sgtsandman
US Veteran
The .308 is the hotter round of the two, so my guess is that less gas is needed to cycle the BCG.
Failure to feed problem
- Thread starter jayferguson
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What's the difference between win white box and the commercial ammo you speak of? I mean besides the .308 and 7.62 issue? I don't shoot reloads unless white box is a reload
Also, I think the manual states that both types can be shot.
Thanks for the comments.
sgtsandman
US Veteran
White box tend to be military/government ammunition.
I've shot white box and been fine. Apparently, not everyone is so lucky. Just like any other firearm though, it seems each individual M&P10 likes some ammo better than others and hates others.
As an example, my Catamount Fury won't cycle with low brass and some low recoil high brass no matter how I adjust the gas block even though Century Arms and the Owner's Manual says I should be able to.
I've shot white box and been fine. Apparently, not everyone is so lucky. Just like any other firearm though, it seems each individual M&P10 likes some ammo better than others and hates others.
As an example, my Catamount Fury won't cycle with low brass and some low recoil high brass no matter how I adjust the gas block even though Century Arms and the Owner's Manual says I should be able to.
M&P 10 failure to feed
I'm new here but have used info so much I decided to join. I have a Smith M&P 10 also with many of the same problems listed here in this thread. I've added one Tubb's Precision AR-10 CS Buffer spring, a CMC 3.5 pound trigger group, and a 3-12 UTG scope. The trigger is very nice but I won't go into the install since that's covered here in another thread. When I use any .308 round I have zero issues and fairly good accuracy at 100 yards. That's any .308 I've used from Federal to PMC and a few in between. I've never had good luck with any 7.62x51 ammo. Failure to feed and failure to lock back after last shot. The only change to the system to affect it is the spring which made it operate smoother. This gun is for .308 and if you find it, hotter 7.62 rounds. I like the gun. I like to run .308 and now I'm looking at the right weight .308. From the threads here it looks like it's closer to 168grains then to 150. Please, since I'm new, let me know if I've missed anyone having problems with the .308 round not cycling the rifle correctly.
I'm new here but have used info so much I decided to join. I have a Smith M&P 10 also with many of the same problems listed here in this thread. I've added one Tubb's Precision AR-10 CS Buffer spring, a CMC 3.5 pound trigger group, and a 3-12 UTG scope. The trigger is very nice but I won't go into the install since that's covered here in another thread. When I use any .308 round I have zero issues and fairly good accuracy at 100 yards. That's any .308 I've used from Federal to PMC and a few in between. I've never had good luck with any 7.62x51 ammo. Failure to feed and failure to lock back after last shot. The only change to the system to affect it is the spring which made it operate smoother. This gun is for .308 and if you find it, hotter 7.62 rounds. I like the gun. I like to run .308 and now I'm looking at the right weight .308. From the threads here it looks like it's closer to 168grains then to 150. Please, since I'm new, let me know if I've missed anyone having problems with the .308 round not cycling the rifle correctly.
.308 pressure
Mistwolf. I guess I made an assumption that everyone here would know that .308 is a higher pressure,thus, it would cycle the bolt better with less fail to feed due to short stroking problems. At least that is my experience with my M&P 10 and seems to be a common problem. I'm thinking an adjustable gas valve would be the ticket like on the Ruger 762 and a few more. The gas port would be another place to look but I like to start with less drilling at the beginning of troubleshooting.
Thanks by the way. My shooting partner that has years of experience over me didn't know .308 has higher pressures.
Mistwolf. I guess I made an assumption that everyone here would know that .308 is a higher pressure,thus, it would cycle the bolt better with less fail to feed due to short stroking problems. At least that is my experience with my M&P 10 and seems to be a common problem. I'm thinking an adjustable gas valve would be the ticket like on the Ruger 762 and a few more. The gas port would be another place to look but I like to start with less drilling at the beginning of troubleshooting.
Thanks by the way. My shooting partner that has years of experience over me didn't know .308 has higher pressures.
An adjustable gas block will not help an undergassed gun. The issue is the gas port size.
You can allways gas down with an adjustable block, but you cannot gas UP, because it is running wide open now! It only receives what comes out of the port!
Please read my comments in the other related thread just below this one.
In the case of S&W 10, COMMERCIAL means US made hunting ammo and match ammo by US makers.
