AR15.Com Archives
 Carpenter 158 steel bolt vs. 8620 steel bolt
mike89  [Member]
3/7/2013 11:07:50 AM
I have a feeling this is one of those "can of worms" type topics, but I need to know. Which is "better" and why. Assume the carrier is 8620.

Thanks!
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Medicfrost  [Team Member]
3/7/2013 11:25:57 AM
Carpenter. There is no dispute on this. Its stronger, but more expensive, which is why there are 8620 bolts also.
IL2windhawk  [Member]
3/7/2013 11:29:28 AM
How about 9130 steel? That's what the JP enhanced bolt is made from.
jmreagan  [Member]
3/7/2013 12:07:30 PM
I'm interested to know just how many have broken 8620 bolts from hard use compared to 158...
blwngazkit  [Team Member]
3/7/2013 12:16:02 PM
As I understand it, Carpenter 158 is a case(surface) hardened steel where 8620 is through hardened.

This would allow C-158 to be very hard on the outside to prevent wear and crack formation while the inside is softer and more flexible to prevent crack propagation and absorb shock loads.

8620 being through hardened can either be softer and better at shock, or harder and better at wear but not both.



The above is just a guess based on what I know about metal hardening from knifeworking...
DSArms_FAL  [Member]
3/7/2013 2:40:00 PM
For the bolt 158 or 9310 is what you want 9310 is about 8% stronger if that matters to you. 9310 would be better if you can find one that said 158 is the milspec so that will work too. I like above milspec whenever possible.

For the carrier 8620 or a good SS, you could do carriers in 9310 but it would be $$$$$$$$
deuc224  [Member]
3/7/2013 8:48:19 PM
I thought 8620 was mil-spec?
GeneralPurpose  [Team Member]
3/7/2013 8:50:41 PM
Originally Posted By deuc224:
I thought 8620 was mil-spec?


For the carrier it is, not for the bolt.

I can't understand why anyone ever buys things below-milspec.
GHPorter  [Team Member]
3/7/2013 9:38:39 PM
Originally Posted By jmreagan:
I'm interested to know just how many have broken 8620 bolts from hard use compared to 158...


A bolt is one part I do not want to go cheap with. I don't know of any 8620 bolts that have broken, but if I have a say in it, there won't be one in any rifle of mine.
Medicfrost  [Team Member]
3/7/2013 9:47:13 PM
Originally Posted By deuc224:
I thought 8620 was mil-spec?


It isn't. Carpenter 158 is mil-spec.

Originally Posted By jmreagan:
I'm interested to know just how many have broken 8620 bolts from hard use compared to 158...


7, 566
Sheddy  [Team Member]
3/7/2013 9:48:39 PM
Originally Posted By GHPorter:
Originally Posted By jmreagan:
I'm interested to know just how many have broken 8620 bolts from hard use compared to 158...


A bolt is one part I do not want to go cheap with. I don't know of any 8620 bolts that have broken, but if I have a say in it, there won't be one in any rifle of mine.


Are you saying going with Carpenter 158 is a way of cheaping out?
apierce918  [Team Member]
3/7/2013 10:18:12 PM

Originally Posted By Sheddy:
Originally Posted By GHPorter:
Originally Posted By jmreagan:
I'm interested to know just how many have broken 8620 bolts from hard use compared to 158...


A bolt is one part I do not want to go cheap with. I don't know of any 8620 bolts that have broken, but if I have a say in it, there won't be one in any rifle of mine.


Are you saying going with Carpenter 158 is a way of cheaping out?

how'd you get that? lol
Sheddy  [Team Member]
3/7/2013 11:35:32 PM
Originally Posted By apierce918:

Originally Posted By Sheddy:
Originally Posted By GHPorter:
Originally Posted By jmreagan:
I'm interested to know just how many have broken 8620 bolts from hard use compared to 158...


A bolt is one part I do not want to go cheap with. I don't know of any 8620 bolts that have broken, but if I have a say in it, there won't be one in any rifle of mine.


Are you saying going with Carpenter 158 is a way of cheaping out?

how'd you get that? lol


He was saying 8620 is milspec and that he doesn't know of any that have broken, I don't know, fuck I'm drinkin some more. I bought a Bravo Company bolt.
GHPorter  [Team Member]
3/8/2013 6:47:19 AM
Originally Posted By Sheddy:
Originally Posted By apierce918:

Originally Posted By Sheddy:
Originally Posted By GHPorter:
Originally Posted By jmreagan:
I'm interested to know just how many have broken 8620 bolts from hard use compared to 158...


