3x fired brass not chambering - 300PRC

dukerugger25

dukerugger25

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Apr 2, 2017
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Utah
#1
I'm having a problem with my 300PRC, in that 3x brass will no longer chamber. Brass was resized and the shoulder was bumped back 0.002", just like the first two times I reloaded it. This time however the bolt is hanging up at the downstroke. Checked headspace and it is correct, same as the 2x fired rounds that I still have loaded up. Case length is the same.

I even bumped the shoulder back another 0.005" on a few pieces to see if that would help, still will not chamber. It's almost like the case is not getting fully resized down by the head? Any assistance would be greatly appreciated.
 
#5
You need to take some measurements. If the die is not sing the body diameter it will show. Other things can cause this also. Something binding the ejector or stopping the extractor from easily popping over the rim.
 
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#6
What measurements in particular? Where on the case?

I've got Hornady brass that I have at 6 loadings in same rifle and have not seen this issue if that helps.

Also m using a Forster coax press
 
#7
One a little above the extractor grove, one in the middle, and one in-between those two. You could measure the diameter a little below the shoulder also to make sure its not there. Then size the case as see if any of them change.

Do they make a small base 300PRC die yet?
 
#10
Attached is a picture of measurements for hornady 300PRC brass (6x) compared to ADG (3x). The hornady brass chambers perfectly. Measurements are taken from the base of the case using a tool scope. I took measurements from 7 different locations.

Hornady brass on left, ADG brass on right
 

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  • 300 PRC Brass.jpg
    300 PRC Brass.jpg
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#11
Can you chamber the round if you place the rim of the cartridge behind the extractor before pushing the bolt in? Just want to rule out the extractor getting in the way.

Also, what is the case length between the two and do you trim your brass?
 
#14
dukerugger25 said:
Attached is a picture of measurements for hornady 300PRC brass (6x) compared to ADG (3x). The hornady brass chambers perfectly. Measurements are taken from the base of the case using a tool scope. I took measurements from 7 different locations.
Click to expand...

You can see where the ADG brass might be sticking. It is interesting that the Hornady brass is maintaining a smaller diameter. It would seem like neither are touching the die at the base. You are going to want to rule out extractor and ejector problems first.
 
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#15
i placed the round behind the extractor before pushing the bolt in - would not chamber. Also placed round in magazine, pushed bolt forward until it was tight, reversed bolt slightly and then pushed back in - would not chamber.
Did the same thing with the hornady brass and loaded factory rounds - both chambered like butter.

Case length for both is 2.570" - yes i trim all brass.

Regretfully i do not have 3x fired brass that has not been resized.

i loaded up some fresh (0x) ADG brass tonight - will try to get out to shoot next weekend and see how the fresh brass reacts.
 
#16
To be clear - ADG brass is top notch, it's all I shoot in 5 other rifles. I only mentioned the name above in hopes that I'm doing something silly/stupid and there is an easy fix. Not to nock the brass / manufacturer.
 
#19
Lots of guys are having the same problem with 6.5 PRC, myself included. I’ve tried Hornady and Forster. Ryan Furman and Broz are working on a fix. Neither manufacturer was willing to help me. Redding also said they weren’t willing to make a custom die that would size the base more.

Patriot Valley Arms is working on a universal small base die, which will be awesome, but I’ve been waiting months and this Corona crap probably isn’t going to speed things up much. I did find that I seemed to get a little more sizing after trimming my brass to minimum and one-shot spray lube rather than wax.
 
#20
dukerugger25 said:
Holy smokes, that video was awesome!

I know what I'm doing next week - sending fired brass to whidden for a new die ? I've used them before with a ton of success
Click to expand...

I've got a custom 300 PRC from them. The first time I used it, I needed some extra umph to get each cased size. Been very happy with it.
 
#21
Whidden made the original dies for my 300 Norma Improved, but had the exact same problem with those dies. Ryan Pierce ended up having Hornady make a proper sizing die for it. You must have had better luck! How much did a custom sizer cost?
 
#23
I am getting them sized down enough to size and shoot, they’re just a little sticky on extraction. PVA won’t be much cheaper if they ever come in stock. Unfortunate that both PRC’s are having this issue.
 
#30
I’m using ADG brass in my 6.5. I don’t have a 300. I shoot 156 Berger’s out of my Seekins Havak at 2950 w/o suppressor, 2970 with. No signs of pressure, and wonderfully accurate with great ES. The issue is a die problem, not brass, not rifle, and not excess pressure. The case gets fully fire formed after 2-3 firings, and the dies won’t size the base enough. I’ve got a thread on this in LRH, LRO, and maybe even on Rokslide. Ryan Furman tried Redding with no luck, but I didn’t ask if it was a body die... I didn’t think that would work any differently than a full length die, but you guys think it might? I’ll order one tonight if that’s the case. My ADG brass is perfect after 3 firings, just needs a little more squeeze!

between Broz, Furman, and I, I believe we’ve tried every die manufacturer within reason (not Warner Tool, etc) same problem. My experience has all been with the 6.5, but Furman says the 300 does the exact same thing.
 
