Bad pressure issues and can't figure out Update

[Trevor300wsm]

I shot a match today and had some very bad pressure issues arise and I can't figure out why. I'll try to be as detailed as possible here. I'm not new to reloading, but I'm not a pro either.

Gun: 6.5x47 on a 591 action.

Load: Lap brass
42.5 H4350
Berger 130 VLD's
CCi 450's

This is a load that I worked up that I've shot over 100 rounds of so far with NO pressure issues until today. The load was developed in 40* to 55* degree temps. It has a average speed of 2,924fps over multiple chrono tests.

Brass was 3 times fired, but annealed before this last loading (the rounds I fired today). I neck size only. The rounds are right there at the point that the shoulders need t be bumped back, but I figured I could get one more firing out of them. The bolt is a lil tight when chambering them, but not exsessive.

The match conditons today were almost identical to my load development conditons and my zero conditons. The temp started out around 45* and climbed into the upper 50's by the end of the match. Elevation was within 150 feet of my home range.

On the first round of the match, I kicked ass with no issues, other than a tight bolt on ejection, which was expected since the shoulders need to be bumped. On the second round is where the problems started. This was out of the same lot of ammo, loaded with the same lot of powder and same lot of bullets, loaded at the same time. Anyway, I began having bad extractor swipe, bolt so tight I had to beat it up with the palm of my hand, and I blew two primers completely out. Oddly, my dope was still correct, or correct enough to still make hits inside 775yds on 1MOA targets.

What gives???

1.) Ive pretty much ruled out temp. It's 4350 which isn't temp sensitive and it was only in the upper 50's today while shooting.

2.) Could it have been the fact that the shoulders were needing to be bumped? I have always fired them until the bolt wouldn't close on them, then it's time to bump the shoulder. Can this cause pressure issues?

3.) I've checked my scales, it's not a charge issue, not one I can identify anyway. The scales are actually still set on the beams from when i loaded a few nights ago. Powder is new, same lot as I used during load development. I've check overall COAL and it's 3.129" measured on the ogive. My charge dropper is still set as well since 6.5x47 is about all I ever reload.

4.) Should I have full length resized after annealing rather than just neck sizing like normal?

I'm going to set up the chrono tomorrow and fire a few of these rounds and see what data I come up with.

Any help would be apprecitated. I'm stumped unless it has something to do with the shoulders needing to be bumped causing the pressure issues.

 

[country888]

Re: Bad pressure issues and can't figure out why.

Chit, that is strange! I dont have a guess! If the first rounds did ok & second had pressure, doesnt make since. Im sure someone on here will chim up with a good answer! Anyway, good luck & let us know what you find out

 

[turbo54]

Re: Bad pressure issues and can't figure out why.

First thing that comes to mind is some kind of slick substance in your chamber or on your brass. A warm (but totally OK load) can blow primers and cause big ejector marks with just a little oil/grease in the chamber. Even a little moisture can do it.

 

[QuiggyB]

Re: Bad pressure issues and can't figure out why.

First I dont know why the shoulder would case a pressure issue. I did find a 1.5 grain shift between some powder I bought back in August and some I bought in October.

Did you pull the bullet on one of your hot rounds and measure the powder in the case? Are you sure the bullets aren't accidentally being seated too far and being pushed into the lands? Could anything else have caused extra neck tension? Are the case necks possibly too long and getting crammed into the bullet when you close the bolt?

If you were riding the line on pressure before maybe the gun getting dirty during the first match pushed it over the edge.

 

[linedrive301ft]

Re: Bad pressure issues and can't figure out why.

trevor, can you check your throat area for carbon build-up or

a ring forming?

Regards

Mark

 

[Mark Walker]

Re: Bad pressure issues and can't figure out why.

As noted, a carbon ring is a possible culprit.

 

[Trevor300wsm]

Re: Bad pressure issues and can't figure out why.

