BCG discussion

[awp_101]

I’ve got just about everything on my “good” carbine up to snuff now for my needs. Last night I was looking at my unknown BCG and debating if I should should start thinking about a replacement. It’s unmarked with an unknown round count and the carrier key staking meets the technical definition in that there’s metal displaced near the screws but certainly nothing that’s going to be of any use. It might be a PSA, Brownells or something that came with a long gone upper, I flat don’t remember.

A recent thread suggested Toolcraft as a replacement BCG for someone else’s rifle and some looking shows them to be $50 less (give or take) than BCM, SOLGW, etc. I don’t recall reading anything negative about Toolcraft BCGs and I think I’ve seen they’re actually OEM for some brands.

My specific question is, is there any significant difference between the Toolcraft and other BCGs besides the logo? Is there a corner being cut besides the lasered logo? Different steels or alloys?

For general discussion, what makes a good BCG? Let’s define “good” as maybe just under duty grade but above definite hobby grade. Something you could feel good putting in a serious use rifle but wouldn’t feel like overkill in your range only fun fun build.

[tlong17]

Following with interest.

I have been doing a similar search. I have found that the Geissele "M4A1" BCG looks to be a decent price for "mil-spec" BCG. It has no markings on it at all and G claims it to be produced by a "Tier 1 DoD supplier". They also sold Colt BCGs on their site until a few days ago when they ran out of stock. Priced at $150ish.

I'm not sure what their Reliability Enhanced BCG really offers for almost twice the price. I am also partial to having no logos on the port side.

[Casual Friday]

Toolcraft BCGs are hit or miss. You're much better off going with a SOLGW BCG. They're Microbest sourced and SOLGW warranties them for life.

[inkslinger]

It’s probably a similar situation like the FN manufactured barrels for PSA. Or the companies that forge lowers and supply the market. It all depends on the specifications/QC of the manufacturer/supplier that sells them in the last step of the process. If Toolcraft sends a product to BCM and PSA, it’s doubtful that they are made to the same tolerances.

[Rick R]

I used a Toolcraft BCG in a 20” rifle I put together and after 5-600 rounds it’s been flawless. No obvious wear or tear, the staking looks good, marked as “MPI”. It has the black O ring and post extractor spring enhancements.

During a bout of pandemic shopping this month (there may have been ETOH involved) I decided that I needed a spare complete BCG so I ordered a second Toolcraft from Armor Ally. Once it got here it looks good to go too. I opened the plastic tool box that I use for AR parts to stow it and discovered an ALG BCG that I bought during the Black Friday sale and forgot I had.

I’m taking this as an omen to build another rifle...

EdiTed to add, both the Toolcraft BCGs are their nitrided / Carpenter 158 offerings.

[Colt191145lover]

My go to BCG anymore

https://www.centurionarms.com/bolt-carrier-group-p/bcg-c4.htm

[ssc45]

Since I consider the BCG to be the heart of my rifles, I only use SOLGW, or Sionics in my new builds. I would suggest ordering from Primary arms. I do have other BCG's that include Colt, Lmt and BCM.

However, I think the above are my current recommendations based on using them and research.

https://www.primaryarms.com/sionics-weapon-systems-m16-556-bolt-carrier-group-phosphate

Cheers, Steve

[Casual Friday]

It’s probably a similar situation like the FN manufactured barrels for PSA. Or the companies that forge lowers and supply the market. It all depends on the specifications/QC of the manufacturer/supplier that sells them in the last step of the process. If Toolcraft sends a product to BCM and PSA, it’s doubtful that they are made to the same tolerances.

That's what people don't always realize, the different companies have different specs they want their products to meet.

BCM are Microbest sourced.

[Nephrology]

I have been satisfied with Toolcraft BCGs. It is true that the specs will vary by the retailer and what they request (finish, bolt material, extractor spring, etc). They also do not manufacture the bolts - they procure those from other suppliers. IIRC most of them are made by swan machine inc. I sourced my BCGs from Spicetac, which advertises them as MPI, but not HPT.

Here is a 10k round test of a Cryptic Coatings sourced Toolcraft BCG. I am happy with them, for whatever that's worth. Not a hi speed low drag guy so YMMV

http://www.weaponevolution.com/forum/showthread.php?7435-Cryptic-Coatings-BCG-10K-rounds-Review

edit to add: mine are all nitrided. I haven't messed with any other coatings.

