Old School 611 Posted March 17, 2017 Yep I have loads of BCGs on hand but I'm putting together a 22 Nosler that I expect to push pretty hard pressure wise. I really want the stongest bolt I can get for a standard barrel extension. What are your thoughts? Don't need a special extractor or any of that fancy stuff just a very strong Bolt only for a standard carrier. Quote Share this post Link to post Share on other sites
High Exposure 5,635 Posted March 17, 2017 A standard truly MiL-spec bolt should do fine. Daniel Defense, BCM, COLT. Avoid the boutique finishes and fancy cuts. 1 Quote Share this post Link to post Share on other sites
Ray Ray 3,566 Posted March 18, 2017 A standard truly MiL-spec bolt should do fine. Daniel Defense, BCM, COLT. Avoid the boutique finishes and fancy cuts. I would add AIM surplus and Spikes Tactical. Quote Share this post Link to post Share on other sites
Old School 611 Posted March 18, 2017 A standard truly MiL-spec bolt should do fine. Daniel Defense, BCM, COLT. Avoid the boutique finishes and fancy cuts. Absolutely pass on the coated stuff. Generally out of spec from pre coating polishing. Daniel Defense, BCM, COLT...Yep these were my thoughts. 1 Quote Share this post Link to post Share on other sites
MidwestPX 172 Posted March 18, 2017 Hands down toughest bolt I have come across is LMT's enhanced bolt. Aermet is a ridiculously tough material for the application. 1 Quote Share this post Link to post Share on other sites
High Exposure 5,635 Posted March 18, 2017 Hands down toughest bolt I have come across is LMT's enhanced bolt. Aermet is a ridiculously tough material for the application. Doesn't that bolt require a proprietary carrier? Or is that the Knights bolt? Quote Share this post Link to post Share on other sites
High Exposure 5,635 Posted March 18, 2017 Ray, I wouldn't trust Spikes anything to be spec. AIM - maybe, but probably not. Quote Share this post Link to post Share on other sites
Ray Ray 3,566 Posted March 18, 2017 Ray, I wouldn't trust Spikes anything to be spec. AIM - maybe, but probably not. I believe they are one in the same, meaning they are made by the same company. Aero Precision I think. Mil-spec is Mil-spec. Now, S&W or Bushmaster? Nope Quote Share this post Link to post Share on other sites
Shane45 807 Posted March 18, 2017 Except when its not and everyone and their room mate in collage claim mil spec. The KAC bolt is proprietary in that it uses a different size cam pin. I have never heard of a KAC bolt breaking including rifles that went reportedly over 90,000 rounds. 1 Quote Share this post Link to post Share on other sites
MidwestPX 172 Posted March 18, 2017 Doesn't that bolt require a proprietary carrier? Or is that the Knights bolt? Nope. The KAC bolt required a proprietary extension but the LMT doesn't. Quote Share this post Link to post Share on other sites
Old School 611 Posted March 18, 2017 Hands down toughest bolt I have come across is LMT's enhanced bolt. Aermet is a ridiculously tough material for the application. Are you referring to their mil-spec or enhanced bolt? Quote Share this post Link to post Share on other sites
blksheep 466 Posted March 18, 2017 I have personally seen Colt Bolts with easily 100,000 rounds through em with 0 issues. Quote Share this post Link to post Share on other sites
Old School 611 Posted March 18, 2017 All good info - Thanks Folks Just to clarify...The life cycle of this rifle will not excede 3000 most 4000 rounds. These loads will be high intensity in excess of 60,000 psi. I'm not sure about the correlation between longevity and intensity. Quote Share this post Link to post Share on other sites
blksheep 466 Posted March 18, 2017 It all equals out. Its the same people that say you cant use a condom more than once. 1 Quote Share this post Link to post Share on other sites
Old School 611 Posted March 18, 2017 It all equals out. Its the same people that say you cant use a condom more than once. Help me out here I don't understand the condom reference Quote Share this post Link to post Share on other sites
Purple Patrick 638 Posted March 18, 2017 It all equals out. Its the same people that say you cant use a condom more than once.That's nasty Sent from my SM-G920V using Tapatalk Quote Share this post Link to post Share on other sites
bhunted 887 Posted March 18, 2017 They make great balloons at kids parties. [emoji12] Sent from my iPhone using Tapatalk Quote Share this post Link to post Share on other sites
Shane45 807 Posted March 18, 2017 All good info - Thanks Folks Just to clarify...The life cycle of this rifle will not excede 3000 most 4000 rounds. These loads will be high intensity in excess of 60,000 psi. I'm not sure about the correlation between longevity and intensity. A failure analysis done by a friend left me with the strong impression that in the AR platform there would be a correlation. IIRC the reasoning behind it is how fast the unlock occurs in an AR bolt. If you look at how short the path is compared to rifles like the SCAR you can see it. So if your adding more energy into the system it would seem logical to me it will be harder on the bolt. However will it be an issue for a sub 4k round count? Im sure you will find out! Quote Share this post Link to post Share on other sites
