Old thread reposted from RFC. This one is "Chrono info and diff between short and long barrels"

[Kisssofdeath]

The original post was 4/6/19.

Well, finally got to get my data together for the CZ lineup of rifles I have. I will summarize the report first then show all the data for view.

Only two types of ammo was used for this comparison. Thirty rounds each of CCI SV at 1070 fps advertised and CCI AR Tactical at 1200 fps as advertised. Same lot number was used in the SV test and the AR Tactical was all the same lot number. I have included the SD value also for those interested.

Four CZ 452 rifles were used, all having different barrel lengths.

Highest average velocity with the CCI SV is as follows.

1. 452 American TB Barrel length 17.25" --1093.6 fps
2. 452 American Barrel length 22.5" -------1086.5 fps
3. 452 Varmint Barrel length 21" ---------- 1085.3 fps
4. 452 Ultra Lux Barrel length 28.75" ------1068.6 fps

So as it appears the lower velocity ammo is burning all its powder within the 17.25" barrel and anything longer "that I have" is only slowing it down. Now let's compare the high velocity AR Tactical ammo.

1. 452 Varmint at 1258.5 fps
2. 452 American at 1254.1 fps
3. 452 Amer TB at 1251.8 fps
4. 452 Ultra Lux at 1249.9 fps

It appears the 21" barrel is optimized for this ammo.

Highest velocity average with both ammo together is.

1. 452 Varmint at 1174.6 fps
2. 452 Amer TB at 1172.7 fps
3. 452 American at 1170.3 fps
4. 452 Ultra Lux at 1159.3 fps

So what have we learned?

1. A longer barrel length doesn't always mean a higher velocity.
2. The 21" barrel is optimal for the HV ammo.
3. The shorter 17.25" barrel is faster with both ammo than the longer 28.75" barrel. I am losing right at 1 fps for every inch in the Ultra lux barrel.

I have plenty of both ammo left. Next I will test both in my 10" barrel Anschutz Exemplar and my 10" TC Contender. It will be interesting to see where the velocity is between the two but more so with the 10" barrels compared to the Ultra Lux's 28.75" barrel.

Ok, here is the snip photos for each rifle.

More data coming soon.

 

[Kisssofdeath]

Original post was 5/3/19.

I don't know of a way to upload a spreadsheet either. I just use the MS Snipping Tool to capture my image.

Here are some other data from my 10" barreled Anschutz Exemplar. Since the CCI SV ammo slowed down so much out of the Ultra Lux barrel I wondered how far behind the FPS would be out of the 10" barrel.

The velocity FPS didn't surprise me but the SD sure did. This is the same LOT ammo I have shot for months and the same used in all the CZ test. Same for the AR Tactical.

 

[srt-4_uk]

Without using the same barrel and cutting it down, the comparison is kinda pointless. The velocity differences theybare seeing can be barrel specific instead of length specific.

 

[Kisssofdeath]

Without using the same barrel and cutting it down, the comparison is kinda pointless. The velocity differences theybare seeing can be barrel specific instead of length specific.

LOL. that's something a "clique" member on RFC would say. Don't read any more into it that what it is.

I never once said this applies to all rifles ever made; nope never said that. I simply made a comparison with 4 of my rifles with different barrel lengths and one handgun and posted the results. The discussion at that time on RFC was what's the optimum barrel length to get the highest velocity out of SV ammo. People said this, some said that and I said to myself, "I'll just do a test since I have everything to do it with and we will see."

Maybe you would like to run your test with your rifles and post the results?

 

[srt-4_uk]

In your "what have we learned" it should say "what applies to my 4 rifles, ymmv."

 

[Kisssofdeath]

In your "what have we learned" it should say "what applies to my 4 rifles, ymmv."

Ok, that's fair enough. I can "somewhat" see your interpretation of what I said could have been meant for the rimfire world in general, however that was not my intentions. By using the word "The" instead of "A" should have indicated I was referring to my rifles and no one else's.