KVP (Faxon) 9mm 16 inch Barrel chamber

[DBEAM]

Does head spacing affect the plunk test? Is it different then it is for a pistol? When I perform the plunk test I drop the bullet in the barrel and see if it will turn freely. On my g17 and Taurus PT 111 American eagle and WWB both do this with no issues.

 

[LiveLife]

When I perform the plunk test I drop the bullet in the barrel and see if it will turn freely.

You also need to check if case base is sticking above the barrel hood.

On Walkalong's thread for determining max OAL, it is illustrated with using barrel hood. If the base of case sticks above the hood, it is too long (bullet nose is hitting the rifling) and when the breech wall of slide hits the back of case base, it will jam the bullet into the rifling - https://www.thehighroad.org/index.p...rel-find-a-max-o-a-l-with-your-bullet.506678/

With carbine upper that has barrel attached, you need to perform the plunk test while visualizing the chamber end in relation to the bolt face (you may need to use calipers for measurement). If the case base sticks past the chamber end too much in relation to the bolt, then bolt face will slam the nose into the rifling. While you can load your rounds shorter but if your barrel does this with factory ammunition, head spacing needs to be increased.

 

[DBEAM]

Well now that I see that I think I see what you mean but I don't think I have a head space issue, I think I have a throat issue. I don't need my chamber to be any longer I just need the leade longer so that when the brass is held by the chamber the bullet is not contacting the rifeling.

 

[LiveLife]

So have you contacted Kaw Valley Precision?

 

[DBEAM]

No I haven't, Nathan sent me the rma to return the barrel to Faxon before he even posted that here. I honestly wasn't to impressed KVPs handguard, it came crooked and when I asked them how I could straighten it out they pretty much acted like it should just be left crooked. After all was said and done I didn't like their means of attachment for the forearm in the end so I bought a different hand guard from another manufacturer which attaches much more securely and I can get it on straight.

I guess in a nut shell I was not impressed with KVP but I was impressed with the barrel, which happened to be made by Faxon, I just think the lead should have been able to handle factory ammunition.

I have had no issues with Faxon's service except when I lost communication with them for 3 weeks and was starting to worry I wouldn't see my barrel again. I now believe they have been very busy, it was over a vacation heavy period and they had shot show. I really don't want to have to spend anymore time going through anybody else and would just like to get to shooting.

Again, I have been impressed with Faxon. Considering that I think the lead is too short for factory ammunition on the barrel they manufactured but I still think highly of them I think speaks volumes for their quality and service. I just can't say they are perfect yet until I have the barrel back and it is working correctly. When that happens, which I'm pretty confident it will you will hear nothing but praise out of me and I will probably get one of their 45 barrels someday.

 

[Walkalong]

I don't think I have a head space issue, I think I have a throat issue. I don't need my chamber to be any longer I just need the leade longer so that when the brass is held by the chamber the bullet is not contacting the rifling.

Lot's of quality barrels use short throats in pistol calibers. If the headspace is OK there is nothing wrong. Headspace has nothing to do with the bullet, it is about the case only.

If the throat, leade, etc is so short that it makes you seat the bullets to deep to feed 100%, then you have an issue and someone will have to use a reamer to give the bullet more space before engaging the rifling. Not increasing the chamber (Which would affect headspace), only increasing the free space between it and the rifling.

I think I can safely develop a load to 1.135 to avoid this but does anyone think that the wwb and the ae are a danger to shoot out of this barrel?

That is plenty long for HPs and TrFPs. If it is shorter than what is used in the data you are using adjust the max charge down.

Is this what made you think you had a headspace problem? Have you articulated this to Faxon?

 

[LiveLife]

+1. The depth of the bolt face should be .125" +/- a few thousandths. Case base should stick out of the chamber about the same amount.

If the case base sticks out past the depth of bolt face because bullet's ogive/bearing surface is hitting the start of rifling (and case mouth not contacting the chamber), then when the bolt is slammed forward, the bullet will likely jam against the rifling and get seated deeper.

You can use resized cases without bullet to measure how much case base sticks above the chamber to factor out bullet ogive/bearing surface hitting the start of rifling. Since mixed brass length varies, I would use longer resized case lengths.

 

[DBEAM]

I never said a thing about head space, some one else mentioned it earlier in the post. It just bothers me that factory ammo, Winchester White Box 115 fmj one of the most common practice rounds available does not pass the plunk test along with AE 115 fmj which is basically Federal. I believe Nathan that it is possible these ammo manufactures are loading a little out of spec but I want a barrel that will shoot factory ammo with no issue and I think its easier to get my barrel adjusted rather then to get Winchester and AE to start adjusting the OAL of their bullets. I do reload 9mm to save some money but I also often by factory ammo when I break in a new gun and when I'm to lazy to load up any at the moment.

That is plenty long for HPs and TrFPs. If it is shorter than what is used in the data you are using adjust the max charge down.

