Seems like there have been quite a few recent posts by new members asking about SL8 to G36 conversions so I thought I would write a comprehensive thread on what people should know. This is going to be a long one so grab a cup of java and have a seat...
THIS THREAD ASSUMES THAT YOU ALREADY KNOW THE FUNDAMENTALS ABOUT THE VARIOUS FACTORY G36 MODELS. IF YOU DO NOT, PLEASE VISIT "THE WORLD OF HK" FOUND ON THE HKPRO HOME PAGE.
DISCLAIMER: All of the information covered here, to the best of my knowledge, is within Federal guidelines. State laws may vary and as such, I strongly recommend that you contact your State Police for specific laws and restrictions imposed by your state.
Ok, let's get started...
Over the years there have been many SL8 to G36 conversions. Some are very popular while others are simply single instances of creativity to accomodate one's particular tastes or to satisfy varying state laws. This thread will cover what I believe are the three most popular.
CONVERSION TYPES (folding stock attachment)
1) Probably the most popular and highly regarded (and most expensive) is the one that myself and member Tbostic do where the back section of the SL8 recevier is precision milled and the rear-stub of a demilled G36 is plastic welded (and reinforced with a steel plate) to the SL8 recevier. This process is very time consuming and extremely technical. It is not for the average do-it-yourselfer. To comply with Federal Law, the rear of the SL8 receiver is carefully trimmed off around the s/n plate as never to detach it from the receiver. This conversion style does require the recevier to be refinished during the conversion process. If you are on a budget or do not like the idea of having your receiver refinished, then this conversion style is not for you. The end result however, is the closest thing you can get to a cosmetically correct civillian-legal semi-auto G36.
For more information on this method, see here...
http://hkpro.com/forum/showthread.php?t=81580
2) The HDPS "stock-block" conversion. The most popular of the stock-block conversions is the one by HDPS. A "block" is bolted to the back of the SL8 recevier to which the folding stock is attached. No modification to the receiver is required. There are two issues (for some) with this method. First, the block adds nearly 2" to the length of the rear of the recevier. Thus when attaching a standard length stock (K or E) the length-of-pull (LOP) is too long for some shooters. To compensate, may choose to attach the shorter C-stock however the LOP is still approx 1/2" longer than that of a spec G36 receiver with standard length stock. If you are after the LOP of a G36C, you will not achieve it with this menthod unless you have the stock cut and shortened. Member Tbostic can shorten a stock for you if you need it done. Second, you can not fire the weapon with the stock folded as the butt-end of the stock partially covers the spent casing ejection port. This method very affordable (in the scope of things) and can be done by the average do-it-youselfer.
For more infromation in this method, see here...
http://www.hdps.org/htm/5-1-1.htm
3) The Top-Notch (TN) "stock-block" conversion. Top-Notch aka Black Market Parts (BMP) aka Special Weapons (SW) was probably the first to come to market with an SL8 to G36 conversion kit. With this method, the pistol grip and stock-block are a single piece. Like the HDPS conversion, it simply bolts to the back of the recevier. The limitation is that the only (unmodified) stock that fits is the one from TN. A factory stock requires modification to fit. Some have claimed that no modification is necessary while other (including myself) have had to. I suspect that it is a result of varying production specs. As with the HDPS method, the weapon can not be fired with stock folded and LOP can be an issue for some shooters. The benefit to this conversion is that it counts as two U.S. made parts (when using the TN stock) for ATF 922r parts compliance (I will cover this later).
For more information on this method, see here...
http://www.shop.black-market-parts.com/product.sc?productId=36&categoryId4
I will not go into details on this thread but I will mention a 4th conversion type by HERA. This is also a "stock-block" method that resembles an AR-style pistol grip with integrated "tube" block to accomodate telescopic M4-style stocks.
CONVERSION TYPES (hi-capacity magazines)
By physical limitation, the U.S. importable SL8 variant (SL8-1 and SL8-6) will only accept single-stack magazines. You have four choices for hi-cap magazines...
1) G36 mags (double-stack)
2) AR mags (double-stack)
3) Promag (single-stack)
4) Magpul (double-stack -- not available till later this year)
To use a double-stack mag, the mag cavity in the receiver must be milled. The SL8 has a large depression on the right side which prevents acceptance of the wider double-stacked mags. This depression is what must be removed (along with other minor milling in the cavity). Milling out of the depression does reduce torsional rigitity of the receiver and exposes a large "window" under the ejection port. There are two methods to address this...
