My barrel is dead, right?

[milktree]

How was the wind? Most of your groups have more horizontal than vertical. Did the scope have AO and did you set it correctly to dial out parallax (not just to 100 or 200)? Were all screws torqued to spec? How stable is a carrying handle mount? The 1:7 might have been happier with some heavier bullets. (69 Sierra Matchking?) In the summer, I have always been concerned when a round sits in a hot chamber longer than the previous rounds. I think it will cause some of the vertical stringing. Just because a rifle will shoot 1" at 100 does not necessarily mean that it will do 2" at 200 as minor variations tend to multiply not add... Those groups look pretty good compared to the earlier ones. Moving in the right direction.
White Feather

Aw crap, more learning. No, wait... I mean, Oh cool! something new! I didn't know what AO was, so I stuffed "AO scope" into google, and got this:

http://www.pyramydair.com/article/What_does_AO_mean_September_2005/25

Based on that, yes, it does, and it was set to 200Y. It was actually set to 200Y when I was shooting at 100Y, too, because forgot to adjust it. Also, I'm pretty sure I got my eye in nearly exactly the same place each time (which should compensate for lack of AO, right?) by looking at the red/green halo around the bull of the target. I held my eye/head such that the halo was as close to gone as I could make it. That might be one advantage of a sub $2,500 scope

I'm not sure what you mean by "set it correctly to dial out parallax (not just to 100 or 200)", so maybe I didn't use the adjustment correctly.

No wind that I remember.

The carry handle isn't removable, it's a straight A2 upper.

I didn't have a tiny torque wrench when I installed the scope, but I followed the directions as best I could. I'm a pretty good motorcycle mechanic, so I hope I have a good intuitive feel for what torque feels like. Certainly the scope has never come loose or moved in its mounts, and I know I didn't torque it down so tight as to deform anything.

I think I was wrong about the barrel, the interweb I think it's actually a 1:8 twist.

I have some 75 gr HPBT I got from Wideners, I'll do a similar test with some of those, and try some different loadings with the 55gr. next!

 

[white feather]

Setting the AO on the scope to the range that you are shooting gets you close. With the gun steady on the bags, move your head/eye around behind the scope without moving the gun. Turn the dial a tiny bit until the cross hairs do not move on the target as you move your head. When the parallax is dialed out, the distance number on the scope AO dial will be close to but probably not exactly the same as the distance you are shooting.
White Feather

 

[mac1911]

I infer from the above that even with careful load refinement I'm not going to get much better than that from Hornady bulk 55gr bullets. Is that what you meant? Do ladder tests even make sense for a .223 heavy barrel? (more of a question for the reloading section perhaps)


What does "hotter" mean in this context? Anything above ambient, or uncomfortable to touch? The above was 20 rounds shot over about 40 minutes, which doesn't seem like it should generate enough heat to make much difference. Am I naïve about that?



Off the bench on sandbags, the rifle wasn't moving at all before the shot. Or at least it wasn't moving to any degree I could see through a 12 power scope; so I doubt it's breath related. I can imagine variations in how the butt of the rifle was supported might change the shape of the group. Fixing that "problem" (not really a problem in the grand scheme) might be beyond my interest for this rifle. If I get a bench rest rifle, that might change

I have loaded a good amount of the Hornady 55fmjbt with several different powders/charges. I wanted the most accurate cheap ammo I could load. Out of all the powders my most consistent grouping out of my 1/8 wilson arms barrel was surprisingly W844 and TAC. I posted a picture in previous post.... thats about as good as it gets with 55 fmjbt for me.
I didnt have any loads with 55fmjbt or any powder or charge that shot groups of more than 2" vs m193/855 all but a few handfulls have been 2" on a good day.

heat can effect every gun differently: even the ambient temp or slight changes in metal temp. I have a 1942 SA M1 garand that groups like shit in the summer and shots wonder. give it a 20 degree day in Jan and the groups tighten up. My k98 will after about the 8-10th shot will string up a few inches until about shot 16 or 17 then settles and groups high for the rest of the match... my RRA NM AR will shoot about 10 rounds in a nice little group slow fire @ 10 plus rounds I can expect POI vs POA to shift... pattern so far is it likes to go a bit high and left.
Thing is all of this is only noticeable/measurable shooting from the rifle rest. Heat( ambient) also plays with your eyes. I shoot best in cool air.... this summer heat sucks.