Is this what made you think you had a headspace problem? Have you articulated this to Faxon?

 

[LiveLife]

So how do you explain Winchester White Box and American Eagle/Federal ammunition working in other barrels/pistols/carbines?

I have Just Right carbine with 9/40/45 barrels and built several PSA 9mm carbines from completed uppers/full kits and factory ammunition works fine. No headspacing issues.

In fact, I have tested various bullet types/nose profiles and even 124 gr RMR RN loaded long at 1.160" works fine - https://www.thehighroad.org/index.p...n-9mm-40s-w-45acp.799231/page-4#post-10338994

 

[Walkalong]

I never said a thing about head space, some one else mentioned it earlier in the post. It just bothers me that factory ammo, Winchester White Box 115 fmj one of the most common practice rounds available does not pass the plunk test along with AE 115 fmj which is basically Federal. I believe Nathan that it is possible these ammo manufactures are loading a little out of spec but I want a barrel that will shoot factory ammo with no issue and I think its easier to get my barrel adjusted rather then to get Winchester and AE to start adjusting the OAL of their bullets.

Gotcha. Yea, I would thing factory WWB etc would "plunk". It will be interesting to see what they say and what they do to the barrel. As far as being loaded in "spec", as long as the case is not too long, is not to wide anywhere, and the loaded round doesn't exceed 1.169, it's in spec. I know of no spec for what kind of ogive it has or what kind of short leades it must fit. Military chambers are generally "generous" for a reason.

As I posted, a lot of makers of pistol barrels like short leades/throats etc because it supposedly helps accuracy, dunno. I do know better bores and rifling do. How much a tad more jump affects it I don't know.

Again, interested in the outcome.

 

[DBEAM]

Great news!!! Barrel was sitting at my house today. Over all I am happy with FAXON. I will be honest I was starting to cuss them a little and think they were never going to get me my barrel back. That being said I wouldn't have said this yesterday but, praying that the accuracy has held, I would/will buy another FAXON barrel. That being said I would probably check with them first to be sure they think their barrel is built for accepting factory ammo/to the tolerances I'm looking for.

I do want to say that I am impressed with the company, I feel many would have just blown me off. I feel they went above and beyond by fixing my particular problem directly (didn't not make go through retailer or brand) and it did not cost me a dime, not even the shipping.

THE GOOD
1.All ammo now plunks, even my hand loads.
2.Head spacing with my bolt appears good, can't push bullet any further with bolt on barrel and slight gap before extractor grabs on way out. (I do not believe head space was ever an issue but it came up in this thread)
3.Compensator had been removed for me and was sent back as I requested, appreciated.
4.10 test rounds of american eagle fired flawlessly and did not stick.

THE NOT PERFECT
1.Slight ding at base of barrel, had to sand it off before it would go in reciever.
2. When looking in barrel I can see coating is gone where leade was extended but i don't see it being and issue, don't see how it could have been avoided.
3.It took 3 months total (wrong I think whole process was more like 2), feels like an eternity when you really want to shoot, and honestly it is a long time.

THE UNKNOWN
1.Have not tested for accuracy
2.Durability
Will update on both.

I want to give a thanks to Nathan for working with me and getting it done.

 

[DBEAM]

Just wanted to update that I think it was more like 2 months and a week after I did the math, not short, but much better then 3 months.

 

[DBEAM]

Have now put 200-300 rnds through the barrel with no issues. I have posted some pictures to give an idea of accuracy. The last 3 pictures are off of a sand bag. I don't think I lost any accuracy from the little I shot it before sending it in.
1st pic 1st 4 shots 115 FMJ AE at aprox 50ft open sights
The rest of the pictures are at 50 yards
2nd pic 17 rnd group of 124 GD 1x4 scope (questioned mount)
3rd pic 17 rnd group AE 115 fmj 4.5x14 scope larue mount
4th pic 17 rnd group 124 GD 4.5x14 scope larue mount
5th pic 5 rnd group 115 AE after scope removed and reattached (same scope setup as last 2 pics)
1st

 

[DBEAM]

Have now put at least 800 rounds of different manufactures ammo, mostly 115 fmj, through the gun with 0 malfunctions. As far as accuracy I had no trouble shooting 6 inch square targets with open sights at aprox 150-200 feet. I think they nailed the angle to put on the feed ramp of the barrel for reliable feeding. I have yet to clean the gun but it does stay pretty heavily oiled. The thing gets incredibly dirty fast but I think the heavy buffer, spring, and bolt keep powering through with no issues.

 

[LiveLife]

Good to hear and thanks for the update.

I am thinking about building an upper with NFA/Joe Bob LRBHO receiver for my NFA/Joe Bob Glock lower and will consider using Faxon barrel.

I have yet to clean the gun but it does stay pretty heavily oiled. The thing gets incredibly dirty fast

Most blowback carbines will get dirty even with clean loads. I usually run my carbines on the dry side.