I have a newer 6.5 Grendel and the second round from the mag won’t go into battery. I replaced the rifle buffer with a nice JP captured spring buffer and still no dice. The thing shoots great as a single shot, but both factory and hand loads have the same issue. Tried two different mags, same thing. ideas?
6.5 Grendel issues
- Thread starter Recoil shoulder
- Start date
A springco(Tactical Springs TX) RED spring will force it in there. A lot of LEO use the red spring and H2 buffer to keep things moving when they get hot, dry and dirty. Barrels must be ported correctly to work with a stiffer spring and heavy buffer.
You may want to take a close look and figure out exactly what is slowing it down. Is it the tip of the bullet or feed lips on the mag? In the past we have trimmed the front corner of the feed lips on a 45* angle, it will release the cartridge smoother. You may also want to look for sharp edge on the feed lips.
You may want to take a close look and figure out exactly what is slowing it down. Is it the tip of the bullet or feed lips on the mag? In the past we have trimmed the front corner of the feed lips on a 45* angle, it will release the cartridge smoother. You may also want to look for sharp edge on the feed lips.
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Not sure about OP, but for me it’s on the feed ramps. Bullet tip is not touching back of barrel. In the above picture I have a sprinco red installed and that’s the first round in the mag.
I haven’t tried other mags yet. Also the feed ramps on this barrel (criterion) are the worst and toughest I’ve ever seen. Plan is to pull barrel and polish.
I haven’t tried other mags yet. Also the feed ramps on this barrel (criterion) are the worst and toughest I’ve ever seen. Plan is to pull barrel and polish.
Definitely polish the feed ramps if they are rough. Be careful not to re-shape them if you don't know what effects that has.
What magazines, and how many rounds are you putting in them? I've found my 15 round ASC mags just work better with only 12-13 rounds in them. Would be nice if the full 15 was gtg, but they aren't 100% that way so it's a simple fix. I have other larger mags if I want more capacity.
Even in 5.56, the times I've seen an issue like the picture above, it's been a magazine issue, either from too many rounds (guys jamming 31 in a 5.56 mag) or something like the ASC mags I described.
Mags were my next move since I thought the JP H2 captured buffer and spring would take care of it.
Two or 3 rounds in a 10 round mag. I‘ll look into another mad, but I might try to take some friction off the feed lips
mine is not so dramatic looking. Appears to be in battery, but not quite getting enough closure and bolt rotation. Usually require a good yank on the charging handle to eject the live round. If loaded one at a time either by bolt release or charging handle there are no issues.
Thanks and you guys ran down a lot of the stuff I suspected, but didn’t alleviate the issue. I am trying to look at the mags next. Perhaps I need to look at the gas system even though the bolt is locking back. I’m thinking about getting a buddy to shoot it and watch the system as it fires and goes back into battery orthis rifles version of it. this would be so much easier to hate the whole thing if it didn’t shoot so nice otherwise. All brilliant ideas are accepted. I’ll even take som mediocre thoughts. Appreciare the feedback.
This sounds like a totally different issue - sounds to me like the chamber in your rifle is too tight, requiring rounds to be jammed in to fully chamber. Needing a yank on the charging handle sounds like it's sticking even on partly chambered rounds. When you single load into the chamber and drop the bolt, the bolt has a lot more energy and can/will deform the case enough to force it to chamber.
If I'm right - I bet you can't easily remove an unfired round from the chamber if you've single loaded and dropped the bolt. If that is the case, stop shooting it and have the manufacturer correct the problem.
Who made the barrel? Is it one of the cheapo brands like Bear Creek?
It's an Atheris. I don't recall any issues with properly chambered rounds ejecting with difficulty, but will have to recheck. No pressure signs on primer or cases. I think the sticking is the bolt not properly rotating.
Had the same problem, and others. Tried literally "everything" (gas, buffer, etc). Surprisingly ... turned out to be magazine issues. Tried other magazines with varying results, until I plugged in a 6.5-Grendel E-Lander mag that I got from OpticsPlanet ... and have not had a feed or fire problem since. Got a new 224 Valkyrie and had similar issues ... also SOLVED by their 224 E-Lander mags.
Made me a true believer in this magazine brand !!!
Thanks, but I am using and E-lander as one of the mags that's not working. I appreciate the input. I think I will mess with the mag to see if there is too much friction.
Interesting ... had "fits' with jams in my 6.5-G and 224-V builds ... and both were 100% solved by switching to E-Lander mags. Sorry that won't work in this case. You have the "6.8 SPC / 6.5 Grendel" version ... right?
Yes. I am buying a tack hammer to beat myself in the head. At least, it will feel better when I stop. I heard nothing but good stuff about E-lander mags.
Feed ramp / barrel extension issue.
Possibly mag catch / mag position to feed ramp issue; geometry not right causing extra energy to be used getting round out of mag, up feed ramp and into chamber.
Have you tried upper on a second lower from different Mfg’er?
Freebore issue, if really short freebore and bullet is into lands, energy lost stripping round from magazine is enough to prevent going into battery.
How much jump do you have with reloaded ammo?
What bullet are you using?
Possibly mag catch / mag position to feed ramp issue; geometry not right causing extra energy to be used getting round out of mag, up feed ramp and into chamber.
Have you tried upper on a second lower from different Mfg’er?
