Seekins SP10 barrel swap

[Mike4837]

I have a Seekins SP10 in .308(Not the "M" variant). It's a factory rifle, with less than 1000 rounds on the barrel, but I want to make it a 6.5 Creedmoor now. Some barrels I see on the market require a headspaced bolt to have any kind of accuracy guarantee. My question is this: is it really as simple as buying an aftermarket barrel like a Proof Research and changing barrels? My current rifle is capable of 1/2 moa with Federal Gold Medal ammo, but I typically shoot 3/4 to 1 moa on my best days with consistency cuz I suck. My biggest concern is changing the gun and losing that dependability. Oh yah, it also needs to run reliably too.

 

[bigjake83]

Yes it really is that easy, especially since you can order a 6.5 Creedmoor Barrel from Seekins website. I do believe they are standard DPMS style Barrel extensions but I would call seekins to verify that, and if that is the case you can get a JP, proof, or customs in any flavor you want. Also I would recommend getting a +2 gas system (that is the only reason I have yet to buy a seekins SP-10 6.5 Creedmoor for some reason they run a rifle length gas system). and upgrade your handguard to the 15" Seekins Rail.

Whatever Barrel you decide to use just make sure it's headspace to a HP Bolt.

Jake.

 

[Mike4837]

@bigjake83 I’m waiting on an email back from Seekins next week to verify, but I did ask them already if I need a head spaced bolt with a new barrel. They told me my current bolt would be perfectly fine. Does that mean a proof or similar barrel would take the same bolt too? Assuming of course they’re DPMS barrel extensions.

 

[Mwalex]

You don’t have to have a barrel headspaced and mated to a specific bolt. If you do that though it will ensure that everything will chamber correctly. I believe Proof uses JP bolts internally. If you are concerned by a set of go/no go gauges and check the chambering yourself. There are a ton of videos on YouTube that shows how to use the gauges.

 

[bigjake83]

@bigjake83 I’m waiting on an email back from Seekins next week to verify, but I did ask them already if I need a head spaced bolt with a new barrel. They told me my current bolt would be perfectly fine. Does that mean a proof or similar barrel would take the same bolt too? Assuming of course they’re DPMS barrel extensions.

If you were buying all quality parts for a AR-15 I'd say go for it, but there is this too many slight variations from one manufacturer to the other when it comes to large frame AR'S not even taking into account ArmaLite vs. DPMS and other proprietary platforms.

The advice given by Mwalex above is only half right, Proof Research is one of the best quality barrels on the market and they OPENLY STATE! that they use JP BOLTS to headspace their barrels.

IF YOU WANT TO PLAY THE MIX AND MATCH GAME WITH LARGE FRAME AR'S YOU DO SO AT YOUR OWN PERIL.

If you want to swap barrels from another DPMS style Barrel, I would first call and ask what bolt the barrel company uses to headspace with and I'd also get a set of headspace guages and confirm once you have new barrel

And as far as Seekins is concerned, yes that is correct, they are another top-notch company so parts interchangeability should be none issue IF USING THEIR BARRELS, but I would still reconfirm to find out if they use a HP bolt in the 308 and the 6.5CM

 

[bigjake83]

@bigjake83

If it was me and JP, Seekins or Proof wasn't on my sort list, I would just take your current Seekins Bolt (IF ITS A HP BOLT ONLY) And have a Custom 6.5CM Barrel Spun up by a Smith with that Bolt.

It doesn't matter what style of rifle I'm building, one thing that i always have done is the match the barrel and bolt, If you do this your chances of have problems is cut by 80%.

 

[Mike4837]

If it was me and JP, Seekins or Proof wasn't on my sort list, I would just take your current Seekins Bolt (IF ITS A HP BOLT ONLY) And have a Custom 6.5CM Barrel Spun up by a Smith with that Bolt.

It doesn't matter what style of rifle I'm building, one thing that i always have done is the match the barrel and bolt, If you do this your chances of have problems is cut by 80%.