A bolt is one part I do not want to go cheap with. I don't know of any 8620 bolts that have broken, but if I have a say in it, there won't be one in any rifle of mine.


Are you saying going with Carpenter 158 is a way of cheaping out?

how'd you get that? lol


He was saying 8620 is milspec and that he doesn't know of any that have broken, I don't know, fuck I'm drinkin some more. I bought a Bravo Company bolt.

NO. I'm saying that the spec for bolts is Carpenter 158, that's the kind of bolts I will stick with, and I'm not going to buy a bolt made of 8620 (which is the spec for CARRIERS only).

45FMJoe  [Team Member]
3/8/2013 8:21:46 AM

Originally Posted By GHPorter:

NO. I'm saying that the spec for bolts is Carpenter 158, that's the kind of bolts I will stick with, and I'm not going to buy a bolt made of 8620 (which is the spec for CARRIERS only).



Exactly. Why anyone would buy lesws than mil-spec is a mystery to me.
RUTGERS95  [Member]
3/8/2013 8:43:15 AM
this thread got me thinking, does anyone know what is used in the bolts on a lars-ops 4 side chargers?
mc556  [Team Member]
3/8/2013 9:34:56 AM
I will add to this by saying you could use unobtainium for the bolt but it wouldn't be worth shit if the heat treat is wrong.
So in certain cases a inferior metal could outperform a better one if the heat treat is to hard,soft or uneven.
This is a case where the suppliers should be just as important as the material
wolverine05  [Team Member]
3/8/2013 9:43:58 AM
Originally Posted By mc556:
I will add to this by saying you could use unobtainium for the bolt but it wouldn't be worth shit if the heat treat is wrong.
So in certain cases a inferior metal could outperform a better one if the heat treat is to hard,soft or uneven.
This is a case where the suppliers should be just as important as the material



Right on brother!
fishorwife  [Team Member]
3/8/2013 10:44:10 AM
Originally Posted By blwngazkit:
As I understand it, Carpenter 158 is a case(surface) hardened steel where 8620 is through hardened.

This would allow C-158 to be very hard on the outside to prevent wear and crack formation while the inside is softer and more flexible to prevent crack propagation and absorb shock loads.

8620 being through hardened can either be softer and better at shock, or harder and better at wear but not both.



The above is just a guess based on what I know about metal hardening from knifeworking...


8620 can be case hardened by carburizing.
tstanfield12  [Team Member]
3/8/2013 12:13:54 PM
Originally Posted By wolverine05:
Originally Posted By mc556:
I will add to this by saying you could use unobtainium for the bolt but it wouldn't be worth shit if the heat treat is wrong.
So in certain cases a inferior metal could outperform a better one if the heat treat is to hard,soft or uneven.
This is a case where the suppliers should be just as important as the material



Right on brother!


Which is why I buy BCM bolts whenever I can...
jmreagan  [Member]
3/8/2013 1:12:34 PM
Originally Posted By 45FMJoe:

Originally Posted By GHPorter:

NO. I'm saying that the spec for bolts is Carpenter 158, that's the kind of bolts I will stick with, and I'm not going to buy a bolt made of 8620 (which is the spec for CARRIERS only).



Exactly. Why anyone would buy lesws than mil-spec is a mystery to me.


I had a build going right before Zero got elected and bolts were mostly unobtainable. So I bought a PSA bolt; stupidly thinking everything PSA sold was mil-spec and was lucky enough to find any bolt then. I didn't even check to see if it was 158, hard lesson . So I ended up with an 8620 bolt from PSA and that's how I have a rifle with a less than mil-spec bolt. It pisses me off because every damned part of the rifle is mil-spec or better. When 158's become plentiful and prices get realistic I'll pull the 8620 and replace it. Until then, I'll run it hard and see how durable 8620 is...
SciFiNut  [Member]
3/8/2013 1:18:18 PM
Take a gander at the Troubleshooting forum... Several threads there where malfunctions (including sheared lugs) have been tracked back to 8260 bolts.
Pay the extra $ for a milspec bolt.
mc556  [Team Member]
3/8/2013 8:13:01 PM
Originally Posted By jmreagan:
Originally Posted By 45FMJoe:

Originally Posted By GHPorter:

NO. I'm saying that the spec for bolts is Carpenter 158, that's the kind of bolts I will stick with, and I'm not going to buy a bolt made of 8620 (which is the spec for CARRIERS only).



