Stuck case in chamber

[BoomFlop]

If he used a Hornady modified case (which is SAAMI spec) the case will head space on the belt. If he is sizing his case based on the shoulder, he can get a drastic different distance to lands. Even more so than an non-belted modified case.

Steve

 

[jdyoung]

If he used a Hornady modified case (which is SAAMI spec) the case will head space on the belt. If he is sizing his case based on the shoulder, he can get a drastic different distance to lands. Even more so than an non-belted modified case.

Steve

If you have a 7.3mm drill bit for the pilot hole and a 5/16"-36 thread tap, you can make your own version of a Hornady Modified Case from brass ( belted mag or otherwise) that you properly Fire Formed.

 

[BoomFlop]

If you have a 7.3mm drill bit for the pilot hole and a 5/16"-36 thread tap, you can make your own version of a Hornady Modified Case from brass ( belted mag or otherwise) that you properly Fire Formed.

I realize that, however, I do not have any indication that the OP made his own from a case fired in his chamber.

Steve

 

[jdyoung]

I realize that, however, I do not have any indication that the OP made his own from a case fired in his chamber.

Steve

Just throwin' out there that there is a diy alternative for the Stoney Point/Hornady Comparator System Modified Case .

 

[DHBWA]

Lots of rabbit trails and misguided information in this thread.....
Here is my recommendation after hand loading for 40 years and probably twice that many hunting rifles.....

Nosler Load Data shows 73.0 IMR 4381 as max with a COAL of 3.330 and 94% load density running 3160 FPS in a 24" barrel. You are below that and longer in COAL. Doesn't mean its not over max in your rifle. What velocities were you getting? Many pressure signs to look for, Not all show up simultaneously. New chamber certainly needs new work-up. Back off and work back up slowly, checking everything in every step along the way. We read about the awesome speeds others are getting and we are often tempted to chase speed rather than accuracy.

 

[BearDog]

Lots of rabbit trails and misguided information in this thread.....
Here is my recommendation after hand loading for 40 years and probably twice that many hunting rifles.....

Yeah, there was a member in here who has some software that computes load percentages, pressure ranges, and whether the load would be considered safe or compressed. I'm loading in .2gr increments starting at 69 and working up through 70. I'll be checking for pressure signs along the way. I'm also using virgin brass and have two groups of three each loaded. One .040 off lands and the other .020. I did not use a fire formed shell and tap it, but used that modified Hornady case and OAL gauge along with a comparator. I never measure my OAL and always go by ogive but it will be longer than SAAMI specs.
I caused a lot of confusion stating that's I loaded it .005 off the lands in my original post when I had it at .040. I don't know why I had that number in my head but that's why I write everything down. I think using brass that had been fired out of my old chamber played a significant role in the initial sticking. I measured the diameter immediately above of the belt on the full sized once fired brass, and it was significantly bigger than the radius on the virgin brass. I think that paired with being as far off the lands as I was caused the over pressure, and I know that 70g is the upper pressure threshold Being .040 off lands in that chamber.
I haven't been loading that long, maybe five years, and I could not figure out what was causing the issue. Glad I raised the question to the group. Learned a lot.

 

[DHBWA]

One more comment. Do not worry about being .005 off the lands. Although I rarely load that close, if they don't kiss they won't stick and unless you are already at max pressure it won't matter....
I bought a Labradar which makes sooooo easy that I chrono every shot. You never wonder.....

 

[257RobertsMan]

Looking at the pic of your primers, there's a lot going on from 69.0grs to 69.5grs and even more up to 70.0 grs. The primers are noticeably flatter and it looks like ejector marks are present. You are at Max or above with this load/chamber. Back off, double check each measurement, double check your scale and cautiously work your load back up as stated as in the advice given by some herein. I once owned a 300 RSAUM that my 308 could almost keep up with! That gun just pressured out way before reaching published book values.

Redo, re-work, go slow carefully, you'll figure it all out and good luck. Just remember this.... if you have heavy bolt lift, hard extractions/stuck cases, stop load development immediately and figure out why! Do not shoot a heavier charge weight of powder!

 

[BearDog]

Looking at the pic of your primers, there's a lot going on from 69.0grs to 69.5grs and even more up to 70.0 grs. The primers are noticeably flatter and it looks like ejector marks are present. You are at Max or above with this load/chamber. Back off, double check each measurement, double check your scale and cautiously work your load back up as stated as in the advice given by some herein. I once owned a 300 RSAUM that my 308 could almost keep up with! That gun just pressured out way before reaching published book values.

Redo, re-work, go slow carefully, you'll figure it all out and good luck. Just remember this.... if you have heavy bolt lift, hard extractions/stuck cases, stop load development immediately and figure out why! Do not shoot a heavier charge weight of powder!

I agree that there is flattening but do you believe any flattening to be bad? I feel that in almost all cases one could expect a certain degree of flattening but at what point do you think it becomes an absolute no go. In regards to my pictures, at 70 do you believe it to be too much? 69.5?
I know I'm seemingly adamant about staying around 70g, but that's because that is my most accurate load, by a long shot.

 

[DHBWA]

It's all about speed....You can tell a lot when you know the speed.........

 

[257RobertsMan]

I agree that there is flattening but do you believe any flattening to be bad? I feel that in almost all cases one could expect a certain degree of flattening but at what point do you think it becomes an absolute no go. In regards to my pictures, at 70 do you believe it to be too much? 69.5?
I know I'm seemingly adamant about staying around 70g, but that's because that is my most accurate load, by a long shot.

If you have heavy bolt lift, extraction problems, flattened primers, ejector marks/swipes.... they are over pressure indicators!!! BACK OFF!!!

There are several indicators of over pressure and one by itself my not indicate that you are at Max or already over MAX, but you very well could Be!

To be safe, reduce your load, double check and double measure everything; powder, scale, primers, case measurements (before & after), chamber measurements, etc! Keep notes, be meticulous!! Check chamber, barrel
for carbon ring, copper, etc. Work back slowly in 0.2gr increments, measuring everything before and after firing, record.

You may be able to work back up to your desired charge, however if you encounter pressure signs drop back to the next lowest node. NO VELOCITY OR GROUP IS WORTH YOUR FINGERS, EYESIGHT OR LIFE!

 

[DHBWA]

I'll say it again.....If you know the velocity you are 90% there........Hint!!

 

[BearDog]

Gents, I follow what you're saying...Like I've said I do all those things and have for years. I reload in exactly that manner. What I'm asking is, is any flattening of a primer an indication that you should back off your load, or is there an acceptable amount one should expect?
Additionally why is muzzle velocity important while testing? I don't chase FPS and never measure velocity until I'm satisfied with my accuracy. So if one is putting accuracy as my most important objective, and Im not getting indications of high pressure, why is tracking muzzle velocity important during load testing important?

 

[DHBWA]

Velocity equals pressure. Google it.
Seriously....