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  #11  
Old 06-24-2019, 08:36 AM
Rootsy Rootsy is offline
 
Join Date: Feb 2013
Location: Monroe, Michigan
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Quote:
Originally Posted by HighpowerRifleBrony View Post
I think Bullseye shooters can manage that. Heck, they get to use BOTH hands!
Take a look at Saturday’s 80 & EIC scores from Viale in competition tracker and tell me where you think most competitors need to concentrate their training efforts.
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  #12  
Old 06-24-2019, 12:24 PM
Josh N Josh N is offline
 
Join Date: Jan 2019
Location: In my house
Posts: 11
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So, most folks will use 20 round magazines for the the reasons listed. 20 or 30 are acceptable. The rules stipulate that the magazines must be the same dimensions as a 20 or 30 round issued magazine, this actually includes the single round sleds. Polymer or USGI steel or aluminum, your choice.

I also live in the peoples republic of Maryland. Quite simply the laws for magazines in Maryland are stupid. You are not limited on capacity. You can own a magazine of any capacity you want, you just can't purchase it Maryland. You must "take possession" outside of the state. Taking possession amounts to laying your hands on it. Get your mags in VA, PA, or DE; whichever is closest.

For ammo I have been using aquila 62 gr BT for 200 and 300 and the 75 gr Frontier for the 600.

Did you manage to get to the SAFs in Manassas this past weekend?
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  #13  
Old 07-14-2019, 11:30 AM
adv_rider24 adv_rider24 is offline
 
Join Date: Jun 2019
Location: Bowie MD
Posts: 6
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Hi guys. Riddle me this:

Fired some Frontier ammo last weekend and all went well. I then put together some dummy rounds and upon feed testing I was getting bolt overrides.

Test procedure for dummy rounds:

1. Load magazine up with 5 dummy rounds and insert into rifle
2. Lock bolt back
3. Press bolt release (want to eliminate inadvertently short stroking or riding the bolt by manually cycling). Verify round happily chambered.
4. Pull bolt back to eject round and return to step 2 until magazine is empty

On about every 2nd or 3rd round the bolt would fail to strip off a round (often leaving a light scratch) or partially strip off a round and override/crunch it.

I think my test procedure eliminates a true short cycle since I always start from a locked back bolt.

I did observe the above would often happen when there was a small (~2mm) gap between the rear of the case and the magazine feed lip for the round about to be stripped.

This seems to indicate a magazine issue (not enough spring pressure to get the end of the next case up and flush against the feed lip or misaligned feed lips). Highpowerriflebrony did warn about this, but I find it odd that the Frontier ammo worked without issue.

Could the issue be present on my dummy rounds because of longer COL? My dummy rounds were 2.250 (75gr Hornady HPBT). The Frontier ammo I used has a COL of about 2.190. The 2.25 COL fits in the magazines, but not by a whole lot. The rear of the case really has to be at the rear of the magazine, so horizontal alignment issues of the case are exacerbated.

Just trying to figure out what to focus on - magazines or ammo dimensions. I hope it is not a mag issue since getting the 20 rounders (not sold in state) was a bit of a PIA.

Thanks!
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  #14  
Old 07-14-2019, 05:01 PM
VALKRIDER VALKRIDER is offline
 
Join Date: Apr 2010
Location: Ohio
Posts: 418
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2.250 should be ok.That's what we load 77's to for XTC.Did you get some off brand mags that might be tight inside?OKAY brand(used to be NHMTG) mags are the best aluminum GI style mags out there unless you can find some real Colt mags.Brownells are ok also but are slightly tighter inside.Never caused me any issues but I switched to OKAY's because I didn't like how close 77's were to the inside of the Brownell mag.Pmags are legal for competition also.I understand it's a PITA to get mags where you are but trusting your equipment is worth points.Start with the simple things first.I would suspect mag before rifle unless the rifle has had issues before.Good luck .
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  #15  
Old 07-14-2019, 05:50 PM
adv_rider24 adv_rider24 is offline
 
Join Date: Jun 2019
Location: Bowie MD
Posts: 6
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I ended up getting a bunch of new Brownell aluminum mags and a steel mag. Rifle has only 40 rounds through it for barrel break in - no misfeeds or issues with the commercial ammo.

Kind of curious as to why the mags worked fine with the Frontier and not my dummy rounds. I inspected the empty Frontier cases and there were no marks from rough feeding.

Maybe my test for the dummy loads was bad?

I think I might work up a small batch for my next range trip. If I get a failure to feed I'll mark the magazine, switch to a SLED, finish up at the range, then do more testing at home.
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  #16  
Old 07-14-2019, 11:04 PM
HighpowerRifleBrony HighpowerRifleBrony is offline
 
Join Date: Nov 2015
Location: Texas
Posts: 139
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So with 3-4 rounds in the magazine it's overriding? And you see a 2mm gap above the rear of a round that is overridden?


For me it was 1-2 rounds and similar attitude. I found it to be the feedlips too far apart.


Dunno about the factory ammo running fine. May be just the recoil and vibration of firing help the rounds move up.
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  #17  
Old 07-15-2019, 01:09 PM
champ0608 champ0608 is offline
 
Join Date: Sep 2010
Location: Arizona
Posts: 90
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If your dummy rounds aren't full length sized they could be a little wide for the magazine. I've seen that in different style rifles.
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  #18  
Old 07-16-2019, 04:50 PM
adv_rider24 adv_rider24 is offline
 
Join Date: Jun 2019
Location: Bowie MD
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I did FL size my dummy rounds, so they should be good dimension wise.

So with a 20 round magazine loaded with 5 dummy rounds it would randomly override the 2nd - 5th round. On an overridden round there would be a small (1-2 mm) gap between the top of the case and lower edge of the feedlip.

I'm starting to think the firing of the rifle helps jostle everything into position as suggested and there probably is no problem.

For fun here is the feedlip gaps I measured with calipers. I measured gap at the rear of the feedlips:
steel mag: 0.450 (different design than the aluminum mags)
aluminum mag 1: 0.460
aluminum mag 2: 0.462
aluminum mag 3: 0.458
aluminum mag 4: 0.460

Overall the aluminum mags were way more consistent than I would have guessed!

Hope to get some time this weekend to try some loads out.

Thank you all for the tips!
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