.308 Hand load issue, stovepipes

[MJP68]

Having some issues with my .308 reloads "stovepiping" 20% of the time on avg
NO issues at all with factory ammo
Using once fired LC and WIN brass, sized trimmed and chamfered to specs per my Speer manual, using RCBS AR series small base dies
CCI 200 primers, Varget and H335 powders, speer 150gr,168gr and Nosler 165gr projectiles.
all powder charges were measured one at a time at different levels from 41g to 46g (Varget) in multiple test batches of 10 rds.

Rifle used is a POF P308 20", again NO issues AT ALL with factory ammo, so the issue must be with my skills or equipment.
Best description of the malfunction would be.. round fires, spent case gets caught by the bolt cycling forward and partially chambering a fresh round.
I'll try to post a "simulated" pic

I have had no issues with my 9mm and .45acp reloads as well as my .223 reloads

 

[diderr]

hmmmm. Is there any damage to the case rims? Cant be your gun since factory ammo will extract fine. Unless it's a dwell timing issue with the powder charge you're running.

 

[MJP68]

No sir, no evidence of damage to the case rims from the extractor.
I had assumed I was under charging, so I stepped up the charge level .5gr at a time with the same results
suspected an out of spec die, but sized case measurements are in "spec" but a few thousandth's larger than factory new ammo

 

[ChrisGarrett]

How does your headspace compare to the factory rounds that are working? How does the COAL compare to the factory rounds that you're using, which work?

Chris

 

[NICETRY]

I am going to assume your gas system is adjustable on your POF P308. Try turning your gas system down so it does not eject a round a round and start turning it up till it does. When I started loading for my JP 204 Ruger this was recommended to me so I was not over gassing the system.

 

[MJP68]

Chris, I will check head spacing.
COAL is slightly shorter than production ammo, I can remeasure to be exact
thank you

 

[MJP68]

NICETRY, the piston system has 3 settings, normal, suppressed and off .
I have not tried the suppressed or off settings

 

[Danco411]

Have you tried making three or four dummy rounds and cycling them by hand? Do they drop into the chamber and come out easily? My be is your bumping the shoulder back too much on your sizing an changing the headspace. This will cause a tight chamber fit and slow ejection. Small based dies are just that, smaller. They can be finicky to set up for sizing. I had some that dropped into and out of a Wilson case gauge easy but were bumped back just enough to cause extraction problems. When I tested them in my bolt gun they where hard chambering. Readusted the die and viola!

 

[cavemanlrrp]

Do any of the ejected brass have a half moon shaped dint on side of case? This can be caused by brass slamming into back of ejection port, BCG traveling too fast, over gassed.

Best
caveman

 

[MJP68]

MtnCreek, thats what I originally thought but charge levels made no difference. No chrono yet and mixing brass with same loads.

Danco, I did that when I set up the die 6 months ago.. I need to do it again as I really think it may be the issue.

caveman, no dents on the brass. In fact some of the spent cases dont even make it off of the bench

 

[cavemanlrrp]

It sure may be something else, but as NICETRY said give that suppressed setting a try and see what happens.

I had similar problem, piston AR none adjustable gas, some stove pipes and brass just pooping out at 1 o'clock.
Long story short, after much messing with bolt etc. H2 buffer and wolf extra power spring worked for me. No more stove pipes, ejects 4 feet at 3 o'clock. Had to slow things down a little.

Keep us posted, it's how we learn.

Best
caveman

 

[P7id10t]

Ive had this problem on my DpMs 308 when other people shoot it. FTE or stovepipe. It's as if they limp wrist it.
I'm anal about how i load my ammo.
All of them 43.5grs 4064, 175 SMK & 2.810 OAL (iirc). My buddy will jam on 5 out of a mag of 20, I have never jammed. Boggles the mind.

 

[MJP68]

It sure may be something else, but as NICETRY said give that suppressed setting a try and see what happens.

I had similar problem, piston AR none adjustable gas, some stove pipes and brass just pooping out at 1 o'clock.
Long story short, after much messing with bolt etc. H2 buffer and wolf extra power spring worked for me. No more stove pipes, ejects 4 feet at 3 o'clock. Had to slow things down a little.