Seekins did tell me that my bolt would work perfectly in the 6.5 configuration and all I would need is one of their barrels. I assume this means their bolts are all HP bolts. Their barrels are backordered so I’m waiting to hear what their lead time is. My preference is the Seekins barrel cuz that seems like the easy button. Proof is probably my second choice, but I’d rather stay Seekins.

 

[bigjake83]

Seekins did tell me that my bolt would work perfectly in the 6.5 configuration and all I would need is one of their barrels. I assume this means their bolts are all HP bolts. Their barrels are backordered so I’m waiting to hear what their lead time is. My preference is the Seekins barrel cuz that seems like the easy button. Proof is probably my second choice, but I’d rather stay Seekins.

Don't just look at the Proof CF Barrels their SS barrels are top notch ad have the CAM GAS design. most people who are competitively running proof barrels are actually running the SS not CF.

 

[Mike4837]

Don't just look at the Proof CF Barrels their SS barrels are top notch ad have the CAM GAS design. most people who are competitively running proof barrels are actually running the SS not CF.

Agreed. Their steel barrels are intriguing and half the price.

 

[Mwalex]

If you were buying all quality parts for a AR-15 I'd say go for it, but there is this too many slight variations from one manufacturer to the other when it comes to large frame AR'S not even taking into account ArmaLite vs. DPMS and other proprietary platforms.

The advice given by Mwalex above is only half right, Proof Research is one of the best quality barrels on the market and they OPENLY STATE! that they use JP BOLTS to headspace their barrels.

IF YOU WANT TO PLAY THE MIX AND MATCH GAME WITH LARGE FRAME AR'S YOU DO SO AT YOUR OWN PERIL.

If you want to swap barrels from another DPMS style Barrel, I would first call and ask what bolt the barrel company uses to headspace with and I'd also get a set of headspace guages and confirm once you have new barrel

And as far as Seekins is concerned, yes that is correct, they are another top-notch company so parts interchangeability should be none issue IF USING THEIR BARRELS, but I would still reconfirm to find out if they use a HP bolt in the 308 and the 6.5CM

What was I half right about?

 

[bigjake83]

What was I half right about?

You don’t have to have a barrel headspaced and mated to a specific bolt.

That's some of the worst advice you can give anybody when it comes to large frame ARs, especially a guy you can tell is new to this.

 

[Mwalex]

That's some of the worst advice you can give anybody when it comes to large frame ARs, especially a guy you can tell is new to this.

Base on what? Your opinion? How many AR barrels have you bought with a mated bolt? Have you ever head spaced a bolt/barrel combo? I would guess not because headspacing always tells you if the bolt and barrel will work.

In addition please tell me the difference between the chambers/barrel extensions on an Armalite and DPMS AR308 barrel.

 

[bigjake83]

Base on what? Your opinion? How many AR barrels have you bought with a mated bolt? Have you ever head spaced a bolt/barrel combo? I would guess not because headspacing always tells you if the bolt and barrel will work.

In addition please tell me the difference between the chambers/barrel extensions on an Armalite and DPMS AR308 barrel.

Base on what? Your opinion? How many AR barrels have you bought with a mated bolt?

Between 40-60 Easy! And that's just Large Frame.

Have you ever head spaced a bolt/barrel combo?

Yep! Every time even if it does come with a supplied headspace Bolt.


and as far as the difference between ArmaLite and DPMS Barrel extensions you can look that up yourself when you're done acting like a Twat.

Are you related to Primus?

 

[Mwalex]

Between 40-60 Easy! And that's just Large Frame.




Yep! Every time even if it does come with a supplied headspace Bolt.


and as far as the difference between ArmaLite and DPMS Barrel extensions you can look that up yourself when you're done acting like a Twat.

Are you related to Primus?