I dont think it's a carbon issue. The barrel only has 220 rounds thru it and it's been cleaned regularly. I can't "feel" a ring when I'm cleaning the bore. I don't have a bore scope so I can't look in there.

 

[DIBBS]

Re: Bad pressure issues and can't figure out why.

Have you changed any of your components recently, ie new lot of powder or new batch of bullets (different bearing surface?)or different lot of primers?

At one of our shoots last year, a couple of the guys got raindrops on their cases, increasing thrust to the bolt face because the cases wouldn't grip the chamber, and they had pressure problems.

If you're able to diagnose the cause of your problems, please report back what you found. Good Luck!

 

[dieselten]

Re: Bad pressure issues and can't figure out why.

I had a similar problem with a 6BR. It turned out to be Donuts had built up inside the case at the base of the neck. To test this I would drop a bullet into a fired case. If there is a donut the bullet will hang up and not fall all the way through.

I do not know exactly what causes this but it could be Lapua brass which is thick in the shoulder area growing into the neck area. Or it could be from a bushing type sizer die that does not size all the way to the base of the neck and into the shoulder area.

To remove I used a round needle file inside the case neck at the shoulder junction - careful not to touch the actual inside neck, just the shoulder junction.

 

[MALLARD]

Re: Bad pressure issues and can't figure out why.

i dont think annealing had anything to do with it. 2929 fps is fast for a 6.5x47 lapua isn't it ? You might be shooting a hot load.

 

[Trevor300wsm]

Re: Bad pressure issues and can't figure out why.

Ok,
I pulled out 3 pieces of fired brass from the match yesterday that showed to have the highest pressure issues (minus the ones that I blew the primer on). The 3 pieces i picked had bad extractor swipe. I checked these 3 fired pieces of brass to verify that the bolt would NOT close on them when chambered.

I measured these 3 fired pieces. OAL was .002"-.005" over virgin brass. So, no issues there. I check for the donut ring inside the case neck. No issues there. I then took these 3 pcs and deprimed them, bumped the shoulder back in a body die, then neck sized them. AFTER all this, I again checked them in my chamber. The bolt closed on them EASILY without issue. I then primed them and charged them with 42.5 grains of 4350 and seated the bullets.

I took the rifle and cleaned it. The bore cleaned up completely with only 3 wet patches of Butch's Bore shine. I mopped the chamber and blew it out with a can of air. Cleaned the bolt and lubed it with some CLP.

I got the chronograph set up.

I took 3 rounds from another box that I had that has 3 firings on it. I wanted to fire these 3 first to foul the bore and to also compare chrono numbers from these that had not been annealed against those that had been annealed. The first 3 rounds from the other box all chambered fine and ejected with no heavy/sticky bolt. Chrono numbers were right at 2900-2917 fps on a cold clean bore. The 3 rounds produced a nice 1/4"-3/8" group at 100yds. Here is a pic of those first 3 rounds.

I waited 5 minutes and then loaded the brass from yesterday that I bumped, neck sized and charged just this morning. All 3 rounds chambered easily, BUT all 3 had very stiff/sticky bolt lift on ejection. I blew the primer on the second round fired. Obvious signs of pressure. However, the chrono numbers were right where they should be, right around 2900-2910 fps. Here is a pic of those 3 cases.

I don't know what the hell the deal is guys. This one has got me stumped.
My scales are fine so i don't think it's a over-charge issue. Plus the chrono numbers are right where they always have been. The case necks might be getting long, but I took the 3 pressured cases and color the end with a black sharpie and chambered them several times to see if I could get any friction marks on the face of the case mouth indicating they are too long, but all 3 came out fine with none of the sharpie rubbed off.

Is there anyway I could have done something during annealing? Got them too hot? Too soft? I don't think that's the case, but I'm just grasping at ideas.

 

[Kiwi Greg]

Re: Bad pressure issues and can't figure out why.

My <span style="font-weight: bold">Guess</span> is an annealing "issue"

How did you anneal them ?

