Shoulder bump issues getting bolt to free fall

[Freezebomb]

Have you checked the length of the brass and chamber? does the brass need trimming?

Haven’t checked chamber but oal is 1.554. Normally trim after I size. But this falls into the range for trim length per my notes. (I’m a rookie so bear with me)

 

[Eagle Six]

Nothing on the shoulder but have this rub spot on the two piece I tested.

attached is how far the bolt travels before it stops. Slight push will lower a little but not free fall after the stop at the top.

@6Creed73 that was my suspicion as well. As @Farmerboy78 suggest maybe push that bump a little further with either die or both, check the bolt drop and then compare measurements of the .200 line between the fired and sized brass.

 

[M995]

Don’t have a feeler gage unfortunately but with the cortina…. Screw in to touch shellholder then 1/8 to 1/4 from there to start. Harrell was just past touch

First of all you need a set of feeler gauges in the future. If both of these dies call for for touch then crank in additional amount, you'll put your press in a mechanical lock ( all kinds of problems happen after that ). You need to contact the gunsmith that installed the barrel for reamer specs. This cartridge is a "wildcat", there is no "SAMMI" spec for this ( I should have looked at the cartridge before getting involved )

 

[60723]

I had the exact same issue with BR, Dasher and BRA. Set for minimal headspace when chambered. Easy load and extract but no bolt fall with a stripped bolt and a sized case. Fixed by using a small base body die.

 

[JFrank]

This appears on the surface to be a body sizing issue, i would compare the before and after dimensions at the case shoulder junction and the .200 line just above the web. A couple thousandth difference would be ideal but it doesn’t look like that’s happening.

 

[Freezebomb]

Appreciate all the tips. I’ll be giving these a try. Last dumb question of the night. All the brass that I tested with bumping way too much .005 or more…. Are those safe to shoot and keep in rotation as fowlers? Or pitch em as a sacrifice to brass gods of learning?

 

[JFrank]

Shoot um

 

[Andy Work]

Appreciate all the tips. I’ll be giving these a try. Last dumb question of the night. All the brass that I tested with bumping way too much .005 or more…. Are those safe to shoot and keep in rotation as fowlers? Or pitch em as a sacrifice to brass gods of learning?

You're not asking dumb questions at all.

 

[B Nettesheim]

Try cleaning your chamber out
A good amount of brass can adhere to the walls especially towards the rear

 

[Olde Man]

Take one case that wont fit and trim .025 off the neck and try it again. You can use this case to make your chamber length gauge later. Eliminate the easy one. This post has brought back memorys as I have fallen for all three of these. Short chamber, tight at base and rough chamber.

 

[William Vogel]

Take a piece of fired brass that’s bumped back 0.002 and confirm that the neck diameter is sized back also. Without the bolt installed, push the brass into the chamber. If the brass body and neck is sized to slightly less than the chamber, it should pretty much fall back out when the barrel is inclined vertically. I’d also take a bore scope and look at the end of the brass at the chamber end and confirm that the brass has “growing room”, a gap and no carbon ring. The sharpie marked case shows contact on the shoulder and the body near the case head. I’m wondering how many chambers have been cut with that reamer and if it has worn and needs sharpening. I cut my chambers to 0.000 or -0.001 so that the headspace gauge fits without barrel torque and bolt slightly drags with barrel torqued because new brass is usually just short and won’t stretch on firing. This requires me to machine 0.005 off the top of my shell holders. It would be nice for you to use a headspace gauge and see how the bolt closes.

 

[Coyotefurharvester]

You still haven't said how fired, unsized deprimed brass chambers? Bolt falls closed, bolt has slight resistance just as bolt stops, bolt unable to cam?

 

[gunsandgunsmithing]

Ink the neck/shoulder junction area up and chamber it a few times. Guessing the radius at that junction is slightly different die bushing to chamber

 

[Alex Wheeler]

Defiance cuts their extractor a little too deep which causes it to drag on the case rim. Remove the extractor, degrease and put a couple layers of tape on the bottom side to hold the extractor out a little. I have .010" tape I use for this so it only takes one layer. Standard practice on a defiance. You will never get a free drop out of them otherwise.

 

[Kracken McGraw]

Defiance cuts their extractor a little too deep which causes it to drag on the case rim. Remove the extractor, degrease and put a couple layers of tape on the bottom side to hold the extractor out a little. I have .010" tape I use for this. Standard practice on a defiance. You will never get a free drop out of them otherwise.

Alex would you mind posting a pic of that sometime. I remember you mentioning this before but seeing it would help. Thanks!

 

[Alex Wheeler]

 

[Kracken McGraw]

View attachment 1519921View attachment 1519922

Thank You!

 

[COLT45SA]

Cannot figure out what I’m doing wrong but I have a 6bra with twice fired brass. Brass is lapua 6br. I removed the firing pin and ejector from my bolt and confirms it free falls on its own. Using a sac comparator I measure approximately 1.1250 for the twice fired brass. Confirmed bolt won’t drop. Resized and bumped back .002 and bolt won’t drop. Resized and bumped to .006 for a test and the bolt still would not free drop.

Any ideas on what I’m doing wrong on this? Is the brass need another firing to fireform all the way? Grasping for straws. Appreciate any ideas.

Thanks

Just had problems with one of the two different fresh batches of Lapua 6MM-PPC cartridges neck sized to .262. One batch chambered, the other didn't. Everything seemed to measure well, but on very close visual inspection I found that there was a difference in the point where the shoulder intersected with the cartridge body. The difficulty was resolved with a shoulder bump that replaced the sharp angle intersection with a smoother gentler intersection.

 

[fisherman987]

Just had problems with one of the two different batches of Lapua 6MM-PPC cartridges. One batch chambered, the other didn't. Everything seemed to measure well, but on very close visual inspection I found that there was a difference in the point where the shoulder intersected with the cartridge body. The difficulty was resolved with a shoulder bump that replaced the sharp angle intersection with a smoother gentler intersection.

How did you do that, different die?

 

[Freezebomb]

Defiance cuts their extractor a little too deep which causes it to drag on the case rim. Remove the extractor, degrease and put a couple layers of tape on the bottom side to hold the extractor out a little. I have .010" tape I use for this so it only takes one layer. Standard practice on a defiance. You will never get a free drop out of them otherwise.

This is awesome to know. Was beating my head against the wall but learning a lot in the process so it’s a win in my book. Now to go figure out how to remove the extractor correctly. Thanks, Alex