1) Steel reinforce the receiver over the "window" and fuse a cover piece over top. All seams are plastic welded and sanded smooth. This greaty strengthens torsional rigitiy and gives a factory-correct appearance. This method can be used with the G36 magwell or the TN AR magwell adapter (with slight modification).
For more information on this method, see here...
http://hkpro.com/forum/showthread.php?t=112094
2) Epoxy attach a piece of plastic over the window. This method sucessfully covers the window but does nothing for strengthening torsional rigidity. Even with plastic welding the seams, there is a very high probablity that the seams will eventually crack and the cover plate may come loose.
NOTES:
- The TN AR magwell adapter has an integrated "window" cover. It does not add strength but does do a good job of covering the window (assuming the depression was milled correctly). When using either of the above two methods, the integrated "window" cover can be milled off without affecting function.
- G36 mags are wider than AR mags. It is possible to mill the cavity for use with G36 mags and attach the TN AR magwell adapter. While many have had sucess with this, I do not recommend doing so. If you plan to use AR mags, the cavity should be milled accordingly.
- Worn out AR mags or those with weak springs have a tendency to mis-feed or cause problems with the last-round bolt-catch.
- Use of the 20rnd Promag does not require receiver modification as it is a single-stack mag designed to be ussed directly in the the SL8.
More information on the 20rd Promag can be found here...
http://www.promagindustries.com/ProductDetails.asp?ProductCode=HEC-A6
- If you use double-stack mags, you have to replace the SL8 bolt-head with a G36-style bolt-head suited for feeding double-stack mags. The SL8 bolt-head will not feed double-stack mags.
FIRE CONTROL GROUP (FCG)
There is much debate on whenther or not it is really necessary to install the SL8 FCG into your conversion. I won't go into detail as I do not wish to re-stir this debate, however please note that certain parts of the G36 FCG are considered machine gun parts. As such, I very strongly recommend that the complete SL8 FCG be installed into your conversion.
BARREL AND OVERALL LENGTH
For Title-1 status, Federal Law requires that the barrel be no shorter than 16" and overall length be no shorter than 26". When doing the G36 rear-stub conversion method, the receiver is shortened slightly. Therefore, with this style of conversion, barrel length must be approx 16.5" which will yield approx 26.1 overall length with stock folded. When doing any of the "stock-block" conversion methods, a 16" barrel will yield greater than 26" overall length with stock folded.
Continued...
THIS THREAD ASSUMES THAT YOU ALREADY KNOW THE FUNDAMENTALS ABOUT THE VARIOUS FACTORY G36 MODELS. IF YOU DO NOT, PLEASE VISIT "THE WORLD OF HK" FOUND ON THE HKPRO HOME PAGE.
DISCLAIMER: All of the information covered here, to the best of my knowledge, is within Federal guidelines. State laws may vary and as such, I strongly recommend that you contact your State Police for specific laws and restrictions imposed by your state.
Ok, let's get started...
Over the years there have been many SL8 to G36 conversions. Some are very popular while others are simply single instances of creativity to accomodate one's particular tastes or to satisfy varying state laws. This thread will cover what I believe are the three most popular.
CONVERSION TYPES (folding stock attachment)
1) Probably the most popular and highly regarded (and most expensive) is the one that myself and member Tbostic do where the back section of the SL8 recevier is precision milled and the rear-stub of a demilled G36 is plastic welded (and reinforced with a steel plate) to the SL8 recevier. This process is very time consuming and extremely technical. It is not for the average do-it-yourselfer. To comply with Federal Law, the rear of the SL8 receiver is carefully trimmed off around the s/n plate as never to detach it from the receiver. This conversion style does require the recevier to be refinished during the conversion process. If you are on a budget or do not like the idea of having your receiver refinished, then this conversion style is not for you. The end result however, is the closest thing you can get to a cosmetically correct civillian-legal semi-auto G36.
For more information on this method, see here...
http://hkpro.com/forum/showthread.php?t=81580
2) The HDPS "stock-block" conversion. The most popular of the stock-block conversions is the one by HDPS. A "block" is bolted to the back of the SL8 recevier to which the folding stock is attached. No modification to the receiver is required. There are two issues (for some) with this method. First, the block adds nearly 2" to the length of the rear of the recevier. Thus when attaching a standard length stock (K or E) the length-of-pull (LOP) is too long for some shooters. To compensate, may choose to attach the shorter C-stock however the LOP is still approx 1/2" longer than that of a spec G36 receiver with standard length stock. If you are after the LOP of a G36C, you will not achieve it with this menthod unless you have the stock cut and shortened. Member Tbostic can shorten a stock for you if you need it done. Second, you can not fire the weapon with the stock folded as the butt-end of the stock partially covers the spent casing ejection port. This method very affordable (in the scope of things) and can be done by the average do-it-youselfer.
