SP10 Feeding Issues

[JB.IC]

Update: issue resolved by completely closing the gas key.

Specs:
- SP10 22” 6.5CM
- Omega Suppressor
- Seekins low profile gas block
- JP LMOS
- JP SCS Gen2 - Standard with heavy spring (yellow/red)

When I use p-mags (LR/SR) 10 or 20 rounders I get feeding issues. See pics below. It’s like clockwork with either sized p-mag. It will jam around the 4th-6th firing every time. However, when I use my KA mags, it feeds fine.

Just looking for feedback. The gas block has been adjusted to a reasonable level. It’s not over-pressured or under-pressured. I’d like to be able to use the 10 round p-mags for PRS matches.

I also have L7AWM mags but the SCS system does not have enough force to chamber a round when the bolt is locked back and then released. It cycles fine otherwise but requires more gas than my KA mags for chambering rounds. I think the L7AMW spring applies too much upward force against the round and the lips. Also tried it with the heavy buffer and full mass BCG and the L7AWM mags just seem to have too much to feed a round.

 

[LawnMM]

Get rid of the stupid LMOS, that gun is running on higher pressures than you think.

The light bolt is increasing the cyclic rate and beating the fuck out of the action. Is it ejecting brass like 10ft at your 1 o'clock angle from the barrel?

Had a similar setup when I first put my AR10 together and didn't have a clue, sheared an extractor claw right off in the middle of a match.

 

[JB.IC]

Get rid of the stupid LMOS, that gun is running on higher pressures than you think.

The light bolt is increasing the cyclic rate and beating the fuck out of the action. Is it ejecting brass like 10ft at your 1 o'clock angle from the barrel?

Had a similar setup when I first put my AR10 together and didn't have a clue, sheared an extractor claw right off in the middle of a match.

Lmao. You called an earlier issue I had. It was sending them at 1 o’clock at something like 6-8ft away when I first was adjusting the gas block. Notice the brass markings near the front of the ejection port. The brass really trying to join in on the fun.

That issue has been since resolved. My gas block is practically closed and it sends them to my 3-4 o’clock at like 2-3ft away.

 

[broke_again]

You may need the variable mass carrier to slow that cycle speed down.

 

[hlee]

Use the KA mags for the comps. There is value in loading ~12 rounds in a 10 round stage. Especially in a gasser. Otherwise, KA has 10 round mags listed as currently available on their site right now.

 

[mrtoyz]

Specs:
- SP10 22” 6.5CM
- Omega Suppressor
- Seekins low profile gas block
- JP LMOS but with Seekins bolt (ejection seemed less harsh with Seekins bolt)
- JP SCS Gen2 - Standard with heavy spring (yellow/red)

When I use p-mags (LR/SR) 10 or 20 rounders I get feeding issues. See pics below. It’s like clockwork with either sized p-mag. It will jam around the 4th-6th firing every time. However, when I use my KA mags, it feeds fine.

Just looking for feedback. The gas block has been adjusted to a reasonable level. It’s not over-pressured or under-pressured. I’d like to be able to use the 10 round p-mags for PRS matches.

I also have L7AWM mags but the SCS system does not have enough force to chamber a round when the bolt is locked back and then released. It cycles fine otherwise but requires more gas than my KA mags for chambering rounds. I think the L7AMW spring applies too much upward force against the round and the lips.

View attachment 8155690
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Curious what made you think you needed a LMOS carrier?

 

[JB.IC]

Curious what made you think you needed a LMOS carrier?

Nothing “made” me think I “needed” it. Just like the plethora of guns parts that many people do not “need.” I bought it like 3-4 years ago because many people said they were nice to use. Only way to find out was to try it myself so I bought it. I tried it and shot it at a few matches. Switched back to my bolt action for matches. LMOS + SCS does feel better under the scope than the standard H2 spring and BCG setup. But I’m not going to pretend it’s worth the price of admission because like many custom gun parts, it’s not needed.

 

[JB.IC]

Use the KA mags for the comps. There is value in loading ~12 rounds in a 10 round stage. Especially in a gasser. Otherwise, KA has 10 round mags listed as currently available on their site right now.

The 20 rounders to play well for low shooting positions. Had that issue of a few matches. I didn’t know they had 10 rounders. Thanks for the heads up.