Exactly. Why anyone would buy lesws than mil-spec is a mystery to me.


I had a build going right before Zero got elected and bolts were mostly unobtainable. So I bought a PSA bolt; stupidly thinking everything PSA sold was mil-spec and was lucky enough to find any bolt then. I didn't even check to see if it was 158, hard lesson . So I ended up with an 8620 bolt from PSA and that's how I have a rifle with a less than mil-spec bolt. It pisses me off because every damned part of the rifle is mil-spec or better. When 158's become plentiful and prices get realistic I'll pull the 8620 and replace it. Until then, I'll run it hard and see how durable 8620 is...




When I look on there site all there bolts in there rifles and the BCG that are sold separate say they are Carpenter 158
Look here


I take it back they do have one on the site that is listed as 8620 BCG
It doesn't look like what they use but had it for sale along with other brands
jaqufrost  [Team Member]
3/8/2013 8:14:11 PM

Originally Posted By mc556:
SNIP




When I look on there site all there bolts in there rifles and the BCG that are sold separate say they are Carpenter 158
Look here

They did a run a few months back of 8620 bolts.
mc556  [Team Member]
3/8/2013 8:17:13 PM
Originally Posted By jaqufrost:

Originally Posted By mc556:
SNIP




When I look on there site all there bolts in there rifles and the BCG that are sold separate say they are Carpenter 158
Look here

They did a run a few months back of 8620 bolts.



Damn your quick I was editing the post but you caught it before I got it fixed
jaqufrost  [Team Member]
3/8/2013 8:20:54 PM
It popped up on active topics and I had already read the rest of the thread, lol.
weaponoutfitters  [Dealer]
3/8/2013 10:12:52 PM
I've seen bolts where every single lug was sheered off, haha.

While materials may be important, I think that correct manufacturing process is what makes a good bolt good, much as how good wheat and hops don't necessarily make a good beer
jmreagan  [Member]
3/9/2013 8:41:49 AM
Originally Posted By mc556:
Originally Posted By jmreagan:
Originally Posted By 45FMJoe:

Originally Posted By GHPorter:

NO. I'm saying that the spec for bolts is Carpenter 158, that's the kind of bolts I will stick with, and I'm not going to buy a bolt made of 8620 (which is the spec for CARRIERS only).



Exactly. Why anyone would buy lesws than mil-spec is a mystery to me.


I had a build going right before Zero got elected and bolts were mostly unobtainable. So I bought a PSA bolt; stupidly thinking everything PSA sold was mil-spec and was lucky enough to find any bolt then. I didn't even check to see if it was 158, hard lesson . So I ended up with an 8620 bolt from PSA and that's how I have a rifle with a less than mil-spec bolt. It pisses me off because every damned part of the rifle is mil-spec or better. When 158's become plentiful and prices get realistic I'll pull the 8620 and replace it. Until then, I'll run it hard and see how durable 8620 is...




When I look on there site all there bolts in there rifles and the BCG that are sold separate say they are Carpenter 158
Look here


I take it back they do have one on the site that is listed as 8620 BCG
It doesn't look like what they use but had it for sale along with other brands


A few months back PSA didn't have any carriers in stock, only their own "PSA" branded bolts. I figured since their rifles came with 158 Carpenter steel bolts their "PSA" house branded bolts sold separately were the same as the ones in their rifles; dumb ass assumption on my part. It still pisses me off though and I still feel cheated a little by PSA and this bolt. They really have disappointed me over the last 6 months, sending the wrong ammo, a CHF barrel with a misaligned index pin, this substandard bolt I speak of, their lack of customer service after repeated e-mails until I make a "stink eye" thread in their industry forum and this one. I view them as a dime store vendor now sadly as they were my go to...
apierce918  [Team Member]
3/9/2013 9:06:24 AM

Originally Posted By jmreagan:
Originally Posted By mc556:
Originally Posted By jmreagan:
Originally Posted By 45FMJoe:

Originally Posted By GHPorter:

NO. I'm saying that the spec for bolts is Carpenter 158, that's the kind of bolts I will stick with, and I'm not going to buy a bolt made of 8620 (which is the spec for CARRIERS only).



Exactly. Why anyone would buy lesws than mil-spec is a mystery to me.


