Blown Primer with 6GT =(

[YerrowSniper]

Ok Ok,
At my latest match, I had about 30-40% blown primers. Primers that got blown out of their pocket causing all kinds of jams... totally messed up my day!
This is a fairly new build and I only have about 400ish round down the pipe.

Build/Load:
Big Horn TL3
26.5" Bartlein Barrel
34.2gr of Precision Rifle from the same 8# Jar
CCI Small Rifle Primer
109gr Berger
COAL: 2.578" +/- 5 Thou. This I accounting to my builder 20 Thou off the lands.
Load the load I am getting 0.3MOA Grouping.

I have loaded 500 rounds the same way this blown primer issue only showed up at my latest match. I shot about 80 rounds and 30-40% blew the primer, I didn't change the recipe.

When I first got the gun a few months back I was around 2950-2960 FPS, short the gun for about 200ish rounds (I am in GA).
No sign of pressure, I did occasionally get the typical ejector mark due to the Big Horn Action geometry. I was told it was normal.
My Smith in AZ was getting 3050ish, same load (He is in AZ)
I didn't change the load since I was getting 2950 consistently.

Recently I installed the ATS tuner, during my tuning session, my velocity started to go up. 2990-3000, again this is the same lot of ammo I made.
I am using the ATS and an Area 419 comp in front of it. While I was tuning, 60 or so rounds only one round felt/shot funny, this is the first time me seeing this. That shot felt off, sounded off, smelled off. There was a black ring around the primer pocket the primer was still there. Since it was only one, I didn't care much...

The following day was a competition day... well fuck.
In the first stage, I got a blown primer! Causing all kind of malfunction throughout the day.
What gives?!

 

[Go Cougs]

What brand of brass are you shooting?

 

[YerrowSniper]

What brand of brass are you shooting?

GAP brass made by Hornady

 

[Reload10]

I bet you haven't cleaned the carbon COMPLETELY out of it in those 500 rounds. There's excess carbon buildup causing the pressure increase.

 

[YerrowSniper]

I bet you haven't cleaned the carbon COMPLETELY out of it in those 500 rounds. There's excess carbon buildup causing the pressure increase.

I clean it at 150 rounds. Used Wipeout and I have a bore cam BUT I will clean again.
Here is a picture of the suspected carbon ring and one showing the relationship to the lands

 

[FALex]

400 rounds doesn't seem like enough to get a significant amount of carbon to cause this issue. I haven't seen this in any of my comp rifles, not even close, but they are not 6GT's.

How many reloads do you have through the cases you used? Any chance they are running too long?

 

[YerrowSniper]

400 rounds doesn't seem like enough to get a significant amount of carbon to cause this issue. I haven't seen this in any of my comp rifles, not even close, but they are not 6GT's.

How many reloads do you have through the cases you used? Any chance they are running too long?

Brand new Brass, first load.
I am personally remeasuring distance to the land to make sure...

I need a bomb proof method that cannot be fucked up lol.

 

[CK1.0]

COAL: 2.578" +/- 5 Thou. This I accounting to my builder 20 Thou off the lands.

Sounds like a weird one for sure... But, that line sounds a little vague amongst everything else listed, +/-5 thou is kind of a lot? COAL is pretty coarse measurement compared to CBTO (the only time I care about COAL is whether or not they'll fit in a magazine really lol). What's your target CBTO for your 20 thou jump, you didn't accidentally seat 'em long (inadvertently jamming them)?

I read somewhere of guys getting pressure spikes because of lube left on the cases, IDK?

 

[padom]

You need to measure distance to lands in YOUR RIFLE with your bullets....get the CBTO measurement where you contact lands with said bullet... do your own load work up and load your length using that CBTO measurement to ensure you aren't on the lands....you have a hot load or in the lands or both. Without putting the work in you won't have an answer.


And I have 5 TL3... been shooting them since they first came out. I don't get ejector swipe on any brass when I've properly worked up a load. Who told you it's normal and just how the action is designed because they are wrong??