[DDTSGM]

At 80.00 to 119.00 for a C158 BCG, compared to 149.00 for a C-158 thats been shot full auto - I'm going with the Toolcraft.

80.00 - Phosphate w/1bib6 cage code https://www.wcarmory.com/toolcraft-223-5-56-bcg-phosphate-chrome-1b1b6-carrier-with-c158-mpi-bolt.htm

98.00 - Black Nitride https://www.armorally.com/shop/toolcraft_5-56_nato_black_nitride_bolt_carrier_group/

115.00 - Nickel Boron https://www.wcarmory.com/toolcraft-223-5-56-bcg-nickel-boron-1b1b6-carrier-with-c158-mpi-bolt.htm

119.00 Ion Bond DLC https://www.wcarmory.com/toolcraft-bcg-223-5-56-ion-bond-dlc-laser-logo-carrier-with-c158-mpi-bolt.htm

149.00 to 159.00 - Phosphate https://sonsoflibertygw.com/solgw-5-56-bolt-carrier-group-158-carpenter-sp-hpt-mpi/

Both have lifetime guarantees. I've actually talked with Toolcraft about this - no matter who you buy it from, they will warranty it.

I buy Toolcraft pretty much exclusively, I spread my shooting out over 4 or 5 AR's so none have extremely high round counts, but so far no problems.

[5pins]

FWIW Toolcraft makes carriers for the military. Not sure if they make the bolts or not.

[DDTSGM]

FWIW Toolcraft makes carriers for the military. Not sure if they make the bolts or not.

They don't, but they are also warranted.

Toolcraft, like Microbest, is an OEM supplier. They make what they make and then source from other OEM suppliers to finish the assembly. Just like most do.

Folks don't seem to understand this, IDK who makes DCM or Sionics components, some of them, no doubt, are made in house, but other parts, probably most, are sourced.

Why would you spend money re-inventing the wheel when there are companies that specialize in make the items you need?

[wrmettler]

Search Instructor Chad on YouTube.
He runs the School of the American Rifle.

He diagnoses BCG, lowers, etc.
I enjoy the videos but after going over about 10 different BCGs, it can get boring.

[dontshakepandas]

I'd also suggest Sionics, or Forward Control Designs which is an "improved" Sionics BCG.

[OlongJohnson]

Phosphate/Parkerizing may have advantages for a bolt carrier. The phosphate is basically a "sponge" grown on the surface of the metal, which does an excellent job absorbing and retaining oil. That provides both corrosion protection and excellent lubricity. It can wear away, but is also easily and relatively inexpensively restored. It may provide some advantage in extending lubrication intervals, but most users these days seem to run them wetter than in the past.

I haven't run enough rounds through different configurations to know what the long-term win is on that versus the hardness of nitride and the tradeoff of wearing the inside of the UR vs. the bolt carrier.

Aray, come educate us if you can talk about phosphate and lubrication more intelligently than I.

[BWT]

BCM has my vote from first hand experience - there are six rifles in my family no issues. Colt is also very well regarded.

Instructor Chad does do good BCG physicals - it’s somehow incredibly relaxing.

There’s others that are quality, but I can’t personally vouch for them with never handling them or using them.

[MistWolf]

I was looking at my unknown BCG and debating if I should should start thinking about a replacement...

Install a Colt or Sprinco extractor spring (no O-ring) and shoot the hell out of it. Have a spare BCG waiting in the wings. Install a Colt or Sprinco extractor spring (no O-ring) and make sure the bolt is Carpenter 158, properly heat treated and shot peened.

[rob_s]

make sure the bolt is Carpenter 158, properly heat treated and shot peened.

The problem is, in 2020, that’s almost harder to discern than it was 10 year ago. Now with so many more commercially-available options and many of them offering supposed “milspec” versions plus various unicorn-jizz coatings, alternate metallurgy, various extractor redesigns, etc. all claiming “better” it seems harder and harder to just buy a known-good BCG.

Which is why I’d still just go “standard” BCM (https://bravocompanyusa.com/bcm-bolt-carrier-group-mpi-auto/) or Colt (https://www.brownells.com/rifle-parts/bolt-parts/bolt-carrier-groups/m16-5-56-bolt-carrier-group-prod70973.aspx). Only way to know for sure.