I had a build going right before Zero got elected and bolts were mostly unobtainable. So I bought a PSA bolt; stupidly thinking everything PSA sold was mil-spec and was lucky enough to find any bolt then. I didn't even check to see if it was 158, hard lesson . So I ended up with an 8620 bolt from PSA and that's how I have a rifle with a less than mil-spec bolt. It pisses me off because every damned part of the rifle is mil-spec or better. When 158's become plentiful and prices get realistic I'll pull the 8620 and replace it. Until then, I'll run it hard and see how durable 8620 is...




When I look on there site all there bolts in there rifles and the BCG that are sold separate say they are Carpenter 158
Look here


I take it back they do have one on the site that is listed as 8620 BCG
It doesn't look like what they use but had it for sale along with other brands


A few months back PSA didn't have any carriers in stock, only their own "PSA" branded bolts. I figured since their rifles came with 158 Carpenter steel bolts their "PSA" house branded bolts sold separately were the same as the ones in their rifles; dumb ass assumption on my part. It still pisses me off though and I still feel cheated a little by PSA and this bolt. They really have disappointed me over the last 6 months, sending the wrong ammo, a CHF barrel with a misaligned index pin, this substandard bolt I speak of, their lack of customer service after repeated e-mails until I make a "stink eye" thread in their industry forum and this one. I view them as a dime store vendor now sadly as they were my go to...

Cheated because you didn't read the description?
RUTGERS95  [Member]
3/9/2013 9:29:08 AM
so who has carp bolts in stock right now?
jmreagan  [Member]
3/9/2013 1:11:12 PM
Originally Posted By apierce918:

Originally Posted By jmreagan:
Originally Posted By mc556:
Originally Posted By jmreagan:
Originally Posted By 45FMJoe:

Originally Posted By GHPorter:

NO. I'm saying that the spec for bolts is Carpenter 158, that's the kind of bolts I will stick with, and I'm not going to buy a bolt made of 8620 (which is the spec for CARRIERS only).



Exactly. Why anyone would buy lesws than mil-spec is a mystery to me.


I had a build going right before Zero got elected and bolts were mostly unobtainable. So I bought a PSA bolt; stupidly thinking everything PSA sold was mil-spec and was lucky enough to find any bolt then. I didn't even check to see if it was 158, hard lesson . So I ended up with an 8620 bolt from PSA and that's how I have a rifle with a less than mil-spec bolt. It pisses me off because every damned part of the rifle is mil-spec or better. When 158's become plentiful and prices get realistic I'll pull the 8620 and replace it. Until then, I'll run it hard and see how durable 8620 is...




When I look on there site all there bolts in there rifles and the BCG that are sold separate say they are Carpenter 158
Look here


I take it back they do have one on the site that is listed as 8620 BCG
It doesn't look like what they use but had it for sale along with other brands


A few months back PSA didn't have any carriers in stock, only their own "PSA" branded bolts. I figured since their rifles came with 158 Carpenter steel bolts their "PSA" house branded bolts sold separately were the same as the ones in their rifles; dumb ass assumption on my part. It still pisses me off though and I still feel cheated a little by PSA and this bolt. They really have disappointed me over the last 6 months, sending the wrong ammo, a CHF barrel with a misaligned index pin, this substandard bolt I speak of, their lack of customer service after repeated e-mails until I make a "stink eye" thread in their industry forum and this one. I view them as a dime store vendor now sadly as they were my go to...

Cheated because you didn't read the description?


Because they sell junk like that and the other things I mentioned...
FMJ  [Team Member]
3/9/2013 1:25:53 PM
Originally Posted By GHPorter:
Originally Posted By jmreagan:
I'm interested to know just how many have broken 8620 bolts from hard use compared to 158...


A bolt is one part I do not want to go cheap with.


+1


Thats why I only use Colt/LMT bolts on my go to.
jaqufrost  [Team Member]
3/9/2013 1:38:09 PM

Originally Posted By FMJ:
Originally Posted By GHPorter:
Originally Posted By jmreagan:
I'm interested to know just how many have broken 8620 bolts from hard use compared to 158...


A bolt is one part I do not want to go cheap with.


+1


Thats why I only use Colt/LMT bolts on my go to.
Why not AR15performance, JP, or LWRC?