 

[YerrowSniper]

Sounds like a weird one for sure... But, that line sounds a little vague amongst everything else listed, +/-5 thou is kind of a lot? COAL is pretty coarse measurement compared to CBTO (the only time I care about COAL is whether or not they'll fit in a magazine really lol). What's your target CBTO for your 20 thou jump, you didn't accidentally seat 'em long (inadvertently jamming them)?

I read somewhere of guys getting pressure spikes because of lube left on the cases, IDK?

Because I am measuring COAL and there are variance in the tip of the bullet and probably a thou or so in the RCBS Die/Coax, this results in +/- 5 thou when I measure my loaded rounds.

 

[YerrowSniper]

You need to measure distance to lands in YOUR RIFLE with your bullets....get the CBTO measurement where you contact lands with said bullet... do your own load work up and load your length using that CBTO measurement to ensure you aren't on the lands....you have a hot load or in the lands or both. Without putting the work in you won't have an answer.


And I have 5 TL3... been shooting them since they first came out. I don't get ejector swipe on any brass when I've properly worked up a load. Who told you it's normal and just how the action is designed because they are wrong??

 

[YerrowSniper]

You need to measure distance to lands in YOUR RIFLE with your bullets....get the CBTO measurement where you contact lands with said bullet... do your own load work up and load your length using that CBTO measurement to ensure you aren't on the lands....you have a hot load or in the lands or both. Without putting the work in you won't have an answer.


And I have 5 TL3... been shooting them since they first came out. I don't get ejector swipe on any brass when I've properly worked up a load. Who told you it's normal and just how the action is designed because they are wrong??

That last picture we when the primer hasn’t blown yet.
The one with a blown primer are way more apparent.
When I just got the rifle and shooting around 2950 there was only a very faint mark.

 

[YerrowSniper]

You need to measure distance to lands in YOUR RIFLE with your bullets....get the CBTO measurement where you contact lands with said bullet... do your own load work up and load your length using that CBTO measurement to ensure you aren't on the lands....you have a hot load or in the lands or both. Without putting the work in you won't have an answer.


And I have 5 TL3... been shooting them since they first came out. I don't get ejector swipe on any brass when I've properly worked up a load. Who told you it's normal and just how the action is designed because they are wrong??

Any resources where I can get a good repeatable method to measure that?

 

[padom]

Yea man that's a HOT ass load with that deep mark on your brass.

 

[CK1.0]

Any resources where I can get a good repeatable method to measure that?

You need a comparator and bushing, plus your calipers... that's what I was alluding to earlier about CBTO.

There are a bunch of ways to find "jam" and/or "the lands", but you have to have a way to measure it.

 

[YerrowSniper]

Yea man that's a HOT ass load with that deep mark on your brass.

I don’t get it...
Load hasn’t changed...
Nothing changed.
Why did the pressure suddenly increased?

 

[YerrowSniper]

You need a comparator and bushing, plus your calipers... that's what I was alluding to earlier about CBTO.

There are a bunch of ways to find "jam" and/or "the lands", but you have to have a way to measure it.

I have all the tools to measure, SAC makes some awesome inserts and Mitutoyo makes great calipers.
Reason I went with that is because I have actually sent my brass and my bullet to my smith to just give me COAL.
I’ll look up how to measure jam point.

 

[padom]

Any resources where I can get a good repeatable method to measure that?

First youll need tools to properly measure. An overal length gauge, bullet comparator, case comparator and a good set of calipers are tools I would never reload without. Hornady and Short Action Customs both sell kits to do this with.

Step 1

Find the distance to the lands with every one of the bullets you plan to shoot in that gun. Measure each of them using the Hornady Overall Length Gauge and a modified case for that specific caliber. I keep a log for every gun, chamber, barrel combo. When I first get that gun I measure distance to the lands with every bullet Im going to load in that gun and write down the COAL and CBTO in my log. I measure the CBTO in the tool with the bullet comparator.


Hornady Overall length guage

Hornady Lock-N-Load Overall Length Ga Bolt Action

The Hornady Lock-N-Load Overall Length Gauge is one of the best kept secrets to accurate reloading. This tool allows reloaders to quickly and easily...

www.midwayusa.com

You need a modified case for every caliber you are check distance to lands. Here is one for 6GT (Or, if you ship me a case Ill make one with one of your 1x brass.

