I'm trying to work up loads for my AR in 22 wylde chamber. In the past, I've loaded up a bunch of 55 grn with good results. Today, I tried some 69 grn loads. They ran fine and accuracy was decent (I have more work-ups to do), but my bolt wasn't staying open on the last round. I didn't try any of the 55 grn today, because I didn't have any with me. But I'm guessing it has something to do with my new loads, as everything ran fine with my 55s last week. Any thoughts?
Bolt Won't Hold Open on Last Round
- Thread starter BTShooter
- Start date
This is what I was thinking as well, but I'm not sure how to correct it. The 62 grn loads are a bit hotter than than the 55s were. I have a rifle-length buffer now. Do I need a heavier buffer?
I plan to try 77s next, so I'd like to get this fixed.
Have you checked to make sure the gas block and gas port are properly aligned? Are you using some kind of fancy light weight BCG? If you are not, I find it hard to believe that you are over gassed and out running stuff. Whos barrel? Gas block? whos BCG?
If it's not a gas issue it's most likely a buffer weight/spring problem. Eliminate variables one by one.
It's a stock Rock River Varmint upper, except for the Geissele trigger. They used a Wilson 20" heavy barrel. Nothing fancy. Worked just fine last week with the 55s, which is why I'm confused.
Double check your gas block and make sure it isn't leaking gas, is properly lined up. This is where I would start.
I would suggest varying the charge up and down on the heavy bullets to see if you can fix it, otherwise you may have to use two different buffers
I did that. I tested 6 different charges today, all had had the same problem.
How do I know if it's leaking gas? I understand the alignment issue, but if it is properly aligned, can it still leak?
Using the same mags as with the 55gr loads? I have some that don't work nearly as well as others at pushing up the catch.
Also double check the bolt catch, I've had some that were a little rougher or wider or the channel in the lower was narrower or the spring got old and shitty or whatever, but it boiled down to mechanical failure of the catch itself. Run it slowly by hand and check for any sticky spots or broken shit.
I love my SCSs, but a new bolt catch spring is a hell of a lot cheaper.
Also double check the bolt catch, I've had some that were a little rougher or wider or the channel in the lower was narrower or the spring got old and shitty or whatever, but it boiled down to mechanical failure of the catch itself. Run it slowly by hand and check for any sticky spots or broken shit.
I love my SCSs, but a new bolt catch spring is a hell of a lot cheaper.
Stupid experience time. Did you try more than one magazine and how old are they? Over the course of Atlantic Fleet and All Navy East Matches last year I went from 1 magazine to 4 magazines giving me a problem over the course of the week. Turns out after a thorough cleaning of the rifle and mags I had a handful of magazine springs that wore out.
I tried 4 different mags, all have less than 100 rounds through them. Same mags that worked fine for the 55 grn loads last week. The bolt stays open fine when pulled back manually on an empty mag.
I think short-stroking is the issue and I may have just figured out why. I have one of those adhesive buffer pad things you stick on the buffer to save wear on the bolt/buffer. I've read of others having this problem and removing the pad fixed it. I'll remove it and see what happens. Couldn't hurt.
Check and make sure your gas tube is seated well in the gas block. Check the gas key and make sure it’s tight and not leaking. If you’re shooting full power loads and your gas is properly getting to the key then I would try a lighter buffer plug or spring.
Ok, thanks. I also checked the gas block alignment and made sure the gas tube was clear. No issues.
So, I decided that I was due for a change in my buffer and also in my stock. I've been running an Ace Skeleton stock for years. I ended up ordering a JP Silent Capture, along with a Magpul PRS stock.
I'm very fortunate to have a wife that doesn't ask a lot of questions when boxes get delivered.
Giving an update as it appears the problem is fixed. I removed the plastic buffer pad and the rifle is running great, along with the action holding open on the last round (I didn't install the Silent capture buffer yet). Looks like the plastic pad was the problem.
On another note, my goal of getting a 1" group at 200 yards with mag-fed reloads was almost met today. I tried 77 grain SMKs with varying charges of varget and got a group of 1.08" using 25.5 grains. It was a bit windy today. I'll try the same load on a calmer day.
On another note, my goal of getting a 1" group at 200 yards with mag-fed reloads was almost met today. I tried 77 grain SMKs with varying charges of varget and got a group of 1.08" using 25.5 grains. It was a bit windy today. I'll try the same load on a calmer day.
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