt lift. I backed off to 68.8 and shot 20 rounds all great no issues no pressure signs.

-I bought Forster FL Die set and used a RCBS shell holder. I cut all once fired brass to 2.095" (max is 2.10" trim is 2.09").

-I noticed on FL sizing the unloaded cases wouldn't chamber smoothly when the die was fully seated against the shellholder (per instructions). Research showed likely a mismatch issue with RCBS vs Forster (they only use universal holders with theirs press from what I can tell).

-I shaved .002" off the top of shellholder allowing the clearance to fully size the back of the case and it chambered perfect.

- I prepped mouths. Loaded from 68.3 to 68.8 to double check pressure with the sized brass.

- Started at 68.3 at the range. Roughly same velocity as with virgin brass (20fps more but 80 rnds through). BUT very heavy bolt lift (almost needing mallet).

-switched to factory load. No issue. Switched to original 68.8 virgin brass. No issue. Then back to 2nd shot handloads. Heavy again.

-Came home rechecked headspace using go/no go. Good.

-checked shoulder using comparator and the Hornady modified case(for COAL measurements) measured 3.972", once fired measured 3.971-.973", twice fired same, and FL resized measured 3.965".

-measured OAL of fired brass and it was roughly 2.105" (.01" growth from sizing/cutting).

So initial thought was a pressure issue. But would be a bit weird using less powder than original load and getting similar velocities, but haven't ruled it out.

Other thought is something with my Die setup. I find it a bit weird it is sizing the shoulder back .07" (never measured on any other round so not sure that's normal for FL die). Also find is a bit strange to see .01" case growth with one firing. Maybe related?

Thinking the next step is to load down to maybe 67 and work up from there BUT like many, pretty low on my CCI250 primers and hate to blindly troubleshoot and waste some not knowing when more will be had.

Appreciate the teams thoughts.

 

[Dmagna]

Did you clean your barrel at all?

 

[tahoe1305]

Did you clean your barrel at all?

Barrel and chamber have been cleaned many times. Normal break in procedure cleaning. For first 50 rounds or so. And cleaned after every time after the range since then.

 

[Dmagna]

I have had the same problem before, I have had left over cleaning product in the barrel or chamber. Ruins brass, then will instantly copper foil your barrel. Try loading a few fouling rounds at 3 grains lower than your load then shoot your specific load and see if it still does it. I have to do this with my 300 prc, or the bolt will have to be hit with a hammer if I leave any oil in the chamber at all.

 

[tahoe1305]

I'll give it a try. Only concern is after I noticed the issue I shot some factory stuff and it shot fine with normal lift.

 

[1000yards]

I have had the same problem before, I have had left over cleaning product in the barrel or chamber. Ruins brass, then will instantly copper foil your barrel. Try loading a few fouling rounds at 3 grains lower than your load then shoot your specific load and see if it still does it. I have to do this with my 300 prc, or the bolt will have to be hit with a hammer if I leave any oil in the chamber at all.

Ditto on the lube. Same issue on my 7wsm. Racked my limited brain for awhile until finally REALLY cleaning cases after sizing. Problem went away

 

[tahoe1305]

So the lube could be it for sure. Would make sense why virgin and factory didn't have issues. I'll do both and give it a shot.

I'll re-tumble.

****before I threw in the once fired brass to tumble just now measured a handful and all were total length under 2.10" vs the re-sized and fired at 2.105". *****

 

[LongBomber]

If lube isnt your problem, your die is likely not sizing the base of the case down enough. You are pushing your shoulder back pretty far, most seem to go for a .002" bump, you are around .007".
How does a resized case (empty) chamber and bolt lift/eject?

 

[tahoe1305]

If lube isnt your problem, your die is likely not sizing the base of the case down enough. You are pushing your shoulder back pretty far, most seem to go for a .002" bump, you are around .007".
How does a resized case (empty) chamber and bolt lift/eject?

So messed with die some more tonight also thinking .007" is too much. I backed die out and set .002". They appeared to chamber just fine a very slight but comfortable amount of bolt tension......then I got a case stuck....fml.

that said I measured back by case head and it was .01" bigger than my factory round (using caliper not micrometer). So now like your saying not sure if it isn't sizing far enough down and/or if that's not sign of too much pressure (likely).

 

[LongBomber]

There is a thread on the 6.5 prc dies on here, same issue seems to be happening with several cartridges. Not being able to squeeze the bottom section of the case down enough to chamber correctly.

So messed with die some more tonight also thinking .007" is too much. I backed die out and set .002". They appeared to chamber just fine a very slight but comfortable amount of bolt tension......then I got a case stuck....fml.

that said I measured back by case head and it was .01" bigger than my factory round (using caliper not micrometer). So now like your saying not sure if it isn't sizing far enough down and/or if that's not sign of too much pressure (likely).

 

[tahoe1305]

There is a thread on the 6.5 prc dies on here, same issue seems to be happening with several cartridges. Not being able to squeeze the bottom section of the case down enough to chamber correctly.

Good to know I'll look at those.

I was starting to think after checking lube issues, pressure, I would attempt to fix the .007 shoulder bump (if I can with my die and still size it enough to chamber) to see if that fixes it.

 

[L.Sherm]

Its likely a die to chamber issue with the brass not being sized back enough at the base.

 

[Beluebow]

Have you tried measuring at the .200 line on your brass?...I think this is where you will possibly find the issue.

 

[tahoe1305]

I did. On my factory Hornady rounds it measured .550".

On my once and twice fired rounds it measured .560" (I will double check those when I get home).

The resized rounds I have been working are measuring the same there .560". But they are chambering ok now. (Haven't fired to see if there is a heavy lift again).