I see it now…Nope, you're right 2.26 Coal…..old man eyes got me…I fixed it!
Last edited:
Pressure Signs - M16 High Power Rifle
- Thread starter grizlywinkleman
- Start date
Help Support Long Range Hunting Forum
Switch to CCI 450 or 41. Another option is the Federal 205MAR.
I support the TX Junior program, cranking a dozen barrels a year for them from Shilen donated blanks. They average north of 5K rounds fired by each member. The team management strictly use the thicker cup primers. No catering encountered even on their hot 80 grain 600 yard loads.
For the kids who do not follow strict gun cleaning regimen when they train on their own, I had a carbide reamer made to the same spec as the reamer I designed for the team. The difference is the only sharpened section is the throat area. The team equipment manager using a special guide rod I made, he runs the carbon ring remover reamer on suspect barrels.
Here is an old chart of primer cups for reference.
I support the TX Junior program, cranking a dozen barrels a year for them from Shilen donated blanks. They average north of 5K rounds fired by each member. The team management strictly use the thicker cup primers. No catering encountered even on their hot 80 grain 600 yard loads.
For the kids who do not follow strict gun cleaning regimen when they train on their own, I had a carbide reamer made to the same spec as the reamer I designed for the team. The difference is the only sharpened section is the throat area. The team equipment manager using a special guide rod I made, he runs the carbon ring remover reamer on suspect barrels.
Here is an old chart of primer cups for reference.
Citified
Well-Known Member
I think it is important to point out he stated increasingly flattened primers so before we make recommendations on changing primers,
He should double check carbon ring and case length after sizing. He could switch to the harder primers, but that could mask other issues. I personally have never needed to switch to the military primers and have not experienced slam fires or blown primers.
I shoot about the same Varget loads he does up to 77 grains in 7 and 8 twist barrels.
He should double check carbon ring and case length after sizing. He could switch to the harder primers, but that could mask other issues. I personally have never needed to switch to the military primers and have not experienced slam fires or blown primers.
I shoot about the same Varget loads he does up to 77 grains in 7 and 8 twist barrels.
In my opinion this is the simplest answer, and I've been through all this. When first reloading 5.56, I was getting the pancake primer shown above all the time, no matter how mild the load, but no carbon ring on the bolt face.
Long story short, swaging IS the problem. Getting it perfect is easy, but consistently perfect without constantly adjusting and throwing out brass is impossible.
It is very easy to over swage and expand the primer pocket without noticing it. I only identified the problem when I finally obtained a go/no-go primer pocket gauge. I tossed all the brass that the no-go slipped into. This eliminated half the problem - I still got pancaked primers (no carbon ring) about half the time. I then tossed all the brass which the no-go gauge even just started to stick at all. I didn't have much brass left, but this cured the problem.
I tried to set up my swager to avoid the issue in the future, and found instead I was crushing primers in the press way too often. I switched to reaming and no more problems at all.
I have given up swaging all together. I use a reamer in my drill press now, followed by a no-go gauge. I immediately toss anything that even slightly sticks with the no-go gauge.
So, my advise would be to obtain a go/no-go primer pocket gauge (or a set of pin gauges for the same range) and check your brass that didn't pancake against those that did, and you will identify the problem just as I did.
I was going to weigh in until I saw Bamban post. I'd pay attention to what he's saying for these reasons;
1) he's a longtime, high level service rifle competitor.
2) he's a Texas competitor where they shoot lots of N540. He's probably got the biggest knowledge base in N540 in the country on tap.
3). His latest avocation is turning and chambering AR competition barrels and supports one of the top junior teams in the country with that. With that comes inside knowledge on longevity, accuracy and cleaning of accurate AR barrels (based on waaay more than a couple handfuls of barrels and probably hundreds of thousands of accurate rounds fired).
He just dropped some big hints for you.
1) he's a longtime, high level service rifle competitor.
2) he's a Texas competitor where they shoot lots of N540. He's probably got the biggest knowledge base in N540 in the country on tap.
3). His latest avocation is turning and chambering AR competition barrels and supports one of the top junior teams in the country with that. With that comes inside knowledge on longevity, accuracy and cleaning of accurate AR barrels (based on waaay more than a couple handfuls of barrels and probably hundreds of thousands of accurate rounds fired).
He just dropped some big hints for you.
marshalldodge
Member
In my experience with N540, 24.6 grains should provide 2700 FPS out of a 20" 5.56 barrel.
I only see one primer that I would be concerned about in your pics. bambam made a good point about using primers with thicker cups. My preference is the CCI 450 when getting on the upper end of a powder charge.
