This is a weird one to me. I have a 16" mid-length BCM carbine that ran like a top for over 5,000 rounds, with 75% being steel case wolf and tula. The extractor hook wore down to almost nothing, and I started having occasional FTEs. I replaced it with a BCM extractor and Colt extractor spring and insert. I also took the time to disassemble the ejector and put a new Colt ejector spring in as well.
The rifle itself has always had an H buffer, and I switched to a Sprinco blue spring about two years ago. After the bolt revamp it runs like normal with any steel case ammo, with very strong and consistent ejection, making neat piles of casings ~15 feet away at 4 o’clock. In fact, it was never this consistent with ejection before.
However, any brass ammo I try has extremely weak ejection. Like 1 foot at most, at 2 o’clock. This includes grant’s magtech 62gr, prvi m855 62gr, and some prvi match 75gr. I have always experienced the ejection angle changing more forward when shooting brass versus steel, but never seen a difference in ejection strength like this. Before the extractor and spring changes it ejected around 5-10 feet, depending on the specific ammo.
The bolt always locks back on the last round, regardless of ammo, even when holding the rifle very loose.
Presumably the bolt speed is much faster with stronger ammo, but it seems counter intuitive to me that the ejection would be so weak. Inspecting the brass doesn’t show any abnormal markings from the extractor and ejector, although it does look like the cases are hitting the front corner of the deflector and leaving a small crease about halfway along the case. Ultimately I don’t care about the direction, but the fact that the brass is just barely dribbling out of the ejection port makes me wonder if I’ll start to see some interesting malfunctions unless this is resolved.
The extractor hook wore down to almost nothing:
Is this some what normal for a extractor after 5000 rounds?
My colt has over 12,000 rounds on the extractor.
Bingo. The Colt gold extractor spring is stronger than their original spring. If the ejector spring doesn’t also increase in strength, you will have an imbalance that looks exactly like this at first; 100% function, but with weird ejection.
When the brass casings are hitting the front edge of the deflector some of their energy is dissipated; they go forward and not as far. When the bolt is cycling slower with steel case ammo the vector that describes the case trajectory is angled further away from the gun so the steel cases don’t hit the front of the deflector. When the bolt cycles faster with brass cased ammo the vector is angled closer to the gun and the ejected cases strike that front edge. Nothing to worry about that I see. Maybe play around with heavier buffers if you want to change ejection patterns.
Hard to diagnose in my opinion because you changed multiple items at once. Try a new (or old Ejector spring) and see what happens. If same, try a new (or old) extractor spring. If same try a new extractor. The only way to identify the offending part is to zero it out. Once you know which aprt is causing the troubles, you can identify what to do to correct.
The Colt spring is meant to work well with a mil-spec ejector spring, and I have run them on every weapon I have, and all my friends do. NEVER have ANY of us had an issue with it. It should work fine if the ejector spring is in spec.
If you have it/them on hand, humor me, and run an H and H2 buffer with a mil-spec action spring. Pick the one you like best after feeling each. Just try it…
Thank you all for the help. I made a short stop at the range today after I put the old extractor spring/insert in and the ejection with brass cased ammo is much stronger. Ejection with steel seemed the same as before.
The new colt extractor spring was definitely stiffer feeling when compared to both the old and unused BCM springs.
Springco is making ejector springs now. Firing high round counts, this MAY be something that could add some longevity. I have been using a Springco 5 coil extractor spring w/ insert but w/o an O-Ring in my BCM 14.5" middy to excellent effect.
Yeah… I’d be very nervous about running anything Springco. It’s likely a CS spring. The LAST thing I’d want to do is put a CS spring in a hard to remove area like the ejector… even on a recreational gun. A year down the road, and I’d forget I had that thing in there.
I know you LOVE some CS spring action , but I have at least 3 buddies with over 5k rounds on their Springco 5 coil extractor springs. One of those is a 6920 that runs almost 100% suppressed.
, but I have at least 3 buddies with over 5k rounds on their Springco 5 coil extractor springs. One of those is a 6920 that runs almost 100% suppressed.