Keep us posted, it's how we learn.

Best
caveman

Thanks, I will try it next time I am at the range

 

[MJP68]

Ive had this problem on my DpMs 308 when other people shoot it. FTE or stovepipe. It's as if they limp wrist it.
I'm anal about how i load my ammo.
All of them 43.5grs 4064, 175 SMK & 2.810 OAL (iirc). My buddy will jam on 5 out of a mag of 20, I have never jammed. Boggles the mind.

Thats crazy!

 

[P7id10t]

Thats crazy!

Yes, bat sh1t crazy!

 

[Sargesniper]

Try taking factory rounds apart and charge with your loads. Might tell you about your brass/sizing method. Just a guess.

 

[MJP68]

I was thinking the same thing as well Sarge.
Going to try a few things mentioned above today, and maybe hit the range tomorrow

thanks everybody for the advise and suggestions

 

[JRM83]

I have a 20" POF P308 I purchased back in October 2012 with the exact same issues that you are having. I have a bunch of pictures identical to yours on my phone.

I swapped the collapsible stock over to a PRS (correct spring and buffer verified), and never fired it with the factory stock.

My rifle has only seen about 10 rounds of factory ammunition - all FGMM 168 with no issues, but I can't say for sure I wouldn't be having problems running factory ammunition. I have tried several different loads with the rifle and it seemed that the hotter loads caused the rifle to stovepipe more frequently. So far I have tried 42.4 gr of Varget in WCC brass, 44gr in Win brass, one load cfe223 near max charge (don't have my load data handy at the moment), and one of cfe223 at minimum charge. All loads showed no pressure signs and shot well. All underneath a 168 Nosler seated at 2.800

I measured the headspace of several fired cartridges using an RCBS precision mic and found most were right about .001 above saami min. I set my die to resize .002 under saami min, and checked with dummy rounds and all cartridges chamber and extract without difficulty.

Just wanted to add an extra data point to this discussion, good luck with your troubleshooting, and if I learn anything I will post here.

 

[MJP68]

Thank you, I have had no pressure signs as well.
To this point all I have had time to check is sliding some sized cases and factory loads into the chamber all move in and out easily.. not sure if that means
anything. To be honest I'm going to have to research how to check headspace..

 

[MJP68]

Sorry for the delay and thanks again for all the input.
once fired LC 7.62-51 brass headspace measured with the Hornaday cartridge headspace kit
3.627 I also measured the brass at the base of the body .470 again this is once fired Lake City
3.624 headspace and .4665 base measurement for NEW Winchester 7.62-61
3.626 and .4670 for NEW magtech 7.62-51
3.6205 and .4665 for new Remmington .308
3.622 and .4685 for my once fired cases after resizing (Winchester case on this measurement)

Again, all factory ammo I have used in this rifle has functioned perfectly

 

[wilecoyote]

factory ammo are often builded with some crimp,glue or equivalent trick to have a more reliable round_
that has an effect about offering more resistence after the ignition, before the bullet can start down the barrel, raising pressures_
without that, even w/same charge/powder and bullet, pressures can result quite different (on the LOWER side), due to different neck constriction,etc.)_
only another 2c._
for sure Kevin Thomas, if readin',could explain better

 

[MJP68]

I have been using a very light crimp, in the process of resetting everything.

The measurements on "new" brass above was done with live rounds.
picked up some new Winchester bare brass tonight measurements are

3.624 headspace and .4645 at the base of the case

 

[wilecoyote]

can be that your very light crimp produces some lower pressures than factory firmer crimps,or other ways to better secure their factory bullets in their factory cases_ the lower pressures can slow the cyclin' and ejecting process, with consequent ejection failure_
(a cheap try can be tested employing the .308 LEE FACTORY CRIMP die_ for me,handloading LCs on FAL, it's a must)_

 

[MJP68]

I'm willing to try anything at this point, I'll tighten up the crimp a bit.
gonna run a few different batches tonight.. range tomorrow
Thanks

 

[wilecoyote]

if you would find that's a crimping & related pressures issue only, the cheap LEE gizmo will be the more forgiving about the bullet's jackets_
good luck,anyway!