#31
Btw, my cases were not excessively long, some were .002-003 past max length. However, the 6.5 PRC has a trim to number which is .015 shorter than max rather than .010 like most, which is interested to me.
 
#33
Last week I had a customer come in with a Parker Hale and a 243win (after market) barrel on it. He could barely chamber factory rounds, and couldn't size brass properly to fit the chamber. Head space was fine, as was OAL. I ended up pulling the barrel and licking it with a chamber reamer. I was astonished how much material came out. Re-assembled, and everything was fine after that.

No idea who chambered it, but their reamer was a few thou undersize at the base. Should have taken a pic of the swarf that came out. Not small shavings, but swarf.

Customer is happy and apparently it's shooting good.

Tight chambers exist. Get dies to suit, or get it built correctly in the first place.
 
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#34
dukerugger25 said:
Attached is a picture of measurements for hornady 300PRC brass (6x) compared to ADG (3x). The hornady brass chambers perfectly. Measurements are taken from the base of the case using a tool scope. I took measurements from 7 different locations.

Hornady brass on left, ADG brass on right
Click to expand...

According to your measurements you have a bulge in the brass as it tapers down from the head, it should be less than the 0.532 According to saami it's probably just over chamber size at that point in the case. Hard to belive your full length die wont get that high up on the case.

Try bumping the shoulder a little more.

20200412_110957.jpg



20200412_105745.jpg
 
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#35
If you are going to have to do a 2 step process to get brass to size is bore the shoulder out of a cheaper die, then shave 20 thou off the bottom and use it to constrict the brass. Then bump it in your die.
I have the same crap going on in 25 saum and 2 Whidden dies, one FL, one fL bushing, the reg die will constrict it, but not until it makes a trip in the reg FL die first, it is that tight.
I have never had a custom die made, giving it serious consideration, but not sure if I like the case enough to mess with it.
 
#36
I'd try a small base die, a 'ring' die (same general idea as the PVA universal small base bushing die), or a custom sizer made from your fired brass.

Small base dies are kind of rare outside calibers like the .223 Rem and .308 Win that are shot thru a semi-auto, the PVA die has been out of production for a while now, the guy that made my 'ring' die is pretty hit-or-miss as far as comms, and I've always resented the fact that you almost need to buy a neck sizer die just long enough to fire a hand full of cases a couple times to get them fully formed to your chamber, before you send them off to get a custom die made. My two attempts at custom dies - a custom F/L sizer, and a custom seater (hand die) - were less than satisfying.

Kind of a PITA, any way you slice it.
 
#37
It is interesting, most these new super cartridges 28 Noslers, 300NM, PRC, DTHOMAS’ 6GT etc. that promise more speed with less case capacity, once run at their advertised max speed on a bit softer brass, seem to have classic case head issues.

These are exhibiting the same exact symptoms that many experience when we realized our rimmed magnums and LMs still had 100-150 fps in them when we handloaded with other powders. If we didn’t use Lapua brass the number of reloads showing the same symptoms as above showed up early.

What I am suggesting is the current shared max load data for these super cartridges is way closer to the edge than old data for similar class cartridges of yesterday.

As an example my 7mm mag runs published 170 class bullets around 2900- 2950; but with handloads up to 3150 out of a 26” barrel. That's as fast as the published 280 Nosler, But the rub is both calibers running in that weight / speed class can get case head expansion after a bunch of reloads.

Just adding something to think about.
 
#38
2aBaCa said:
According to your measurements you have a bulge in the brass as it tapers down from the head, it should be less than the 0.532 According to saami it's probably just over chamber size at that point in the case. Hard to belive your full length die wont get that high up on the case.

Try bumping the shoulder a little more.

View attachment 7296752


View attachment 7296744
Click to expand...
Thank you for the drawings and info.

Interesting observation - after resizing (bumping shoulder) back on all ADG brass to .008" all rounds were able to chamber with the Redding die. However - there is a very distinct line on the case, where the lube has stopped, showing how far down the brass the die is going. Measuring from base of case to the line is ~0.210". The line is on the surface of the case only, wipes right off. I will load up all brass and shoot next week.

As for load - I'm using 76.1gr of RL-26 pushing a 215 Berger.
 
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#39
What are you using to measure the shoulder and what is the measurement?

How fast are those bergers moving? I'm loading up a variety of rounds for a new rifle now and that combo is one of them.
 
#40
dukerugger25 said:
Thank you for the drawings and info.

