I’m stumped..help

[Alaskashooter]

I’ve been wrestling with a demon on this 338 for a while and I’m running out of ideas. Surgeon XL action with a Krieger barrel chamber is a Sami spec. The issue is the bolt is very heavy and does not want to cam over without using a bit of force, this is not the issue with factory prime ammunition though. Factory prime runs as intended. Handloads are where the issue is coming from, one fired brass when put back in the chamber will give resistance on closing the bolt (expected). I clean trim and full length resize using redding dies, followed by using a neck bushing die to resize and then seat using redding competition seating die. Doing this the bolt will close as intended, fire the round and heavy bolt lift with a very heavy stop on the final cam over to recock. I have tried once fired prime and my once fired Lapua brass. The load is the absolute MINIMUM charge of h1000 as per Hodgdons reloading manual. No signs of pressure (ejector swipe, cratered and or flat primers).

What am I missing here guys?

 

[mdmp5]

Did you buy the brass used?

 

[FreQRiDeR]

It sounds like you’re not bumping the shoulder back enough. Screw your sizing die in a quarter turn more until your brass chambers more easily. Many times when you full length resize, the brass will actually grow, this is a sign you havent bumped the shoulder back enough. I find when I bump the shoulder back properly, (.002-.003) I don’t have to trim my cases as much, if any.

 

[Alaskashooter]

Did you buy the brass used?

Yes brand new Lapua brass now once fired and I would assume the prime factory ammo is brand new.

 

[Alaskashooter]

It sounds like you’re not bumping the shoulder back enough. Screw your sizing die in a quarter turn more until your brass chambers more easily. Many times when you full length resize, the brass will actually grow, this is a sign you havent bumped the shoulder back enough. I find when I bump the shoulder back properly, (.002-.003) I don’t have to trim my cases as much, if any.

After bumping the shoulder the bolt closes nicely. After firing it gets hard to lift again. If it wasn’t bumped back far enough wouldn’t it still be hard to close the bolt?

 

[supercorndogs]

Heavy bolt lift after firing is a sign of too much pressure.

 

[RTH1800]

It is a very remote possibility that you have some soft brass, a bad scale or a hot lot of powder. Something is causing brass flow.

 

[RNWRKNP]

An upside down bushing will also create this problem.

 

[Fig]

Check your speed.

I would switch powders and see if it still happens.

 

[mdmp5]

A guy in another thread was inquiring about something said in the Hornady manual about staying away from the minimum loads with slow powders, because of the risk of jacked up pressure. I offered my hypothesis based on knowledge of basic chemistry (Boyle’s law) but that was actually the first I’ve heard of it. What is your charge weight with H1000 and which bullet? I’m wondering if the Hornady manual is telling the truth and maybe the move is to increase the charge a bit.

 

[Fig]

That has to do with static inertia. You may also want to back off the lands another couple of thou and give yourself some more jump. An undercharge with a bullet seated to the lands can most definitely create an overpressure even when the speed wouldn't indicate it.

That said, a lot of small things have to line up and be wrong for this to be the problem.

 

[RTH1800]

The slow powder/overpressure issue is caused by detonation. Primer flashes across the reduced powder charge and it burns instantly rather than incrementally. This is unlikely with any published charge. It is normally only for those using much reduced charges with slow powders. I have personally seen two rifles that were destroyed by this. After the fact, not during the event.

I would advise against bumping up the charge on an overpressure load.

 

[Fig]

These threads are kind of funny. It's like a doctor trying to make a diagnosis over the phone without examining the patient. We at least need some pictures of the fired/unfired brass, and whatever else evidence can be posted to do anything other than stab wildly in the dark. Of course, I'm happy to do it! I just don't know how useful it is...

 

[BoomerC]

Take a piece of a new once fired brass that has not been resized and see if the bolt is easy to close and open. If it’s hard to close/open then I would suggest checking the headspace.

If it’s easy to close/open then you have an issue with your reloading process.

 

[BJames]

I agree with the too much pressure opinion. Need more info to opine on the why. What’s your seating depth? Jamming hard could be bumping up the pressure with a min load.

By the way, is that you Ryan? I recognize that rock.

 

[Alaskashooter]

It is a very remote possibility that you have some soft brass, a bad scale or a hot lot of powder. Something is causing brass flow.

Two different lots of prime ammo and one lot of Lapua brass both being soft seems less than likely, scale reads correct according to test weights, forgot to mention this happens with both h1000 and RL33

 

[Alaskashooter]

Check your speed.

I would switch powders and see if it still happens.

Original load was with RL33 this was changing powders and getting speeds in the mid 2,500s which is about exact as per the book.

 

[Alaskashooter]

A guy in another thread was inquiring about something said in the Hornady manual about staying away from the minimum loads with slow powders, because of the risk of jacked up pressure. I offered my hypothesis based on knowledge of basic chemistry (Boyle’s law) but that was actually the first I’ve heard of it. What is your charge weight with H1000 and which bullet? I’m wondering if the Hornady manual is telling the truth and maybe the move is to increase the charge a bit.

