Stuck case in chamber

[DHBWA]

Velocity-To-Charge Ratio: A Good Way To Work Up Safe Loads

A couple of situations have occurred recently that reminded me of the fact you can always learn--or relearn--something new and significant related to safe handloading practices. I thought I'd share them with you.

www.shootingtimes.com

 

[BearDog]

Velocity-To-Charge Ratio: A Good Way To Work Up Safe Loads

A couple of situations have occurred recently that reminded me of the fact you can always learn--or relearn--something new and significant related to safe handloading practices. I thought I'd share them with you.

www.shootingtimes.com

Thank you! That's what I was after.

 

[hunter0528]

Just another thought. Are you loading one at a time or utlizing the magazine. Could the bullets be backing out from firing? Are the bullets just seated or crimped?

 

[Its204fast]

I have a 7MM RM and had the same problem, FL sized, cases would chamber fine, extracting the fired case was a nightmare. when I finally got the case out, it had swipe marks from the bolt turning on the face. I chalked it up to BELT BULGE. I have heard if you have a micrometer or caliper that measures out to .0001 you can measure it. Previously the cases were Neck sized, i noticed some tension opening the bolt so i went and FL sized them, finally I pulled the 10 i had loaded, deprimed the unfired primers and trashed the cases. When the barrel is done on this rifle I'm rechambering for something not belted in the .284 family.

 

[wbm]

The belt is not the problem.

 

[smokepoler]

My two cents, chasing loads with brass fired in another chamber, even one cut with the same reamer. As others have posted, use new brass.

 

[DHBWA]

Using new brass is never a bad idea but if the used brass chambers effortlessly before firing it rarely ( never for me) is/should be hard to extract after firing unless you have other issues (over pressure or chamber dimension)

 

[Tiny Tim]

Using new brass is never a bad idea but if the used brass chambers effortlessly before firing it rarely ( never for me) is/should be hard to extract after firing unless you have other issues (over pressure or chamber dimension)

I would only add that if it also extracts effortlessly w/o firing.

 

[antelopedundee]

Let me throw another one at the hive. I made a mistake referring to my measurements earlier. My average Chamber length was 2.890 (case length to ogive). I loaded all my rounds to 2.850 (ogive). That would give me .040 off lands...not the .005 like I had thought. Guess that's why you keep notes.
I've added a photo with the primers and charges. You can see there is some flattening, I just don't really believe that it is significant enough that I should be concerned with the pressure at 70grains. Again this yielded the best group at about .5moa. Could slight flattening be an indication of excessive head space? It's still closer to the lands than factory ammo, but with higher charge, I'm wondering if this could be a culprit to the stuck case at 70.5g, and if my 70g load, which shot great and had no extraction issues, should even be a concern at all?

Those primers don't look all that flat to me. I've seen some that fill the primer pocket to the point where they get a small rim on them. Be interesting to see the spent primer from 70.5 grain round.

I was out today and had some test loads of 6.5-06AI with 62 grains of H1000 a Federal 210 primer and a 30 grain Sierra GameChanger bullet. The first shot had that feel to it that you sense when the load is getting near max. I shot 6 shots with the primers ending up looking a lot like the ones in your pic. I was always told that Federal primers were down there with CCIs as far as softness goes. There is a faint ejector mark in the first 2 cases; one near the R and the 2nd between the 0 and W. The ejector marks pretty much went away after the second round which is sort of weird tho the 4th case from the left could have one by the N in WIN. Then again Nosler brass is on the soft side so the ejector marks don't necessarily indicate a problem.

 

[PBR driver]

I recently had a proof barrel put on my .300WM Sendero. I'm working on developing a load, and have yielded good results from 70gr of IMR4831, with a Nosler AB 180gr. In fact that is the same recipe for the weapon prior to adding the new barrel.

Here is my "hmmmm" moment. I had no indication of over pressure from that build. No bulging, cracking, sticking, and primers looked good. HOWEVER...when I went up to 70.5 during my test, my case was stuck and I had to try quite a few times to get the bolt to latch on and extract. This was the same for all of the rounds loaded at 70.5. At 71 gr I had to use a rod to get it out. I tested it again with a factory load and had no issues with extraction. All my cases are full length sized and under max case length. Bullet is seated .005 off lans. The max load for that powder is 73.

Why this worries me is if I'm getting stuck with a .5 gr increase going 70 to 70.5, is 70gr too risky to use when hunting? I was lucky enough to draw a moose tag for my home state and can't have a stuck case screwing that up. I don't know if temp changes will impact the material enough to where even the expansion for my 70gr charge will cause the case to stick. Could it be something else??

When you changed barrels you changed everything. You can not just pick up where you were before on your old BBL.
Every reamer when used gets smaller making it a tighter chamber and your bore may very well be tighter.
If you fire factory ammo through your new BBL you can take the case expansion measurements and use this as your base line by using a 0.0001" micrometer.
In hand loading as you work up from the minimum load, which you should do when changing the BBL.
measure your case expansion with a 0.0001" micrometer.
When you have achieved the same case expansion as your factory loads then in your chamber with your components you have found the maximum load in your chamber with your components.
Hope this can help you, good luck.

 

[MTtimberline]

This is the way I find the lands. I used to do the dummy round and comparator however I was finding lots of discrepancies. I started using Alex's method and it is very consistent. Give it a try and see if it changes things for you.



Jayson

Thanks for posting . I will have to give this a try.