65 gr in 1/8 twist

[joem]

As a update on my 1/8 twist barrel I loaded up some 65 gr varmint bullets. I varied the charge from min to max, going up .5 gr at a time. HORRIBLE GROUPS, worse than anything else I tried. I'm at my wits end trying to make that thing shoot at good group, (less that 2" @ 100 YDS. Options now include a trip to the band saw, install it in a hyd bender or light the cutting torch.:eek::eusa_wall:

[Hefights]

What powder(s) and charge range are you using? What seating depth? Where did the rifle come from?

[joem]

I bought this upper from a club member that found it was too heavy for him to lug around as he was in quite poor health. I doubt he fired 50 rounds through it. I've tried 55 gr FMJ, 62 gr FMJ, two different manufactures of 69 gr bullets. I've tried AA2230C and some mil surplus. Charges were from the min to max going up .5 gr at a time. Better groups were obtained with 62 gr SS109 and 2 different types Mil surplus powder but I don't have the numbers in front of me. In frustration I loaded up some 30 rounders and 20 rounders and fired as fast as I could one day. Those groups were much smaller and as it cooled off the groups opened up. I've inspected the crown with a 20X magnifing glass. I couldn't see any dings or bad spots. The powder residue on the crown looks equal all around. Seating depth is .010 under max. The reloads are not crimped.

[Former Cav]

not to be a wize guy or anything, but:
How long have you been reloading?
reviewing the basics... did you trim the brass to length and deburr it inside and outside of the neck. (reason I ask, is when I first got started, I did not realize you had to trim the brass and all of the sudden my groups opened way up)
a 1 in 8 twist should be able to handle 69, 75, 77, and 80 grain bullets.
My only "guess" is what you might want to do is buy some Black Hills brand (blue box) reloads in 77 grain and see how those shoot. People have won NRA matches shooting that stuff. See how those loads compare to your loads.
I've been reloading with great success using 77 grain sierra match king bullets, LC and Winchester brass, Small standard winchester brand rifle primers, and 24.5 grains of Varget. (good luck in FINDING varget in this market...which is why I recommend you buy the Black Hills stuff as it is a KNOWN quality)
Of course, all disclaimers apply on the load I sited. Reduce loads 10 percent and work up from there. If your are using CCI 41 primers they are considered to be MAGNUM primers so reduce the load another 10 percent.
Good luck and let us know how this turns out.
HTH
Bob

[Hefights]

Ok, sounds like the barrel is broken in. One more question. Who made the upper? I think that matters. Just my own experience, none of the combinations you report have been the most accurate in my 1:8 upper. I agree with Former Cav, you can try some good quality factory match ammo in 69 or 77 as a control or basis for comparison.

Aside from that, I can only recommend you get some AA 2520 or Varget and try 24-25 grains in a 69 gr Sierra MK. Seat the bullets at "mil spec" length which I think is about 2.26 or 2.25 OAL from memory. (When I did that, my groups tightened up.) If your brass is prepped well and good quality, and your cases or loaded rounds are not suffering from huge runout, you should have accurate groups in a 1:8 barrel.

I can only say from my experience if the rifle will not shoot good quality factory match ammo and/or those reloads with decent groups, something else is wrong.

[joem]

Cav; I've been reloading for at least 20 years. I trim every case as part of the reloading process. By the way I've also tried 75 gr bullets and they were not any better. For primers mostly I use regular CCI small rifle primers or Winchester primers. Neither one is a improvment. Maybe it's a bad barrel. I don't know the manufacture of the upper. If I did I'd send it to them to be checked out.

[Hefights]

Scope? I will assume you have checked sights / optics early on and nothing is wrong there. 20 inch barrel, service rifle configuration, 24 inch bull barrel? Are you not willing to try some factory match loads for comparison?

I'm done asking questions that do not seem to be helping. However, before you cut it up, send it to me. If it is capable of tight groups, I will find it out.

[joem]

I plan on ordering some factory loads just for a test.

[Former Cav]

I plan on ordering some factory loads just for a test.

good idea. Then you will know.
I have two so called match rifles, one is in "service rifle" (a cheap DPMS with target grade upper) configuration with a 1 in 8 twist barrel, and the other is in "target rifle" (Rock River arms receiver but custom built flat top, Gehman apertures etc.) configuration and it is a 1 in 7 twist. With the load of 24.5 grains of varget, small standard rifle winchester brand primers, LC or Winchester brass (I used the NEW winchester brass for the 600 yard line, and the others for 200, 300) and 77 and 80 grain sierra match kings and the rifles shoots better then I can ever hope to hold. Before I got the die set, I was using 69 grain blue box and 77's when I could find them, from black hills and they worked great as well.
If you've been doing it for 20 years, my best guess is that it is going to end up being the rifle. Have you made sure the sights are flopping around in the breeze?
HTH
Good Luck.

[snakehunter]

I plan on ordering some factory loads just for a test.

When I want to test the potential accuracy of a rifle, I use factory loaded Federal match rounds. If it won't shoot those to my specs, I dump it.

[snakehunter]

As a update on my 1/8 twist barrel I loaded up some 65 gr varmint bullets. I varied the charge from min to max, going up .5 gr at a time. HORRIBLE GROUPS, worse than anything else I tried. I'm at my wits end trying to make that thing shoot at good group, (less that 2" @ 100 YDS. Options now include a trip to the band saw, install it in a hyd bender or light the cutting torch.:eek::eusa_wall:

Half a grain per step is a little too much for that small a cartridge. Try .2 grains per step.

[joem]

Got the Black Hills 75 gr Match ammo in so it's off to the range to try them out.

[Former Cav]

good luck. I hope it works out to the way you want it too.
keep us posted.

[Johnny P]

Haven't seen it in so long I don't remember the model, but I bought one of the Colt flat tops with the heavy SS 1-9 barrel. It was shooting everything into 3 - 4" at 100 yards. Looked at the crown and there was a wire edge around half the muzzle. Re-crowned barrel and now shooting into 1.5 - 2" at 100 yards with best loads. Talked to John Feamster and he recommended Sierra .224 55 gr. HP boat tail. This is not a match bullet, but has a very long bearing surface. That was what worked in my rifle, as it shoots .75 -1" with virtually any load with them.

[Pete D.]

A different take on the barrel, the twist and the bullet. I have a Colt Hbar an A2 with a 1-8 twist barrel.
Normally I shoot the Sierra 77s. BUT when I was developing loads years ago, I shot what remains the best 5 shot group that I have ever done with iron sights. It was one half inch. The distance was 100 yards, the powder was 26 grains of Accurate 2460 and the bullet was a 52 grain Hornady.

[joem]

Cut a new crown at 45 degree and now shoots less that 1" @100 yds with 77 ge Black Hills match ammo. When the cutter touched the muzzle it caught on the right side and took a cut off there. Now it shoots !" oe less @ 100 yds from a rest.

[Pete D.]

Very good.

Pete

[Former Cav]

happy to hear it worked out for you.