6mm GT Modified Case – Copper Creek Cartridge Co.

coppercreekcartridgeco.com

Hornady Bullet Comparator

HORNADY LOCK-N-LOAD BULLET COMPARATOR BASIC SET | Brownells

Measuring cartridge lengths across the bullet tips is not a reliable (or repeatable) method for measuring loaded rounds. Its common for variations of up to .025" to exist from one round to the next. Hornady's Bullet Comparator measures rounds from...

www.brownells.com

Here is the hornady case headspace gauges you should be using to measure your case for proper sizing

Hornady Lock-N-Load Headspace Ga 5 Bushing Set Comparator

The Hornady Lock-N-Load Headspace Gauge is a great tool for increasing the accuracy of your loaded ammunition. The Headspace gauge measures from the...

www.midwayusa.com

Once you have the CBTO to lands with your bullet. Seat your bullets 0.01" or 0.02" off lands and do your load work up. Once you find your load, do seating depth test closer to lands in .005" increments.

Now you have found your proper load and proper seating depth where you arent blowing primers, arent leaving any marks on your case heads, and have an accurate, low SD safe load.

 

[YerrowSniper]

First youll need tools to properly measure. An overal length gauge, bullet comparator, case comparator and a good set of calipers are tools I would never reload without. Hornady and Short Action Customs both sell kits to do this with.

Step 1

Find the distance to the lands with every one of the bullets you plan to shoot in that gun. Measure each of them using the Hornady Overall Length Gauge and a modified case for that specific caliber. I keep a log for every gun, chamber, barrel combo. When I first get that gun I measure distance to the lands with every bullet Im going to load in that gun and write down the COAL and CBTO in my log. I measure the CBTO in the tool with the bullet comparator.


Hornady Overall length guage

Hornady Lock-N-Load Overall Length Ga Bolt Action

The Hornady Lock-N-Load Overall Length Gauge is one of the best kept secrets to accurate reloading. This tool allows reloaders to quickly and easily...

www.midwayusa.com

You need a modified case for every caliber you are check distance to lands. Here is one for 6GT (Or, if you ship me a case Ill make one with one of your 1x brass.

6mm GT Modified Case – Copper Creek Cartridge Co.

coppercreekcartridgeco.com

Hornady Bullet Comparator

HORNADY LOCK-N-LOAD BULLET COMPARATOR BASIC SET | Brownells

Measuring cartridge lengths across the bullet tips is not a reliable (or repeatable) method for measuring loaded rounds. Its common for variations of up to .025" to exist from one round to the next. Hornady's Bullet Comparator measures rounds from...

www.brownells.com

Here is the hornady case headspace gauges you should be using to measure your case for proper sizing

Hornady Lock-N-Load Headspace Ga 5 Bushing Set Comparator

The Hornady Lock-N-Load Headspace Gauge is a great tool for increasing the accuracy of your loaded ammunition. The Headspace gauge measures from the...

www.midwayusa.com

Once you have the CBTO to lands with your bullet. Seat your bullets 0.01" or 0.02" off lands and do your load work up. Once you find your load, do seating depth test closer to lands in .005" increments.

Now you have found your proper load and proper seating depth where you arent blowing primers, arent leaving any marks on your case heads, and have an accurate, low SD safe load.

Thanks!

 

[padom]

I don’t get it...
Load hasn’t changed...
Nothing changed.
Why did the pressure suddenly increased?

You may have been kissing and now are jamming and your powder charge was not worked up for kissing or jamming so ANY slight change in carbon build up, weather/temp change, seating change by just a slight bit, different lot of brass, primers, etc can easily cause this. And that is more evident but you saying you had marks, but less of a mark on you case heads before you started blowing primers.

I have work up and shot 100,000's of rounds in my 5 TL3's over the years. That is a mark from an over pressured load. No doubt about it. I can send you 1000 pictures of case heads from all my different TL3's in all the different calibers I currently shoot, 223rem, 224V, 220TB, 6.5cm, 6.5x47L, 6BR, .300blk, .308win... None of them have that mark on the head.....

 

[CK1.0]

I don't know why in the world it matters that you sent you brass and bullets to your smith or that you have nice calipers smh lol?

