Figuring out a new Faxon barrel

[Pappabear]

I recently acquired a used Burris 1-8 scope. I set it up on a 11.5 Sionics barrel with AAC can and it was pretty sweet. But I really wanted to run the scope out at distance and 11.5 is not ideal.

Therefore, I bought a new Faxon 16 inch 1/8 barrel new in wrapper off EE. Upon delivery, the fit and finish was very nice and the profile was super thin. I bought an SLR GAS block, geissele 15 rail and had a spare LMT MARS lower with SSA Trigger.

I took my new beloved rig out and drove the time proven load of 77 grain SMK and TMK. Well well well,
With the suppressor it offered up 5 inch groups, without 4 inch groups. We shot multiple groups thinking no way. But it was consistent.

I contacted Faxon and they suggested 60-70 grain bullets. The following week, with little hope any barrel is going to shoot lighter bullets to any satisfaction, the gun grouped 1.5 and one moa group. The 62grain BTHP shot 1.5 and some other load I had shot MOA. Mark may remember the load.

I forgot to take 69 grain SMK's. Range report to follow from this Sunday shoot.

Very strange, I wish it shot 77's well, it was built for distance.

[joeg26er]

Is this faxon 1/8 twist?
I've had similar issues with another 1/8 twist
Any heavier than 62g the group opens up
I've heard of folks who have around moa
Group with 1/7 twist 11.5 barrels using 77smk

[Pappabear]

I have every possible size barrel in 1:7 , 10.3, 11.5, 14.5, 16 all group moa with 77's. I was shocked when this 16 inch barrel shot atrocious with SMK 77's.

I am hopeful to get SMK 69's to cruise with this barrel. That would suffice me. I've never seen any barrel close up groups THAT MUCH by dropping a few grains off the BULLET.

I not super impressed but I'll live with it.

[joeg26er]

hmmm - looks like I'm going to cross off any 1/8 twist barrels from my future builds...sigh

[fledge]

I would contact Faxon on this. Something besides twist rate is off. They should stand behind a new barrel.

I shoot 77gr TMK and OTM with a 1:8 twist rate match barrel from another manufacturer and it is sub-Moa at 100yds.

Twist rate isn’t causing the problem.

[Pappabear]

I contacted them and they said shoot 60-70 grain bullets. Seems strange even if they are right. I agree 1/8 isn't the issue.

PB

[joeg26er]

I have every possible size barrel in 1:7 , 10.3, 11.5, 14.5, 16 all group moa with 77's. I was shocked when this 16 inch barrel shot atrocious with SMK 77's.

I am hopeful to get SMK 69's to cruise with this barrel. That would suffice me. I've never seen any barrel close up groups THAT MUCH by dropping a few grains off the BULLET.

I not super impressed but I'll live with it.

Just to reduce any wild cards, Got any factory ammo to run through it? I am assuming you are using custom loads since you referred to "proven loads"
I would be interested to hear how faxon treats you on this
I am looking at a pencil or gunner for my next build...

[joeg26er]

I contacted them and they said shoot 60-70 grain bullets. Seems strange even if they are right. I agree 1/8 isn't the issue.

PB

Hmm- I missed that. So they ARE saying their 1/8 will NOT group rounds over 70grain? Ouch
What exact barrel is this?

[Pappabear]

Just to reduce any wild cards, Got any factory ammo to run through it? I am assuming you are using custom loads since you referred to "proven loads"
I would be interested to hear how faxon treats you on this
I am looking at a pencil or gunner for my next build...

I'm taking the trusty Black hill next week, just to do so. Not positive which barrel, but it's skinny skinny skinny

PB

[1168]

Could be useful:
https://www.m4carbine.net/showthread...Ammo-Selection

I’ve read that when manufacturers label a barrel twist, there can be a fudge factor one way or the other. Don’t remember where I saw that or what the reason is. Perhaps your 1/8 is actually 1/9; you could measure it with a twisty cleaning rod and jag.