I am new to ar's and conversion kits, so I have a stupid question: when I put the dpms conversion in my upper, there is a gap between the bolt and the new chamber face. This is not good right?? it seems as if the whole contraption is slightly too long because as I close the upper to the lower, the carrier is pushed forward about 5 millimeters to create the gap. there do appear to be some screws at the rear of the carrier and it appears that it may be able to adjust the length a little. should I try to do this?? there were no directions with the kit. any help would be greatly appreciated!
The unit is simply a Colt unit with the fake 223 shell at front removed, with the .450" dia hole left in the doughnut... this doughnut slips over the tail of the barrel....
With the unit out of the firearm.... the bolt sits flat on the doughnut .... right.
When you install unit to the upper and onto tail of the barrel, close the upper. Now look inside, look through the magwell and see if the bolt face is sitting flat to the end of the barrel (barrel might be sitting beyond doughnut slightly)... and have a slight airgap to the doughnut..
This is fine, as it is just a slight pre-load on the recoil spring. You should be fine.
Whatever you do, DO NOT TAKE APART the unit... there is a recent topic burried here in the last week or so.