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View Full Version : FTE caused by ammo? Need advice



Bugaboo
09-17-06, 07:22
I am shooting Wolf ammo and after several magazines downrange I am getting bad cases of FTEs. I found several reasons for this throughout the Internet. I also know I could easily get rid of the problem by using a brass-cased ammo, however...
I can get Wolf here for about the same price as in US, while the cheapest brass cased ammo is at least twice that price; getting away from the Wolf would seriously shrink my budget.

So, is there some measure to get rid of this problem and still use the Wolf? I really will appreciate any input towards solving this!

M4arc
09-17-06, 07:43
Give us the details of your carbine and the failures. My first thought is you need to change out the extractor spring and/or add an O-ring or Defender. But without hearing the details of the FTEs I can't say for sure.

If you have the empty case in the camber with the new case then my first thought might be right. However if the cases are still partially in the chamber adding more extractor tension will only compound your problems.

In other words, we need more information :)

Bugaboo
09-17-06, 08:49
OK, here goes:
First 5 magazines blast away nicely, I have sometimes FTF, but that are my old mags or dirty ramps, does not belong here.
After some ammo sent down range one case gets stuck in the chamber and even using a cleaning rod it is hard to ram it free.
I had a broken extractor spring (black buffer) and I could only get a DPMS spare-parts set with a spring with blue buffer. If I am correct there is some difference?
The extractor looks nice, no wear or damage I can see (compared with the spare part)
The problem persists and even my shooting buddies are getting the same FTEs like me (we shoot the same ammo even from the same batch as we are able to get a very nice price here). it is true that ocassionally I have blown or punctured primers (over preassure???)
We all have Canadian Dlask Arms "DAR 701", I have 14,5" heavy barel non-chrome-lined, my buddies have 16" pencil chrome-lined barrels (the standard with grenade launcher attachement point)
I first thought the trouble is the steel cases dont expand enough to seal the chamber like brass does and powder residue is getting blown into the chamber and sticks to the walls of the chamber, resulting with the case getting "glued" to the walls by the said residue.
But yeasterday on another forum I found out one training company is heaving similar problems and they shoot a lot more in one year than I have shot in my entire life. The chief instructor/owner identified the problem as excess polymer coating glueing the cases in the chamber.
Sorry, I am still picking my way through the AR15/M4 lingo, so I hope I describer the parts the right way. Does it make any sense?

Boom
09-17-06, 09:50
My recent experience with Wolf has shown that after the rifle gets real hot it melts the polymer and leaves residue behind in the chamber. The polymer collects unburned powder and other crap which causes the cases to stick in the chamber.

There are two solutions to the problem that I see.

1. Clean the chamber after a couple hundred rds.
2. Slow down your rate of fire so the chamber has a chance to cool. The hot chamber is what is causing the problem. Removing the heat issue will solve the problem. Slowing my rate of fire has worked for me.

Now this has not always been a problem for me. My last case of wolf has been a real issue with FTE. I have a feeling that the instructor is right and they have simply applied to much polymer to the cases. Until this last case I have never had this problem before with the newer wolf. Hopefully the newer cases will not have this problem.

FYI shooting the wolf thru a Colt 1/7 chromed chamber with new spring and defender insert. This rifle works great with all other known ammo. Brass or otherwise.

Bugaboo
09-17-06, 09:54
What is defender, please?

Boom
09-17-06, 10:24
What is defender, please?

The defender is a rubber insert that slips over your extractor spring. It helps the extractor apply pressure to the case rim to help pull the case out. They work very well.

Bugaboo
09-17-06, 10:36
Is it this thing: http://www.adcofirearms.com/itemdetails.cfm?inventorynumber=2689 ? And could it help to solve the problem I am experiencing?

Boom
09-17-06, 11:00
Is it this thing: http://www.adcofirearms.com/itemdetails.cfm?inventorynumber=2689 ? And could it help to solve the problem I am experiencing?

The crane O ring is the same thing. They look a little different but work the same. I swear by the defender. It has solved a lot of my FTE problems. Will it solve yours, I do not know. My best advice is to clean the chamber often when using wolf. But I would get the O ring if given the chance.

Bugaboo
09-17-06, 11:18
Simple classic O-ring, a seal? Great, will find the right diameter. Thanks a bunch

Bonk2029
09-18-06, 06:57
I had two FTE's last month over the course of about 100 rounds of Wolf. I cleaned the chamber a little more than I normally do, and haven't had the problem since. When in doubt, scrub it - a good cleaning will solve or at least improve many issues.

Voodoochild
09-18-06, 08:05
I had the exact same problems all caused by Wolf. That is the only ammo my RRA Carbine wont shoot right.

Bugaboo
09-18-06, 17:14
What is the service life of the O rings? And what si the difference between D-fender and O ring? Which should I get?

Heavy Metal
09-23-06, 17:26
The service life of the D-Fender is the life of the bolt.

meateater
09-26-06, 17:43
crane o-rings or defender , by far the most cheapest upgrade to my mrp.
well worth it too.....

Griz
09-26-06, 18:55
My recent experience with Wolf has shown that after the rifle gets real hot it melts the polymer and leaves residue behind in the chamber. The polymer collects unburned powder and other crap which causes the cases to stick in the chamber.

Boom, I must respectfully ask how you determined that the polymer coating melted? I ask because I've seen this theory repeated so many times that I decided to do a simple test of my own. I heated up a polymer coated Wolf case with a propane torch until it was glowing red. The coating did not melt and didn't get tacky. I couldn't even scrape it off with the knurled shaft of a punch that I had handy while the case was red hot.

Based on this, I find it hard to believe that the polymer is actually melting during and sticking to the chamber wall.

I believe that the most likely answer is that Wolf ammo is more dirty in the first place than most, and that the "excessive blow-by" theory may be correct. I have measured unfired ammo and fired cases both brass and steel in the same gun and the steel Wolf cases start bigger than the brass cases, but end up a few thousands smaller than brass cases after firing. I have no way to figure out if they actually expand more and them spring back, or if the fired case measurements support the theory that the steel cases expand less in the first place, so this is still just a plausable theory to me that I can't confirm yet.

I have found that I don't get stuck cases with Wolf if I thoroughly clean the chamber and then make certain that there is absolutely no oil in the chamber.