 

[204 AR]

I have had that issue with 2 dpms rifles, though neither was a 308. The first was a 300 Saum, I would get a stovepipe once in a while with my loads using rl17. Once I switched to H4350 no more problems. The other is my 243. It also runs perfectly with H4350, while the same bullets over 4064 will stovepipe once in a while.

Assuming your loads chamber and extract fine, I would try a different powder. Although I have to admit I would think Varget should work perfectly in a 308. It does in mine, as does 4064 and H4895 and everything else I've tried.

 

[MJP68]

It sure may be something else, but as NICETRY said give that suppressed setting a try and see what happens.

I had similar problem, piston AR none adjustable gas, some stove pipes and brass just pooping out at 1 o'clock.
Long story short, after much messing with bolt etc. H2 buffer and wolf extra power spring worked for me. No more stove pipes, ejects 4 feet at 3 o'clock. Had to slow things down a little.

Keep us posted, it's how we learn.

Best
caveman

Hit the range today with some new loads in different configurations. 2nd round stovepiped and the next as well using 42g varget on once fired LC with 168g projectile..switched to suppressed mode and no issues at all for ANY of my load configurations (120 rounds total) I left the rifle in suppressed mode and switched to production Magtech 7.62-51 and was short stroking instantly
Guess ill buy some weights to check my scale and or lower my charge levels..
thanks again for everybodys input, please keep the suggestions coming

 

[204 AR]

FWIW the Magtech ball ammo short stroked my 308 also, that stuff is really loaded light. I wouldn't match my reloads to that cheap ammo.

 

[former naval person]

204ar may have something...the pressure curve is different with various powders.

 

[wilecoyote]

reading all that, seems only a problem related to low pressures: if that come from wrong powders type/quantity,wrong gas setting(if any), too much light neck constriction, or no crimping, that don't change the results_ In Italy suppressors are prohibited, therefore I haven't tested them, but if my sensation that a supp. can help to maintain inside some residual pressure, boosting the cycling,could be right,and if WITH the supp. the cycling work o.k., that could reconfirm the low pressure hypothesis expressed above...I hope
(if my thinkin'about suppressors is wrong, I will be interested to be corrected, of course_thanks)

 

[MJP68]

FWIW the Magtech ball ammo short stroked my 308 also, that stuff is really loaded light. I wouldn't match my reloads to that cheap ammo.

I haven't had any issues with any production ammo (haven't tried any steel case), the short stroking disappeared when I set the gas piston back to the normal setting.

 

[MJP68]

204ar may have something...the pressure curve is different with various powders.

Thanks, I am taking that into consideration as well but powder choices are very limited right now.. lucky to find anything around here
I have a few out of state friends with the same rifle and powder combination working flawlessly

 

[mtrmn]

I'm coming in very late in this game, but doesn't "suppressed" mode cut the gas levels back a bit to compensate for the higher gas pressures when running suppressed? If so, and your loads work in suppressed mode, then the rifle must be way overgassed in normal mode and the brass could be hitting the ejection port and bouncing back into the action. Just my opinion due to past experience with overgassed direct impingement rifles. I've never run a piston gun.

 

[MJP68]

reading all that, seems only a problem related to low pressures: if that come from wrong powders type/quantity,wrong gas setting(if any), too much light neck constriction, or no crimping, that don't change the results_ In Italy suppressors are prohibited, therefore I haven't tested them, but if my sensation that a supp. can help to maintain inside some residual pressure, boosting the cycling,could be right,and if WITH the supp. the cycling work o.k., that could reconfirm the low pressure hypothesis expressed above...I hope
(if my thinkin'about suppressors is wrong, I will be interested to be corrected, of course_thanks)

Up until sunday all my shooting was done with the gas piston system set to normal (larger orifice=more gas flow to the piston) setting to suppressed (smaller orifice) slowed the cycling down and allowed my overcharged? handloads to cycle properly
wilecoyote, an added suppressor would increase the pressures in the gas system

I hope Im heading in the right direction with calibrating my scale and backing off on the powder charge if the scale is correct.. maybe changing the seating depth (OAL)....