FMJ  [Team Member]
3/9/2013 1:55:38 PM
Originally Posted By jmreagan:
Originally Posted By apierce918:

Originally Posted By jmreagan:
Originally Posted By mc556:
Originally Posted By jmreagan:
Originally Posted By 45FMJoe:

Originally Posted By GHPorter:

NO. I'm saying that the spec for bolts is Carpenter 158, that's the kind of bolts I will stick with, and I'm not going to buy a bolt made of 8620 (which is the spec for CARRIERS only).



Exactly. Why anyone would buy lesws than mil-spec is a mystery to me.


I had a build going right before Zero got elected and bolts were mostly unobtainable. So I bought a PSA bolt; stupidly thinking everything PSA sold was mil-spec and was lucky enough to find any bolt then. I didn't even check to see if it was 158, hard lesson . So I ended up with an 8620 bolt from PSA and that's how I have a rifle with a less than mil-spec bolt. It pisses me off because every damned part of the rifle is mil-spec or better. When 158's become plentiful and prices get realistic I'll pull the 8620 and replace it. Until then, I'll run it hard and see how durable 8620 is...




When I look on there site all there bolts in there rifles and the BCG that are sold separate say they are Carpenter 158
Look here


I take it back they do have one on the site that is listed as 8620 BCG
It doesn't look like what they use but had it for sale along with other brands


A few months back PSA didn't have any carriers in stock, only their own "PSA" branded bolts. I figured since their rifles came with 158 Carpenter steel bolts their "PSA" house branded bolts sold separately were the same as the ones in their rifles; dumb ass assumption on my part. It still pisses me off though and I still feel cheated a little by PSA and this bolt. They really have disappointed me over the last 6 months, sending the wrong ammo, a CHF barrel with a misaligned index pin, this substandard bolt I speak of, their lack of customer service after repeated e-mails until I make a "stink eye" thread in their industry forum and this one. I view them as a dime store vendor now sadly as they were my go to...

Cheated because you didn't read the description?


Because they sell junk like that and the other things I mentioned smart ass...


As a long time member here before 2001
I can see why BCM has earn there good following here at AR15.com

But I dont get PSA at all.

If I was to buy a Bolt for my SD/HD carbine ?
Colt
LMT
Stag /CMT marked bolts

I wonder if Paul gets his bolts from one of the above?

pun  [Member]
3/9/2013 3:03:40 PM
M14 receivers were made from a 12lb hammer forged and hardened 8620 receiver..no ?
gunnut284  [Team Member]
3/9/2013 3:39:11 PM
Originally Posted By pun:
M14 receivers were made from a 12lb hammer forged and hardened 8620 receiver..no ?


What's your point? The right material for one application does not mean its right for another.
RUTGERS95  [Member]
3/9/2013 4:27:52 PM
Originally Posted By FMJ:
Originally Posted By jmreagan:
Originally Posted By apierce918:

Originally Posted By jmreagan:
Originally Posted By mc556:
Originally Posted By jmreagan:
Originally Posted By 45FMJoe:

Originally Posted By GHPorter:

NO. I'm saying that the spec for bolts is Carpenter 158, that's the kind of bolts I will stick with, and I'm not going to buy a bolt made of 8620 (which is the spec for CARRIERS only).



Exactly. Why anyone would buy lesws than mil-spec is a mystery to me.


I had a build going right before Zero got elected and bolts were mostly unobtainable. So I bought a PSA bolt; stupidly thinking everything PSA sold was mil-spec and was lucky enough to find any bolt then. I didn't even check to see if it was 158, hard lesson . So I ended up with an 8620 bolt from PSA and that's how I have a rifle with a less than mil-spec bolt. It pisses me off because every damned part of the rifle is mil-spec or better. When 158's become plentiful and prices get realistic I'll pull the 8620 and replace it. Until then, I'll run it hard and see how durable 8620 is...




When I look on there site all there bolts in there rifles and the BCG that are sold separate say they are Carpenter 158
Look here


I take it back they do have one on the site that is listed as 8620 BCG
It doesn't look like what they use but had it for sale along with other brands


A few months back PSA didn't have any carriers in stock, only their own "PSA" branded bolts. I figured since their rifles came with 158 Carpenter steel bolts their "PSA" house branded bolts sold separately were the same as the ones in their rifles; dumb ass assumption on my part. It still pisses me off though and I still feel cheated a little by PSA and this bolt. They really have disappointed me over the last 6 months, sending the wrong ammo, a CHF barrel with a misaligned index pin, this substandard bolt I speak of, their lack of customer service after repeated e-mails until I make a "stink eye" thread in their industry forum and this one. I view them as a dime store vendor now sadly as they were my go to...