all in all there are much better ammo choices than "nato" when ever I read specs on M855 NATO its never really mentioned "accuracy". I see Velocity, penetration , Function on the top of the list. I couldnt get the link to work but here is a little piece of of a article in shooting illustrated testing m855 ammo I dont expect anything better from m193

M855 / XM855 / SS109 “Green Tip” Ammunition Comparison
Load Muzzle Velocity (fps) Standard Deviation (fps) Smallest Group (inches) Largest Group (inches) Group Average (inches)
Sellier & Bellot SS109 3,006 10 0.57 1.8 1.1
PMC X-Tac Green Tip-LAP 2,899 17 1 1.4 1.1
Prvi Partisan M855 2,944 24 1.2 1.7 1.4
Olympic SS109 2,993 24 0.7 2 1.4
Lake City Arsenal M855
(’11 headstamp) 2,978 25 1.4 2.8 2
American Eagle/Lake City XM855 (’11 headstamp) 2,951 28 1.6 3.2 2.1
Double Tap Ammunition SS109 2,871 28 1.7 3.6 2.6
Winchester M855 2,990 27 2.9 4.4 3.7
All loads tested using a Citizen Arms Eastern Predator 16-inch-barreled Carbine with a Bushnell Elite Tactical 1-6.5X24 mm scope with BTR-2 reticle.
Velocities measured using an Oehler Model 35P positioned 15 feet from the muzzle for 10 rounds per load.
Accuracy testing performed at 100 yards from a prone-supported position for five, five-round groups per load.

 

[mac1911]

View attachment 112907 not bad for 100 yds......

just noticed my crapy software needed fix'n , little better

 

[mac1911]

[video]https://www.youtube.com/guide_ajax?debug_prerolls=false&layout=mobile&tsp=1&utcoffset=-240&app=desktop[/video]

When I started installing scopes on my pellet guns I learned a lot about scopes.
Theses videos are pretty good. AO scopes you cant trust the markings. They get you close but need tweaking ..... those 75 grainers are those the "mil spec branded match" bullets.

 

[M1911]

I would be perfectly happy with 1.5 MOA at 200 yards.

 

[mac1911]

I would be perfectly happy with 1.5 MOA at 200 yards.

I wish I could hold a 1.5MOA group @ 200 especially off hand!

 

[M1911]

I wish I could hold a 1.5MOA group @ 200 especially off hand!

Offhand is an entirely different beast than off a bench. I was talking off a bench. No way I could hold 1.5 MOA off hand.

 

[mac1911]

Offhand is an entirely different beast than off a bench. I was talking off a bench. No way I could hold 1.5 MOA off hand.

Ok re phrase that.... I wish I could hold 1.5 MOA XTC and off the bench all the time!

 

[rkwjunior]

PPU / Prvi Partizan is terrible ammo if you're expecting reliability/accuracy/safety

In rifles you may get pie plate sized groups at 50 feet

In pistols it will jam constantly

Their hollow point ammo does NOT expand

They have been known to put the wrong primers in ammo (small rifle in a small pistol)

I know of a couple stories of guns blowing up / being seriously damaged from using PPU ammo

avoid PPU / Prvi Partizan, Made in Serbia

I've used PPU alot over the past couple years ,pistol and rifle, have never had a jam, explosion, etc etc. As far as accuracy, i have no idea, i hit the plate most of the time, if i don't it's probably me.

 

[milktree]

[video]https://www.youtube.com/guide_ajax?debug_prerolls=false&layout=mobile&tsp=1&utcoffset=-240&app=desktop[/video]

When I started installing scopes on my pellet guns I learned a lot about scopes.
Theses videos are pretty good. AO scopes you cant trust the markings. They get you close but need tweaking ..... those 75 grainers are those the "mil spec branded match" bullets.

That video link didn't work for me, what're the search terms so I can use youtube's search?

 

[mac1911]

That video link didn't work for me, what're the search terms so I can use youtube's search?

there are few others

Learning about scopes has made me spend to many nights up late looking at the endless info..... parellax is more of a issue up close. It will though help out a little.
get into the different reticles "mil-dot" ect ect you can go a bit nutty. front focal plane, true mil dot, the effect of MagX....yikes

plus you have the scope mounted way up on top of carry handle right.......what do you use for a comb riser?