While it could be a possible, I have never had an issue with carbon rings in 223. For other cartridges, I have had success with soaking bores with Birchwood Casey bore scrubber. It's nasty smelling, but works well, and usually takes a few days to get the heavy stuff loosened up.
I only see one primer that I would be concerned about in your pics. bambam made a good point about using primers with thicker cups. My preference is the CCI 450 when getting on the upper end of a powder charge.
While it could be a possible, I have never had an issue with carbon rings in 223. For other cartridges, I have had success with soaking bores with Birchwood Casey bore scrubber. It's nasty smelling, but works well, and usually takes a few days to get the heavy stuff loosened up.
Citified
Well-Known Member
You know, he has a point about the thicker cup primers. After checking for the carbon ring, an upgrade with the primers might be the answer. I use BR4s almost exclusively which might explain why I haven't had the same issue.
RegionRat
Well-Known Member
Like @bamban I swim in the XTC pool for a while now and the experience with MIL/LEO and XTC all combines to say just a few things here.
1) Typical XTC loads are hotter (higher pressure) than folks think. They are very hard on brass to say the least. Ejector marks are common and normal. The primer flow he is showing is not. Expect to scrap short line brass after 4 cycles, when normal pressure give something on the order of 14 cycles.
2) Even Varget can be edgy at the top, and all it takes is a hot day or fouled barrel to tip it over. Don't play at the very top till you have more experience, (if ever in hot weather, you really don't need to anyway).
3) The barrel and extension the OP was given was from a known problematic batch, I would say it isn't worth the trouble. Go get that upper re-barreled by WOA and sleep easy. If you are getting serious with XTC, you should consider owning two uppers anyway.
4) The known typical velocities of the 77 and 80 class bullets in these SR rigs is not a mystery, and when the value goes too high or too low, we stop and investigate with known good reference ammo (Black Hills, or an expert's hand loads to be specific) and a chronograph. If a barrel causes too many issues, we huck it. Life is too short to waste much time on bad barrels, and those come along every year. Yes, the borescope inspection should not show a fouled barrel or do not pass go. Scrub it to clean and then re-test.
5) At any XTC club with well attended matches, hand that gun, brass, and notes to one of the mentors and you will get an honest debug in short order.
6) Run an AR friendly primer like a REM 7.5 or Fed MAR, not a common small rifle one.
This AR pattern knowledge base in the XTC game has gone on since the early 90s. It only took about two seasons to see the lines adopt the black guns and the wooden ones disappeared quickly.
That happened for two reasons, the performance was equal or better, but the operating cost and reliability were not even close.
Thus, the experience base we have for the AR-15/M16 in this respect is long and deep. We can't debug this over the internet, but it would take a short visit at the club or base to pass or reject this rig/ammo.
1) Typical XTC loads are hotter (higher pressure) than folks think. They are very hard on brass to say the least. Ejector marks are common and normal. The primer flow he is showing is not. Expect to scrap short line brass after 4 cycles, when normal pressure give something on the order of 14 cycles.
2) Even Varget can be edgy at the top, and all it takes is a hot day or fouled barrel to tip it over. Don't play at the very top till you have more experience, (if ever in hot weather, you really don't need to anyway).
3) The barrel and extension the OP was given was from a known problematic batch, I would say it isn't worth the trouble. Go get that upper re-barreled by WOA and sleep easy. If you are getting serious with XTC, you should consider owning two uppers anyway.
4) The known typical velocities of the 77 and 80 class bullets in these SR rigs is not a mystery, and when the value goes too high or too low, we stop and investigate with known good reference ammo (Black Hills, or an expert's hand loads to be specific) and a chronograph. If a barrel causes too many issues, we huck it. Life is too short to waste much time on bad barrels, and those come along every year. Yes, the borescope inspection should not show a fouled barrel or do not pass go. Scrub it to clean and then re-test.
5) At any XTC club with well attended matches, hand that gun, brass, and notes to one of the mentors and you will get an honest debug in short order.
6) Run an AR friendly primer like a REM 7.5 or Fed MAR, not a common small rifle one.
This AR pattern knowledge base in the XTC game has gone on since the early 90s. It only took about two seasons to see the lines adopt the black guns and the wooden ones disappeared quickly.
That happened for two reasons, the performance was equal or better, but the operating cost and reliability were not even close.
Thus, the experience base we have for the AR-15/M16 in this respect is long and deep. We can't debug this over the internet, but it would take a short visit at the club or base to pass or reject this rig/ammo.
grizlywinkleman
Well-Known Member
Ok... Whole lot of great responses from you all. Thank you so much! I didn't get to even read them all but here is some additional info and my strategy moving forward.
