Below is a summary of parts required to convert a DAO or a LEM pistol to a DA/SA (also known as Variant 1 or simply V1). Note that the information herein only applies to USP, USP Compact, HK45, and HK45 Compact pistols. You cannot convert a P-Series pistol (P30, P30L, P30SK, P2000, or P2000SK) from LEM to DA/SA because the frame does not have the cut-out to accommodate the Sear (with Decocker).
Also worth mentioning is that Variant 1 (V1) on a USP-Series or HK45-Series pistol is a Double Action/Single Action (DA/SA) trigger as opposed to V1 LEM, which is a Light LEM on a P-Series pistol (P30, P30L, P30SK, P2000, and P2000SK).
Parts can be purchased direct from HK Customer Service (706-568-1906), HKWebShop, or from any of these online vendors: Brownells, Numrich, TopGunSupply, Midwestgunworks, and HKParts. HK Customer Service will usually have the best prices.
HS = Hammer Spring
TRS = Trigger Rebound Spring
FPBS = Firing Pin Block Spring
Important Notes
• There are 2 different DA/SA hammers, one is the old-style hammer (214825) and the other is the new-style hammer (218570/50218570) that has a notch on the right side of the hammer. The old-style hammer will require an old-style catch and the new-style hammer will require a new-style catch. Both hammers are available in spurred and bobbed versions.
• If you are converting from a LEM variant, you already have the new-style Catch. If you are converting from a DAO USP/USPc (not LEM), you might have an one-piece or a two-piece catch. If you have an one-piece catch, you will need an old-style hammer. If you have a two-piece catch, you can use an old-style hammer or upgrade your catch to a new-style catch and use the new-style hammer. See the comparison photos below for one-piece vs two-piece catch, and old and new-style catch.
• If you have or want to use the old-style catch (short), you must use the old-style hammer (without the notch on the right side of the hammer). See the comparison photos below for old and new hammer
• If you are converting from Light LEM to DA/SA, you will not need to replace any springs (TRS, FPBS, or HS)
• If you are converting from DAO or Heavy LEM to DA/SA, you must replace all three (3) springs (TRS, FPBS, and HS)
• For USP Compact or HK45 full-size, you can use hammer spring 215694 or 214300/50214300. The difference is that the 215694 spring is about 1 to 2 lbs lighter than the 214300/50214300 spring and was the stock hammer spring that came with all USP Compacts and HK45s made prior to BC=2012. Recent models of the USP Compact and HK45 come with the 214300/50214300 spring.
Photos of the one-piece Catch (left) and two-piece Catch (right) for comparision.
Photos of the old-style Catch (left) and new-style Catch (right) for comparison.
Photos of the old-style Hammer (left) and new-style Hammer (right) for comparison. Note the notch on the new Hammer (circled in Red).
USP Full-Size
1. Safety/Decocker Lever (214184)
2. V1+2 Detent Plate (214949)
3. Slide Plate (214105 or 50214105)
4. Slide Plate Compression Spring (214104 or 50214104)
5. Sear (229882 or 50229882)
6. Hammer Axle (214774 or 50214774)
7. Spurred Hammer (218570 or 50218570)
8. Hammer Spring (214300 or 50214300)
9. Trigger Rebound Spring (214164/50214164 or 209266)
10. Firing Pin Block Spring (214192 if AE or earlier, 209296/50209296 if AF or later)
USP Compact
1. Safety/Decocker Lever (215818)
2. V1+2 Detent Plate (214949)
3. Slide Plate (214105 or 50214105)
4. Slide Plate Compression Spring (214104 or 50214104)
5. Sear (229882 or 50229882)
6. Hammer Axle (214774 or 50214774)
7. Bobbed Hammer (215692)
8. Hammer Spring (215694 or 214300/50241300)
9. Trigger Rebound Spring (214164/50214164 or 209266)
10. Firing Pin Block Spring (214192 if AE or earlier, 209296/50209296 if AF or later)
HK45 and HK45 Compact
1. Safety/Decocker Lever (234339)
2. V1+2 Detent Plate (234465)
3. Slide Plate (214105 or 50214105)
4. Slide Plate Compression Spring (214104 or 50214104)
5. Sear (229882 or 50229882)
6. Hammer Axle (214774 or 50214774)
7. Spurred Hammer (218570 or 50218570)
8. Hammer Spring (215694 or 214300/50214300 for HK45 / 234479 for HK45c)
9. Trigger Rebound Spring (214164 or 50214164)
10. Firing Pin Block Spring (209296 or 50209296)
Also worth mentioning is that Variant 1 (V1) on a USP-Series or HK45-Series pistol is a Double Action/Single Action (DA/SA) trigger as opposed to V1 LEM, which is a Light LEM on a P-Series pistol (P30, P30L, P30SK, P2000, and P2000SK).
Parts can be purchased direct from HK Customer Service (706-568-1906), HKWebShop, or from any of these online vendors: Brownells, Numrich, TopGunSupply, Midwestgunworks, and HKParts. HK Customer Service will usually have the best prices.
HS = Hammer Spring
TRS = Trigger Rebound Spring
FPBS = Firing Pin Block Spring
Important Notes
• There are 2 different DA/SA hammers, one is the old-style hammer (214825) and the other is the new-style hammer (218570/50218570) that has a notch on the right side of the hammer. The old-style hammer will require an old-style catch and the new-style hammer will require a new-style catch. Both hammers are available in spurred and bobbed versions.
• If you are converting from a LEM variant, you already have the new-style Catch. If you are converting from a DAO USP/USPc (not LEM), you might have an one-piece or a two-piece catch. If you have an one-piece catch, you will need an old-style hammer. If you have a two-piece catch, you can use an old-style hammer or upgrade your catch to a new-style catch and use the new-style hammer. See the comparison photos below for one-piece vs two-piece catch, and old and new-style catch.
• If you have or want to use the old-style catch (short), you must use the old-style hammer (without the notch on the right side of the hammer). See the comparison photos below for old and new hammer
• If you are converting from Light LEM to DA/SA, you will not need to replace any springs (TRS, FPBS, or HS)
• If you are converting from DAO or Heavy LEM to DA/SA, you must replace all three (3) springs (TRS, FPBS, and HS)
• For USP Compact or HK45 full-size, you can use hammer spring 215694 or 214300/50214300. The difference is that the 215694 spring is about 1 to 2 lbs lighter than the 214300/50214300 spring and was the stock hammer spring that came with all USP Compacts and HK45s made prior to BC=2012. Recent models of the USP Compact and HK45 come with the 214300/50214300 spring.
Photos of the one-piece Catch (left) and two-piece Catch (right) for comparision.