[MistWolf]

The problem is, in 2020, that’s almost harder to discern than it was 10 year ago. Now with so many more commercially-available options and many of them offering supposed “milspec” versions plus various unicorn-jizz coatings, alternate metallurgy, various extractor redesigns, etc. all claiming “better” it seems harder and harder to just buy a known-good BCG.

Which is why I’d still just go “standard” BCM (https://bravocompanyusa.com/bcm-bolt-carrier-group-mpi-auto/) or Colt (https://www.brownells.com/rifle-parts/bolt-parts/bolt-carrier-groups/m16-5-56-bolt-carrier-group-prod70973.aspx). Only way to know for sure.

Very true and excellent advice.

PS- In my previous post, I should have said "In your spare BCG, install a Colt or Sprinco extractor spring (no O-ring) and make sure the bolt is Carpenter 158, properly heat treated and shot peened."

[awp_101]

Going through my box o’ stuff this afternoon I found one of these bolts (https://www.brownells.com/rifle-parts/bolt-parts/bolts/m16-5-56-bolt-assembly-nitride-mp-prod105379.aspx?avs%7cMake_3=AR-15&avs%7cManufacturer_1=brownells) I’d forgotten I’d picked up a while back.

According to the specs it’s 9310 instead of 158. I’m not a metallurgist so I don’t know the significant differences between the two. I’ll keep it as a spare but if I’m not running full auto, does it make a tinker’s damn that it’s not 158??

[Nephrology]

Going through my box o’ stuff this afternoon I found one of these bolts (https://www.brownells.com/rifle-parts/bolt-parts/bolts/m16-5-56-bolt-assembly-nitride-mp-prod105379.aspx?avs%7cMake_3=AR-15&avs%7cManufacturer_1=brownells) I’d forgotten I’d picked up a while back.

According to the specs it’s 9310 instead of 158. I’m not a metallurgist so I don’t know the significant differences between the two. I’ll keep it as a spare but if I’m not running full auto, does it make a tinker’s damn that it’s not 158??

afaik there is a lot of handwringing about this but i have no reason to believe 9310 steel bolts are meaningfully different from c158 bolts. I did a lot of googling on this, and found a lot of long debates on M4C but nothing really definitive.

[rob_s]

Going through my box o’ stuff this afternoon I found one of these bolts (https://www.brownells.com/rifle-parts/bolt-parts/bolts/m16-5-56-bolt-assembly-nitride-mp-prod105379.aspx?avs%7cMake_3=AR-15&avs%7cManufacturer_1=brownells) I’d forgotten I’d picked up a while back.

According to the specs it’s 9310 instead of 158. I’m not a metallurgist so I don’t know the significant differences between the two. I’ll keep it as a spare but if I’m not running full auto, does it make a tinker’s damn that it’s not 158??

First, it probably doesn’t really matter and I probably wouldn’t suggest throwing it out or buying another one (what I personally would do is probably different than what I’d suggest for someone else)

Now for minutiae...
Maybe a decade ago I started working on a far more detailed write up to go with The Chart. I got really into the weeds regarding the various ratios of various steels, why one recipe did one thing vs another, etc. I can’t even seem to find that research today.

However, my take is this...

Assuming that 9310 was available when the AR system was designed, I only see two possibilities
1) c158 is better for the system, as designed
2) the original designer(s) got it wrong

I prefer to trust in the designers, and go with the material they chose. When it comes to the internals of the gun, my preference is to start with the as-designed system and only deviate when there is a proven good improvement, and even then, what exactly is the impact of that improvement and does that improvement relate to me (a car with better gas mileage is “better” economically, but if I have a company gas card, what do I care?)

There is that other possibility. That 9310 wasn’t available when the gun was designed. But that still doesn’t mean it’s better, just different.

And no matter what, you have to ask yourself why a manufacturer would choose 9310, and for that we can also look to which manufacturers use 9310. Did they choose it because it’s “better”, or because it’s cheaper, more readily available and easier to source (which is also effectively “cheaper” for a business), or, like the bushmaster giant gas ports that were designed to make the guns run with almost any cheap ammo in order to reduce warranty returns, is there some benefit to the manufacturer that isn’t even clear?

[LittleLebowski]

First, it probably doesn’t really matter and I probably wouldn’t suggest throwing it out or buying another one (what I personally would do is probably different than what I’d suggest for someone else)

Now for minutiae...
Maybe a decade ago I started working on a far more detailed write up to go with The Chart. I got really into the weeds regarding the various ratios of various steels, why one recipe did one thing vs another, etc. I can’t even seem to find that research today.