 

[LawnMM]

I'm telling you, get rid of that carrier.

Here's another easy way to test it, don't change anything else, but take the suppressor off and see if it still happens

You're running a gas heavy weapon, with a high pressure cartridge, AND suppressing it. Your gun ain't a candidate for low mass anything.

I'd swap the SCS weights out for tungsten and either get a full mass carrier or that vmos carrier JP makes.

 

[JB.IC]

I'm telling you, get rid of that carrier.

Here's another easy way to test it, don't change anything else, but take the suppressor off and see if it still happens

You're running a gas heavy weapon, with a high pressure cartridge, AND suppressing it. Your gun ain't a candidate for low mass anything.

I'd swap the SCS weights out for tungsten and either get a full mass carrier or that vmos carrier JP makes.

I’ll test it but be more specific to this: “and see if it still happens.” Are you talking about the 10ft 1 o’clock brass (which isn’t an issue) or the pmag feeding issue?

I have two Seekins BCG I can test as well.

 

[LawnMM]

Your feeding issue

The bolt is cycling faster than the mags, that's the issue. The gas block may be almost closed but there's only so much it can do.

Just to rule out the dumb shit you're running this thing pretty wet with lube, right?

 

[JB.IC]

Your feeding issue

The bolt is cycling faster than the mags, that's the issue. The gas block may be almost closed but there's only so much it can do.

Just to rule out the dumb shit you're running this thing pretty wet with lube, right?

So wet that if you don’t have eye pro on you might get 5w30 in your eyes lol

 

[Rancid Coolaid]

I have a gen1 SP-10 (6.5) that was a bitch to break in, now runs great. Mine is so great, a friend bought one too, his had similar issues to yours. We sent it back to Seekins and they swapped the BCG to a newer version, and the friend promptly sold it.

That gun can be awesome and can be an absolute dog.

I'd involve Seekins in the conversation, but I'd also run their BCG in it regardless.

It is not an under-gassed gun, especially suppressed...

And lube, lotta lube. The general rule is when you think you have too much, you have almost enough.

 

[JB.IC]

I have a gen1 SP-10 (6.5) that was a bitch to break in, now runs great. Mine is so great, a friend bought one too, his had similar issues to yours. We sent it back to Seekins and they swapped the BCG to a newer version, and the friend promptly sold it.

That gun can be awesome and can be an absolute dog.

I'd involve Seekins in the conversation, but I'd also run their BCG in it regardless.

It is not an under-gassed gun, especially suppressed...

And lube, lotta lube. The general rule is when you think you have too much, you have almost enough.

I’d say the issue right now isn’t with Seekins considering I’m using other parts which is why I listed them. That being said, I’m not sure why the KA mag works over the p-mag. But then again, I’ve had magazine feeding issues even with bolt actions: Zeus, ATX, and Mausingfield. And who knows how much different chassis and stocks have their effect as well. They all like the lips to be a certain way.

I have this large mouth water bottle full of 5w30 that is used as a dunk tank for the BCG since I’m lazy. Let the BCG drain for a little bit and it’s good to go.

 

[Rancid Coolaid]

If that works for you, cool. Then again, it doesn't sound like it is all working.

My first thought would have been to return the gun to factory configuration and see if the problem goes away.

If you are happy to do your own troubleshooting (no pun intended), then carry on with what could be an endless set of variables. If the problem is the gun, swapping to after-market parts has limited potential for success.

But I wrong-think sometimes.

 

[mrtoyz]

Definitely go back to factory. I’d be shocked if it didn’t solve your issue. Seekins probably won’t want to talk to you till you do anyway

 

[hlee]

The 20 rounders to play well for low shooting positions. Had that issue of a few matches. I didn’t know they had 10 rounders. Thanks for the heads up.

No problem. I had to look them up. Pricey, but if they’re the only ones that run, they’re the mags to use.

I retrofit all of my comp mags with 5 round extensions, because 2 extra rounds will often make up for a minor feeding issue without requiring a mag change. But, making the 10 round pmags run with the extensions requires a bit of work with a file. And, I wouldn’t attempt it until and unless you get the pmags running 100%.

 

[JB.IC]

Issue has been resolved by completely closing the gas key. Cycles fine with p-mags now.