300blk out problems

[thedude824]

Aero M4E1 upper and lower with Ballistic Advantage 8" barrel. Originally ai was setting the VMAX at 2.10" and it jammed into the feed ramps with each round. Im now doing the Vmax 110 grain at 2.20 COAL. Every mag i still get several rounds that jam into the feed ramps and require tremendous force to extract. I thought perhaps it was an overgassing/undergassing issue, but it continued regardless of gas setting. Im using 19.8 grains of H110. I purchased a Criterion 8.5" and I'm going with a fixed gas block, but haven't shot it yet. Is it likely an issue with feed ramps that a better barrel would correct? Noth the barrel and upper have M4 feed ramps. I can't think of anything else? Im using Lancer mags. Gas block is properly placed. H2 buffer with Law Folder. I need 100% reliability from this rifle, so the Criterion makes me feel better anyway. Im using a Rise Armament 535 and a Lantac BCG. I cant see anything wrong with the feed ramps visually. I know BA barrels can be hit and miss so maybe I got a miss. Ideas? Anything else to try? Im going to the range on my next set of days off and I'd love to have a list of possibilities. Thanks all

 

[White_Shark]

Try seating to 2.050” OAL

 

[thedude824]

Try seating to 2.050” OAL

The incidence of malfunctions dropped dramatically when I went from 2.10" to 2.20". You think going shorter might be the solution? It would be easy enough to seat a mags worth at 2.05" and see i guess. I was thinking full mag length at 2.25" might be the solution.
Edit: doing some searching on COAL shows quite a few issues like mine that were solved with a COAL of 2.04-2.05". Thank you. I really thought it was going to be a feed ramp issue.

 

[r.tenorio671]

...straight from AAC, the developer of the 300BLK cartridge...YMMV

 

[thedude824]

Update.. going to COAL of 2.05" completely resolved the issues. So if anyone is wondering.. yes.. 0.05" in seating depth will make the difference between reliable and unreliable function.

 

[Constructor]

There is a difference i feeding when using 5.56 mags and 300 mags also. I use the Nosler 110s, they wont feed from 5.56 mags but will from 300 mags.

 

[thedude824]

There is a difference i feeding when using 5.56 mags and 300 mags also. I use the Nosler 110s, they wont feed from 5.56 mags but will from 300 mags.

Really? I always use the Lancer 556 mags with supers. Ive got Lancer 300blk out mags for subs, but never tried the 110s in them. I never thought to try them. Thank you

 

[Constructor]

Really? I always use the Lancer 556 mags with supers. Ive got Lancer 300blk out mags for subs, but never tried the 110s in them. I never thought to try them. Thank you

Funny I started shooting the 208gr Hornady subs, they worked in 5.56 pmags. Later I started shooting the 110 Nosler and they wouldn't work in 5.56 mags so I purchased 300 BLK mags. The 147s I have will not work in 5.56 pmags either. I 'm sure it's different for different mag brands also.

 

[DHDeal]

I've only been playing with the 300BO for about 6 months or so. Never had a lot of interest in the caliber but then the suppressors arrived....

I always measure my max OAL for every bullet I may use and have on hand, write it down, and then decide how far off the lands I want to load to. That said, I never tried anything but 300BO magazines for the 300BO and both Magpul and Lancer have never failed to feed. I knew it could be a problem as so many mention having failure to feed with this caliber but I just never had an issue with 110/115/125 supers or 190/208/220 subs regardless of 300BO magazine brand.

Try your Lancer (or Magpul) 300BO magazines with the 110's. You may notice your original seating depth will work with them (if you wanted that seating depth for a particular reason that is). I don't measure OAL as my measurements are distance from the lands/jam. It is less than max magazine length so that isn't an issue. Hornady/Sierra/Nosler 110/115/125 grain bullets all work for me.

I will say your 19.8 grain H110 load is spicy but if it works for you roll with it.

 

[Constructor]

When the BO first came out one of the biggest hype/selling points was all you had to do was change the barrel, you could use 5.56 mags. A few years later they came out with BO mags with a change in the front rib.

 

[thedude824]

I will say your 19.8 grain H110 load is spicy but if it works for you roll with it.

Is that considered hot? I saw a bunch of guys saying 20+ grains. Ive never had any over pressure signs. They shoot amazingly well. Despite that fact I'm a snob and want a Criterion barrel so I'll be swapping to that. Hopefully it shoots as well as the cheap Ballistic Advantage barrel did. Chrome lined barrels make me feel warm and fuzzy

 

[the monk]

When the BO first came out one of the biggest hype/selling points was all you had to do was change the barrel, you could use 5.56 mags. A few years later they came out with BO mags with a change in the front rib.

I have never had an issue with factory ammo and magazines in 300 Blackout. I generally always use emags for 300 as they look different and I have a bunch of them but doesn't seem to matter. I have had at least 6 300 blk rifles of various sizes including the OG 9" AAC that I still have. This seems to be a a newer problem, I don't know if it is caused by ammo makers or barrel makers.

 

[DHDeal]

Is that considered hot? I saw a bunch of guys saying 20+ grains. Ive never had any over pressure signs. They shoot amazingly well. Despite that fact I'm a snob and want a Criterion barrel so I'll be swapping to that. Hopefully it shoots as well as the cheap Ballistic Advantage barrel did. Chrome lined barrels make me feel warm and fuzzy

I've seen 296 and H110 data that warm so not necessarily too hot. I was just going off of my experience. I run 19 grains of H110 with 110's and it is warm enough for me and my rifle. I wasn't judging your recipe as it works for you just commenting it would be spicy for me.

Believe it or not, even though my barrel came in a Rainier box (and was chambered by Craddock Precision per the Lore) it is a Criterion. I'm an accuracy for accuracy's sake freak regardless if it's a benchrest rifle, PRS style rifle, or an AR and my little 300BO makes me smile. I've never regretted spending money on good barrels, triggers, stocks, or optics (because I have a problem and know it). Like in cooking, if you start off with good ingredients you are more likely to have a good final product. My one Criterion (or Rainier Ultra Match if you will) is a ringer especially considering the caliber and rifle system.