 

[dieselten]

Re: Bad pressure issues and can't figure out why.

At this point, annealing is the only difference we are aware of. Please describe your annealing process with great detail

 

[Trevor300wsm]

Re: Bad pressure issues and can't figure out why.

This was the first batch of brass I've ever annealed, but I don't know what I could have done wrong. I used a regular small gas torch like everyone else uses. I did the brass one at a time. I put a 1/2" deep socket on a cordless drill and put the brass in the socket. I turned the lights off in the room and spun the case neck in the flame until it was just hot enough to show up in the dark of the room. It certainly wasn't red hot at all. I then dropped the case in a bowl of water. The heat line on the brass is a little less half way down the body, just like on new Lapua brass. I kept the flame on the neck at a 45* angle and tried not to get on the shoulder at all.

 

[QuiggyB]

Re: Bad pressure issues and can't figure out why.

The problem is that work area is way too clean.

 

[longshooter]

Re: Bad pressure issues and can't figure out why.

Do you know what your neck clearance is, with a loaded round, And, what the distance is to the end of the chamber (neck), for comparison to case oal?

 

[Trevor300wsm]

Re: Bad pressure issues and can't figure out why.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: longshooter</div><div class="ubbcode-body">Do you know what your neck clearance is, with a loaded round, And, what the distance is to the end of the chamber (neck), for comparison to case oal?</div></div>

I do not know that information. That's why I checked the 3 cases after I bumped them by coloring the face of the case mouth with a black sharpie to see if they were hitting the end of the chamber and being compressed, but after chambering them several times, I never got any shiny spots on the face of the case mouth indicating any friction between the face of the case mouth and the end of the chamber.

 

[longshooter]

Re: Bad pressure issues and can't figure out why.

What is your fired case neck diameter?

 

[Smith44699]

Re: Bad pressure issues and can't figure out why.

I had a similar problem this year with a 308. Laupa brass. It turned out after firing the case more than 3 times and full lenghth sizing my necks got thicker. Which lapua is a little thicker to start with. That combined with a tight match chamber resulted in my bolt sticking. My loads were very mild. I had many stressful hours trying to figure it out. Tom Sarver (TVP) gave me some pointers to check. The first thing was to check a fired case and see if a bullet would fall to the bottom. Mine wouldn't. So when I fired the case neck had no room to expand. My pressures spiked like crazy. Anyway to fix the problem I necked turned some of the brass. No problems since then. Although I am going to have Tom open my chamber a little. I hate neck turning. The rifle isn't a bench rifle anyways. I hope this helps.

 

[Trevor300wsm]

Re: Bad pressure issues and can't figure out why.

A bullet will fall freely thru the neck to the bottom of one of my fired cases, so I don't think a super tight chamber is the issue.

I bought (4) one pound cans of 4350. It's all the same lot #. I switched to a new can on this batch of 50 bullets. Would powder from the same lot#, but different can have a big variation?? If this can is hotter, why haven't the chrono speeds increased over the loads that were loaded with the last one pound can? Why just pressure increases, but no speed increase?

 

[targaflorio]

Re: Bad pressure issues and can't figure out why.

Your annealing looks beautiful to me.

 

[Downzero]

Re: Bad pressure issues and can't figure out why.

Load that same load in some new cases and let us know if you blow primers. I bet you have loose primer pockets and not pressure issues. Those primers don't look very flat at all. It's hard to believe that a hot load wouldn't flatten the primers.

Velocity is normal, primers look normal, and the only sign of pressure is blowing primers....I blame the brass.

 

[X-fan]

Re: Bad pressure issues and can't figure out why.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: trevor300wsm</div><div class="ubbcode-body">Ok,
I pulled out 3 pieces of fired brass from the match yesterday that showed to have the highest pressure issues (minus the ones that I blew the primer on). The 3 pieces i picked had bad extractor swipe. I checked these 3 fired pieces of brass to verify that the bolt would NOT close on them when chambered.

