IMPORTANT: This information is strictly for informational purposes only. None of us are engineers, metallurgists or even machinists. We are strictly amateurs and this just happens to be what we have done for our own use. Modifying any weapon, ESPECIALLY blank adapting one, is extremely dangerous. Pressures can range up to 60,000 PSI or even higher. Variations of aperture size accuracy, recoil springs, weapon maintenance, and even basic weapon usage can create an extremely hazardous situation in one weapon when the same settings function correctly in another. Basically, do not attempt anything mentioned herein without first consulting a qualified gunsmith or an engineer much more knowledgeable in weapon modifications.

M1 Garand Blank Adapter Aperture Sizes

For Updates Contact: Drew Ballard
Initial information compiled by Dave from Gopher Munition Works, edited and arranged by Chris Guska

M1 Garand Blank Adapting FAQ

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BFA Type	Manufacturer	Size	Drill Size
1.) Danish Surplus / Military Surplus		Not Adjustable	(Functions)
	Atlantic Wall Blanks
Notes: With this adapter, since it is non-adjustable, it is indicated if it functions the M1 or not.	Blanksguys (Satterfield)
	DSC Blanks
	Gopher Munitions Works Blanks
	Ketchum Blanks
	Nartron
	Pops Blanks
	Swanson Blanks
	US M1909 Red Cap		Yes
	US M1909 Star Crimp		Yes
	WW II Blanks
2.) Tube style	Atlantic Wall Blanks	#17	0.173
Notes: Gauge this adapter prior to use.  Many adapters come drilled @ 0.156 out of the box	Blanksguys (Satterfield)	#17	0.173
	DSC Blanks
	Gopher Munitions Works Blanks	5/32	0.156
	Ketchum Blanks
	Nartron
	Pops Blanks
	Swanson Blanks
	US M1909 Red Cap
	US M1909 Star Crimp	#17	0.173
	WW II Blanks
3.) Gas Cylinder Lock Style	Atlantic Wall Blanks	#17	0.173
Notes: Gauge this adapter prior to use.  Many adapters come drilled @ 0.125 out of the box	Blanksguys (Satterfield)	#17	0.173
	DSC Blanks
	Gopher Munitions Works Blanks
	Ketchum Blanks
	Nartron
	Pops Blanks
	Swanson Blanks
	US M1909 Red Cap
	US M1909 Star Crimp
	WW II Blanks
4.)Restrictor Plate	Atlantic Wall Blanks	#17	0.173
Notes: This is the Pops type adapter.	Blanksguys (Satterfield)	#17	0.173
	DSC Blanks
	Gopher Munitions Works Blanks	3/16	0.187
	Ketchum Blanks
	Nartron
	Pops Blanks	3/16	0.187
	Swanson Blanks	3/16
	US M1909 Red Cap
	US M1909 Star Crimp	#17-3/16	0.172-.185
	WW II Blanks
5.) Gas Cylinder Lock Set Screw	Atlantic Wall Blanks	#17	0.173
Notes: This is the Guiette type adapter.	Blanksguys (Satterfield)	#17	0.173
	DSC Blanks
	Gopher Munitions Works Blanks	3/16	0.187
	Ketchum Blanks
	Nartron
	Pops Blanks	3/16	0.187
	Swanson Blanks	3/16
	US M1909 Red Cap
	US M1909 Star Crimp	#17-3/16	0.172-.185
	WW II Blanks
6.) Threaded Barrel Set Screw	Atlantic Wall Blanks	#17	0.173
Notes: This is the true "Hollywood" in barrel type adapter.	Blanksguys (Satterfield)	#17	0.173
	DSC Blanks
	Gopher Munitions Works Blanks	3/16	0.187
	Ketchum Blanks
	Nartron
	Pops Blanks
	Swanson Blanks
	US M1909 Red Cap	#17	0.173
	US M1909 Star Crimp	#17-3/16	0.172-.185
	WW II Blanks