Home Forums Hunting & Shooting AR and Tactical Rifles 24HC Black Rifle Challenge Thread

That's a Bushmaster barrel, looks like it does good enough. With that group on the right I think I'd have to try the challenge again.

I'll get a target up in the near future.

Put together a new load of 50gr VMax, 24.0 gr Xterminator. Need to test it out so this challenge seems like a good fit.

A bulls bag is legal? I gotta do it again!

I did order a shooting mat that will allow me to load my bipod but it won't be in till next month. what the heck I started shooting pistols and had to buy a timer, then a Dillon, a mat won't ever be noticed.

I'm going to have to give this a shot. Looks like too much fun and I've never shot a 10 shot group with any rifle. I've got to say up front though, I'm one of those shooters that likes to use the whole target. I can't see shooting up only a small part of it, so I go for even coverage…

hmm.. reminds me we are supposed to have a dillon mat around here somewhere too... it wasn't worth a flip for highpower matches but Carolyn loved it cause it was blue... I need to see if I can find it again, would be ideal for this instead of our customized mats....

Confirmed zero with 5 rounds of 62gr barrier, then shot cold no prep. .6mil shift from 62gr barrier to 60gr LimPen.











1st Group- 2.024 inches
2nd Group- 1.718 inches

Average= 1.871 inches



Rifle- SOPMOD BLK II M4A1 with Giessele Trigger and Surfire brake/Suppressor adaptor
Optic- Vortex 1-6x
Ammo- 60gr Limited Pen

So in the interest of discussion, here is a target that I used for zero confirm with the same gun/ammo and model of scope. Four different 5 round groups spread over one month. The end result is that the overall group size for all rounds is about the same as one average 10 round group. I have done this a bunch of times and it's always the same whether it's a bunch of 1 shot "groups" on the same target, a bunch of 3 shots "groups" on the same target, or a bunch of 5 shot "groups" on the same target. The reason for this is simple- statistical relevancy.

It isn't the size of those three or five shots groups that's the issue (it is... but), it's the fact that those three and five shot groups don't land in the same place every time. The whole purpose of " grouping" is to know the size of the cone to allow one to know how accurate that rifle is (hitting targets).


In any case..

1st five (looks zeroed, right?)-





2nd five (notice how the group isn't looking so centered anymore...)-



3rd five (again notice center)-






Last five (





That target compared to the 2x 10 round groups from today.




There is 1/10th of an inch difference between them and it's in the 10 rounds groups favor.




The gun doesn't know whether it's firing it's 1st round, 3rd round, 5th round, or 50th. If a gun is a "sub MOA" gun, then that means that of a sub MOA target is hung not one single round will miss it.

The vortex seems to be holding zero.

Formidilosus,

Nice shooting, nice rifle, and good example of why 3 shot groups don't cut the mustard for this type of shooting. What barrel is on your Block II?


Current Rankings:

Optics:

1) wareagle700: 1.246 MOA
2) BGunn: 1.265 MOA
3)Formidilosus: 1.787 MOA
4) TWR: 2.308 MOA

Iron Sights:
1) wareagle700: 167-0x (3.320 MOA)

wareagle,

It is a standard Colt M4A1 SOCOM barrel with a bit over 6,000 rounds on it. Very near the end of it's service life.









The one that was used for the 4x5 round groups had a catastrophic failure less then a week after the last group.






That is the third 1-6x Razor to do so. We'll see how long the currents one lasts.

You could work that up a bit. X-Terminator always gives me the best accuracy pushed to max. In a 5.56 chamber you can take that load at least 2 grains higher.

I'm hoping to get to the range this weekend, to shoot one of these targets.

You all not going to count my DD barrel/optics 1.25?

I don't doubt it.

I was running 25.0 gr XTerm under the 50 VMax and accuracy was about 1 moa in the Ruger American Predator, and about 1.5-2.0 moa in the AR-15.

I was hoping that dropping pressure a bit might tighten it up, but we'll see. You may well be right in that 26.0+ might be the sweet spot.

Unless I am reading it wrong, I only saw one group from that rifle in your post. You need to average two 10 shot groups and have the appropriate pictures for the entry. Look back at the original post for the format to follow. If you want to enter two different rifles, please make separate post. Thanks!