Freebore issue, if really short freebore and bullet is into lands, energy lost stripping round from magazine is enough to prevent going into battery.
How much jump do you have with reloaded ammo?
What bullet are you using?
I can definitely swap lowers to try a different manufacturer. I am using primarily Hornady 123 SST. Does it with factory ammo as well. I can't recall what the seating depth is and can check my logs tonight, but I am certain that the OAL is the same as factory. Both are worthwhile to look into. I'll start with the lower and I am thinking of trying a 6.8 SPC mag, since I heard that they might work better.
Does it stop where you took the photo half in and half out of the mag or is the cartridge going in the chamber but the bolt does not lock in?
That wasn't my pic. That was an example from another guy. Mine looks like the bolt is closed, but it appears the bolt isn't rotating into battery as I have minor difficulty opening the action with the charging handle. If I load a single round in a mag and hit the bolt release or release the charging handle it fires. However, it won't pick up the next round in the mag, chamber and fire it.
Maybe try to video the firing sequence. You can slow down the replay if need be to help detect an issue.
Okay my bad for not noticing.
Sounds like it is short stroking to begin with, is the adj gas block all the way open? What length barrel and gas system ? I would try to get it locking back on the last round first then see if the extra travel is enough to strip the cartridge and chamber the round completely.
A spring like that will slow down the carrier in the rearward movement. If you have a plain carbine spring and buffer try those. Make sure there are no gas leaks around the gas block. As a last resort you may need to enlarge the port in the barrel. Let me know what length barrel and gas system and I can tell you what size the port needs to be.
Can't remember gas block designer, but 24" barrel. Bolt locks on firing on empty mag. Originally had a rifle buffer, but switched to JP captured H2 to give it some more force, but no discernible difference in operation. I'll check on gas block.
24" rifle gas port should be .089-.093"
If it locks back on an empty mag after firing it isn't short stroking.
I would look at headspace (which could be case shoulder not pushed back enough)or bullets jamming into the lands next.
If it locks back on an empty mag after firing it isn't short stroking.
I would look at headspace (which could be case shoulder not pushed back enough)or bullets jamming into the lands next.
At least, IMHO, you can safely rule out magazine issues as a root case of the problems.
This description pretty much rules out any potential issues with gas port sizes/locations, feed ramps, or anything like that.
What you describe is either a sizing issue between your ammo and chamber, or something wrong with your bolt as you were suggesting.
On the bolt - does it move in and out of the carrier freely as it should? You are oiling the cam pin location, right?
If the bolt moves correctly, and you're using several brands of factory ammo, this has to be a tight or rough chamber issue.
You already said it's hard to extract a partially chambered round - put some sharpie on a case and do that again, and show us a pic of where it rubs off.
Also, you didn't answer my earlier question: when you chamber the first round and drop the bolt - are you able to extract it without firing it? That's an important detail that will tell us a lot about what's going on.
Another thing to try (and please tell us the answer): lock your bolt back, point the barrel down, and drop a fresh round in the chamber. Does it plunk into the chamber fully and easily? Or does it need to be pushed in by hand, and if so, can you get it out again without using the bolt?
I did have a extractor that caused issues in a 6.5 Grendel. I had to replace original spring w/Wolff extra power spring and removed o-ring from between extractor / bolt body.
That's one I thought of as well, and is worth mentioning, but the symptoms are a little different - it prevents bolt closure because the extractor doesn't want to jump over the rim. When that happens the bolt can be retracted easily by hand, it just doesn't pull the cartridge with it.
Recoil Shoulder said his bolt stops partway closed, and then is hard to open again, presumably because either a round is jammed in the chamber (meaning the extractor jumped over the rim fine) or something is wrong in the BCG.
I’ll try that tomorrow And post some pics. I was messing with the mags and they do seem super tight. Loaded one to max and letting the ammo just sit in it to see it breaking tha mag in a little helps. Seems like a ton on tension on the rounds. I dropped a round in the chamber sans BCG as suggested by Yondering and round dropped in and came out easily. No tapping bouncing or messing with it to plunk and or remove from the chamber. Seems to me mag/ bcg related, but if I knew for sure I would have fixed it by now.
Was my pic since I’m having similar issues. I’ll hold off so as to not steal OP’s thread. I’ll make my own when I get time to mess with this rifle.
OK, probably not a chamber issue then.
Remove the BCG from the upper and verify the bolt moves in and out freely and is properly oiled. Look inside the upper in the area the gas key occupies and see if the gas key has been gouging the aluminum upper.
If all that checks out, it may be contact between the magazine feed lips and bolt carrier, or from pressure of the rounds themselves. Check for feed lip contact with an empty mag.
If you can reproduce the issue, try removing the mag and see what happens. Does the bolt close easily with the FA? Is it easy to extract the round? It may be the magazine causing the difficulty in extraction.
Finally got to the range and tried some new mags and no change. Switched lowers with my Colt AR and no problems. So clearly the rifle length tube and buffer are a no go. Looks like I need to shit can the stock and buffer system, unless someone thinks it can be fixed some other way. Hate to switch out, but seems to be the path of least resistance.
Do you have the correct buffer and spring in there? Maybe post some pics showing what you have so we can know for sure and help figure it out.
There's nothing wrong with a rifle buffer and tube, but there can be problems when people mix up rifle and carbine buffer and spring parts. It sounds like you've got something screwy going on with your lower, hard to guess what at this point.
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