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Posted: 7/27/2014 6:41:19 PM EDT
| Went to the range yesterday with my new 5.45x39 build. Got set up, first 5 shots go bang. 7th or 8th shot click. Cleared round, click again, cleared round, goes bang then click again. Cleared rounds looked like bad primers or light strikes. Worked action several times, changed to new box of ammo, 4 rounds pop then same thing. Switched rifles to a new Saiga I had converted to test ammo and it ran like a champ. By now I'm guessing that the problem is the plastic trigger group that came with the lower when I bought it. I had already changed out the stock hammer spring to a Wolff heavy duty spring because I'd read about regular springs not being able to ignite the primers on surplus rounds. I decided to try the AR one more time, (as many of the old hands around me opined I was just having break in issues), when again I got another FTF, but this time bolt was jammed closed. Range guy came to the rescue with a hammer and rod. Hammered my new Spikes bolt back, and out came the case along with spilling powder, and the bullet remained jammed in the barrel. Tapped out the bullet with the rod, and upon examination case and bullet appeared normal. Ammo is regular 60 grain Wolf. Upon closer examination of one of the rounds I thought was a light hammer strike it appears the bullet is not seated fully in the casing. I'm wondering is this something that happened in the chamber? I didn't headspace the rifle when I built it, as I'd read that on AR's this is not necessary. Could this be the result? |
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Quoted:
You may have a couple different issues going on. First off, you need to make sure the chamber, barrel, and headspace is correct. Obviously, this is a big deal. Once you verify the headspace, then you will probably want to get a steel trigger group. These answers given are correct. First, verify headspace (as was said). There are at least 2 standards used in 5.45 AR bolts- these affect headspace. And, a good FCG will help, but a good FCG will not make up for bad headspace. And clean and check the chamber. I have not had any problems popping primers on Wolf 5.45 ammo, but the last crate of 7N6 has offered up a few dud primers, totally inert- also a few rounds are not proper dimensions and jam in my chambers. Never had this problem in the first 8 cans, this last can must have been loaded after a major holiday of heavy drinking, the stuff in this can looks fine, just very poor QC. Don't give up on that build, it just needs tweaked- you should enjoy it once the bugs are worked out. |
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Where did you get your BCG and barrel from? There are a couple different standards, and they won't play nice with each other. See the headspace section of the FAQ from Ballistic Advantage here: http://ballisticadvantagellc.com/?page_id=692 |
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I have built nearly a dozen 5.45 AR's over the years, and have suffered from just about every ailment one can find. In order to keep one running optimally (like an AK) there are several "tweaks" one should make when building:
• Mil-spec fire control group • Heavy hammer spring • Enhanced firing pin • Hardest available extractor • Extra Power extractor spring None of the above enhancements will overcome crappy ammunition or magazines, but if the cartridge is capable of detonating and has a sufficient powder charge, the above enhancements will ensure the rifle runs reliably. |
| I've had good primer ignition on surplus 5.45 ammo using stock GI triggers with a heavy spring, GI triggers with stock springs and a bobbed hammer, and with various unmodified two stage triggers from RRA and Geissele. Anything using a GI trigger will have an occasional failure to ignite (very rarely though). The two stage triggers have given nearly 100% ignition. |
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I have a BA barrel & Model1 5.45 bolt machined to the proper depth to work with the BA barrel. This in combination with an SSA trigger.
When I first built the rifle I had an enhanced firing pin in it and was getting light strikes. I swapped it out for a stock firing pin and it runs like a champ now. It's all trial and error. |
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