308 / 6.5CM FP tip sizes, and the variety I found.

[bfoosh006]

While a lot of this info is in another thread... I thought others might like it more cohesive.

This is gonna be about the various FP tip sizes, and styles and bolt FP holes I have found.

IMHO... All manufacturers should post FP tip sizes and bolt FP hole diameters... Yeah I know.. Good Luck.

Much like everything else in the Non- Mil-spec world of Large Frame AR's ( LFAR ) ... firing pins and bolt face FP holes can vary by quite a bit.

I am posting so someone can hopefully avoid using / purchasing a incorrect FP size.

This is not a be all list , but is some of the brands I have bought and measured.... Please NOTE, the FP style also varies... IE , Tapered v. standard.
Tapered on the left.. standard on the right.. the middle is in the pic because of the less than squared of edges at the rings.

I will say , and to cut to the chase... try to buy a brand bolt that comes with a firing pin.


Using a wrong size FP tip size , in a poorly matched bolt FP hole diameter will cause excessive primer cratering and primer flow.

Measurements were done with a Pin gauge set and caliber.


For the "most" part, "standard" 308 BCG's and bolts ( Non HP ) come with a approximate FP tip size of .076-.079 and bolt FP hole of .080-.083

My List of measured "308" FP tips and Bolt Hole sizes...

3ea Generic CDNN bought 308 FP.... .078"

PSA / Toolcraft 308 BCG... FP tip size.. .077" , bolt FP hole... .081
10ea PSA FP measured.. varied between .076" ( 2ea ) .077" ( 7ea )and .079" ( 1ea )
Standard style. ( Non Tapered )

Please NOTE.. the PSA dual ejector 6.5CM BCG uses a smaller HP FP tip size . More later

Links provided to be specific.
https://palmettostatearmory.com/psa-pa10-308-nitride-bolt-carrier-group-516446490.html
https://palmettostatearmory.com/psa-pa10-308-nickel-boron-bolt-carrier-group.html
https://palmettostatearmory.com/308-firing-pin.html

Lantac 308 FP , Nib 308 Bolt, and Nitrated 308 bolt, .... .076" FP tip size ( 4ea ) .081" Bolt FP hole on both... these are sold as "spare parts".
Standard style. ( Non Tapered )

PLEASE note... the Lantac ENHANCED BCG uses a different FP tip size and Bolt face FP hole !! ( More later )

https://www.lantac-usa.com/product-page/lantac-308-7-62-bolt-choose-finish-nib-qpq
https://www.lantac-usa.com/product-page/lantac-308-7-62-firing-pinFP

RTB Blem 308 BCG ( Toolcraft ? ) ... .076" FP tip size,... .080" bolt face FP hole.
Non tapered FP.
Link no longer available

Others measured info...

Fulton Armory actually shows a 308 Bolt for DPMS pattern.. for use with a .078" FP
https://www.fulton-armory.com/bolttitanstripped.aspx
https://www.fulton-armory.com/bolttitanstripped-2.aspx
https://www.fulton-armory.com/firingpinchrometitan.aspx

msgriff... "The original DPMS LR-308 bolts were a 0.080" bolt face firing pin orifice with a 0.076" firing pin tip diameter."
Non tapered.

Top O' Texas tapered v. standard profile FP photo.. Some of the tip sizes vary on the Tapered FP and Standard profile.

 

[bfoosh006]

A odd ball in the middle... JP Enterprises "Enhanced" 308 bolt and FP .... NOT The HP JP setup.

IMHO, use of the JP enhanced FP in a "DPMS" typical bolt ... will induce primer flow / cratering.

Again.. buy and use your FP and Bolt from the same manufacturer.. and you will be just fine.

While JP is a "standard" default for HP Bolts and FP's... the also sell a "standard" "Enhanced" 308 bolt and FP.
JP standard Enhanced FP ( 3ea ) .0735" ... both the Titanium and standard
I didn't order the Bolt for these... but given JP's OCD, Lol... I would imagine a NON HP Bolt face hole of around .077" ish.

https://jprifles.com/buy.php?item=JPEB-308
https://jprifles.com/buy.php?item=JPFP-308
https://jprifles.com/buy.php?item=JPFP-308TI

 

[bfoosh006]

Small Diameter / HP setups... Both Tapered and Standard profile FP.