I measured these 3 fired pieces. OAL was .002"-.005" over virgin brass. So, no issues there. I check for the donut ring inside the case neck. No issues there. I then took these 3 pcs and deprimed them, bumped the shoulder back in a body die, then neck sized them. AFTER all this, I again checked them in my chamber. The bolt closed on them EASILY without issue. I then primed them and charged them with 42.5 grains of 4350 and seated the bullets.

I took the rifle and cleaned it. The bore cleaned up completely with only 3 wet patches of Butch's Bore shine. I mopped the chamber and blew it out with a can of air. Cleaned the bolt and lubed it with some CLP.

I got the chronograph set up.

I took 3 rounds from another box that I had that has 3 firings on it. I wanted to fire these 3 first to foul the bore and to also compare chrono numbers from these that had not been annealed against those that had been annealed. The first 3 rounds from the other box all chambered fine and ejected with no heavy/sticky bolt. Chrono numbers were right at 2900-2917 fps on a cold clean bore. The 3 rounds produced a nice 1/4"-3/8" group at 100yds. Here is a pic of those first 3 rounds.

I waited 5 minutes and then loaded the brass from yesterday that I bumped, neck sized and charged just this morning. All 3 rounds chambered easily, BUT all 3 had very stiff/sticky bolt lift on ejection. I blew the primer on the second round fired. Obvious signs of pressure. However, the chrono numbers were right where they should be, right around 2900-2910 fps. Here is a pic of those 3 cases.

I don't know what the hell the deal is guys. This one has got me stumped.
My scales are fine so i don't think it's a over-charge issue. Plus the chrono numbers are right where they always have been. The case necks might be getting long, but I took the 3 pressured cases and color the end with a black sharpie and chambered them several times to see if I could get any friction marks on the face of the case mouth indicating they are too long, but all 3 came out fine with none of the sharpie rubbed off.

Is there anyway I could have done something during annealing? Got them too hot? Too soft? I don't think that's the case, but I'm just grasping at ideas. </div></div>

Am I the only guy that sees the case deformation in the bottom picture?

Left to right ejector mark locations:
left- Lapua trade mark
middle- on the X
Right- On the U

The 6.5X47 is smaller than either the Creedmore. My (hunting) 260 just reaches 2900fps with 125 partitions. I don't shoot the 6.5X47, but how can that not be high pressure?

 

[Trevor300wsm]

Re: Bad pressure issues and can't figure out why.

Xfan,
I agree with you. No denying the pressure signs on the brass in the bottom pic. The problem is WHY is it there. The pic on the top is the same brass, loaded with the same charge, same primer, and same bullet. The issue was why did I start having pressure issues with just this bunch of 50 cases in my match. This is a load I've shot many times in the rifle and never had any pressure issues with it.

 

[Sean the Nailer]

Re: Bad pressure issues and can't figure out why.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Dibbs</div><div class="ubbcode-body">Have you changed any of your components recently, ie new lot of powder or new batch of bullets (different bearing surface?)or different lot of primers? </div></div>
I too will ask, have you tried changing primers? I didn't see any comments regarding this. Though, I may have missed it.

 

[mavrick10_2000]

Re: Bad pressure issues and can't figure out why.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: MALLARD</div><div class="ubbcode-body">i dont think annealing had anything to do with it. 2929 fps is fast for a 6.5x47 lapua isn't it ? You might be shooting a hot load. </div></div>

Not with 130 VLD's. A warm to hot load can easily push 130's over 3K FPS.

 

[Trevor300wsm]

Re: Bad pressure issues and can't figure out why.

Guys,
I appreciate you all taking the time to comment here. However, some of you are suggesting that I try different components or shoot a lighter load. That's not what I'm asking for help on. This is NOT a new load. I've shot over 200 rounds of this load thru this rifle with NO issues from it until Saturday. The reason for my posting is see if anyone knew what might have caused the sudden pressure issues like something I've done or havent done to my brass. Nothing has changed in this equation except I annealed the lot of 50 cases and opened a new can of powder (that was the SAME lot#).

