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Discussion Starter · #1 ·
Got to play around with the chrono today. I only shot 20 of each round. 10 rounds of each @25 yards to get chrono data... and 10 rounds at 100 yards just to see groupings. When I shot for groups, I only had enough time to do ONE ten-shot group for each type of ammo.

For the Bushmaster 450, I was only able to get a 5 shot group because the scope mount came loose and I ran out of ammo before I realized what had happened.

I plan to go back tomorrow to test for more groups on the bench.

Rifle 1: Noveske N4 Light Lowprofile 14.5" Barrel, 1/7 twist barrel, FF forend, ACOG TA-11F







Rifle2: Bushmaster .450, FF Forend, 16" Barrel, Millet 1-4x






Here is the ammo I will be chrono'ing.




Ready to start.




.223 Load4, 69gr Sierra MatchKings, 24.6 gr H-Varget, Lake City 06 Brass, CCI 400 Primer, OAL: 2.25"
Mean Average (feet per second): 2549
High (feet per seconds): 2561
Low (feet per seconds): 2523
Standard Deviation: 15.52
10-shot-group mean diameter (inches): 1.5"



Igman M855, SS109 62gr FMJ
Mean Average: 2909
High: 2930
Low: 2874
Standard Deviation: 17.56
10-shot-group mean diameter: 2.62"



Prvi M193 55gr FMJ, 2007 Headstamp
Mean Average: 3041
High: 3063
Low: 3012
Standard Deviation: 16.19
10-shot-group mean diameter: 2.5"



Prvi .223 75gr HPBT Match
Mean Average: 2424
High: 2510
Low: 2325
Standard Deviation: 73.29
10-shot-group mean diameter: 2.87"



Silver Bear .223, 62gr HPBT
Mean Average: 2822
High: 2869
Low: 2786
Standard Deviation: 25.73
10-shot-group mean diameter: 2.52"



Wolf .223, 55gr FMJ, Black Box
Mean Average: 2872
High: 2914
Low: 2839
Standard Deviation: 36.19
10-shot-group mean diameter: 2.35"



Hornady Bushmaster .450, 250gr FTX
Mean Average: 2097
High: 2162
Low: 1856
Standard Deviation: 96.18
5-shot-group mean diameter: 2.1"
 

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Discussion Starter · #2 ·
The Prvi M193 is good stuff. The brass is nice and shiny and reloads easily. I am even gonna go out on a limb and say the brass on the Prvi is just as good as Lake City.

I was really surprised how poorly the 75gr Prvi did, normally I have really good luck with this ammo.

On the flip side, I have never done better than 3" with Wolf, so getting a 10 shot group under 2.5 inches is quite an accomplishment for me.

All in all they all grouped in under 3" so you really can't ask for anything more than that from a 14.5" Carbine. I cleaned the barrel after each 10 shot group to keep things fair. I was on a bench fully supported front and back with a sand bag up front, and a a small ammo box in the rear (underneath the pistol grip) so there is really no excuse not to get good groups.

I need to take more samples and results are really not conclusive because it was only one sample. Also there was a 20 mph crosswind that was coming and going... it was only 100 yards so the wind probaby did not affect accuracy but it was strong enough to shift my POA. I think the 75gr Privi got a raw deal as there was a lot of wind when I shot it. The Silver Bear had no wind when I shot it. So definenately need more samples, maybe 4 of each. Or even a mean average of one 40 shot group.

For precision work, I don't like the chevron reticle of the TA-11 much, I felt like I could not consistenly get my POA in the right place. The target was all 1 MOA dots, I had no problem seeing it with an 3.5x ACOG, but as mentioned, it was just hard to consistently get the same POA with the chevron. The 1 MOA dot of the Millet was actually better, as all I had to do was paste the 1 MOA dot of the Millet on the 1 MOA dot of the target.

I will try to get some more groupings, hopefully on a non-windy day to really see what she can do.
 

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I agree with you that the m193 prvi is good stuff. It's shot perfectly for me since I've had it, and pretty accurately too. It's my "top shelf" ammo these days :-\
 

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Good rundown, I wish I had more time to take my chrono out and shoot over it. Are those reloads you pet load for the rifle? All in all those are great groups at 100 for a 14.5" gun. I was suprised the wolf did so well.

If i get a chance I will take this 9" gun I have been playing with out and chrono it.
 

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Thanks for posting... yeah, those Privi 75gr results are dissappointing, aren't they?

For your group sizes, what do you mean by "mean diameter"? Was that the diameter of your group, or something else (I understood that you only shot one group of each, right)?
 

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Discussion Starter · #6 ·
Thanks for posting... yeah, those Privi 75gr results are dissappointing, aren't they?

For your group sizes, what do you mean by "mean diameter"? Was that the diameter of your group, or something else (I understood that you only shot one group of each, right)?
I got the idea of "mean diameter" from someone on Arfcom, forgot who. He actually uses "mean radius" though. He picks a point on the target that is the middle of all his shot holes. He then measures the distance of each shot from this center point, then he will average this out to get mean radius. I take it one step further and mulitply the radius by 2 and this gives me the mean diameter, basically your average bullet spread.

It was pointed out the Military uses the "mean radius" method to measure shot groups. Most people consider group size to be the measurement of the largest spread, but what if the spread was 5" but 99% of your shots were within 2"? The largest spread really does not tell you anything, just like 3 shot groups do not tell you anything. Much better to fire off as many shots as you can on one POA and take an average of all those shots. This way all shots are factored in, even "the flyers" reason I double quoted that was because I had one friend tell me "that last shot does not count as part of the group because it was a "flier" hahahahha :D
 

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Discussion Starter · #7 ·
Good rundown, I wish I had more time to take my chrono out and shoot over it. Are those reloads you pet load for the rifle? All in all those are great groups at 100 for a 14.5" gun. I was suprised the wolf did so well.

