Not sure why dd would not mark it hpi? My buddy has one, i will ask him if its marked.I too got a bcm at $180, not nickel boron, bout a year ago.....i NEVER see them for less than that. Now that i have some different ones i am always looking for good deals. My findings show good ones on sale around $100, good nb ones on sale around $150. Of course, this deal is sold out.
Yup...good info...spikes is dual marked mp/hp as well if i remember correctly. Those all round out the best ones for any that are interested, or care about that. If you run any of these, your doing fine in my book. I kick myself a little when i think i could have an ar for the money ive spent JUST on upgrade bcg's. Ohh well, i know they should never fail me.....thats what makes it worth it.
Full auto...basically there is more surface area in the carrier portions and they are larger. This makes them heavier, which usually equates to smoother operation. The bolts of all these have been tested, magnetic particle inspected...mpi, and/or high pressure tested...hpt. Either both tests, as in bcm's and spikes. Or just mpi. Either way, it says alot, to me anyway, to have a bolt that has been tested and is marked as such. It is then capable of hard use, if needed, with no worry of failure. Of course the rest of the weapon system needs to be in line as well.