PSA / Toolcraft 6.5CM Dual ejector BCG... FWIW, my first one of these comes from May 2018. And the latest from a month ago.
Tapered SD Tip FP... .068 and .069" , Bolt face FP hole... .071"
https://palmettostatearmory.com/psa-nitride-6-5-creedmoore-bcg-with-double-ejector.html

PSA Single ejector 6.5CM ....
Tapered FP, ... SD Tip size... .067" ... bolt face hole... .070"
Bought years ago .. so no link.

CMC / Santan complete 308 BCG ( with 3 exhaust ports on the carrier , "Suppressor Optimized" , single ejector )
Tapered FP SD Tip... .067".... bolt face FP hole... .070"
https://cmctriggers.com/product/cmc...ppressor-optimized-milspec-black-nitride-308/

Lantac "Enhanced complete 308 BCG".. single ejector, "forward facing gas ports" w/ Small Diameter FP Tip size and Bolt face hole.
NOTE... the The Lantac sold Bolt and FP I mentioned in the first post... DO NOT interchange parts, with this Bolt and FP tip size .... one or the other Bolts and FP's most be used with the other.
You can use the the other mentioned individual Lantac Bolt Spare parts, and FP , with the carrier. But the FP tip sizes matter.
As in ... the Larger tip sized FP won't work with the "Enhanced" bolt face small diameter hole.
Tapered SD FP tip size... ( 2x ) .067.... Bolt face FP hole... .070"
https://www.lantac-usa.com/product-page/enhanced-bcg-full-auto-style-223-5-56-nitrided

Rubber City Armory...
.066" tip size with a regular shank. ( Non Tapered )

https://rubbercityarmory.com/product/firing-pin-for-308-hp/
"Engineered specifically for the High Pressure 308 bolt face."
https://rubbercityarmory.com/product/308-win-multi-hp-calibers-bolt-firing-pin/

2ea spare tapered SD FP tip sizes... I have little idea where I bought these years ago...
.068" and .069" tip size.

Recently bought Headspaced to barrel bolt and FP to a Craddock Precision RTR 308 Barrel...
Tapered SD FP tip size... .067" , Bolt face FP hole size... .071"

.



Other folks info... along with interesting comments.

"Cascade Hemi" probably Toolcraft.. Tapered SD FP tip... .0675", Bolt face tip hole.. .069"
Also from Cascade Hemi... Here is the No Name Low Mass bolt/BCG in the picture above:
https://www.righttobear.com/lightweight-ar10-dpms-pattern-bcg-308-bolt-carrier-group-black-nitride/

"NtxGlock" "Noveske sent me a headspaced hp bolt but no firing pin"... "Noveske told me they do not sell individual pins and they sourced that bolt from Rubber City Armory.. I have sent Rubber City Armory a email. No reply yet. I did get another dual ejector bolt today w/pin from them (RCA).

Update: Rubber City Armory called me this afternoon. The tech told me that they do NOT sell AR10 bolts to Noveske, only 5.56 bolts. So, I will get back with Noveske. Jeez."

Top O' Texas.... "Also, the design keeps you from using a tapered pin in a non-hp bolt and vice versa. I can't say that about all hp bolts/fp's, only the few I have."
I haven't checked this out, yet.... but...


FWIW.... I have yet to see the Tapered SD FP tip size for sale by itself. HOWEVER.. I do have 2 spares, Lol
I have some of the Toolcraft AR10 Small Diameter Firing Pin, on back order.

 

[bfoosh006]

I realize most people don't "need" to have spare parts... but hopefully others can gain by this info.

After receiving the Toolcraft SD FP tip size... I will update the thread.

I have also e-mailed Craddock Precision, asking where they source their supplied headspaced bolt and Tapered FP.

For anyone with more measurements... please add your info !!

Thanks ahead of time

 

[bfoosh006]

Azimuth / Aero Precision Nitrided 308 / 7.62 BCG Single Ejector

To Aero's credit they at least publish a comment concerning the size of the firing pin hole. "firing pin hole diameter is reduced to .070"

TAPERED SD FP tip size... .068" .... Bolt face hole... .070"

https://www.aeroprecisionusa.com/308-bcg-black-nitride
https://www.aeroprecisionusa.com/catalog/product/view/id/536/s/308-bcg-black-nitride/category/201/

Tell tale, rounded gas key ends of the Azimuth 308 BCG..