Cheated because you didn't read the description?


Because they sell junk like that and the other things I mentioned smart ass...


As a long time member here before 2001
I can see why BCM has earn there good following here at AR15.com

But I dont get PSA at all.

If I was to buy a Bolt for my SD/HD carbine ?
Colt
LMT
Stag /CMT marked bolts

I wonder if Paul gets his bolts from one of the above?



why Colt given all the qc issues we've seen?

You throw STAG in there but won't look at PSA? I do not get that at all

agree with the poster above, why not ar performance, LWRC, or a host of others that are proven?
RUTGERS95  [Member]
3/9/2013 4:29:01 PM
Originally Posted By gunnut284:
Originally Posted By pun:
M14 receivers were made from a 12lb hammer forged and hardened 8620 receiver..no ?


What's your point? The right material for one application does not mean its right for another.


no offense but are you saying the M14 receiver is gonna see less stress than than a AR bolt?
eesmith  [Team Member]
3/9/2013 5:19:08 PM
Originally Posted By RUTGERS95:
Originally Posted By gunnut284:
Originally Posted By pun:
M14 receivers were made from a 12lb hammer forged and hardened 8620 receiver..no ?


What's your point? The right material for one application does not mean its right for another.


no offense but are you saying the M14 receiver is gonna see less stress than than a AR bolt?


A different type of stress, with more material involved, so it's an apple and oranges comparison. 8620 and 158 are different materials, and 158 has properties better suited to the peculiar stresses imposed on an AR bolt.
gunnut284  [Team Member]
3/9/2013 5:19:26 PM
Originally Posted By RUTGERS95:
Originally Posted By gunnut284:
Originally Posted By pun:
M14 receivers were made from a 12lb hammer forged and hardened 8620 receiver..no ?


What's your point? The right material for one application does not mean its right for another.


no offense but are you saying the M14 receiver is gonna see less stress than than a AR bolt?


I'm saying the applications are different and the comparison is not necessarily valid. Rainier lists their Select barrel extensions as being 4140AE, why don't we have bolts made from that? The total volume of stress is less important than how the stress is applied and distributed.
RUTGERS95  [Member]
3/9/2013 5:23:22 PM
Originally Posted By gunnut284:
Originally Posted By RUTGERS95:
Originally Posted By gunnut284:
Originally Posted By pun:
M14 receivers were made from a 12lb hammer forged and hardened 8620 receiver..no ?


What's your point? The right material for one application does not mean its right for another.


no offense but are you saying the M14 receiver is gonna see less stress than than a AR bolt?


I'm saying the applications are different and the comparison is not necessarily valid. Rainier lists their Select barrel extensions as being 4140AE, why don't we have bolts made from that? The total volume of stress is less important than how the stress is applied and distributed.


agree on most points and thanks for clarifying but the overall level of stress application is still important and probably the biggest factor in malfunctioning/breaking parts.

Regardless, way too much is made of this back and forth on these boards. We've got $hitty Colt bolts breaking frequently and we know they use good materials so it's not just the materials. As someone said earlier, it's not just the material but the way it's made, hardened, and cut.
pun  [Member]
3/9/2013 7:57:54 PM
My point is M14 receivers take alot of abuse and H&R receivers were not heat treated right and became brittle they lost the contract..my point is if its heat treated right and made right it should be fine.I had a Bushmaster bolt in 93 go 14k rounds before I lost 2 lugs and they dont use at that time anyway carpenter 158.
gunnut284  [Team Member]
3/9/2013 8:08:19 PM
Originally Posted By pun:
My point is M14 receivers take alot of abuse and H&R receivers were not heat treated right and became brittle they lost the contract..my point is if its heat treated right and made right it should be fine.I had a Bushmaster bolt in 93 go 14k rounds before I lost 2 lugs and they dont use at that time anyway carpenter 158.


Got it. I certainly agree that heat treat and proper manufacturing processes are key to a quality end product. I would take a properly made 8620 bolt over an improperly made C158 bolt but will stick with properly made C158 bolts if at all possible. It appeared you were suggesting 8620 was fine because it was used in M14 receivers.
PursuitSS  [Team Member]
3/10/2013 1:23:22 AM
8620 is Mil Spec for M-16 bolt carriers, Carpenter 158 is the correct Mil Spec for M-16 bolts.
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