Just what I thought you have no idea in the difference. There is no diffference. The primary difference between the two barrels is the length of the gas tube. If there is a bolt difference then head spacing will sort that out.

Name calling? That is very adult of you.

 

[bigjake83]

Just what I thought you have no idea in the difference. There is no diffference. The primary difference between the two barrels is the length of the gas tube. If there is a bolt difference then head spacing will sort that out.

Name calling? That is very adult of you.

308 Barrels & 308 Barrel Extensions
The DPMS pattern barrel extension is the most common. This translates in to many 308 AR barrel options. RRA LAR 308 will also work with a DPMS barrel. The Armalite AR-10 barrel extension is not dimensionally identical to the DPMS. Therefore Armalite AR-10 rifles must use barrels designated for the Armalite AR-10 and vice versa.

https://308ar.com/ar-10-308-ar-compatibility-reference-guide/

https://www.google.com/amp/s/308ar.com/ar-10-barrel-extension-ar308-barrel-extension/amp/

You're seriously a Dumb Cunt.

As far as any further interaction with you, you are ignored but I will be looking forward to other members comments once they read your stupidity first-hand.

OP I am sincerely sorry for the interruption of your legitimate thread.

 

[MarinePMI]

@Wolfhunter

Listen to BigJake; LR platforms are not as standardized as AR platforms, so variations can and do exist.

As to the +2 gas system, as I understand it, this is to ensure better functioning with the heavier bullets in the 6.5CM. The early variants (like my POS DPMS) won't shoot the 140's worth a shit, but shoots the 120's like a house on fire. The 140's (I think) are just pushing the recoil impulse just a tad too quickly (weird case obturation, and rounded shoulders on the brass indicating unlocking of the bolt prematurely), so the +2 system gives the pressure curve a little more time before flowing back down the gas tube to unlock the bolt. Kind of similar to a pigtail gas tube on a short AR...

 

[Mike4837]

@Wolfhunter

Listen to BigJake; LR platforms are not as standardized as AR platforms, so variations can and do exist.

As to the +2 gas system, as I understand it, this is to ensure better functioning with the heavier bullets in the 6.5CM. The early variants (like my POS DPMS) won't shoot the 140's worth a shit, but shoots the 120's like a house on fire. The 140's (I think) are just pushing the recoil impulse just a tad too quickly (weird case obturation, and rounded shoulders on the brass indicating unlocking of the bolt prematurely), so the +2 system gives the pressure curve a little more time before flowing back down the gas tube to unlock the bolt. Kind of similar to a pigtail gas tube on a short AR...

Good to hear from you @MarinePMI. I definitely appreciate the insight from this thread. That’s interesting about the gas system. I’ll be using a select adjustable gas block and a suppressor so taming the gas shouldn’t be a big problem, but I definitely want it to cycle properly with all ammo. I’m likely just going to shoot berger 130 factory. That stuff shoots like a dream in my 20” AI. Like I said, I think my preference is to stick with a seekins barrel since they’re building them for these guns, but I like to have a plan B. I love how soft and accurate my .308 is now and worry about losing that in the switch.

 

[bigjake83]

Good to hear from you @MarinePMI. I definitely appreciate the insight from this thread. That’s interesting about the gas system. I’ll be using a select adjustable gas block and a suppressor so taming the gas shouldn’t be a big problem, but I definitely want it to cycle properly with all ammo. I’m likely just going to shoot berger 130 factory. That stuff shoots like a dream in my 20” AI. Like I said, I think my preference is to stick with a seekins barrel since they’re building them for these guns, but I like to have a plan B. I love how soft and accurate my .308 is now and worry about losing that in the switch.