However, my take is this...

Assuming that 9310 was available when the AR system was designed, I only see two possibilities
1) c158 is better for the system, as designed
2) the original designer(s) got it wrong

I prefer to trust in the designers, and go with the material they chose. When it comes to the internals of the gun, my preference is to start with the as-designed system and only deviate when there is a proven good improvement, and even then, what exactly is the impact of that improvement and does that improvement relate to me (a car with better gas mileage is “better” economically, but if I have a company gas card, what do I care?)

There is that other possibility. That 9310 wasn’t available when the gun was designed. But that still doesn’t mean it’s better, just different.

And no matter what, you have to ask yourself why a manufacturer would choose 9310, and for that we can also look to which manufacturers use 9310. Did they choose it because it’s “better”, or because it’s cheaper, more readily available and easier to source (which is also effectively “cheaper” for a business), or, like the bushmaster giant gas ports that were designed to make the guns run with almost any cheap ammo in order to reduce warranty returns, is there some benefit to the manufacturer that isn’t even clear?

I've got a metallurgy guy...hopefully kedminster will weigh in sooner or later.

[kedminster]

I've got a metallurgy guy...hopefully kedminster will weigh in sooner or later.

Unfortunately I am not familiar with either of these alloys and neither is listed in the most recent MMPDS. I would agree that alloy is just one factor and heat treat and surface finish may be just important, if not more important, than the base alloy itself.

[tlong17]

Springfield Armory uses 9310 to craft the BCG included with the SAINT rifles, if that is any indication. They do at least pin the gas block and stake the gas key and castle nut.

[theJanitor]

Has anyone had the actual bolt carrier break (crack, etc)? Not talking about the bolt, or the key, but the carrier itself? what metal are the carriers made from?

eta: I just paid $200 for a spare bolt for my SR15. At least KAC makes choosing the parts easy, LOL

[SecondsCount]

Has anyone had the actual bolt carrier break (crack, etc)? Not talking about the bolt, or the key, but the carrier itself? what metal are the carriers made from?

eta: I just paid $200 for a spare bolt for my SR15. At least KAC makes choosing the parts easy, LOL

I was going to ask the same thing. I haven't seen a bolt or bolt carrier break in years, and the last time was on a carbine upper that a friend had who was bragging that he paid $250 for the complete setup.

[ReverendMeat]

https://faxonfirearms.com/blog/why-9310-steel-in-an-ar15-m16-bolt/

[awp_101]

Assuming that 9310 was available when the AR system was designed, I only see two possibilities
1) c158 is better for the system, as designed
2) the original designer(s) got it wrong

I prefer to trust in the designers, and go with the material they chose. When it comes to the internals of the gun, my preference is to start with the as-designed system and only deviate when there is a proven good improvement, and even then, what exactly is the impact of that improvement and does that improvement relate to me (a car with better gas mileage is “better” economically, but if I have a company gas card, what do I care?)

There is that other possibility. That 9310 wasn’t available when the gun was designed. But that still doesn’t mean it’s better, just different.

And no matter what, you have to ask yourself why a manufacturer would choose 9310, and for that we can also look to which manufacturers use 9310. Did they choose it because it’s “better”, or because it’s cheaper, more readily available and easier to source (which is also effectively “cheaper” for a business), or, like the bushmaster giant gas ports that were designed to make the guns run with almost any cheap ammo in order to reduce warranty returns, is there some benefit to the manufacturer that isn’t even clear?
All fair and valid questions.

I think 9310 is a "recent" alloy, or at least newer than the original milspec for the AR. Is it possible it's an alloy that provides the attributes of 158 (or close enough) while being easier on tooling?

[TGS]

All fair and valid questions.

I think 9310 is a "recent" alloy, or at least newer than the original milspec for the AR. Is it possible it's an alloy that provides the attributes of 158 (or close enough) while being easier on tooling?

From what I've read, it's a somewhat similar steel that is suitable for AR 15 bolts but more widely available, and thus cheaper. Carpenter 158 is apparently bought from a sole-source supplier with a close hold on the production rights. It's the "gold standard" for AR15 bolts, but it's expensive because of its trade name, not because it's a wonder steel that is the "best" possible steel in 2020.

*I am not an engineer, just passing on what I've read from engineers.