Old School 611 Posted March 18, 2017 A failure analysis done by a friend left me with the strong impression that in the AR platform there would be a correlation. IIRC the reasoning behind it is how fast the unlock occurs in an AR bolt. If you look at how short the path is compared to rifles like the SCAR you can see it. So if your adding more energy into the system it would seem logical to me it will be harder on the bolt. However will it be an issue for a sub 4k round count? Im sure you will find out! Shane - the only problem I have with your reasoning is gas behind the piston relieves pressure on the bolt before it unlocks. Thus higher pressure would not (in my way of thinking) Increase the resistance to unlocking the bolt. Quote Share this post Link to post Share on other sites
Vlad G 345 Posted March 18, 2017 Shane - the only problem I have with your reasoning is gas behind the piston relieves pressure on the bolt before it unlocks. Thus higher pressure would not (in my way of thinking) Increase the resistance to unlocking the bolt. That is my thinking as well, to a point. You are relieving the pressure on locking logs in the early phases, but the more velocity you impart to the carrier the more stress you will put on the cam pin and bolt in the cam pin area when the rotation starts. Personally I have not seen broken lugs but I've seen broken bolts at the cam pin hole, including one of mine, specially when shooting high pressure rounds, my long range ammo is around 60k according to the load data. For me, I've chosen to go to the new JP bolts that have a reinforcement band around that area, and also go to adjustable gas systems to reduce the pressure in the system. Quote Share this post Link to post Share on other sites
Shane45 807 Posted March 18, 2017 I don't know the answer to this question and this is purely theoretical on my part but I would think that since there is more energy being imparted into the system, it has more energy to do the work of unlocking the bolt at higher pressure. Thus more wear and tear on the bolt group. I wouldn't think that all AR calibers unlock the bolt at the same PSI. Quote Share this post Link to post Share on other sites
Shane45 807 Posted March 18, 2017 ps. Are we talking piston driven or DI? Quote Share this post Link to post Share on other sites
Vlad G 345 Posted March 18, 2017 And I suppose the other factor is that pressure on the lugs does still get exerted before the gas systems comes into play at all, before any gas gets sent out of the barrel. I'm thinking there your best bet is a bolt fitted to the extension maybe, for minimal play? Quote Share this post Link to post Share on other sites
High Exposure 5,635 Posted March 18, 2017 Ammo being equal - Barrel length, gas system length, firing schedule all effect the wear and tear to a significant degree. A16" midlength rifle used for precision shooting and an 11.5" commando used as a training gun will have extremely different amounts of wear and tear after 5000 rounds of identical ammo. I see guys in the team with SBRs (11.5")!have to do much more maintenance in their guns than guys with 14.5" guns even though they are shooting the same ammo in the same drills with the same round count. Quote Share this post Link to post Share on other sites
Old School 611 Posted March 18, 2017 Direct impingement ps. Are we talking piston driven or DI? Quote Share this post Link to post Share on other sites
Ray Ray 3,566 Posted March 18, 2017 Question on Mil-spec bolts. Is Mil-Spec considered the base or minimum requirement? And what if Oldschool goes with a "newer" style of BCG with "upgraded" finishes and cuts? Quote Share this post Link to post Share on other sites
blksheep 466 Posted March 18, 2017 Those Fail Zero and WMD BCGs arent worth the paper the stickers are printed on. Ive seen soo.many issues with those type in guns. Slap a Colt BCG in and they run flawless. I run mostly BCM BCGs. 1 Quote Share this post Link to post Share on other sites
blksheep 466 Posted March 18, 2017 Help me out here I don't understand the condom reference Using a Colt, BCM, DD I would trust. All others MAY not last. Quote Share this post Link to post Share on other sites
Old School 611 Posted March 18, 2017 Using a Colt, BCM, DD I would trust. All others MAY not last. Thank you The condom thing was confusing. I thought condoms were for muzzle covers to keep the shit out of your barrel Quote Share this post Link to post Share on other sites
High Exposure 5,635 Posted March 18, 2017 Question on Mil-spec bolts. Is Mil-Spec considered the base or minimum requirement? And what if Oldschool goes with a "newer" style of BCG with "upgraded" finishes and cuts? The AR is a system. Change one thing, something else is affected. For example - NiB/boutique bolts. They allegedly run cooler with less fouling. Great! Except the gun is still producing the same amount of heat and carbon regardless of what the bolt is made of or coated in. That extra fouling and heat has to go somewhere. So now the barrel extension, barrel, upper receiver, barrel nut, gas block, and gas tube get dirtier and/or hotter than designed - instead of the the part designed to sink the heat and bleed it off and is removable to clean better and easier - the BCG. There is no free lunch. Quote Share this post Link to post Share on other sites