need some help in imi 77gr and wide velocity range

[tucaz]

i have a BA 18” barrel that has a 158fps spread using a garmin xero. imi razor core from 2016 lot. i did 27 shots with:

2848fps high
2684fps low

can a shitty barrel do that? even his Douglas seems extreme and thats no shitty barrel.
garmin problem?
what other info do we need here?
i chrono’ed my buddys douglass barrel and his had a 95fps spread.
2837fps to 2742fps over only 5 shots.

 

[Kopfjager1]

I had similar results in pretty much every barrel length.
11.5": 2498 FPS, SD 30ish ES 119
16": 2744 FPS, SD 22 ES 78
IMI Mk262 just has really high ESs.

 

[Zak Smith]

Some lots of it are very consistent. Some are all over the place.

 

[Darryle]

Have you tried this ammo in another barrel?

I keep 2 factory loads for benchmarks, 69gr FGMM SMK and 69gr Lapua Scenars, not only do they set an accuracy std, they are generally fairly stable velocity wise.

I have tried the AAC, Ammo Inc, Nosler, Norma and Remington and they run all over the map.

 

[roostercogburn98]

I’ve shot 77g razorcore in 3 different rifles, all had wild ES. I might have the numbers saved but they were shot from

-18 inch bartlein on gas gun
-22 inch bartlein on bolt gun
-16 inch factory scar 16

 

[tucaz]

Some lots of it are very consistent. Some are all over the place.

this lot was from 2016. i have some from 2013, 2014 and 2023 that’ll give a try

i never really noticed the inconsistency much in the past when i was only shooting out to 300-400 yards but recently started reaching out to 500-600 and noticed the inconsistency in impacts.

 

[tucaz]

Have you tried this ammo in another barrel?

I keep 2 factory loads for benchmarks, 69gr FGMM SMK and 69gr Lapua Scenars, not only do they set an accuracy std, they are generally fairly stable velocity wise.

I have tried the AAC, Ammo Inc, Nosler, Norma and Remington and they run all over the map.

i have but just recently got the chrono so its a new game for me.

i shot a short string through a LWRC 16” with a spread of 46fps but was only 5 shots so guessing that was obviously not enough for it to show its true colors.

 

[roostercogburn98]

i have but just recently got the chrono so its a new game for me.

i shot a short string through a LWRC 16” with a spread of 46fps but was only 5 shots so guessing that was obviously not enough for it to show its true colors.

My experience is it still groups and shoots fairly well. I have taken it out to 600 with my 18 inch gas gun and 22 inch bolt gun

 

[JerkyFreak]

But.... how does it shoot?

 

[diggler1833]

.233 is easy to get to shoot well, but surprisingly hard to get low ES and SD from. Combine the latter with mass production that has all of the attention to detail that you'll find in a 2nd grade science project (IMI), and you'll often observe some wild disparities in velocity.

Not the barrels, just the ammo causing this.

0-300 it shouldn't make much difference. Past that (especially 600+) you'll just have to account that your vertical is going to be about 2 MOA (or a bit more with a 150FPS spread).

At this point, you're probably better off trying a different ammunition.

 

[Ronin22]

With my lots, I am hard pressed to load any better for ES and precision. I bought around the same time, maybe 2015.

 

[powdahound76]

Shot this last week (just realized date/time are off on my Garmin) doing some testing.

Had a separate 15 rd string about the same.

$0.50/rd AAC 77 OTM

 

[tucaz]

.233 is easy to get to shoot well, but surprisingly hard to get low ES and SD from. Combine the latter with mass production that has all of the attention to detail that you'll find in a 2nd grade science project (IMI), and you'll often observe some wild disparities in velocity.

Not the barrels, just the ammo causing this.

0-300 it shouldn't make much difference. Past that (especially 600+) you'll just have to account that your vertical is going to be about 2 MOA (or a bit more with a 150FPS spread).

At this point, you're probably better off trying a different ammunition.

i was looking for some black hills and fgmm but its sold out everywhere on a quick search. will wait around for that

luckily i have 308’s with better ammo so that can scratch that itch. i can stay inside 400 and be satisfied i guess. haha

 

[tucaz]

Shot this last week (just realized date/time are off on my Garmin) doing some testing.

Had a separate 15 rd string about the same.

View attachment 8613699

$0.50/rd AAC 77 OTM

i have some aac 77’s for another rifle but have such a big stock on imi i get to work thru that first.