For more infromation in this method, see here...
http://www.hdps.org/htm/5-1-1.htm
3) The Top-Notch (TN) "stock-block" conversion. Top-Notch aka Black Market Parts (BMP) aka Special Weapons (SW) was probably the first to come to market with an SL8 to G36 conversion kit. With this method, the pistol grip and stock-block are a single piece. Like the HDPS conversion, it simply bolts to the back of the recevier. The limitation is that the only (unmodified) stock that fits is the one from TN. A factory stock requires modification to fit. Some have claimed that no modification is necessary while other (including myself) have had to. I suspect that it is a result of varying production specs. As with the HDPS method, the weapon can not be fired with stock folded and LOP can be an issue for some shooters. The benefit to this conversion is that it counts as two U.S. made parts (when using the TN stock) for ATF 922r parts compliance (I will cover this later).
For more information on this method, see here...
http://www.shop.black-market-parts.com/product.sc?productId=36&categoryId4
I will not go into details on this thread but I will mention a 4th conversion type by HERA. This is also a "stock-block" method that resembles an AR-style pistol grip with integrated "tube" block to accomodate telescopic M4-style stocks.
CONVERSION TYPES (hi-capacity magazines)
By physical limitation, the U.S. importable SL8 variant (SL8-1 and SL8-6) will only accept single-stack magazines. You have four choices for hi-cap magazines...
1) G36 mags (double-stack)
2) AR mags (double-stack)
3) Promag (single-stack)
4) Magpul (double-stack -- not available till later this year)
To use a double-stack mag, the mag cavity in the receiver must be milled. The SL8 has a large depression on the right side which prevents acceptance of the wider double-stacked mags. This depression is what must be removed (along with other minor milling in the cavity). Milling out of the depression does reduce torsional rigitity of the receiver and exposes a large "window" under the ejection port. There are two methods to address this...
1) Steel reinforce the receiver over the "window" and fuse a cover piece over top. All seams are plastic welded and sanded smooth. This greaty strengthens torsional rigitiy and gives a factory-correct appearance. This method can be used with the G36 magwell or the TN AR magwell adapter (with slight modification).
For more information on this method, see here...
http://hkpro.com/forum/showthread.php?t=112094
2) Epoxy attach a piece of plastic over the window. This method sucessfully covers the window but does nothing for strengthening torsional rigidity. Even with plastic welding the seams, there is a very high probablity that the seams will eventually crack and the cover plate may come loose.
NOTES:
- The TN AR magwell adapter has an integrated "window" cover. It does not add strength but does do a good job of covering the window (assuming the depression was milled correctly). When using either of the above two methods, the integrated "window" cover can be milled off without affecting function.
- G36 mags are wider than AR mags. It is possible to mill the cavity for use with G36 mags and attach the TN AR magwell adapter. While many have had sucess with this, I do not recommend doing so. If you plan to use AR mags, the cavity should be milled accordingly.
- Worn out AR mags or those with weak springs have a tendency to mis-feed or cause problems with the last-round bolt-catch.
- Use of the 20rnd Promag does not require receiver modification as it is a single-stack mag designed to be ussed directly in the the SL8.
More information on the 20rd Promag can be found here...
http://www.promagindustries.com/ProductDetails.asp?ProductCode=HEC-A6
- If you use double-stack mags, you have to replace the SL8 bolt-head with a G36-style bolt-head suited for feeding double-stack mags. The SL8 bolt-head will not feed double-stack mags.
FIRE CONTROL GROUP (FCG)
There is much debate on whenther or not it is really necessary to install the SL8 FCG into your conversion. I won't go into detail as I do not wish to re-stir this debate, however please note that certain parts of the G36 FCG are considered machine gun parts. As such, I very strongly recommend that the complete SL8 FCG be installed into your conversion.
BARREL AND OVERALL LENGTH
For Title-1 status, Federal Law requires that the barrel be no shorter than 16" and overall length be no shorter than 26". When doing the G36 rear-stub conversion method, the receiver is shortened slightly. Therefore, with this style of conversion, barrel length must be approx 16.5" which will yield approx 26.1 overall length with stock folded. When doing any of the "stock-block" conversion methods, a 16" barrel will yield greater than 26" overall length with stock folded.
Continued...