Slab Side of the Azimuth / Aero nitride 308 BCG...

 

[bfoosh006]

And I just realized, I never posted the Rubber City Armory ".308 Win+ Multi HP Bolt and firing pin info.

Proprietary SD Non-Tapered FP... .066" , Bolt face hole... .071"

https://rubbercityarmory.com/product/308-win-multi-hp-calibers-bolt-firing-pin/

 

[bfoosh006]

Recently bought Headspaced to barrel bolt and FP to a Craddock Precision RTR 308 Barrel...
Tapered SD FP tip size... .067" , Bolt face FP hole size... .071"

Craddock Precision says... ( via e-mail ) "We get all of our Bolts/BCGS/Firing Pins from Azimuth"

Now... since I have seen the Tapered SD FP in many other BCG's, I really don't know if Azimuth makes them.

 

[bfoosh006]

I also contacted Aero, asking if they sell the Tapered SD FP as a replacement part.

And while Aero CS was prompt and very helpful... they do not sell it separately.

For that matter... ( and I am sorry to say this ) "one of the techs" recommended buying a replacement from some of the above listed places. NONE of which would have been correct sized or style ( tapered ) . As in to big ( stuck ) and way to small. ( bad primer cratering, if not pierced primers )

It is sad the e-mail contact, while doing his best to help, got piss poor info from "one of the techs"... someone that should know better.

 

[bfoosh006]

CMMG Mk3 6.5 / 308 HP BCG..
https://cmmg.com/bolt-carrier-group-mk3-6-5-creedmoor

Bolt face hole ... .0635" , SD Non Tapered FP, .059"

I also have some spare FP, and rehab kits on the way

CMMG spare FP's arrived... . 075", both the individual and the Bolt replacement parts kit. These are not for above mentioned 6.5CM HP BCG
Note... the webpage says ".080" for these specific parts.
( I could not find the HP SD FP , sold on CMMG's webpage. )
https://cmmg.com/firing-pin-mk3
https://cmmg.com/parts-kit-mk3-bolt-rehab

 

[bfoosh006]

Craddock Precision... has come through with replacement Tapered SD FP's.
These should fit / be suitable replacements for ... ( links above in the tapered SD FP section )

Of course, the Craddock Precision BCG and bolt
PSA/ Toolcraft dual ejector SD BCG's ... and older single ejector SD BCG
CMC 308 BCG
Lantac ENHANCED 308 BCG ,... not the "Mil-spec" 308 bolt.
Aero Precision , current phosphated and Nitrided 308 BCG

IMHO, Joshua at Craddock Precision went way, way above any other company.

He will arrange, my buying some from Craddock Precision, ( he also said others can do so as well. ) I will order enough spare of the SD Tapered FP's for others if they need them.

Aero said no, Never heard back from CMC , Toolcraft never responded... other places have a indefinite back order and they don't seem to know if the FP is tapered or not. And webpage photos are typically a crap shoot.

I REALLY wish the various webpages would sell proper replacements for their own products. ( Lantac, CMC, AERO, Toolcraft / PSA ) and ... at the very least, show the measured FP tip sizes used and style. ( Tapered v. Traditional )

I will post the Craddock Precision, Tapered SD tip sizes and pics after I get them... and if someone needs one...IM me.


So... again a huge Thank You to Joshua Bales at Craddock Precision !!

"If you have people who want to buy more you can send them my way, I don't mind answering emails!" .... [email protected]

 

[Cascade Hemi]

And I just realized, I never posted the Rubber City Armory ".308 Win+ Multi HP Bolt and firing pin info.

Proprietary SD Non-Tapered FP... .066" , Bolt face hole... .071"

https://rubbercityarmory.com/product/308-win-multi-hp-calibers-bolt-firing-pin/

Gross

 

[bfoosh006]

Gross

I believe @padom has said he has used RCA bolts and FP's. And he does recommend them ( and I respect padom's advice ) ... so I can't help but wonder if my current ones are an anomaly.
Maybe padom could measure his that he has.

And honestly, given the "all over the place" tip sizes and styles... I can't help but guess , If FP's are sourced from outside the various manufacturer's production lines.
As an example, Fulton Armory ( I realize they don't make the ones they sell ) just changed their description of the one they sell , because the current batch is .075", rather then the previous batch of .078". ( Non Tapered , BTW )
Kudos to them, for the prompt description change.

