View Full Version : DD/BCM acting up after shooting steel cased ammo
shaneinhisroom
05-07-12, 19:02
Preface: My DD/BCM has NEVER had a malfunction in its ~3000rd career.
So I got a good deal on some Wolf Polyformance, cracked off 120 rounds of it yesterday, and not at a fast pace. Not a single malfunction.
Today I go to the range and decided to put some of my PMC bronze/IMI M193 ammo through it. 60 rounds, 4 FTE's.
I know Wolf is dirty, but damn, didn't think 120 rounds would cause it.
Anyone else have this problem? I guess I just proved that at least in my rifle, the gunk left in the chamber due to steel not expanding can really affect extraction.
Quiet-Matt
05-07-12, 19:20
Chamber brush followed by bore snake and you're back in business. Range bag essentials with steel cased ammo.
http://www.theboxotruth.com/docs/edu18.htm
Long-winded summary: Steel case doesn't expand like brass, so there's more blowback of carbon, etc into the chamber area -- but it'll run fine. However, after shooting the steel case you go back to shooting brass case again, and it fully expands, you get issues.
ETA: I probably should've read your last sentence before posting the above. :dirol:
HackerF15E
05-07-12, 19:44
I know some folks who run a single brass-cased cartridge as the last one in every mag of steel to prevent the problem you're talking about.
shaneinhisroom
05-07-12, 19:47
I forgot that my entire last mag last night was brass...didn't have a problem.
Hmm. Guess the carbon hardened up? Beats me. I just sprayed some M-pro 7, let it sit for 20 minutes, and cleaned out my chamber, and HOLY SMOKES that was a lot of black.
Guys, I second keeping the chamber brush and bore snake in the bag (along with some decent solvent).
I have a question regarding DD/BCM as one of those two will be my next piece.
I have had both shit, garbage AR's that ran either ammo no matter what. I have had a colt that ran anything no matter what. And I currently have another bottom feeder...and it eats everything off the dollar menu (Tula Wolf, precision ammunition) and I can even mix mags.
I seem to read a number of threads where DD/BCM both SEEM (only to me I'm sure) to have occasional hang ups when transitioning to steel. Especially in Mid-length systems which is what I plan to buy. I'm a few hundred away from DDM4V5...but I'm concerned about steel. I know I should only feed such a fine piece steak dinner...but come on, it can't eat the occasional happy meal?
Is this due to a tighter, truer, chamber spec? Gas systems being softer/lower pressure?
Doesn't matter to me one way or the other...my next is most likely gonna be the DDM4V5
I've owned damn near everything except DD, BCM, Noveske, and really top shelf primo pcs like KAC. And none of them have EVER failed in any fashion I've fired over 30,000 rounds through carols rifles, and nary an issue.
So what's up?
Don't beat the shit out of me for asking. Just curious, as ultimately I'm buying DD/BCM no matter what
Check/replace your extractor spring. I had to replace my first around 5k, 2 lightly stuck casings and had to replace again yesterday, 3-4k later, with 2 severely stuck casings. Speaking of which, time to buy another 3 pack from BCM :o For a $4 part, I think I'll be changing more often, just in case. LMT 16" carbine with H buffer and Sprinco Blue action spring if that matters.
I guess I shouldn't let my SBR read this thread. Durng the last Magpul Dynamics Course (April 2012) I fired brass and steel cased (Hornady) in my SBR and another test weapon and they both ran like champs.
I guess I shouldn't let my SBR read this thread. Durng the last Magpul Dynamics Course (April 2012) I fired brass and steel cased (Hornady) in my SBR and another test weapon and they both ran like champs.
I did the same thing with my SBR in a Magpul class zero problems.
Cameron
polydeuces
05-07-12, 21:52
My 11.5" (all) DD SBR, 16" (all)DD mid rifle and 16" Noveske N4 eat steel case dirty cheap crap all day long, round after round, any mag.Then brass, then steel. More steel, more brass. And so on.
And I really do not like to clean, (as in - I just don't clean, other than a quick wipe 'n check) just plenty o lube and go.
Would not worry too much. Lube, shoot and be happy.
I rarely clean either. Just lube and replace extractor springs as needed. I might start replacing sooner as a precaution rather than waiting for a failure. IG 5k is TDP correct?
I know some folks who run a single brass-cased cartridge as the last one in every mag of steel to prevent the problem you're talking about.
Why would this make any difference?
shaneinhisroom
05-08-12, 07:10
I would also like to add that I did not lube up the gun anymore the second time around, it was and felt completely dry upon takedown. That may have been the culprit...these guns like it nice and wet when running steel right?
Absolutely, bro. Keep it wet and I bet you don't have the problem again.
I would second the suggestion to swap out the extractor spring and o-ring. Also, don't forget to occasionally scrape the extractor itself and make sure it's still sharp (enough).
zk
I seem to read a number of threads where DD/BCM both SEEM (only to me I'm sure) to have occasional hang ups when transitioning to steel. Especially in Mid-length systems which is what I plan to buy. I'm a few hundred away from DDM4V5...but I'm concerned about steel. I know I should only feed such a fine piece steak dinner...but come on, it can't eat the occasional happy meal?
Is this due to a tighter, truer, chamber spec? Gas systems being softer/lower pressure?
Doesn't matter to me one way or the other...my next is most likely gonna be the DDM4V5
Bottom line is that the guns weren't designed to function reliably with lower pressure ammo and things like midlength gas systems and heavy buffers can exacerbate the issue. They're pretty much optimized to run brass cased NATO pressure ammunition. Some guns might be able to get away with running cheaper ammo and some might not.
polymorpheous
05-08-12, 10:41
Bottom line is that the guns weren't designed to function reliably with lower pressure ammo and things like midlength gas systems and heavy buffers can exacerbate the issue. They're pretty much optimized to run brass cased NATO pressure ammunition. Some guns might be able to get away with running cheaper ammo and some might not.
This man speaks much truth.
Bottom line is that the guns weren't designed to function reliably with lower pressure ammo and things like midlength gas systems and heavy buffers can exacerbate the issue. They're pretty much optimized to run brass cased NATO pressure ammunition. Some guns might be able to get away with running cheaper ammo and some might not.
Why would slowing down the cyclic rate cause fte's? You do realize that's exactly what heavier buffers and stiffer action springs are for?
Why would slowing down the cyclic rate cause fte's? You do realize that's exactly what heavier buffers and stiffer action springs are for?
Yes, I'm aware that heavy buffers and stiffer action springs are to slow the cyclic rate to help aide in extraction and feeding in guns that are "overgassed" which I do't believe is the case here. I was speaking in general terms and did not attempt to diagnose his problem. Don't read something that's not there.
There is no set number for replacing. 5K is the arbitrary number that some people came up with. Given the low cost, I suppose every 5K or whatever is prudent.
I rarely clean either. Just lube and replace extractor springs as needed. I might start replacing sooner as a precaution rather than waiting for a failure. IG 5k is TDP correct?
You are correct. And steel cased 5.56 ammo was also not around when the M16 came into play.
It's only been a recent thing to allow some people to shoot more due to high ammo prices.
Bottom line is that the guns weren't designed to function reliably with lower pressure ammo and things like midlength gas systems and heavy buffers can exacerbate the issue. They're pretty much optimized to run brass cased NATO pressure ammunition. Some guns might be able to get away with running cheaper ammo and some might not.
I just got a DD 16" mid length upper but haven't shot it yet so I will see if any issue's arise for me as I shoot steel alot and expect to in a carbine class...I don't expect any problems though...even though mid length.
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