 

[longshooter]

Re: Bad pressure issues and can't figure out why.

xfan might be onto it.

On what are you basing your load criteria and case criteria?
Is your gun getting hot, is it baking in the sun?
*Do you leave any load in the gun for a period, before firing?
Why haven't you verified your case length neck clearance yet?

 

[F4D]

Re: Bad pressure issues and can't figure out why.

Interesting topic. Have you tried this load in other brass such as Winchester?

 

[9H_Cracka]

Re: Bad pressure issues and can't figure out why.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: F4D</div><div class="ubbcode-body">Interesting topic. Have you tried this load in other brass such as Winchester? </div></div>

Winchester makes 6.5x47 brass now? Cool!

 

[Trevor300wsm]

Re: Bad pressure issues and can't figure out why.

Xfan isn't onto anything. We all see the pressure signs on the bottom 3 cases. That's why i posted them in comparison to the top 3 cases.

What am i basing my load criteria on?? Well, research, load development, OCW testing, accuracy, results of chrono data and impacts on target. What are are you asking such a vauge question for?

Guys, this isn't my first rodeo. I've already thought of and ruled out all the simple stuff.
No my rounds are not setting in a hot chamber.
No my rifle isn't getting hot baking in the sun. The shoot was in 55* degree temps.
No, heat is not a factor here. I tried to state all that clearly in the very first post explaining load development conditons and shooting match conditons. They were almost the same.

F4D.......the caliber of rifle I'm shooting is a 6.5x47. There is only one company that makes this brass. Did you miss that?

 

[Trevor300wsm]

Re: Bad pressure issues and can't figure out why.

No, annealing makes brass SOFTER, not harder. Geez.....


I'll figure it out guys, thanks for the help.

 

[longshooter]

Re: Bad pressure issues and can't figure out why.

You seem to be argumentative with those attempting to help you work through this problem.

Have you verified your damn case length?

Did you ever tell us you weren't cooking the damn loads?

xfan talks of reduced capacity for this case. Do you understand where he is coming from?

If you start answering some questions, perhaps this will get resolved.

You just keep blowing people off.

 

[Trevor300wsm]

Re: Bad pressure issues and can't figure out why.

Yes, damn right I got aggrevated. People just like you won't slow down and actually ready the information that has already been given.

Yes, I've checked OAL and COAL. It's not a issue, as I've already stated. The case mouth isn't bottoming out on the chamber.

No I didn't tell you I wasn't cooking the loads, but to me that's a elementary level problem. Anybody with any experience in this game knows you can't leave live rounds in a hot chamber. That's a given! Most people know you can't let ammo back in direct sunlight, regardless of outside temps. That's a given! I've already stated several time that "HEAT" is not the issue here. It's ruled out.

This is not a "Hot" load for the caliber. Why would I look at case capacity? This has been a proven good load for me until a few days ago. I don't want to just drop the charge to fix a unknown problem. I want to know what I did or didn't do to cause it to begin with. Yes, reduced charge is a easy obvious fix, but what the hell caused the initial problem when I've fired 200 rounds of this exact load without issue??

I'm very appreciative of help or advice someone gives me. However, this is the reloading section and if you don't really know what the hell your taking about, it may be better just to be quite and see what others come up with. Given any advice here in regards to loads can be potentially dangerous if the other person isn't knowledgable enough to know what's safe or not. People skimming thru this post and then giving some simple random reply that's already been discussed is what's caused my annoyance.

Like i said, thanks to all that commented. I'm going to start over on this from zero and reload the same load, but with virgin brass and see what results it gives me to determine if it's brass related or gun related.

Thanks,

 

[longshooter]

Re: Bad pressure issues and can't figure out why.

No skimming here. I, and otheres, are trying to help you resolve the problem.

You wrote this;

"if you don't really know what the hell your taking about"

If that is directed towards me, I resent it. I am trying to help, and you are not answering direct questions.