 

[bfoosh006]

KAK / Azimuth Technology, Double Ejectors... NON Tapered FP , typical Non-SD FP Tip size.
Good fit though ! .... Bolt orifice hole.... .079" , ... FP tip .077

Replacement FP's sold at KAK... 2ea @ .076", 2ea @ .077"

https://kakindustry.com/lr-308-double-ejector-bolt-carrier-group

https://kakindustry.com/lr-308-bolt-carrier-group-firing-pin

Random internet photo showing the Double Ejector's...

 

[45-90]

What's the big deal, we've had high pressure bolts with small firing pins for years.
They are not all the exact same size or configuration, but the ones from the same manufacturer should fit as long as the firing pin ordered is for their high pressure bolt and not the standard bolt.
I run .065" Toolcraft high pressure dual ejectors on 308, & 6.5 CM
They measure .065".
A titanium bolt carrier has an .069" FP for 308

I use Toolcraft with high pressure bolts on most every AR 10...
Except a few, the 338 RCM with a KAK magnum bolt has a .067" firing pin.
I use full pressure manual 338 RCM maximum loads on this bolt, in AR 10.
Same with the 308 or 6.5 CM.

Seems one should already know that, if you build your own, ARs, from chosen components, not just completed factory uppers, or ordered components without checking.
I order them on purpose, specified by the manufacturer... who already state the firing pin size. Do not buy it, if the firiing pin size is not stated...if that's important to you.
High pressure bolts do not take any more pressure, than standard bolts according to the manufacturer, makes sense...same steel, same heat treat, same dimensions...except for the firing pin, and hole.
I do not have any firing pin problems or primer problems with these bolts.
Slight dimensional differences from the same manufacturer will likely have no impact, as long as it functions.
But, I may not have any problems, with standard dia bolt firing pins,... I just prefer to install the .065" dia ones.
Never had one break, never been a primer problem in the AR 10.

 

[bfoosh006]

What's the big deal, we've had high pressure bolts with small firing pins for years.
They are not all the exact same size or configuration, but the ones from the same manufacturer should fit as long as the firing pin ordered is for their high pressure bolt and not the standard bolt.
I run .065" Toolcraft high pressure dual ejectors on 308, & 6.5 CM
They measure .065".
A titanium bolt carrier has an .069" FP for 308

I use Toolcraft with high pressure bolts on most every AR 10...
Except a few, the 338 RCM with a KAK magnum bolt has a .067" firing pin.
I use full pressure manual 338 RCM maximum loads on this bolt, in AR 10.
Same with the 308 or 6.5 CM.

Seems one should already know that, if you build your own, ARs, from chosen components, not just completed factory uppers, or ordered components without checking.
I order them on purpose, specified by the manufacturer... who already state the firing pin size. Do not buy it, if the firiing pin size is not stated...if that's important to you.
High pressure bolts do not take any more pressure, than standard bolts according to the manufacturer, makes sense...same steel, same heat treat, same dimensions...except for the firing pin, and hole.
I do not have any firing pin problems or primer problems with these bolts.
Slight dimensional differences from the same manufacturer will likely have no impact, as long as it functions.
But, I may not have any problems, with standard dia bolt firing pins,... I just prefer to install the .065" dia ones.
Never had one break, never been a primer problem in the AR 10.

Not everyone realizes the differences between all the various FP sizes.
We all had to learn somehow.

I have never said HP SD FP were bad... just be careful about a replacement FP size and style someone might get if ordered.

This list is for those that don't know about how many different sizes and styles there are, even from a single brand name seller...that's all.
Not every person, that might be wanting spare parts, will know that.

Honestly, my first post in this thread said that.

And hardly any manufacturers / sellers show the FP tip size... so now there is a list of what I have seen... and I hope that will help some one less knowledgeable than you. ( No offense ), if they would like spare parts.

I would love ALL sellers to mention FP tip size... but they don't. So trying to find that spare FP is a crap shoot.

Even when I asked to buy a spare from the same seller.

Some sellers sell spare FP's that don't even fit their fancy BCG's ( spare part tip size is to big, and could get "hammered" into the smaller bolt orifice hole diameter )... with no mention of that fact on their webpage.