Photos of the old-style Catch (left) and new-style Catch (right) for comparison.


Photos of the old-style Hammer (left) and new-style Hammer (right) for comparison. Note the notch on the new Hammer (circled in Red).


USP Full-Size
1. Safety/Decocker Lever (214184)
2. V1+2 Detent Plate (214949)
3. Slide Plate (214105 or 50214105)
4. Slide Plate Compression Spring (214104 or 50214104)
5. Sear (229882 or 50229882)
6. Hammer Axle (214774 or 50214774)
7. Spurred Hammer (218570 or 50218570)
8. Hammer Spring (214300 or 50214300)
9. Trigger Rebound Spring (214164/50214164 or 209266)
10. Firing Pin Block Spring (214192 if AE or earlier, 209296/50209296 if AF or later)

USP Compact
1. Safety/Decocker Lever (215818)
2. V1+2 Detent Plate (214949)
3. Slide Plate (214105 or 50214105)
4. Slide Plate Compression Spring (214104 or 50214104)
5. Sear (229882 or 50229882)
6. Hammer Axle (214774 or 50214774)
7. Bobbed Hammer (215692)
8. Hammer Spring (215694 or 214300/50241300)
9. Trigger Rebound Spring (214164/50214164 or 209266)
10. Firing Pin Block Spring (214192 if AE or earlier, 209296/50209296 if AF or later)

HK45 and HK45 Compact
1. Safety/Decocker Lever (234339)
2. V1+2 Detent Plate (234465)
3. Slide Plate (214105 or 50214105)
4. Slide Plate Compression Spring (214104 or 50214104)
5. Sear (229882 or 50229882)
6. Hammer Axle (214774 or 50214774)
7. Spurred Hammer (218570 or 50218570)
8. Hammer Spring (215694 or 214300/50214300 for HK45 / 234479 for HK45c)
9. Trigger Rebound Spring (214164 or 50214164)
10. Firing Pin Block Spring (209296 or 50209296)
