User Panel
User Panel
User Panel
LA, USA
|
Posted: 4/24/2024 10:31:58 PM EDT
[Last Edit: Cajun_Redneck]
This question is mainly for those that shoot XTC matches or other experienced loaders.
Loading up for an upcoming match. Been running LC brass with 24gr of R15 with 77 and 80 smk’s for years. Heck, I’ve ran 24.8 with 77’s Not running 80’s this time and going with all 77 Problem is I don’t have enough 400 primers to load all 200 So I’m going with the 450 primers No time to rework for accuracy and I’m 100% confident my rifle will run them safely with the 450’s Question is, how much would you back off on the charge and not lose too much velocity? 24gr gets me 2800 fps with 400’s and 13.3 moa at 600 yards from a 200 yard zero |
|
|
|
Posted: 4/24/2024 10:59:10 PM EDT
[#1]
No reduction. Send it.
|
|
|
|
|
Posted: 4/24/2024 11:04:23 PM EDT
[#2]
I never found it to make enough difference to matter. Especially with the slower burning powders.
|
|
|
|
LA, USA
|
Posted: 4/24/2024 11:07:47 PM EDT
[#3]
Quote HistoryOriginally Posted By HighpowerRifleBrony: No reduction. Send it. My first thought as well. And I was hoping you would respond |
|
|
LA, USA
|
Posted: 4/24/2024 11:10:18 PM EDT
[#4]
Quote HistoryOriginally Posted By ar_mcadams: I never found it to make enough difference to matter. Especially with the slower burning powders. Thanks. I’ve never compared them on a chronograph Typically ran the 450’s with blc2 and 55 fmj |
|
|
IA, USA
|
Posted: 4/24/2024 11:24:27 PM EDT
[Last Edit: Urimaginaryfrnd]
[#5]
There’s a thread about the difference between CCI 400 and 450 primers on Snipers Hide. (Short version):
AR-15 ammunition with spherical/ball powder calls for a magnum primer CCI 450 450 Cup thickness 0.025 In a bolt gun with extruded powder CCI 400. 400 Cup thickness 0.020 Floating firing pin guns or ball powder = magnum primers only. (Who Knew…..) I know this doesn’t fully answer your question because loads are worked up starting low and increased while looking for sign of pressure. That said If you have been loading 24.0 RL15 I would stay at 24.0 based on the following: https://www.ar15.com/forums/Armory/White-Oak-Precision-s-handloads-for-National-Match-223-competition/42-509715/?page=1 |
|
|
|
Posted: 4/24/2024 11:57:01 PM EDT
[#6]
If you run full 5.56 pressure with 400’s, it’s just a matter of time before you pierce primers.
Switching to 450’s never changed velocity for me. 450’s for all things 5.56. |
|
|
|
|
Posted: 4/25/2024 6:57:56 AM EDT
[#7]
i have made my life simple, I only use CCI 450 for rifle loads. I have small rifle primer brass for everything.
|
|
|
|
|
Posted: 4/25/2024 7:02:05 AM EDT
[Last Edit: LeadBreakfast]
[#8]
Having used both when availability made it a necessity, I never saw any difference in velocity. If it is safe with a 400 a 450 will be good to go. However, don't move from a 450 to a 400 without starting low again and working back up.
450s only for me. |
|
|
|
|
Posted: 4/25/2024 11:48:20 AM EDT
[#9]
OP you indicated you do not have time to rework the load?
Which would be the appropriate thing to do. But, I have always liked CCI 450's over CCI 400. My favorite 223 primers are Rem 7.5 which was born as a Small Rifle Magnum primer way back when, the CCI BR4 in 223 bolt gun with Varget, and the CCI 450 in 223 with TAC and any bullet. There is no formula to figure how to compensate for a change in primers; other than you flat out reworking the load. I am of the firm belief that primers do affect accuracy. And, wholesale change without doing some leg work could be a problem especially at longer distances. |
|
|
|
USA
|
Posted: 4/26/2024 12:10:49 PM EDT
[#10]
I've never noticed a difference. I'd just load up same as always.
|
|
|
|
Posted: 4/28/2024 9:56:36 AM EDT
[#11]
My son drove in a little too late for us to make the match but we were still able to head out to the range. As per some of the comments I am ditching the 400’s and sticking to the 450’s for match loads.
400’s always did flatten flush with the case head but I’ve never had any issues with them piercing. The magnum primers still had the radius edge on them. With all that said I was able to hold moa or better (off a bag) at 200 yards in blistering wind conditions. 69gr smk’s shot as expected with the same load. |
|
|
|
|
Posted: 4/28/2024 11:24:42 AM EDT
[#12]
How much shoulder bump? In my experience 4 thou plus will start to flatten 400s.
|
|
|
|
|
Posted: 4/28/2024 6:39:38 PM EDT
[Last Edit: Cajun_Redneck]
[#13]
Quote HistoryOriginally Posted By HighpowerRifleBrony: How much shoulder bump? In my experience 4 thou plus will start to flatten 400s. I try to hit .002 69 gr is at 2.25” 77gr is at 2.26” 80gr is .008 off the lands and single shot only (I really need a 223 bolt gun) All loaded with 24gr of R15 Edited to add. My hornady full length sizer will only push the neck down .004 at max from my chamber if i bottom it out on the shell holder. I backed it off just a smidge before setting the lock ring and haven’t touched it since |
|
|
|
|
Posted: 4/29/2024 12:23:47 AM EDT
[#14]
Sounds like it's well fit.
Keep some 400s for future workups. When they flatten and/or crater, you pretty much found MAX .223 charge or a little more. |
|
|
|
Win a FREE Membership!
Sign up for the ARFCOM weekly newsletter and be entered to win a free ARFCOM membership. One new winner* is announced every week!
You will receive an email every Friday morning featuring the latest chatter from the hottest topics, breaking news surrounding legislation, as well as exclusive deals only available to ARFCOM email subscribers.
AR15.COM is the world's largest firearm community and is a gathering place for firearm enthusiasts of all types.
From hunters and military members, to competition shooters and general firearm enthusiasts, we welcome anyone who values and respects the way of the firearm.
Subscribe to our monthly Newsletter to receive firearm news, product discounts from your favorite Industry Partners, and more.
Copyright © 1996-2024 AR15.COM LLC. All Rights Reserved.
Any use of this content without express written consent is prohibited.
AR15.Com reserves the right to overwrite or replace any affiliate, commercial, or monetizable links, posted by users, with our own.