Wow, I've only heard problems with a handful of 1-6 Razor's and they were all in that post. You either have very bad luck or made an enemy at Vortex.

Negative. The reason that people do not see issues with optics is because-

1) They don't test them for function.

2) They make excuses for why shots miss.

3) They change ammo constantly, always playing and therefore never could notice when POI changes.

And


4) The biggest reason is that very few actually shoot enough for it to matter.




I test optics initially upon mounting by zeroing correctly, testing tracking, return to zero, and drop "testing". I then confirm zero every time the scope is used with the exact same lot of ammo as it was zeroed with and log it. It is obvious when a scope loses zero or fails to adjust correctly.


Seeing as many optics as I do a year, with as many rounds fired... trends show quickly. And it's not just from thousands and thousands of rounds fired either. Lots of scope do not function correctly straight out of the box and/or fail within a few hundred rounds.

Well that sucks, I shot two different rifles, 3 different types of ammunition, 10 shots.If you can shoot a 1.25 inch 10 shot group, that should be "statistically significant". Or I can shoot 5 10 shot groups and throw out the bad ones...

I may shoot 1 20 shot group, will that count?

The rifle is a Rock River Arms lower with a Mega Billet side charging upper. It has a Daniel Defense 16" LW barrel with a 7 inch twist. I have a Leupold VX-3 3.5X10 scope on it using Burris PEPR mounts. The forarm is rifle length made by Troy.

This rifle usually has the first three shots touching or nearly touching. The next two usually make a 5 shot group that measures between .5 and .6 inches. I've never shot it for a 10 shot group before and wasn't surprised when it opened up to around two inches. I don't know if the problem is the barrel getting hot because it is really light weight or not, but I suspect that it might be mostly the shooter losing concentration.



The average group size is 2.02 inches. I'm not surprised or disappointed. I'm also not going to change anything because I look at like the danger zone with this rifle increases as the barrel warms up. I circled the first five shots of each group just to see what happened to the rest of the string as I shot.


Range and Daisy the wonder dog.


Rifle on the bench

Formidilosus,
Got ya. What scopes in the 1-4 and 1-6 range would you recommend?

Jimmy,
I would prefer to stick to the plan as described in the OP. You are welcome to post groups here as much as you want but to be ranked in the challenge your entry needs to follow the guidelines. I wasn't pleased with my entry but I posted it anyway. I'll do better next time, that's what this is for. Print out the instructions and take them to the range if you have to, even I had to look back at them before I shot and took pictures.

Mathsr,
Nice, you should have stay put after the first 5 rounds though, looks like getting out of your shooting position opened up the groups. As well as I know you and know where those groups were shot, I need a picture of the range and calipers over a group for your entry to count.

Thanks.

From page one:


The Rules:
ALL targets must be shot from 100 yards.
20 rounds will be scored, flyers included.
The rifle can be shot from any position as long as the shooter is supporting the rifle. Bipods, slings, and rear bags are ok to use. NO bench rest, lead sleds, or machine rest may be used.
All 20 rounds must be fired on the same day, from the same rifle.
Iron Sights will fire two 10 shot groups at the reduced 600 yard NRA targets.
Scoped rifles will fire two 10 shot groups at the target listed below (different targets are ok, just make sure both groups are on the same piece of paper)
Iron sighted rifles and scoped rifles will be ranked separately.


Please have your post in this Order:

1) Picture of rifle and setup.
2) Picture of 100 yard range.
3) Picture of target (optics) or targets (irons) with 20 rounds through them. (place calipers or ruler laying over one group for reference)
4) Description of rifle and ammo used.
5) For optics, list your group sizes and the average. For Iron sights, please list the group size and score.

Mathsr,


Notice the sift in POI between your two circled 5 rounds groups? It doesn't matter how close together the first five are if those five shift on the target (which they will). If you continued to fire five round groups you can take it to the bank that a 2+/- inch group will appear where those ten rounds groups are now.


To put another way- it looks like the circled five are a bit less than an inch? If you hung a target as big as those five, would you hit it every single time?