IDK why this popped into my head but did you consider powder? Is there a chance something is off with how your charges are being thrown?

 

[padom]

I don't know why in the world it matters that you sent you brass and bullets to your smith or that you have nice calipers smh lol?

IDK why this popped into my head but did you consider powder? Is there a chance something is off with how your charges are being thrown?

It matters because he is saying he sent them to his Smith to do the measuring for him and give him the number..... I don't think you have the right info and/or you have too much powdernin the case. Follow what I said above and you'll work up a great, safe load

 

[OHwelder]

I bet you haven't cleaned the carbon COMPLETELY out of it in those 500 rounds. There's excess carbon buildup causing the pressure increase.

This

 

[CK1.0]

It matters because he is saying he sent them to his Smith to do the measuring for him and give him the number.....

THAT'S. FUCKING. CRAZY.

 

[YerrowSniper]

I don't know why in the world it matters that you sent you brass and bullets to your smith or that you have nice calipers smh lol?

IDK why this popped into my head but did you consider powder? Is there a chance something is off with how your charges are being thrown?

Yeah I know I was “lazy”
Back then it charged it with a Charge Master accuracy should be +/- 0.1 - 0.2gr my smith told me that he didn’t see pressure sign until 35.2 that’s a whole grain over.
I still have some bullets from my batch I’ll pull them and re measure. I have an Autotrickler with ADFX scale coming this week.

 

[YerrowSniper]

Ok, while I am waiting on my modified case (Thanks, Padom)
I used a fired case, full-length resized, and cut some slits on the neck. This should get me pretty close to get my "to the land" value. I will check this against using a modified case.

The value I got for Jam/To The Land is COAL: 2.6085"
If we subtract 20thou from this, it gets us 2.5885"

My current load's COAL is 2.5780"
I am at 30thou off the land/jam.

I have also pulled 15 bullets yesterday and used a separate scale to measure the charge.
They all read 34.2gr

I am at a loss...

My next tests would be:

1. Shot without the Kinetic Security ATS. I seriously don't see how an added weight can affect the pressure.
2. Clean the barrel and test again, this barrel has seen a total of 400ish rounds, and I have cleaned it at 150-200 rounds.

Anything else I should try for?

 

[Reload10]

Do you have a borescope? When you clean it I would use iosso paste in the first 10" of the barrel. Don't be scared, you won't hurt it. Scrub until the bore is spotless.

I went through this exact scenario with one of my dasher barrels. Cleaned it with boretech c4 and eliminator and I was still popping primers. I scrubbed the hell out of it with iosso/thorroclean until the bore was spotless and it was back to its normal self after that. Normal velocity and no popped primers.

 

[padom]

Ok, while I am waiting on my modified case (Thanks, Padom)
I used a fired case, full-length resized, and cut some slits on the neck. This should get me pretty close to get my "to the land" value. I will check this against using a modified case.

The value I got for Jam/To The Land is COAL: 2.6085"
If we subtract 20thou from this, it gets us 2.5885"

My current load's COAL is 2.5780"
I am at 30thou off the land/jam.

I have also pulled 15 bullets yesterday and used a separate scale to measure the charge.
They all read 34.2gr

I am at a loss...

My next tests would be:

1. Shot without the Kinetic Security ATS. I seriously don't see how an added weight can affect the pressure.
2. Clean the barrel and test again, this barrel has seen a total of 400ish rounds, and I have cleaned it at 150-200 rounds.

Anything else I should try for?

Im not confused at all, do a load work up which you said you didnt do you went off a charge your smith told you. You did good and got a rough distance to lands with COAL. You should be measuring that round with a bullet comparator to get your CBTO for that distance to lands... Then back .02 off that and set your die to use that number....

Now go do a load work up in .2 or .3gr increments starting a full grain or grain and half below your current charge. Guarantee youll find those wont have the nasty mark on the case heads....

 

[308pirate]

Some guy takes a ton of shortcuts while reloading ammo and has "inexplicable" pressure issues.

I'm shocked.

Shocked, I tell you.

 

[Steel head]

That’s some impressive brass flow and pressure.
As said above, time to do the work required.
Confirm the throat and do a proper load work up.

