Varmageddon FTFs

[sranch]

[sranch]

upSLIDEdown, You can definitely go with higher loads than 17 grains. I went safely up to and over 20 grains but backed off to 19.5 for three reasons.

1. Didn't gain any speed with my 8 inch barrel
2. Why use more powder if it doesn't gain any more speed and I can use in other guns safely and effectively
3. More case space for bullet

[upSLIDEdown]

go much longer. you dont want to go much over 2.1 because the bullet isn't that long but the closer you can get to the lands in the breach of your gun the more accuracy you'll get. 2.02 is way too short. The thing might do a flip before it even enters the barrel

I load most everything about 2.1 but these Varmegeddon 2.09. Pmags

I was loading 2.06, not 2.02. Mainly because in the other threads, that was the number I saw the most. I'll try some longer though. Is there anything else it could be? Are your pmag ribs modified at all?

[sranch]

no, standard pmags

[upSLIDEdown]

Ok, loaded some at 2.09 today and tried them. Had the same issue. I took pictures of the jam this time, and will probably post a thread in the AR forum, as it may more AR related than ammo related. It seems like the bolt is missing the back end of the case when it happens. It's a REALLY ugly jam. Pictures coming in a sec.

[upSLIDEdown]

8" pistol
Mas Defense upper (Cerro Forge receiver)
Rainier BCG
Spikes buffer tube/ ST-T2 buffer


Grumpa's brass (LC once fired)
CCI 450s
110gr Varmageddons
18.0 gr H110
Tried two different OALs. 2.06 and 2.09. Both gave me the same jam. Also tried an M3 windowed Pmag, as well as a metal mag. Both jammed. Seems to want to do it more under rapid fire, but does it during slow fire as well. I can cycle them by hand, pulling the charging handle back and letting slam home, and it ejects and feeds every time. I can also load a single round in the mag and it will lock the bolt back every time, so it doesn't appear to be short stroking...

Cleaned, and relubed the gun. Ran the BCG soaking wet in FP-10 CLP.











That's a couple different jams, and a couple different bullet tips to show what it's doing to them.

Noticed this mark on the case on a couple of them too, which looks like where the bolt dug into the side of the case and shaved a bit of brass off.




This is a picture of the feed ramps. The ramps in the receiver don't appear to match exactly with the ramps in the barrel extension. Could this cause the issue? Thought about widening the lower ones to match the ones in the barrel extension and polishing them. Thoughts on this?

[Alien]

I tried the published OAL of 2.025 on 40, (workups and test) at that OAL never had a Failure to Feed.

I tried 40 more but at 2.060 and had 3 Failure to Feeds, exactly like you are seeing. My groups were much better with the 2.060 but had the feed issue. Just sayin!

[randyrucker]

Thats just ugly. I would try going shorter and see if that helps. Also i would go up to 19.0 gr H110. Load 10 or so at 2.04 and see what that does. This has nothing to do with the extractor does it ?

[JoeHarley13]

1) How many factory rounds through the gun?
2) Does any other ammo run without issue, if so, what ammo - full specs, how many rounds.
3) Shave the ribs down on a PMags. I've done this for all of my FDE PMags.
4) Why are you running a ST-T2 buffer. You should only need a Carbine buffer. You could be mucking up the timing.
5) Give the BCG a good lube job with CLP.

[Omega]

Looks like your slapping the brass deflector quite hard, you running your rounds that hot? I'd put some Velcro on it to at least keep the bluing on the receiver from wearing out.