A good plan B, well actually it's usually a plan A for most people is to get yourself a 22in JP Barrel. They truly are phenomenal barrels for mass-produced button cut style barrels, and they even come with a headspace bolt.....lol. Sorry had to add that

 

[Mike4837]

A good plan B, well actually it's usually a plan A for most people is to get yourself a 22in JP Barrel. They truly are phenomenal barrels for mass-produced button cut style barrels, and they even come with a headspace bolt.....lol. Sorry had to add that

Can’t argue with JP’s quality and performance. I’ll see what Seekins says about the backorder time and look at JP. Thank you

 

[bigjake83]

Can’t argue with JP’s quality and performance. I’ll see what Seekins says about the backorder time and look at JP. Thank you

Check your inbox in a couple minutes.

 

[Mike4837]

@bigjake83 whats your take on the JP heat dissipators? They look kinda funky and I’m not even sure if they’d fit under my handguard, but the concept is nice.

 

[bigjake83]

@bigjake83 whats your take on the JP heat dissipators? They look kinda funky and I’m not even sure if they’d fit under my handguard, but the concept is nice.

If you're running 3 gun or an aggressive PRS style Match then it's definitely a good investment, to this day I've never had to use one since all my shooting is precision based and I just don't get my Barrels hot enough to require one.

 

[Mike4837]

What about Craddock Precision barrels? They carry a premium, but from what I can tell they're supposed to be very accurate?

 

[Mike4837]

@bigjake83 I asked about the barrel extension. Seekins said it's based off the SR25 which rings a bell cuz I had to get the correct charging handle when I bought it. What does that tell me about extensions?

 

[bigjake83]

@bigjake83 I asked about the barrel extension. Seekins said it's based off the SR25 which rings a bell cuz I had to get the correct charging handle when I bought it. What does that tell me about extensions?

Just whatever barrel you choose needs to have a SR25 style Barrel extension. Your Bolt may still be compatible with standard DPMS style extensions( you will need to do some research on that one). But now that you know the facts of your Barrel extension and bolt setup, these are the questions you need to ask and get clarification on before you make your next Barrel purchase.

 

[Mike4837]

Just whatever barrel you choose needs to have a SR25 style Barrel extension. Your Bolt may still be compatible with standard DPMS style extensions( you will need to do some research on that one). But now that you know the facts of your Barrel extension and bolt setup, these are the questions you need to ask and get clarification on before you make your next Barrel purchase.

I’m down with that. As such I called craddock and told him what I have and what I want. It’ll cost a few pennies compared to something off the shelf, but I like knowing my gear isn’t the problem when I miss.

 

[bigjake83]

I’m down with that. As such I called craddock and told him what I have and what I want. It’ll cost a few pennies compared to something off the shelf, but I like knowing my gear isn’t the problem when I miss.

Attaboy! Get yourself a 22" Bartlein 5R 1-8 twist and + 2 gas.

 

[Mike4837]

Attaboy! Get yourself a 22" Bartlein 5R 1-8 twist and + 2 gas.

Essential exactly what I want, except in a 20" cuz I don't want a musket with the can on it. ?

 

[Mike4837]

Got my Craddock barrel in and mounted on the SP10. I'll post follow ups in the coming days.

 

[Mike4837]

I was going to get more time on the gun before I posted anything, but I'm impressed enough that I thought I'd give a preliminary update. I took the new Craddock Precision 6.5 barrel(Bartlein blank) out today to 775 yards. I got my initial zero which was under an inch, but not crazy impressive, tuned the gas system and started working some prone to distance and then the barricade. After 60 rounds I went back to the 100 yard zero(technically 103 yards) and rechecked zero and my numbers. Here's my 5 shot group and 10 shot average on the Labradar. This was all suppressed as well.

The ammo was all 130 grain Berger Hybrid AR OTM factory ammo. I've had really good results with it in my AI AT and it seems the trend will continue with this gun as well. The barrel is a 20" Bartlein blank with a rifle length +1 gas system, Superlative Arms adjustable gas block, and straight fluting for weight savings.

I'll post more in time. Seems like it's going to be a straight shooter though.

 

[MarinePMI]

Isn't that kind of slow for a 130gr 6.5CM load?

