6.5 Grendel "progress"

[Former Cav]

I have a GREAT rock river arms AR15 that is a target rifle.
I had it custom built back in 2001 or so for something like 2400 bucks. It has a Krieger barrel, timney trigger, Gehmann Apertures ladder sights, etc.
Any how, I decided to jump on the 6.5 grendel band wagon so I bought a Bear Creek Arsenal upper.
I;'ve put 30 + different loads through it and only a few loads are under 1 inch at 100 yards. Best is 13/16 using Varget which is not really the most recommended.
Anyhow.... I am FIRE LAPPING the barrel and during the course of doing this, I had a real JAM. Had to POGO STICK it hard to get the round out of the chamber.
When cleaning it, I realized the chamber has some machine marks in it. Any ideas on how to SMOOTH that out a little bit. It functions, but I'm wondering if that contributed to that one round hanging up in there.
Tomorrow, I fire the last of 40 rounds with the compound on them, then I will see if I did any good.
If not, I will be ordering out a Kreiger barrel.
Any suggestions on that chamber??
TIA

PS. to read about fire lapping go here
https://www.gun-tests.com/issues/13_8/features/4953-1.html
I bought the kit direct from NECO as Brownells no longer handles it.

[Former Cav]

Ordered the Krieger barrel. they are 3 months out.

[lyman]

Ordered the Krieger barrel. they are 3 months out.

wow,

late to the party, but did you contact bear creek about the chamber??


wondering if a small bit of polishing compound on a tight cotton type swab would help it?

[Former Cav]

no, I figure why bother. I have two other rifles with Krieger barrels and they shoot better then I will ever hold!
Besides, I can use the BCA barrel to show others what to avoid !

[Former Cav]

I finally got the Krieger Barrel. Now to get it chambered and custom fit to the rifle with NO shims.
Will keep you posted.

[Former Cav]

Progress has come to a halt due to far too many OVER 110 degree days here in Phoenix.
Will be starting up soon on this project. Got the chamber cut, have to work up loads again.
If I had it to do over, I would just buy the Alexander arms upper and be done with it.!
this is getting to "NOT be fun" especially since you can only "rent" one hour time at the range due to Covid and gov't rules etc. Cant shoot in the desert or you will start a fire.

[Former Cav]

Have not fired it since then (oct 2020).
We have moved to TX.

[Former Cav]

UPDATE
JUNE 1, 2023
TESTS with Oehler 35P chronograph at B-Tactical in Caddo Mills.
108 Grain Lupua 27.1 grains IMR 4064 EACH round (powder charge) was weighed kept with 1/10 grain.
H 2398, L 2391 A 2394 sprd 7 SD 5
27.8 grains IMR 4064
H 2453 L 2453 A 2453 spred 0 SD 0

110 Lehigh Solid Copper Match 04264110SP 27.1 Grains IMR 4064
H 2371 L 2346 A2360 Sprd 25 SD 10

123 ELD Hornady Match FACTORY LOAD
2505 Had error readings. Lots of “glint” Was shooting into the sun (facing East at 9 to 11 AM)

123 ELD Hornady Projectiles 27.1 grains IMR 4064
H 2365 L 2329 A 2345 spred 36 SD 13

120 SPEER GOLD Dot 27.1 grains 4064
H2311 L 2254 A 2290 spred 57 SD 26

These tests were just for speeds as getting a 3 skyscreen chronograph lined up on a public range with the RIFLE (path of bullet) Chrono, and Target and near impossible.
These loads were SLOW, so I will be doing some "ladder loads" working up the speeds. When I get to where I want them, THen I will be shooting for the accuracy / groups.

[Former Cav]

without going into GREAT detail (about 40 different loads and speeds and stuff) Here is the latest from Mar 28, 2024
I gave up on the chrono (anybody want a good deal on a Oehler 35 P and lives near Dallas TX?) as it is to hard for my old body at a public range to set up the 3 sky screens and line up the rifle and target at the same time, especially when you are alone. I bought a Lab Radar unit and I really like it. That is what was used for these loads below.

3 LOADS… Mar 28, 2024
FACTORY NEMO 120 Gr FMJ BT
H 2596 Low 2515 Avg 2567 Ext Sprd 81 SD 32.8 Not that tight of a group either
TAC by Ramshot powder 27.8 and 27.2 108 Gr Scenar LUpua bullet
27.2 Gr TAC H 2467 L 2336 AVG 2401 Ext SPRD 131 SD 92 cover 4 with a Quarter last one opened up
27.7 Gr TAC H 2452 L 2425 AVG 2438 Ext Sprd 26 SD 13.1  all 5 bullets you could cover with a dime!
2.221 overall length. CCI 41 starline brass 2nd firing cut to 1.510 Palmetto armory rifle w/ 1 in 8 twist SS
Timney Trigger drop in 3 pound pull, Overall length was at 2.220 (with 123 hornady bullets they would have been at 2.260) I never reset the bullet seater die.
Im Happy with the last group but I'd like to get the speed up to about 2600.
If you want to see all of the data, email me back channel and I'll send it to you. cava3r4ATgmail.com (AT is to screw up robots)