 

[JLP.Payette]

Carbon ring. They build up fast in my 6gt using Precision rifle powder, I had to scrub it out every 150-200 rounds. I've since switched powders.

 

[Dolomite_Supafly]

I don’t get it...
Load hasn’t changed...
Nothing changed.
Why did the pressure suddenly increased?

Moisture or oils in the chamber can cause it.

Changing ANYTHING, like powder or primers or bullets can also cause problems but only if you are already close to max.

Having a case that is trimmed too long for the chamber can also cause this. The case mouth gets jammed into the throat where it is squeezed. This sort of wedges the bullet inside the case mouth and will definitely increase pressures to unsafe levels. You have a bore scope. Chamber a fired case, go down the bore with the scope and see where the case mouth ends relative to the throat. It does not take much to go from safe to dangerous with a case that is too long.

Shooting a bullet that is jammed into the lands can increase pressure. My 6BR has never had an issue with pressures. I decided to try a bit of a jam with the same load and now I get ejector swipes and they can get a little sticky.

What are your velocities across the chronograph? How do they compare to the previous lot?

 

[orkan]

I am personally remeasuring distance to the land to make sure...

I need a bomb proof method that cannot be fucked up lol.

 

[2aBaC̶a̶]

Haha double ^^^

Was just about to post this.

Nice vid!

 

[YerrowSniper]

Moisture or oils in the chamber can cause it.

Changing ANYTHING, like powder or primers or bullets can also cause problems but only if you are already close to max.

Having a case that is trimmed too long for the chamber can also cause this. The case mouth gets jammed into the throat where it is squeezed. This sort of wedges the bullet inside the case mouth and will definitely increase pressures to unsafe levels. You have a bore scope. Chamber a fired case, go down the bore with the scope and see where the case mouth ends relative to the throat. It does not take much to go from safe to dangerous with a case that is too long.

Shooting a bullet that is jammed into the lands can increase pressure. My 6BR has never had an issue with pressures. I decided to try a bit of a jam with the same load and now I get ejector swipes and they can get a little sticky.

What are your velocities across the chronograph? How do they compare to the previous lot?

When I first got the rifle I was getting 2950 and no marks at all.
I did clean the rifle after 200ish rounds.

Went back at it after cleaning and was getting 2990-3000
and at the match, I was blowing primer

 

[YerrowSniper]

THIS IS AWESOME!
Thanks, I knew getting that CPS was gonna pay dividend LMAO =)

 

[YerrowSniper]

OK!
Here are some new findings, Thanks Greg again, this method works magic.

Removed the FP from the bold to get a feel on how the TL3 closes. It doesn't drop close like with Greg's rifle bit does close with minimal resistance; I closed it a few times to get familiar with how it should feel.

I got a few of my fired cases (First-time fire, Hornady Brass) measured them with the SAC 6mm 35 degrees insert, ensuring that all the brass were the same.

I picked 3. Full length resized with the correct bushing that yields a 2 thou neck tension, I have also adjusted the die to bump the neck 2 thou exactly, giving me a set of uniform brass to work with.

I have also picked another 3 and annealed them with the AMP before the full-length resize and neck bump, yielding the same results. Now I have 6 pieces to experiment with.

Note:
If I only bum the neck even 1.5 thou, it does not close freely, ever so slight resistance.
Annealed brass does no resize more, nor does it bump the neck more.

Before proceeding further, I check for runout/concentricity with the 21st-century tool thingy.
Annealed brass yields a 1-2 thou runout, and the non-annealed brass is more like a 2-3 thou runout.

Place the empty brass on the bolt carefully and feel how it closes without a bullet.
Next, I set my bullet way high to 2.6280" COAL (currently, I suspect my lands to be at 2.6080" COAL)

Slowly work my way down until I get to 2.6020" COAL. It's very, very close. I can feel it.
At 2.6000" COAL, it drops free. As free as if there was no bullet in there.

This leads me to believe that my lands are at 2.6020" COAL using the Primal Right's Method. My previous quick and dirty gave me a very similar number. I was at 2.6080" COAL.
I did repeat one more time with another piece of brass, same results.
I did also check for concentricity of the ogive, giving me the same number as the neck around 2 thou.