 

[Mike4837]

Isn't that kind of slow for a 130gr 6.5CM load?

Yah. I think so. Honestly I was a little surprised since my 20” Rock Creek barrel shoots the same factory ammo at 2816 in my AI. I’m going to track it over time and see if it speeds up at all. Could just be the whole, gas gun vs bolt gun thing I guess. Not entirely sure to be honest.

 

[Jigstick]

Does Seekins bed their barrels into the upper on the née production SP10s? Thought I remember seeing a video that if an inexperienced individual tries removing the barrel from the upper that you can cause some damage due to how it’s “press fit / loktite bedded” into the upper in some fashion.

 

[bigjake83]

No they don't do that on the standard SP-10 but that barrel nut is definitely on there, be prepared to add some heat, also make sure to remove all the set screws.

I would also highly recommend you have the proper tools, ie.. Reaction Rod and a proper fitting opened end wrench.

 

[Jigstick]

I’m 5mon out on my SP10. They wouldn’t let me order a +2 gas length unless I went with the M series. Kind of sucks because I don’t require the kind of “support” that the M series comes with.

 

[bigjake83]

I’m 5mon out on my SP10. They wouldn’t let me order a +2 gas length unless I went with the M series. Kind of sucks because I don’t require the kind of “support” that the M series comes with.

That doesn't sound right, who did you talk to?

 

[Jigstick]

One of the guys at the front desk. Forget his name. But he was adamant. Because I upgraded my gas block to the quick adjustable version and wanted that lever out from under the handguard. He said the only way to have that happen was to do the +2 gas length which is only available on the M series. I actually ordered two rifles and he wouldn’t let me do the +2 on either unless I went with an M.

I decided to forgo the M because given the current environment I figured a standard SP10 would be more time efficient to get. Kinda sucks though to have that gas block buried under the handguard. Especially on a 6.5CM. Figured I’d just shoot the barrels out then debarred with a Craddock or simikiar custom with a +2 length at that time. Hence my question on how easy barrel swaps are.

 

[bigjake83]

One of the guys at the front desk. Forget his name. But he was adamant. Because I upgraded my gas block to the quick adjustable version and wanted that lever out from under the handguard. He said the only way to have that happen was to do the +2 gas length which is only available on the M series. I actually ordered two rifles and he wouldn’t let me do the +2 on either unless I went with an M.

I decided to forgo the M because given the current environment I figured a standard SP10 would be more time efficient to get. Kinda sucks though to have that gas block buried under the handguard. Especially on a 6.5CM. Figured I’d just shoot the barrels out then debarred with a Craddock or simikiar custom with a +2 length at that time. Hence my question on how easy barrel swaps are.

Sending you a PM

 

[buggz]

So, is it possible to buy a kit from Seekins, to swap an SP10 from 308 to 6.5CM ?
My 308 SP10 does not have a charging handle upper.
This is required for a 6.5 CM upper ?

 

[bigjake83]

So, is it possible to buy a kit from Seekins, to swap an SP10 from 308 to 6.5CM ?
My 308 SP10 does not have a charging handle upper.
This is required for a 6.5 CM upper ?

Charging handle upper???

Do you mean your current upper is a side charging upper?

 

[buggz]

No, I have a Seekins SP10 in .308.
I got confused with the with side charging uppers, for some reason…

 

[bigjake83]

You can definitely swap out the Barrels to a 6.5CM, I've built several rifle with the SP-10 Builder kits and I've recently rebarreled my personal Seeking SP-10 6.5CM with a Bartlein from Craddock.

 

[buggz]

Good to know, thanks.

 

[Mike4837]

I also rebarreled one of my .308 seekins to 6.5 creedmoor. Like bigjake I used a craddock bartlein barrel. I don’t have pictures handy but it shoots prime and berger factory Ammo better than I’m capable of shooting.

 

[BytorJr]

Glad all you guys are having great luck with Craddock.....