Also thanks for the link to your thread. It helped a bunch!
I'm a little chagrined. I went back and read your post again and realized I misunderstood it the first time.
The more I shoot the Big Smith, the less picky it is about ammo. I've recently swapped the carbine buffer out for an H buffer and the rifle functions fine on handloads that duplicate military ammo without opening up the gas port. However, I'm also using a BABC which I suspect increases back pressure a bit
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I've been hoping to get to that point of less picky and one of the next steps for non-destructive improvement would be the buffer. I'll have to weigh mine since I haven't yet. I like the "Big Smith" comment. I'm going to use it myself now. I'll be at the range tomorrow and using Gold Medal Match .308 168grain. If the gun likes it, then I'll mimic the load of the GMM with a 168grain bullet. I do want this gun to be the gun to carry into trouble or to ideally keep trouble away until help arrives. However, 00 buck in a dark hallway would be the first choice......Thanks again! Tell me what brand H buffer are you using?
Sounds like an H buffer which is 3.8oz if my research is good. I'm still researching the change to another buffer which may cause short stroking if I don't chose the correct weight. I already have short stroking with the 7.62 ammo so I may have to accept the fact that this gun is made for .308 which I think you mentioned in one of your posts. My range day was perfect with .308 ammo. I was way more accurate with the Gold Medal Match 168 grain. So, I'll sit down to a long research session to see which rifle will fire both nato and .308. I think this rifle will be more appealing to a future buyer if I don't drill or cut into it and leave that to the next shooter.
Yea, well, told you so! What kinda groups did you get with the GMM?
You do not have to research anything, it was made to CYCLE US made .308, but it works just fine with 7.62 if you give it a little more gas to work with.
If you want to make it more appealing to a future buyer, you might try selling them a gun that just works with what you put into it!
Oh, and BTW, even at my .073 gas port setting, I am still pushing a H2 buffer to soften things with no issues thus far.
To me, I just want it to work! I may decide to punch a bunch rapid fire one day, then go to precision the next. The gun needs to work! And with what I feed it!
And yes, at the cost of GMM, I can load it myself at half the cost, or buy decent reloads in Amax 168, which have done better thusfar in my gun.
You might try Freedom Munitions.com as an example for some good quality reman Amax at less than a buck per. First order is free shipping!
Do as you like, just sayin.
The GMM surprised me at 3 MOA with 3 of the 5 holes touching in a straight line. 2 flyers but that was me. A little more work and I should have that spread a little tighter but for what I'll use it for it's great grouping. I'm leaning toward the enlargement of the gas port because like you, if things go like we're seeing in the news then I'll need to fire what I find which most likely will be 7.62. I do have plenty of that. I'll reload to the GMM specs when I do another round of .308. I'll check out your Amax link, thanks!
sgtsandman
US Veteran
I guess it depends on the rifle. Lake City 7.62 has been running fine in mine so far.
Yep, at least it has US powder which probably helps! Burn rate is an issue!
How is your ejection pattern?
These things are NOT AR-15, yet same principals apply to an extent. Not sure to what extent.
On a typical AR, a pattern from 1 o'clock to about 5 o'clock is a scale. (over and under gassed) with 3-4 o'clock being more ideal range.
sgtsandman
US Veteran
Ejection has been about the same as shooting match rounds. About the 3-4 o'clock range, with the occasional 1-2 from both. It doesn't happen often but when it does, I have to go outside the shooting shed/house to get them. Otherwise, they are all inside the shed and I have to pray the brass hasn't fallen through the gaps in the floor.
I really need to get a brass catcher. It's not like they are all that expensive or anything....
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rojodiablo said:HOLY COW!!!What an EXCELLENT set of pictures!!
This is a relatively simple polish job. Take a dremel tool with a small round polishing stone, and carefully massage all that. ................
OMG!!!!!!!!!!!!! DO NOT use a small round stone! This is what cratex polishing tips are made for. Much harder to do excessive damage with, but still capable of doing the job.
This is a problem which can be fixed in about 10 minutes total time. Be patient, and do not push too hard.
While true, since the item is still under warranty, you'd be better off to send it back, with a set of those pictures to illustrate what you believe is the cause of the problem. I'd include a couple of pics of those bent rounds.
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