At first I thought it was an overpressured load running RL33 97.3gr pushing a 300gr SMK, however no cratering or flattening of the primers and no ejector swipe was visible. Regardless I tried a lighter load of 83gr of h1000 and still had the same result.

 

[SONIC SAAMI]

Stop, stop, stop... time the fuck out.
Do yourself a favor and try the easiest quickest solution.
Screw the down further .
The easiest solution is usually the answer.
If you’re using published data that just happens to work for just about everyone logic would suggest fucked up dye setting.

 

[Alaskashooter]

Take a piece of a new once fired brass that has not been resized and see if the bolt is easy to close and open. If it’s hard to close/open then I would suggest checking the headspace.

If it’s easy to close/open then you have an issue with your reloading process.

Once fired brass closes easily, and it passes a go/no go gauge test.

 

[Milo 2.5]

If your die is not touching the bottom third of your case, say out of spec, heavier lift and a click at the top of stroke will be noticeable. Take a caliper to your sized and fired brass. If the same a little above the rim, may be it.

 

[Alaskashooter]

I agree with the too much pressure opinion. Need more info to opine on the why. What’s your seating depth? Jamming hard could be bumping up the pressure with a min load.

By the way, is that you Ryan? I recognize that rock.

Yes it’s me lol. Seating depth is 2.67” been a bit since I measured it but I’m pretty far off the lans.

 

[Alaskashooter]

Stop, stop, stop... time the fuck out.
Do yourself a favor and try the easiest quickest solution.
Screw the down further .
The easiest solution is usually the answer.
If you’re using published data that just happens to work for just about everyone logic would suggest fucked up dye setting.

That’s the plan when I get home.

 

[BoomerC]

Once fired brass closes easily, and it passes a go/no go gauge test.

Screw the die down another 1/4 turn and see what happens.

Measure your new brass at the datum line then do the same for resized brass. That will tell you if your die is sizing properly.

 

[Milo 2.5]

If sized unloaded brass fits in your chamber, and the bolt closes freely, no reason to overbump. If the bolt does not close easy, need to find out why.

 

[Sheldon N]

If sized brass chambers easily (sufficient shoulder bump), loaded rounds chamber easily (no jammed bullets), and you are running the book minimum charge of H1000, then I would look at case sizing at the base of the brass (as Milo suggests above).

Base sizing should be measured at the 0.20" line just above the case head. I'd check the diameter of fired brass and then sized brass, using a micrometer if you have one or calipers if you don't. I would be looking for at least 0.0005 of base diameter sizing, and maybe closer to 0.001 would be preferable.

It that's not the issue then I'd be looking at to rule out the possibility of any carbon ring in the throat causing pressure.

 

[Threadcutter308]

I built a 30/338 and used Lapua .338M brass. I had case head seperations after 2 or 3 firings. I had the same problem that you are experiencing. I run nothing but Lapua in everything else and never had any problems. I never really solved the problem before getting rid of the rifle, but I lean in the direction that the brass could very well have been the problem.

 

[supercorndogs]

I built a 30/338 and used Lapua .338M brass. I had case head seperations after 2 or 3 firings. I had the same problem that you are experiencing. I run nothing but Lapua in everything else and never had any problems. I never really solved the problem before getting rid of the rifle, but I lean in the direction that the brass could very well have been the problem.

What would make you lean that way? I always lean toward a reloader problem, or a long chamber when CHS is the failure. You can eat up a lot of your stretch with a chamber that will almost close on a field gauge. On light loads you can bump the shoulder more than you want because the shoulders are not at the datum line of the chamber after one firing.

Over bumping your shoulder creating excessive headspace could cause over pressure and heavy bolt lift as well. It would also cause early CHS.

 

[Milo 2.5]

If sized brass chambers easily (sufficient shoulder bump), loaded rounds chamber easily (no jammed bullets), and you are running the book minimum charge of H1000, then I would look at case sizing at the base of the brass (as Milo suggests above).

Base sizing should be measured at the 0.20" line just above the case head. I'd check the diameter of fired brass and then sized brass, using a micrometer if you have one or calipers if you don't. I would be looking for at least 0.0005 of base diameter sizing, and maybe closer to 0.001 would be preferable.

It that's not the issue then I'd be looking at to rule out the possibility of any carbon ring in the throat causing pressure.

I've had my share of oversized chambers, with a good die it's a non issue. But have also had 3 out of spec dies in mouth area of dies, and it will stump a guy. The issue will most likely surface on the 2nd sizing. I just gave up, but this week have been trying to get twice fired XC brass fired from an oversize chamber into a new chamber(in spec), I've based sized with a cutoff x47 die,, and ran through a 243 small base die with the shoulder removed, then bumped to go -1 on a Whidden case gauge. It chambers, but is so inconsistent 500 pcs are hitting the recycle bin, bought new.
Do agree on carbon ring, light charges producing incomplete burns are the biggest causes of rings, IMO

 

[EXTREMEPREJUDICE]

If I had the problem as described (by the OP) I would start with a comparator or even a case mic would work. I'm just guessing the full length sizing is not correct but without a way to measure the sized case it is only that, a guess.

