It'll just make you more tempted to melt your barrel.
I wouldn't use one unless on an H-Bar .223. It's fun 'cause you can shoot a long time without stopping to reload- but you better be bench shootin cause it's real heavy.
If anybody has a .223 AR I have one NIB with clear back, case and loader, Make you a deal.
Upside - you can keep them loaded forever and they never lose there strength for pushing the bullets up, and they hold alot, I have one on my AR15 pistol, reliable.
down side - weight, wide, cost, and if you don't have brass catcher, a real disapointing reload day, take care from the bear
I have seen them used in 3gun/multi gun matches. Even Jerry Michulek was pictured on a magazine cover using one. They are heavy though I hear well balanced, expensive, and very desired. They are often on backorder.
They DO make a Beta mag for the M14/M1A. Yes, it holds 100rd of 7.62x51
With todays political climate it wouldn't hurt to buy one "just to have". If Hussein rams another assault weapons ban through, (many think he will), they'll skyrocket in price. Just a year or so ago you could buy 75 round drums for the AK-47 for around $75.00. Today they are over $200.00. The biggest issue with the Beta-C Mag is don't drop it. They are plastic and don't bounce too well off concrete, especially when they are full. Bill T.
I own a c-mag for my ar-15 and love it. I purchased it for the BIG DAY. They are expensive but worth it. Not having to reload has big advantages. I have only taken mine out shooting twice. ( Looks goofy at the range). I wanted to test the reliability. Never once jammed. I also like the fact you can keep them loaded forever without wearing anything out. They are great quality. Another nice feature is they are shorter then 30 rd mags so more comfortable shooting from the prone position. I have also shot a c-mag for a MP-5 same results flawless.