Data was barely enough to start analyzing the problem. I won't come onto a thread if data is severely lacking. You didn't tell us factory chamber, custom chamber, tight, loose, blah, blah, blah....

You do not check case length fit in the manner in which you have indicated. Now, it might not be the problem, but it does indicate a lack of reloading experience on your part.

 

[Kiwi Greg]

Re: Bad pressure issues and can't figure out why.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: trevor300wsm</div><div class="ubbcode-body">

Like i said, thanks to all that commented. I'm going to start over on this from zero and reload the same load, but with virgin brass and see what results it gives me to determine if it's brass related or gun related.

Thanks,
</div></div>

I think this is the way forward for you.

I would load some with the fired non annealed brass & annealed brass as well, then shoot them all again under controled conditions as you normally would.

It appeared to me right from the start of the thread that the issue had something to do with the annealing, not sure what & your annealing looks okay.

The 6.5 x 47 is a great cartridge & obviously the brass is well designed & can be run to pretty high pressures to get the performance it does from the ammount of powder it uses compared to the 260 etc.

Having said that as it is running at fairly high pressures it won't take much of an issue to push the cases over the edge.

Good luck with finding the issue I'm sure you will get a lot closer to discovering the cause with your next test.

 

[Trevor300wsm]

Re: Bad pressure issues and can't figure out why.

Thanks Kiwi.
I'll get it sorted out and post back with the results.

 

[frankythefly]

Re: Bad pressure issues and can't figure out why.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: trevor300wsm</div><div class="ubbcode-body">A bullet will fall freely thru the neck to the bottom of one of my fired cases, so I don't think a super tight chamber is the issue.

I bought (4) one pound cans of 4350. It's all the same lot #. I switched to a new can on this batch of 50 bullets. Would powder from the same lot#, but different can have a big variation?? If this can is hotter, why haven't the chrono speeds increased over the loads that were loaded with the last one pound can? Why just pressure increases, but no speed increase? </div></div>

I had issues using Varget that was supposed to be from the same lot. Bought 6 1lb jugs all from the same lot. Used 4 of them no issues. Started to use the 5 1lb and my loads where way slow and all over the place. I now buy my powder 8lb jugs and stay away from the 1lb ones.

 

[longshooter]

Re: Bad pressure issues and can't figure out why.

Also, you might be overloaded. Perhaps your chrono is lying.

 

[X-fan]

Re: Bad pressure issues and can't figure out why.

Trev300,

Have not doubt your regular load is running high pressure. It may be somewhat safe in your rifle, but that doesn't change the pressure. Many experienced bench and F-Class shooters choose to go this route however have no doubt that for the less than very experienced you are playing with fire.
You are making small mistakes and have left yourself no room for any of that.

Get into bigger lots of powder...1 pound is not the way to go...Same lot or not.

Did you anneal with the cases mouth down or up?
Some of the cases seem to show a bit more heat travel than normal. Three cases front row right (slightly set back). The case 3rd from right looks normal while the far right shows way too much heat travel....Once again poor pictures, but there is inconsistency everywhere.
Also there is no way you can shoot into the same group tiny group with 2 differing pressures when your starting point is already hot....This makes me suspect the annealing process.

What is your measured max chamber length vs case length clearance and how did you establish this?
Magic marker = Fail.
Bump the case into the chamber end (ever so lightly) and pressure goes sky high.

As was stated above you need to know your neck clearances.
This is no placed for magic marker noobishness.
Ask your gunsmith for a reamer spec then get the calipers out.

What is your seated bullet to lead clearance?
Run it too close and make a tiny mistake and get rewarded with a 5,000-8,000psi jump How are you measuring this?

I think most guys are best off starting off 20-50 thou off the rifling then tailoring the load to suite. No reason to push pressure into the stratosphere...Least not until you are ready to deal with a critical (twitchy)setup.

Peace

 

[Sidk]

Re: Bad pressure issues and can't figure out why.