 

[supercorndogs]

If I had the problem as described (by the OP) I would start with a comparator or even a case mic would work. I'm just guessing the full length sizing is not correct but without a way to measure the sized case it is only that, a guess.

If you sized cases and they chambered and extracted fine, then were difficult to extract after firing, you would be worried about shoulder bump? I am worried about some of your ability to read.

 

[EXTREMEPREJUDICE]

Professor Dickweed don't worry about my reading ability................worry about your own as obviously you equivocate full length sizing and shoulder bump as similar.

 

[supercorndogs]

Professor Dickweed don't worry about my reading ability................worry about your own as obviously you equivocate full length sizing and shoulder bump as similar.

Maybe try reading it again.

"I clean trim and full length resize using redding dies, followed by using a neck bushing die to resize and then seat using redding competition seating die. Doing this the bolt will close as intended,"

 

[EXTREMEPREJUDICE]

Once again, maybe you should Prof.

 

[mdmp5]

I’ve ripped a bolt handle off trying to extract a fired piece of brass out of my 338. However, the problem was that the brass was previously fired in my factory sako chamber, then when I rebarreled, the new chamber dimensions were a tad tighter. Regardless of sizing the brass, it still wouldn’t fit into the new chamber. Upon measuring, I found that the sticking point was right above the case head, which is the small area the sizing die doesn’t touch. There aren’t no small base dies for 338, so I couldn’t salvage that brass for this particular chamber. Never used small base dies but I have read that they really aren’t a good solution anyway

 

[mdmp5]

Being that the OP can chamber the brass after sizing, I’m kinda lost if he is indeed using 83 gr of H1000. That is stupid light

 

[BJames]

Yes it’s me lol. Seating depth is 2.67” been a bit since I measured it but I’m pretty far off the lans.

Ah, gotcha. I’m curious to see what happens with brass sized down a little further. Out of curiosity, how many rounds down it?

Are you coming down for the October match?

 

[Milo 2.5]

I’ve ripped a bolt handle off trying to extract a fired piece of brass out of my 338. However, the problem was that the brass was previously fired in my factory sako chamber, then when I rebarreled, the new chamber dimensions were a tad tighter. Regardless of sizing the brass, it still wouldn’t fit into the new chamber. Upon measuring, I found that the sticking point was right above the case head, which is the small area the sizing die doesn’t touch. There aren’t no small base dies for 338, so I couldn’t salvage that brass for this particular chamber. Never used small base dies but I have read that they really aren’t a good solution anyway

I've tried a multitude of ways over the yrs, from neck sizing till I had to force the bolt handle down, to 2 neck sizings, then to fl die, and one neck sizing to achieve chamber dimensions. I rarely neck size even once today, but truthfully, my loads with new brass are always damn good loads, so if I had my choice, taking my brass back as close to factory specs, sans growth lengthwise, would be an avenue I'd pursue, and a SB die would give that option, too bad they are only offered in a few cases.

 

[Thud]

I keep reading this statement and a little confused- I clean trim and full length resize using redding dies, followed by using a neck bushing die to resize and then seat using redding competition seating die.
Why are you full length sizing and the neck sizing?
Why not just use a bushing full length sizer die?
By chance are you using a Body die first.
Does your die still have the expander ball in it if it does remove it and use the other collet to hold the deprimer you don't need to work your brass any extra. The expander ball will also stretch the case.
Set you die up to where in the press it bottoms out on the shell holder and about an 1/8 turn up to set the shoulder back. But best way to measure that is with a chamber gauge or a shoulder bump gauge by either Sinclair or Hornady.
Also make sure you lube the cases well because if not they will stretch on the up stroke and will cause the issues your talking about.
Also verify the powder charge make sure your not to light yes it will cause pressure issues when the powder settles and there is a dead spot in the case. This happens in pistols often when powder is unevenly distrubited throughout the case. It will presuer and blow the cylinders up.
Use the published data and work from there you don't sound to experienced in reloading so don't push it.
Also make sure you make one change at a time aand write everything down so you don't have to repeat the investigation again.
Let us know what you find out.

 

[BJames]

We’re hanging here Ryan, what have you tried, updates man, updates!

 

[SPAK]

Couple questions:
After trimming and resizing what is your case length?

What is your actual chamber length? If you don’t know see if you can get the reamer print and find out.

Do loaded rounds have any resistance to chamber at all?

On fired cases does a bullet pass through the fired case neck?

 

[Alaskashooter]

3 years later... out of spec reamer.

 

[bmash]

I love to hear the result of a thread like this! I had that once in a factory supplied barrel - ruined a bunch of brass! Which dimension was off? For example Diameter or headspace or ?

 

[oldiephrt]

bmash thanks for bringing this back up. Lots of knowledge lost thru age.