New CZ 457 24" 1.180 Match Barrel from L3i

[Mark_Dorman]

Alright, we made it out to the range yesterday and got all our data compiled last night.

*Since I get this question all the time: Yes, I shoot at the same range as F-Class John. No, I don't know him, but hopefully will get to meet him one day.

Honestly the barrel didn't seem to hate anything we threw at it. I though we had more Eley left to test than we actually did so the test had a bit less variety than I hoped originally. However, still a decent spread with good data. SD's were very acceptable for most of the ammo and groups were also quite acceptable. The barrel was definitely a huge improvement over the original MTR barrel and we are very happy with the purchase.

Only issue we had was 18/30 rounds of Norma Match-22 fail to eject. Nothing else had Ejecting issues and nothing was hard to feed. I've heard from others that Match-22 can be hard to chamber in some rifles so it might just not be a good ammo candidate for the L3i barrel. The Vudoo didn't like it either and also had FTE issues with it.

Anyways, enough jabbering, here are the results - Conditions: 40 deg F, 2-4mph winds, and rainy.

Ammo Brand	Ammo Series	Lot #	50 Yard Avg (in)	Avg MV (FPS)	Avg SD	Avg ES	Best Group	50 Yard Group 1	50 Yard Group 2	50 Yard Group 3	50 Yard Group 4	50 Yard Group 5
Norma	TAC-22	x	0.299	1062.35	8.9	42.1	0.186	0.345	0.186	0.311	0.26	0.393
ELEY	Tenex	4076	0.305	1104.51	7.5	27.1	0.242	0.365	0.309	0.242
SK	Pistol Match Special	x	0.376	1084.32	9.3	41.3	0.21	0.405	0.412	0.21	0.395	0.458
SK	Standard Plus	21774	0.398	1044.5	7.7	36.5	0.308	0.459	0.32	0.488	0.415	0.308
SK	Standard Plus	24312	0.405	1055.05	9.9	47.3	0.267	0.522	0.267	0.408	0.315	0.513
SK	Standard Plus	21781	0.439	1054.8	9.3	37	0.323	0.455	0.345	0.653	0.42	0.323
SK	Long Range Match	x	0.448	1091.97	9.9	38	0.343	0.539	0.343	0.544	0.37	0.443
SK	Rifle Match	12342	0.454	1024.05	24.4	115.5	0.294	0.345	0.294	0.385	0.601	0.646
Norma	Match-22	x	0.456	1070.48	10.2	52	0.33	0.33	0.403	0.385	0.555	0.609
SK	Standard Plus	21781	0.488	1054.8	9.3	37	0.393	0.594	0.408	0.493	0.552	0.393

 

[Mechdesigner]

@Mechdesigner - could you please confirm the tenon length is 1.195”?
Thank you in advance.

The tenon is 1.195 +\-.001

 

[J_Reacher]

Alright, we made it out to the range yesterday and got all our data compiled last night.

View attachment 8553911
*Since I get this question all the time: Yes, I shoot at the same range as F-Class John. No, I don't know him, but hopefully will get to meet him one day.

Honestly the barrel didn't seem to hate anything we threw at it. I though we had more Eley left to test than we actually did so the test had a bit less variety than I hoped originally. However, still a decent spread with good data. SD's were very acceptable for most of the ammo and groups were also quite acceptable. The barrel was definitely a huge improvement over the original MTR barrel and we are very happy with the purchase.

Only issue we had was 18/30 rounds of Norma Match-22 fail to eject. Nothing else had Ejecting issues and nothing was hard to feed. I've heard from others that Match-22 can be hard to chamber in some rifles so it might just not be a good ammo candidate for the L3i barrel. The Vudoo didn't like it either and also had FTE issues with it.

Anyways, enough jabbering, here are the results - Conditions: 40 deg F, 2-4mph winds, and rainy.

Ammo Brand	Ammo Series	Lot #	50 Yard Avg (in)	Avg MV (FPS)	Avg SD	Avg ES	Best Group	50 Yard Group 1	50 Yard Group 2	50 Yard Group 3	50 Yard Group 4	50 Yard Group 5
Norma	TAC-22	x	0.299	1062.35	8.9	42.1	0.186	0.345	0.186	0.311	0.26	0.393
ELEY	Tenex	4076	0.305	1104.51	7.5	27.1	0.242	0.365	0.309	0.242
SK	Pistol Match Special	x	0.376	1084.32	9.3	41.3	0.21	0.405	0.412	0.21	0.395	0.458
SK	Standard Plus	21774	0.398	1044.5	7.7	36.5	0.308	0.459	0.32	0.488	0.415	0.308
SK	Standard Plus	24312	0.405	1055.05	9.9	47.3	0.267	0.522	0.267	0.408	0.315	0.513
SK	Standard Plus	21781	0.439	1054.8	9.3	37	0.323	0.455	0.345	0.653	0.42	0.323
SK	Long Range Match	x	0.448	1091.97	9.9	38	0.343	0.539	0.343	0.544	0.37	0.443
SK	Rifle Match	12342	0.454	1024.05	24.4	115.5	0.294	0.345	0.294	0.385	0.601	0.646
Norma	Match-22	x	0.456	1070.48	10.2	52	0.33	0.33	0.403	0.385	0.555	0.609
SK	Standard Plus	21781	0.488	1054.8	9.3	37	0.393	0.594	0.408	0.493	0.552	0.393

View attachment 8553912
View attachment 8553914

Can you share your experience with having to modify your optics rail to fit the barrel and headspace (and shims installed) that was used for the above range performance? How does it balance in your stock?