[19852+]

I looked into 9310, on the interwebz, and the conclusion I drew was that it's [9310] quality as a bolt depends on how it is made and tempered. So same as anything else in life...
Giessele is making bolts too and they say theirs uses a special formulation of c158 that's better than the others... Of course.

I have 3 BCG's 2 Colt and one BCM. I have yet to break any. I have one FN bolt as a spare. I just buy known quality.

[OlongJohnson]

https://faxonfirearms.com/blog/why-9310-steel-in-an-ar15-m16-bolt/

The temperatures involved in QPQ nitriding will affect the heat treat condition of steel. Knowing that the end state of the product will be post QPQ is an essential part of the design and manufacturing plan. All that talk about careful and correct heat treatment to be sure everything is right "and then instead of phosphate, we nitride it" is certainly an avenue to screw things up. Doesn't mean it for sure will, or that the pre-nitride process wasn't designed with QPQ in mind, but that's not how they talk about it in that link. A metallurgist with the right tools will almost certainly be able to detect differences in the condition of the material inside the nitrided surface layer before and after the process, or between one that was phosphated and one that was nitrided with all other steps being the same.

To be clear, I don't have any issue with a 9310 bolt that's designed and manufactured well. I do have issues with incomplete and/or incorrect and/or misleading communication in the marketplace, and with incomplete and/or incorrect design and manufacturing engineering.

[awp_101]

To be clear, I don't have any issue with a 9310 bolt that's designed and manufactured well. I do have issues with incomplete and/or incorrect and/or misleading communication in the marketplace, and with incomplete and/or incorrect design and manufacturing engineering.
And that's the $64 (or $164) problem, isn't it? Hype and marketing muddy the waters to the point there's no real usable information (to me at least) in the product descriptions. I need a designer, metallurgist and machinist to read between the lines and tell me what's being left out or over stated.

I get that manufacturers don't want to give away what makes the unicorn jizz secret sauce in their process special but what's wrong with saying "we follow industry standards for XYZ process and take that into account in our design"? Why can't they tell us "here's what makes a 9310 bolt equivalent to or superior than C158"? Why can't manufacturers using 158 tell us why it's superior to 9310 other than "original mil-spec"?

It's almost like everyone is more afraid of someone stealing their magic beans instead of helping the customer or end user make an informed decision. And that applies to more than just the firearms industry but that's a whole 'nuther rant...

[critter]

The problem is, in 2020, that’s almost harder to discern than it was 10 year ago. Now with so many more commercially-available options and many of them offering supposed “milspec” versions plus various unicorn-jizz coatings, alternate metallurgy, various extractor redesigns, etc. all claiming “better” it seems harder and harder to just buy a known-good BCG.

Which is why I’d still just go “standard” BCM (https://bravocompanyusa.com/bcm-bolt-carrier-group-mpi-auto/) or Colt (https://www.brownells.com/rifle-parts/bolt-parts/bolt-carrier-groups/m16-5-56-bolt-carrier-group-prod70973.aspx). Only way to know for sure.

Same here. Set it and forget it.

[Toonces]

Why can't they tell us "here's what makes a 9310 bolt equivalent to or superior than C158"? Why can't manufacturers using 158 tell us why it's superior to 9310 other than "original mil-spec"?It's almost like everyone is more afraid of someone stealing their magic beans instead of helping the customer or end user make an informed decision. And that applies to more than just the firearms industry but that's a whole 'nuther rant...I wonder how much data is out there from tests specific to AR bolts. I’m guessing, outside of government testing, very little. Especially with current commercial alloys. I doubt most manufacturers have the magic beans to be stolen. I’m also not sure how much it matters in the SolidWorks age. From a rather unrelated field (Diesel fuel injection components), the way to make things last is “clean” steel. Clean steel with a good heat treat will allow injector bodies to pass fatigue testing at wall thicknesses (thin) they couldn’t imagine 20-30 years ago. Those material and heat treat advances will also improve AR bolts, if they are not held back by archaic mil specs. (I have a Metallurgy degree and I’ve dealt with mil standards at various jobs. I’m not completely out of my lane. )

[Wonder9]

This thread should be renamed "I'm buying into industry marketing instead of common sense"

Replace your BCG when you finally break a locking lug with a "mil-spec" C158 M16 BCG from one of the many companies that offer one.

53921

[Willard]

This thread should be renamed "I'm buying into industry marketing instead of common sense"

Replace your BCG when you finally break a locking lug with a "mil-spec" C158 M16 BCG from one of the many companies that offer one.