Using this newly found knowledge, we can determine that if I want to load:

20 thou off the lands, COAL = 2.5810" and CBTO = 1.8690"
30 thou off the lands, COAL = 2.5710" and CBTO = 1.8590"

My previous load that was blowing primers was at 2.578" the good news is that I was never near the lands. I still need to determine the cause of the excess in pressure...

1. Dirty Barrel, I will clean again, but like I said, this was cleaned around 200 rounds
2. The current charge, yes, it might be hot, but it doesn't explain my first few hundred rounds shooting at 2950 with an SD of 6-8
3. ATS, yes, I will shoot this without it

I have learned a lot, thanks guys!

 

[Dthomas3523]

OK!
Here are some new findings, Thanks Greg again, this method works magic.

Removed the FP from the bold to get a feel on how the TL3 closes. It doesn't drop close like with Greg's rifle bit does close with minimal resistance; I closed it a few times to get familiar with how it should feel.

I got a few of my fired cases (First-time fire, Hornady Brass) measured them with the SAC 6mm 35 degrees insert, ensuring that all the brass were the same.

I picked 3. Full length resized with the correct bushing that yields a 2 thou neck tension, I have also adjusted the die to bump the neck 2 thou exactly, giving me a set of uniform brass to work with.

I have also picked another 3 and annealed them with the AMP before the full-length resize and neck bump, yielding the same results. Now I have 6 pieces to experiment with.

Note:
If I only bum the neck even 1.5 thou, it does not close freely, ever so slight resistance.
Annealed brass does no resize more, nor does it bump the neck more.

Before proceeding further, I check for runout/concentricity with the 21st-century tool thingy.
Annealed brass yields a 1-2 thou runout, and the non-annealed brass is more like a 2-3 thou runout.

Place the empty brass on the bolt carefully and feel how it closes without a bullet.
Next, I set my bullet way high to 2.6280" COAL (currently, I suspect my lands to be at 2.6080" COAL)

Slowly work my way down until I get to 2.6020" COAL. It's very, very close. I can feel it.
At 2.6000" COAL, it drops free. As free as if there was no bullet in there.

This leads me to believe that my lands are at 2.6020" COAL using the Primal Right's Method. My previous quick and dirty gave me a very similar number. I was at 2.6080" COAL.
I did repeat one more time with another piece of brass, same results.
I did also check for concentricity of the ogive, giving me the same number as the neck around 2 thou.

Using this newly found knowledge, we can determine that if I want to load:

20 thou off the lands, COAL = 2.5810" and CBTO = 1.8690"
30 thou off the lands, COAL = 2.5710" and CBTO = 1.8590"

My previous load that was blowing primers was at 2.578" the good news is that I was never near the lands. I still need to determine the cause of the excess in pressure...

1. Dirty Barrel, I will clean again, but like I said, this was cleaned around 200 rounds
2. The current charge, yes, it might be hot, but it doesn't explain my first few hundred rounds shooting at 2950 with an SD of 6-8
3. ATS, yes, I will shoot this without it

I have learned a lot, thanks guys!

Why isn’t it drop closing with the firing pin assembly removed?

 

[spife7980]

Why isn’t it drop closing with the firing pin assembly removed?

The zermatt has the spring loaded bolt head and you can feel that just a bit

 

[padom]

When I just got the rifle and shooting around 2950 there was only a very faint mark.

When I first got the rifle I was getting 2950 and no marks at all.
I did clean the rifle after 200ish rounds.

Went back at it after cleaning and was getting 2990-3000
and at the match, I was blowing primer

Post #12 you say you have been getting marks since you first got the rifle, just not as deep as you are now....
In post #35 you are now saying when you first got the rifle you had no marks..

Which one is it? youre contradicting yourself in 2 different posts in this thread.

Bottom line, you should have no marks. Having faint marks since day one means you were right on the edge and now something just slightly changed causing the excess pressure... Many have already replied on what that slight change could be but honestly, it doesnt matter.

You need to just stop the wondering and listen to what we are telling you... Just go do a proper load workup in your rifle with your brass and your bullets and your powder and your primers and there will be no mystery. You will have a safe, accurate, low SD load once you do that.