My reload procedures first. I corn cob tumble brass after firing and resize with a RCBS small base sizer die, bumping the shoulder from 3.463 back to 3.460 - 3.458. I then tumble again use a case prep station to run the primer pocket uniformer after every firing (it also cleans the pocket easily), chamfer and debur. If it is the first reload I will also debur the flash hole. I than hand prime all the brass with RCBS palm tool. From there I charge from a Frankfort Arsenal Intelladropper and seat each round to an COAL of 2.260. I do not crimp nor do I turn necks (going to be getting in to turning in the future). I know a lot of folks say that these are not accurate and here recently I was not double checking my charges, but I developed a routine a while ago with the trickle function to get a consistent charge (or at least I thought I did). For simplicity sake I will be reverting back to verifying charge on a separate scale and using a manual trickler.
My rifle is not an actual M16A4, its a civilian variant (semi only). It is a White Oak Armament upper with a Bartlein 1-7 twist 20" barrel, sitting on a Aero Precision lower with an RRA NM trigger, A2 stock (weighted). If I recall correctly the upper was fired less than 1000 shots when I bought it in its current configuration.
I am originally from WI and out here at Fort Bliss for a year for the Army. Obviously much hotter climate and its been 90 - 105 out when I've been shooting. I did load about 600 rounds prior to starting my orders and I do still have that ammo. It did not dawn on me that the hot weather could have an impact this great.
Here is my plan. I have a bore scope for automotive use that I attempted to use but is is too big. Below are the best pics I could get. I ordered a bore scope to check for a carbon ring. Should be here Tuesday. I am not very diligent when it comes to cleaning my rifle barrels and chambers, so it would not surprise me if I do have a ring. Hard to tell what's going on without the correct tool.
I also do have No 41 primers I plan on switching over to. I'll wait to see what the inspection yields as far as carbon ring prior to changing anything. I'm sure I'm forgetting to mention something. I'll definitaly keep you all informed. Thank you for all for sharing your expertise!
Ryan
My reload procedures first. I corn cob tumble brass after firing and resize with a RCBS small base sizer die, bumping the shoulder from 3.463 back to 3.460 - 3.458. I then tumble again use a case prep station to run the primer pocket uniformer after every firing (it also cleans the pocket easily), chamfer and debur. If it is the first reload I will also debur the flash hole. I than hand prime all the brass with RCBS palm tool. From there I charge from a Frankfort Arsenal Intelladropper and seat each round to an COAL of 2.260. I do not crimp nor do I turn necks (going to be getting in to turning in the future). I know a lot of folks say that these are not accurate and here recently I was not double checking my charges, but I developed a routine a while ago with the trickle function to get a consistent charge (or at least I thought I did). For simplicity sake I will be reverting back to verifying charge on a separate scale and using a manual trickler.
My rifle is not an actual M16A4, its a civilian variant (semi only). It is a White Oak Armament upper with a Bartlein 1-7 twist 20" barrel, sitting on a Aero Precision lower with an RRA NM trigger, A2 stock (weighted). If I recall correctly the upper was fired less than 1000 shots when I bought it in its current configuration.
I am originally from WI and out here at Fort Bliss for a year for the Army. Obviously much hotter climate and its been 90 - 105 out when I've been shooting. I did load about 600 rounds prior to starting my orders and I do still have that ammo. It did not dawn on me that the hot weather could have an impact this great.
Here is my plan. I have a bore scope for automotive use that I attempted to use but is is too big. Below are the best pics I could get. I ordered a bore scope to check for a carbon ring. Should be here Tuesday. I am not very diligent when it comes to cleaning my rifle barrels and chambers, so it would not surprise me if I do have a ring. Hard to tell what's going on without the correct tool.
I also do have No 41 primers I plan on switching over to. I'll wait to see what the inspection yields as far as carbon ring prior to changing anything. I'm sure I'm forgetting to mention something. I'll definitaly keep you all informed. Thank you for all for sharing your expertise!
Ryan
grizlywinkleman
Well-Known Member
One final observation... below is a pic of a round I chambered (left) and a round that has not been chambered (right). Every round that I chamber has some light scuffs approximately at the ogive all the way around the bullet diameter (pointing at the line with the tipped bullet in pic). I have read this is a sign of carbon ring build up. So its starting to sound like I do in fact have the ring. It looks worse in person, best I can do for a pic.
grizlywinkleman
Well-Known Member
I also forgot to mention that I do trim to below the max case length after the first firing of brass but not after each firing even if it is a little long. I had never had a problem with it being a little over. The brass in the OP pics is 3x fired.