If i get a chance I will take this 9" gun I have been playing with out and chrono it.
Not really a pet load, but this is my one standard "accuracy" load I use for all my AR's. I don't really load for a particuliar gun, or at least I have not yet.

I have about 5 recipes that I will use from time to time. My other regular load is my "plinking load." 55gr FMJ bullet, 23gr of H335 in any brass case, and CCI 400 primer. It is underpowered for sure, but it cycles in in all my AR's just fine. I see no point in putting wear and tear in the gun for just plinking sake.
 

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According to the data I've been using for 55gr Hornady FMJ and H335, 23.2gr is the max load? And I presume that is for .223 brass rather than 5.56.

I was shooting this combination in the XCR for the first time last weekend, and the hottest load I tried was 22.8gr. Wouldn't 23gr be at or near max especially with 5.56 brass?
 

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Thanks for posting... yeah, those Privi 75gr results are dissappointing, aren't they?

For your group sizes, what do you mean by "mean diameter"? Was that the diameter of your group, or something else (I understood that you only shot one group of each, right)?
I got the idea of "mean diameter" from someone on Arfcom, forgot who. He actually uses "mean radius" though. He picks a point on the target that is the middle of all his shot holes. He then measures the distance of each shot from this center point, then he will average this out to get mean radius. I take it one step further and mulitply the radius by 2 and this gives me the mean diameter, basically your average bullet spread.

It was pointed out the Military uses the "mean radius" method to measure shot groups. Most people consider group size to be the measurement of the largest spread, but what if the spread was 5" but 99% of your shots were within 2"? The largest spread really does not tell you anything, just like 3 shot groups do not tell you anything. Much better to fire off as many shots as you can on one POA and take an average of all those shots. This way all shots are factored in, even "the flyers" reason I double quoted that was because I had one friend tell me "that last shot does not count as part of the group because it was a "flier" hahahahha :D
Well, this is an interesting idea, however... I believe you would have to do some sort of weighted calculation to determine the "center" for this to really be accurate.

Also, personally, I've always considered shot groups in the same light as "a chain is only as strong as its weakest link" type thing. I always measure my groups in terms of extreme spread. If one flyer made the group a lot bigger, I do make a note of it. I will, however, average the extreme spread of a number of groups for a load I like to get an overall idea of how it performs, which might be similar to what you are doing.

I agree that 3 shot groups are useless. I like at least 5; preferably 10. My first three shots this past weekend with one load were all touching. I was getting excited there for a minute. It was back to "normal" size after 12 rounds. :(
 

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Discussion Starter · #10 ·
According to the data I've been using for 55gr Hornady FMJ and H335, 23.2gr is the max load? And I presume that is for .223 brass rather than 5.56.

I was shooting this combination in the XCR for the first time last weekend, and the hottest load I tried was 22.8gr. Wouldn't 23gr be at or near max especially with 5.56 brass?
I see guys that are loading 24.5 or 25 gr of H335 with 55gr bullets and LC brass. I backed off 2 full grains at 23 to start and since it has been good to me, kept at this weight. I took the chrono and it is only about 2800 fps out of my 14.5" Noveske, compared this to standard M193 with 55gr bullet that goes 3050. The Sierra .223 spec sheet I got off the web list 25.7 for the max for their 55gr bullet with H335.
 

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Discussion Starter · #11 ·
Well, this is an interesting idea, however... I believe you would have to do some sort of weighted calculation to determine the "center" for this to really be accurate.

Also, personally, I've always considered shot groups in the same light as "a chain is only as strong as its weakest link" type thing. I always measure my groups in terms of extreme spread. If one flyer made the group a lot bigger, I do make a note of it. I will, however, average the extreme spread of a number of groups for a load I like to get an overall idea of how it performs, which might be similar to what you are doing.

I agree that 3 shot groups are useless. I like at least 5; preferably 10. My first three shots this past weekend with one load were all touching. I was getting excited there for a minute. It was back to "normal" size after 12 rounds. :(
Thought about graph paper, where you calculate the X and Y axis of each bullet hole, then you take the average of that and that gives you the center ;) But I think that will be a waste of time as I believe just visually observing where the center is and picking it will be within 99.9%. Even if you are off, the other bullet holes will be off too, because you are measuring all bullet hole radius from this center, not just one.

I think including the max spread data is valid though and I will include that next time.
 

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These load data discrepancies are the reason I would like to get a chrono... for me it would be another factor to consider when looking at the discrepancies in load data that I seem to see all the time. Everyone on the internet shoots hotter loads than I do, heh...
 

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Discussion Starter · #13 ·
These load data discrepancies are the reason I would like to get a chrono... for me it would be another factor to consider when looking at the discrepancies in load data that I seem to see all the time. Everyone on the internet shoots hotter loads than I do, heh...
A chrono really only tells part of the story. The real story is the CUP pressure measurment, that there tells how hard your receiver is working by the built up pressure; but there is no way to measure this so we have stick with a combo of velocity and PUBLISHED data. Certain powders are rated to go higher velocities than others. For a 55gr FMJ, Sierra list the max velocity of 3000 fps for H335, but AA230 can go 3100.

I figured if LC brass got 3050 staight from the factory, and now my reloads are getting 2800 out of that same brass with basically the same 55gr bullet, then I am good to go pressure wise.
 

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I love my Wolf ammo ;D , never been a disappointment for the price.

Thanks for sharing! Any reason why the prvi match ammo grouped so poorly?
 
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