I am really surprised about the SD for the SK Rifle Match, maybe limited to just that lot? All your other SDs for ammo were sub 10 SD. Also SK RM was also the slowest speed recorded. Also, it seemed to open up as the groups went on (based on recorded average group size). The other ammo seemed to have random variance (expected).

Thanks for sharing this info and target photos. Much appreciated as I am a data "whore" and like to analyze performance. I just take it all in, too soon to make any conclusions (of anything, not looking to knock on the barrel, in case anyone is thinking that).

 

[Mark_Dorman]

Can you share your experience with having to modify your optics rail to fit the barrel and headspace (and shims installed) that was used for the above range performance? How does it balance in your stock?

For sure!
The scope rail was a really easy modification. Maybe 5 minutes with a Dremel and one test fit in the middle to check clearance. I didn't spend a lot of time making it super pretty or symmetrical. I'm usually kind of anal about that but was tired after opening up the stock's barrel channel for like 2 hours lol.

I measured out the headspace while installing the barrel and use the 0.004 shim to set it to 0.043". Everything fed really nicely and didn't have any bolt closing issues.

Balance is damn near perfect IMO. The barrel gave it the perfect amount of weight to balance on a bag and feels quite stable. The whole rig now weighs 15.6 lbs (without a magazine) which is a solid weight for competition.

I am really surprised about the SD for the SK Rifle Match, maybe limited to just that lot? All your other SDs for ammo were sub 10 SD. Also SK RM was also the slowest speed recorded. Also, it seemed to open up as the groups went on (based on recorded average group size). The other ammo seemed to have random variance (expected).

For some reason the CZ just doesn't like this lot of SK RM. My Vudoo did okay with it, but it's not a stellar lot there either being outperformed by some lots of SK Std+ and LRM.

 

[J_Reacher]

For sure!
The scope rail was a really easy modification. Maybe 5 minutes with a Dremel and one test fit in the middle to check clearance. I didn't spend a lot of time making it super pretty or symmetrical. I'm usually kind of anal about that but was tired after opening up the stock's barrel channel for like 2 hours lol.

I measured out the headspace while installing the barrel and use the 0.004 shim to set it to 0.043". Everything feed really and didn't have any bolt closing issues.
View attachment 8553956View attachment 8553958

Balance is damn near perfect IMO. The barrel gave it the perfect amount of weight to balance on a bag and feels quite stable. The whole rig now weighs 15.6 lbs (without a magazine) which is a solid weight for competition.
View attachment 8553960



For some reason the CZ just doesn't like this lot of SK RM. My Vudoo did okay with it, but it's not a stellar lot there either being outperformed by some lots of SK Std+ and LRM.

I see that you didn’t just dremel/cut straight across and preserved the outside appearance perfectly, just rounding out for the OD of the barrel! Bravo sir, bravo! I don’t know if I would have thought of that!

Will you have an opportunity to try same ammo out to 100 yards at some point and duplicate the same set?

I am not able to get to a range with 50 or 100 at this time so I live vicariously through others and ask a crap-ton of questions.

From others feedback, they used 0.002” shim to get 0.043” headspace. Just a data point, nothing to note as differences in tolerance of bolt, receiver and barrel tenon can easily vary by a couple thousandths.

0.043 seems the typical happy value to support the various premium ammo.

Thanks again for the info and postings!

 

[Mark_Dorman]

I see that you didn’t just dremel/cut straight across and preserved the outside appearance perfectly, just rounding out for the OD of the barrel! Bravo sir, bravo! I don’t know if I would have thought of that!

Thank you! I try to keep things looking tidy when possible. I was looking at the clearance before I started and realized I could probably get away with it and it worked out well.

Will you have an opportunity to try same ammo out to 100 yards at some point and duplicate the same set?

I am not able to get to a range with 50 or 100 at this time so I live vicariously through others and ask a crap-ton of questions.

I would like to. I don't know when I'll have time to go next, but that is the plan.

I totally understand your situation. I couldn't got for like 2 months because of my work/travel schedule so I'd been itching to get out.

From others feedback, they used 0.002” shim to get 0.043” headspace. Just a data point, nothing to note as differences in tolerance of bolt, receiver and barrel tenon can easily vary by a couple thousandths.

0.043 seems the typical happy value to support the various premium ammo.

Thanks again for the info and postings!

That makes total sense. Leon said "The tenon is 1.195 +\-.001" and mine measured 1.194. If other people have been getting 1.196 then the 0.002 shim would put us at the same headspace. Though my measurement could also be off by 0.001" lol. I didn't feel any issues with the headspace so I'll probably leave it alone for now.