Workbook

LESSON 800: PARTS EVALUATION

(updated 01-15-01)

To comply with the various and sundry laws, some perfectly good original parts must be replaced with US

made parts. Some are excellent, some are pretty pathetic. Additionally, several companies make custom

parts and accessories, and armorer tools. I have made the following reviews as objective as possible,

although I freely admit that if a company makes 9 parts that are crappy, I'm not going to be too optimistic

about the 10

one.

DSA US cocking handle. Aluminum (T7075T6 –very hard) anodized, with plastic knob. Very nicely made.

The hole for retaining the peg is sometimes a bit large and a tiny stake mark on either side will insure the roll

pin does not fall out. While the original Austrian knob is some kind of rubber-like plastic substance, the DSA

is made of a different type of plastic. Subjecting the Austrian to paint curing temperatures (300 degrees F.

for 1 hour) will usually cause it to dry and crack. Subjecting the DSA to 300 degrees for an hour will cause it

to melt. Curing for 2 hours at 200 degrees seems to be the best choice. (Alloy $50, stainless $60)

Schneider Machine US cocking handle. 4140 steel, in the white. Requires using the original plunger and

peg. retaining pin may be slightly tight and require enlarging slightly groove in peg original ones are

probably drilled together. Includes new plastic handle that can handle 300 degree curing or bluing

temperatures. Requires riveting (rivet included. While require a bit more skill to install than the drop-in

DSA unit, this handle offers the gunsmith more options in matching the part's finish to the rest of the gun.

Excellent customer support available.

DSA US muzzle brake, standard. Threaded, excellent, with three ports on either side, somewhat loud.

($25)

DSA US muzzle brake, short. Two small ports on either side, one large cut-out on top. There is no relief

cut on the back of this brake, so it may be difficult to index properly. I lathe counter-bore the brake about

three threads deep so that rather than butting up flush with the shoulder (and not timing to top dead center) it

extends a few threads over the 15mm portion of the barrel and looks neater. Otherwise excellent, particularly

on short barrels. Looks funny on a full-length barrel. ($25)

DSA fake long flashider. Threaded, resembles the Belgium long flashider. Serves no function other than

cosmetics. Looks very nice. ($35)

Hesse Arms US muzzle brake. This is supposed to be a slip fit, but is usually under-size. It looks most like

the original Belgium design with two sets of three small ports, one at 10 and one at 2 o'clock, and set-screws

in place. I think the set screws are ugly. I turn the portion of the brake with the set screws off and solder into

place. Because it is such a tight fit, it tends to prevent solder from flowing well and covering the whole area.

I turn a few shallow grooves in the portion of the barrel that will be under the brake and fill these grooves

with solder prior to pressing the brake on. It can also be threaded 15mm x 1.0 RH (standard HK rifle pitch)

and your barrel threaded the same. There are a few situations where this brake is particularly desirable: it

can be attached without removing the barrel, and it can be welded to the Israel bipod coupler. its the Israeli

bipod coupler well. A major shortcoming is the brake tends to increase felt recoil. I believe this is because

there is a reduced diameter exit hole, which acts as a baffle. I don't think it allows gas to escape fast enough.

I typically bore the exit hole wider like on the original. This CAN be used as an advantage on short barreled

rifles that are gas starved, as the increased recoil impulse can compensate for lost gas pressure. Now offered

threaded.