More experienced AR folks know what to look for.. but newer people might not.
The world of LFAR's is already confusing enough... trying to buy a replacement FP shouldn't be so tough.

And lots of people turn to the internet for some kind of answer.

We have all seen cratered primer images. I realize not all of those can be attributed to a poor fitting FP but , for me , it is something to consider.
FP tips can be fubar'd by pierced primers so finding a correct FP be a chore given the lack of info out there, again for the less experienced.

I am not trying to blast any single seller, for their Tip size choice. This thread is a list of what sizes they have been in what I have.

@45-90 ... you mentioned the KAK Magnum bolt and its SD FP tip, do you remember if the FP is the Tapered style ?

 

[bfoosh006]

On a side note... why does the tapered FP style exist for DPMS bolts ?
I understand that various manufacturers have used them from day one ( ? ) LMT, KAC, Armalite.
Are they "stronger / stiffer / more durable " over long time use ?

Do they interchange freely ( provided the tip size fits ) with straight style FP's ? Both ways ? IE you can safely use a straight pin in a bolt that came with a tapered FP and vice versa ?

I am not suggesting anyone do that , for obvious reasons (stay with the OEM type FP it came with ), but are all 308 bolts made the same in the bolts firing pin channel ?
Maybe better said, the bolts aren't "drilled" specific to the style of FP used ?

My pin gauge set isn't long enough to useful for checking.

I haven't checked all the various ones I have, via swapping around parts.. but maybe someone already knows.

I really want a FP tip protrusion measuring tool. Lol

 

[45-90]

Not everyone realizes the differences between all the various FP sizes.
We all had to learn somehow.

I have never said HP SD FP were bad... just be careful about a replacement FP size and style someone might get if ordered.

This list is for those that don't know about how many different sizes and styles there are, even from a single brand name seller...that's all.
Not every person, that might be wanting spare parts, will know that.

Honestly, my first post in this thread said that.

And hardly any manufacturers / sellers show the FP tip size... so now there is a list of what I have seen... and I hope that will help some one less knowledgeable than you. ( No offense ), if they would like spare parts.

I would love ALL sellers to mention FP tip size... but they don't. So trying to find that spare FP is a crap shoot.

Even when I asked to buy a spare from the same seller.

Some sellers sell spare FP's that don't even fit their fancy BCG's ( spare part tip size is to big, and could get "hammered" into the smaller bolt orifice hole diameter )... with no mention of that fact on their webpage.

More experienced AR folks know what to look for.. but newer people might not.
The world of LFAR's is already confusing enough... trying to buy a replacement FP shouldn't be so tough.

And lots of people turn to the internet for some kind of answer.

We have all seen cratered primer images. I realize not all of those can be attributed to a poor fitting FP but , for me , it is something to consider.
FP tips can be fubar'd by pierced primers so finding a correct FP be a chore given the lack of info out there, again for the less experienced.

I am not trying to blast any single seller, for their Tip size choice. This thread is a list of what sizes they have been in what I have.

@45-90 ... you mentioned the KAK Magnum bolt and its SD FP tip, do you remember if the FP is the Tapered style ?

So here is a picture for your scrap book of the KAK magnum FP and its tapered profile and .067" dia.

 

[bfoosh006]

So here is a picture for your scrap book of the KAK magnum FP and its tapered profile and .067" dia.

Thank you, You may have just answered where my spare 2 Tapered SD FP's came from.

 

[bfoosh006]

The Craddock Precision / Azimuth Tapered FP's arrived.... 11 of the 12 are .0675... 1 was .068

 

[bfoosh006]

The KAK LR_308 / Magnum HP FP's came back in stock.

They are indeed, Tapered with a SD Tip.... 2ea .068",.. 1ea .069" ( so the same as the PSA Toolcraft 6.5CM Dual ejector BCG )
https://kakindustry.com/magnum-high-pressure-bcg-firing-pin
PLEASE Note the picture in the link above... does not show the proper TAPERED ones I received. I am going to ask KAK to show the correct Tapered FP in their Link.



Also my back ordered Wilson Combat S-7 Steel FP's arrived.... NON-Tapered.. 1ea .075"... 1ea .0745"
https://wilsoncombat.com/firing-pin-ar-10-mil-spec-bullet-proof-s-7-tool-steel-hard-chrome.html