Any chance the bullets shifted under recoil in the magazine and now is into the lands instead of jumping? Just a thought.

 

[DanSavage]

Re: Bad pressure issues and can't figure out why.

I think X-fan is right, the annealing looks a little inconsistent. It seems to me that the annealing shouldn't be half way down the case. I have a torch like yours and I average no more than 15 seconds and annealing is done just passing the shoulder.

 

[LR-WSM]

Re: Bad pressure issues and can't figure out why.

I believe he said he was shooting F-class, thats single load.

Weigh your new brass, compare it to the old stuff that shoots. You might have a heavier run of brass with less internal volume. If your right at the edge as people have suggested, it could be the difference.

 

[QuiggyB]

Re: Bad pressure issues and can't figure out why.

This may have been mentioned but you can put the case on a scale, zero it and see how many grains of water fit inside it and compare that against a previously fired case that is known to work correctly. I guess I would trim both of them to the same length first. That would tell you if something about the annealing process caused a shift in the amount of space inside the case.

Otherwise being careful and scientific you will eventually find the difference. I lean towards something with the new can of powder because I cant really see how annealing would cause pressure to go up but I'm honestly not that experienced with it.

 

[milo 2.0]

Re: Bad pressure issues and can't figure out why.

Trevor,
Been monitoring this post from the start. I think it is a combination of needing a full length bump and the annealing.
Must have given it a bit more neck tension.

I would anneal about 10 more cases, full length size them, load em up and try them. Might solve it??
I shoot a 123 scenar out of mine at 3004fps. Have a friend that somehow gets 3150 with the same combo, just more powder.
No pressure signs.
I'm building another right now, plan to shoot the 130gr Norma, I'm hoping for 2925-2950 out of it, if not it won't be around very long.
Miles

 

[Rthur]

Re: Bad pressure issues and can't figure out why.

Trevor, this might be something to look at. If you have access to a ball micometer check the necks on those fired cases against the ones that weren't to hot. You said this is the third firing and brass may have flowed into these a little more than the average case. That condition would make the rifle a slight tight chamber not releasing the bullets as well and pushing pressure up. Just an idea ymmv.

Rthur

 

[longshooter]

Re: Bad pressure issues and can't figure out why.

I don't anneal. But, I would agree that he might have softened some cases while annealing. As others are saying.

 

[LR-WSM]

Re: Bad pressure issues and can't figure out why.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: longshooter</div><div class="ubbcode-body">I don't anneal. But, I would agree that he might have softened some cases while annealing. As others are saying. </div></div>

I honestly don't believe the annealing has anything to do with creating any over pressure issues. It might amplify one but not create one. It's either thick necks or heavy brass with less internal volume. He's eliminated everything else

 

[Mark Walker]

Re: Bad pressure issues and can't figure out why.

Have you measured the web of the case and compared with ones that are not giving you issues?

I saw this very thing with a friend that had just annealed his brass and a normal load was blowing primers, hard bolt lift etc.

Brass got too hot at the head and softened up - then it cant take the pressure and you see all the same signs.

 

[Mark Walker]

Re: Bad pressure issues and can't figure out why.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: LR-WSM</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: longshooter</div><div class="ubbcode-body">I don't anneal. But, I would agree that he might have softened some cases while annealing. As others are saying. </div></div>

I honestly don't believe the annealing has anything to do with creating any over pressure issues. It might amplify one but not create one. It's either thick necks or heavy brass with less internal volume. He's eliminated everything else </div></div>

Over annealing can definitely create pressure issues. The case head is weakened, it can't take the same pressure as normal, so it shows pressure signs at what are normally safe loads.

It does look like from the pictures the heat marks are significantly too far down the body of the case, as noted above.

Doubtful your load is the issue, works fine in your other brass, and from all I have seen and shot myself, is right in the ballpark. I burned through 3 6.5x47 barrels myself shooting F-Class, so have a bit of experience with them.