 

[MJP68]

I'm coming in very late in this game, but doesn't "suppressed" mode cut the gas levels back a bit to compensate for the higher gas pressures when running suppressed? If so, and your loads work in suppressed mode, then the rifle must be way overgassed in normal mode and the brass could be hitting the ejection port and bouncing back into the action. Just my opinion due to past experience with overgassed direct impingement rifles. I've never run a piston gun.

you are correct sir, and yes I don't think the brass has enough time to exit the port.

 

[wilecoyote]

for what I know, on FAL the manual says that, w. mil.spec ammo, starting from excesssively UNDERgassed setting, the cases will have feeble or no ejection,stoveppipes,etc._ from here, the setting will be progressively regulated to allow more gas to work the piston, and less gas go wasted outside, until the ejecton will be regular and the brass will fall at the intended correct distance_
If the rifle would be OVERgassed, the case would be ejected as well,with a hyper-fast cycling, and launched violently several meters away,(with other problems inherent to damaging some rifle part,in the long haul)_ I understand that I'm talkin'about another kind of rifle, but the concept seems the same ( I hope I'm not creating unvoluntarily more confusion than help, anyway) _

 

[mtrmn]

you are correct sir, and yes I don't think the brass has enough time to exit the port.

When you use factory ammo on the normal gas setting, where does it eject? If almost straight fwd, 1 or 2 o'clock, then the gun is over-gassed and you need to add weight to the reciprocating mass (buffer etc) and maybe a heavier spring. Also, maybe check the strength of the ejector spring, especially if it ejects more to the rear, 4 or 5 o'clock.

I really don't see Varget as being the problem because there are SO MANY people out there that use nothing else in their semis. BUT if you can get your hands on some 4895, Acc 2495, or TAC it would be interesting to see if your problems went away. There may be something about Varget your gun just doesn't like.

MY 308 AR, a Bushmaster BAR10, had no problems with the factory buffer but I installed a heavy buffer from heavybuffers.com when I went suppressed and it runs well with that also. This was the predecessor of the current RRA 308's that use FAL mags. It is direct impingement. May want to go to heavybuffers.com and do a little browsing.

 

[MJP68]

When you use factory ammo on the normal gas setting, where does it eject? If almost straight fwd, 1 or 2 o'clock, then the gun is over-gassed and you need to add weight to the reciprocating mass (buffer etc) and maybe a heavier spring. Also, maybe check the strength of the ejector spring, especially if it ejects more to the rear, 4 or 5 o'clock.

I really don't see Varget as being the problem because there are SO MANY people out there that use nothing else in their semis. BUT if you can get your hands on some 4895, Acc 2495, or TAC it would be interesting to see if your problems went away. There may be something about Varget your gun just doesn't like.

MY 308 AR, a Bushmaster BAR10, had no problems with the factory buffer but I installed a heavy buffer from heavybuffers.com when I went suppressed and it runs well with that also. This was the predecessor of the current RRA 308's that use FAL mags. It is direct impingement. May want to go to heavybuffers.com and do a little browsing.

Normal setting ejects between 2 and 3 Oclock and has no noticeable difference between brands of ammo..
I'm not suspecting Varget as my root cause.. I'm convinced it's something I'm doing wrong during the reloading process

I have replaced the oe POF buffer with the endine hydralic simply to reduce recoil (it helped) but the preexisting issue was unchanged

 

[Rooster931]

Regular full lenght size dies or small base dies? If you have a friend with a set of small base dies try resizing with the small base. Then reload with your normal charge my guess on the fix!

 

[MJP68]

Thank's Rooster. I'm already using the small base die set
I'm almost convinced its a pressure issue

again I truly appreciate everyone's input

 

[Grump]

Ive had this problem on my DpMs 308 when other people shoot it. FTE or stovepipe. It's as if they limp wrist it.
I'm anal about how i load my ammo.
All of them 43.5grs 4064, 175 SMK & 2.810 OAL (iirc). My buddy will jam on 5 out of a mag of 20, I have never jammed. Boggles the mind.

Proof positive if either a design defect or a specimen defect in the rifle.

In general terms. A system should work with multiple users and even tolerate a foreseeable range of "bad technique". Not a problem for a single user for whom it happens to work.

 

[MJP68]

Scale checked out fine.. actually its reading .2 grain high