Interesting observation - after resizing (bumping shoulder) back on all ADG brass to .008" all rounds were able to chamber with the Redding die. However - there is a very distinct line on the case, where the lube has stopped, showing how far down the brass the die is going. Measuring from base of case to the line is ~0.210". The line is on the surface of the case only, wipes right off. I will load up all brass and shoot next week.

As for load - I'm using 76.1gr of RL-26 pushing a 215 Berger.
Click to expand...
You really did not address the issue, you just bumped your shoulders back into the dark ages for another potential issue. Load and fire a few, if you get a distinct click at the top of the bolt lift, with some resistance extracting a case, it will be wise to constrict the case base.
 
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#41
Milo 2.5 said:
You really did not address the issue, you just bumped your shoulders back into the dark ages for another potential issue. Load and fire a few, if you get a distinct click at the top of the bolt lift, with some resistance extracting a case, it will be wise to constrict the case base.
Click to expand...
Yep, spot on. Now he will start losing cases to head separation
 
#42
I agree 100% that I have not solved the issue. I'm @ a loss of what to do to correct the issue . I have never used a body die before, but from my reading, it sounds like it will push the shoulder back as well. Is this thinking incorrect?

I'm using a Hornady comparator (0.420, D) and calipers to measure the shoulder. Measurement is 2.1900 post firing, bumping back to 2.1820. New ADG brass measured 2.1830 on my gauges.

For the Berger's, they are running at 3035fps in a 26" barrel.
 
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#46
On a similar note.
I recieved some brass from somone and 20 pices were once fired. I could not get these 20 pieces resized enough to fit my chamber. They were all bloated around the base, you can see and feel it.

20201223_100821.jpg

20201223_100810.jpg
 
#47
Maybe just the pictures on my phone. It looks like either the chamber it was fired in was oversized or the brass was undersized.

Most likely chamber. That looks like alot of growth a.d alot of imprint onto brass???
 
#48
1moaoff said:
Maybe just the pictures on my phone. It looks like either the chamber it was fired in was oversized or the brass was undersized.

Most likely chamber. That looks like alot of growth a.d alot of imprint onto brass???
Click to expand...
No doubt oversized chamber looking by how much it swelled.

had to toss them. I just could not size that far down. Possibly the brass spring back on the un annealed portion was too much.

Have NOT had any problems with my own fired brass or resizing and definitely do not have that ring.
 
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#49
Hiwayman92 said:
I’m using ADG brass in my 6.5. I don’t have a 300. I shoot 156 Berger’s out of my Seekins Havak at 2950 w/o suppressor, 2970 with. No signs of pressure, and wonderfully accurate with great ES. The issue is a die problem, not brass, not rifle, and not excess pressure. The case gets fully fire formed after 2-3 firings, and the dies won’t size the base enough. I’ve got a thread on this in LRH, LRO, and maybe even on Rokslide. Ryan Furman tried Redding with no luck, but I didn’t ask if it was a body die... I didn’t think that would work any differently than a full length die, but you guys think it might? I’ll order one tonight if that’s the case. My ADG brass is perfect after 3 firings, just needs a little more squeeze!

between Broz, Furman, and I, I believe we’ve tried every die manufacturer within reason (not Warner Tool, etc) same problem. My experience has all been with the 6.5, but Furman says the 300 does the exact same thing.
Click to expand...

So far, I've only made maybe 10 or 12 PRC dies in 300 and 6.5. if your dies are not working, then what you spent is a waste EH? You maybe should ask Jorge Ortiz how the two I've made for him are working out. Yea, you'll wait some to get them, but custom shit starts with each one being designed from your fired brass. It's not off the shelf -- for a reason.
To the OP, -- the brass pictured above looks like a very bad chamber job. Start there and make it correct, then try the dies you have. there is no sense in making custom for something that bad.
I can get it done for you, just not at wally world prices or delivery.
Time to pull parts out of the furnace--- got to go.
Merry Christmas everyone.

HTH
Alan
 
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#50
There's some good info in the following threads:

The PRC Die Problem

PRC Die Not Sizing Enough This thread, while started about the 6.5PRC, also applies to the 300PRC.

The issue isn't the brass, it's the chamber spec at the .200 line and how little it differs from the cartridge spec. Dies are not resizing the area by the web enough. Consensus seems to be the back end of the chamber needs to be opened up .002 or so by polishing the chamber, or opening the reamer (see the first thread, page 10, post 131, but read the thread so you know the context).

ETA - My 1x Hornady 300 PRC brass is similar to the pics posted by 2aBaCa, just not as badly bulged at 1x. AXMC in 300 PRC with a Bartlein barrel chamber by a reputable Smith.

ETA II - Have the Wheeler vids on YouTube been taken down? I can't seem to find any of them any longer.
 
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