 

[YerrowSniper]

Have you left your powder out in the hopper exposed to air? It will speed up when it dries out. The fix if that happens is to drop your charge and work up

No, I never leave powder in the hopper.

 

[YerrowSniper]

Post #12 you say you have been getting marks since you first got the rifle, just not as deep as you are now....
In post #35 you are now saying when you first got the rifle you had no marks..

Which one is it? youre contradicting yourself in 2 different posts in this thread.

Bottom line, you should have no marks. Having faint marks since day one means you were right on the edge and now something just slightly changed causing the excess pressure... Many have already replied on what that slight change could be but honestly, it doesnt matter.

You need to just stop the wondering and listen to what we are telling you... Just go do a proper load workup in your rifle with your brass and your bullets and your powder and your primers and there will be no mystery. You will have a safe, accurate, low SD load once you do that.

Faint to no marks, so are more apparent then others.

I get that a proper load dev is needed. I am just trying to learn and get more opinions on it.

thanks

 

[Ledzep]

Any amount of ejector slot marking on the brass in a bolt gun means you're hot. Period.

Loose primer pockets in 3 firings means you're running hot. Blown pockets in the 1st firing means you're running retarded.

Drop powder charge.

 

[supercorndogs]

Don't think you have to run on the ragged edge. If you want 3k get a bigger case. Run your cases in the window they were made for and see how easy it makes your life.

 

[JLP.Payette]

Don't think you have to run on the ragged edge. If you want 3k get a bigger case. Run your cases in the window they were made for and see how easy it makes your life.

Exactly. I got pressure at 2900 with Shooters World Precision with 108Elds. I've switched to H4350 and could reach 3000 fps but went with a slower node at 2870 with great success.

 

[YerrowSniper]

Yup yup.
Again this is all new to me, I am learning as I got.
This is my very very first PRS rifle
And very easy stages of loading for PRS.

 

[Dolomite_Supafly]

When I first got the rifle I was getting 2950 and no marks at all.
I did clean the rifle after 200ish rounds.

Went back at it after cleaning and was getting 2990-3000
and at the match, I was blowing primer

Barrels do speed up as they break in.

 

[Dirtbiker250]

I had an issue with a rifle .. 6.5 creed proof barrel from proof. Prefit for origin. Started out using alpha brass and h4350 and 140berger. Went all the way to 41.5 with no pressure. Normal 6.5 creed stuff. 40.5 shot the best. So I stuck with it. 200 rounds later I start getting a click on extraction at the top of the extraction cam. Indicating pressure. Also Case head swipe. I messed with it for a good 50-80 rounds. Wouldn’t go away. Cleaned barrel good everything I could think of. Even backed down to 38.5 just to see what happen. Still a hard click at top of extraction. Finally I measured the loaded neck of the brass and it was .0005” smaller than the chamber neck cut in the barrel. Switched to Hornady brass which has more clearance because the brass is slightly thinner.. no more problems. Running 41.5 now at same speed 40.5 was in alpha brass.. so for some reason the brass didn’t start showing pressure till about the 3rd loading Something to check maybe? Just an idea

 

[YerrowSniper]

I had an issue with a rifle .. 6.5 creed proof barrel from proof. Prefit for origin. Started out using alpha brass and h4350 and 140berger. Went all the way to 41.5 with no pressure. Normal 6.5 creed stuff. 40.5 shot the best. So I stuck with it. 200 rounds later I start getting a click on extraction at the top of the extraction cam. Indicating pressure. Also Case head swipe. I messed with it for a good 50-80 rounds. Wouldn’t go away. Cleaned barrel good everything I could think of. Even backed down to 38.5 just to see what happen. Still a hard click at top of extraction. Finally I measured the loaded neck of the brass and it was .0005” smaller than the chamber neck cut in the barrel. Switched to Hornady brass which has more clearance because the brass is slightly thinner.. no more problems. Running 41.5 now at same speed 40.5 was in alpha brass.. so for some reason the brass didn’t start showing pressure till about the 3rd loading Something to check maybe? Just an idea

At this point I’ll check everything! Thank you for sharing!

 

[ChiefW]

Since you said the problems started with new brass, how did you prep them for the loads and what trim length did you use?