Alternatively, you could just replace the bolt.

[rca90gsx]

Looks like PSA really stepped up their BCG game with a new one sourced from Microbest!

[5pins]

https://www.youtube.com/watch?v=mebExLuNDDQ

[Casual Friday]

Saturday evening, a friend from church called and said he was having problems earlier in the day with his new AR pistol. He asked if he could bring it to me to look at, so I asked him to describe what the problem was. As soon as he said the "spent shell and a new round out of the clip" (we're slowly working on proper terminology) "were getting jammed up inside", I figured it was a weak or broken extractor spring or bad extractor. It told him to bring the BCG to church the next day and I'd take it home and check it out.

After I disassembled it I found an extremely flimsy extractor spring, so I replaced it with a Colt M4 extractor spring for him, these are a handy add on to any Brownells order you make. Last night, we went up to my shooting spot and it ran like a scalded cat through 200 rounds of the finest overpriced steel case ammo he could find during this panic. I ran a couple mags of my M193 through it as well and it didn't skip a beat. I wish I'd taken a picture of that spring next to the new Colt spring so you could see the difference in the two. The BCG is a Toolcraft purchased from Armor Ally or Arm Or Ally or Arm Our Ally or something like that, it's an online retailer I'd never heard of, sometime during COVID.

No matter what BCG you're using, having a few spare Colt extractor springs on hand is a good idea.

58794

[OlongJohnson]

The BCG is a Toolcraft purchased from Armor Ally or Arm Or Ally or Arm Our Ally or something like that, it's an online retailer I'd never heard of, sometime during COVID.

Not ready to get into the history of why, but armorally.com is OFF my list of places that are GTG to deal with.

[Casual Friday]

Not ready to get into the history of why, but armorally.com is OFF my list of places that are GTG to deal with.

I hadn't heard of them prior and still haven't looked up their website but I'd be interested to hear more via pm if you don't want to share publicly.

[pooty]

No matter what BCG you're using, having a few spare Colt extractor springs on hand is a good idea.


thx which one is the correct part
?

https://www.brownells.com/rifle-parts/bolt-parts/extractor-parts/extractor-springs/ar15a4-spring-extractor-prod82159.aspx

https://www.brownells.com/rifle-parts/bolt-parts/extractor-parts/extractor-springs/ar15a4-extractor-spring-assembly-prod4840.aspx

[Casual Friday]

thx which one is the correct part
?

https://www.brownells.com/rifle-parts/bolt-parts/extractor-parts/extractor-springs/ar15a4-spring-extractor-prod82159.aspx

https://www.brownells.com/rifle-parts/bolt-parts/extractor-parts/extractor-springs/ar15a4-extractor-spring-assembly-prod4840.aspx

The ones with the insert is what I buy.

[MistWolf]

thx which one is the correct part?
https://www.brownells.com/rifle-parts/bolt-parts/extractor-parts/extractor-springs/ar15a4-extractor-spring-assembly-prod4840.aspx


The ones with the insert is what I buy.

Yes, the copper colored Colt spring with black insert is the right one.

[Nephrology]

Saturday evening, a friend from church called and said he was having problems earlier in the day with his new AR pistol. He asked if he could bring it to me to look at, so I asked him to describe what the problem was. As soon as he said the "spent shell and a new round out of the clip" (we're slowly working on proper terminology) "were getting jammed up inside", I figured it was a weak or broken extractor spring or bad extractor. It told him to bring the BCG to church the next day and I'd take it home and check it out.

After I disassembled it I found an extremely flimsy extractor spring, so I replaced it with a Colt M4 extractor spring for him, these are a handy add on to any Brownells order you make. Last night, we went up to my shooting spot and it ran like a scalded cat through 200 rounds of the finest overpriced steel case ammo he could find during this panic. I ran a couple mags of my M193 through it as well and it didn't skip a beat. I wish I'd taken a picture of that spring next to the new Colt spring so you could see the difference in the two. The BCG is a Toolcraft purchased from Armor Ally or Arm Or Ally or Arm Our Ally or something like that, it's an online retailer I'd never heard of, sometime during COVID.

No matter what BCG you're using, having a few spare Colt extractor springs on hand is a good idea.

58794


grabbed a few BCM BCG Upgrade kits to keep in my range bag just in case. Thanks for the reminder